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ENG450 - Engineering Internship Report Prepared By: Daniel Marsh Academic Supervisor: Dr. Martin Anda Industry Supervisor: Shoba Senasinghe .
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  • ENG450 - Engineering Internship Report

    Prepared By:

    Daniel Marsh

    Academic Supervisor:

    Dr. Martin Anda

    Industry Supervisor:

    Shoba Senasinghe

    .

    http://www.murdoch.edu.au/

  • 1 | P a g e

    Contents Abstract ................................................................................................................................................... 3

    Acknowledgements ................................................................................................................................. 4

    Introduction ............................................................................................................................................ 5

    Background ............................................................................................................................................. 6

    Company ............................................................................................................................................. 6

    Objective ............................................................................................................................................. 8

    Scope ................................................................................................................................................... 9

    Aims .................................................................................................................................................... 9

    Hydrocarbon Source ............................................................................................................................... 9

    Wetlands / Literature Review ............................................................................................................... 10

    Hydrocarbons .................................................................................................................................... 11

    Vertical Flow (VF) Wetlands .............................................................................................................. 12

    Dissolved Oxygen .............................................................................................................................. 12

    Wetland Configuration ..................................................................................................................... 13

    Plant Species ..................................................................................................................................... 13

    Residence Time ................................................................................................................................. 14

    Media ................................................................................................................................................ 15

    Nutrient Loading ............................................................................................................................... 16

    Materials ............................................................................................................................................... 16

    Methods and Practices ......................................................................................................................... 18

    Results and Discussion .......................................................................................................................... 20

    Conclusions ........................................................................................................................................... 30

    Further work ......................................................................................................................................... 31

    Reference .............................................................................................................................................. 32

    Appendix 1 - Internship Roles ............................................................................................................... 36

    Activities Performed ............................................................................................................................. 36

  • 2 | P a g e

    Annual Water Sampling .................................................................................................................... 36

    Groundwater Remediation / Natural Attenuation ........................................................................... 37

    Hydrocarbon Spills (Presentation) .................................................................................................... 39

    Petrochemical Chemistry and Characteristics .................................................................................. 39

    Oil-Water Separator .......................................................................................................................... 41

    Site Procedure and MSDS ................................................................................................................. 43

    Soil Sampling and Remediation Study .............................................................................................. 44

    Stormwater Management ................................................................................................................ 44

    Appendix 2 – Site map with sampling bore locations ........................................................................... 46

    Appendix 3 - Lab results ......................................................................................................................... 0

  • 3 | P a g e

    Abstract

    As a requirement of the Murdoch University Environmental Engineering Degree, enrolment in

    ENG450 Engineering Internship was undertaken by Daniel Marsh. The internship existed as a work

    placement at Coogee Chemicals, a chemical manufacturing, storage and distribution company

    located in Kwinana. Throughout the internship work was completed under the supervision of HSEQ

    Coordinator Shoba Senasinghe.

    The main focus of this internship was the design, construction and testing of a pilot scale wetland for

    the treatment of wastewater generated within Coogee Chemicals Kwinana Site, thus providing

    engineering and environmental science experience to the intern while providing Coogee Chemicals

    with information on the feasibility of treating wastewater using wetlands. The waste streams are

    characterised as containing contaminants such as BTEX (Benzene, Toluene, Ethyl-Benzene and

    Xylene), gasoline and diesel range hydrocarbons, detergents, solvents, caustic, ethanol and diesel.

    The hydrocarbons are sourced from activities such as tank dewatering, pumps and bunded areas,

    gantry floor wash downs and line washing.

    Coogee Chemicals would like to use the pilot wetland as a treatment method to test the possibility

    of installing a larger treatment system within the Kwinana site for the treatment of all appropriate

    waste streams, collectively over 5m3/day of contaminated wastewater. Diesel contaminated

    groundwater was initially trialled followed by pond water which receives effluent from an oil-water

    separator.

    As the internship is an experimental based project, data is being continuously recorded on the

    performance of the treatment capabilities of the wetland systems. At the time of reporting, there

    are six wetland cells operating in three separate treatment streams, making three pairs. Only data

    for the wetland system in South 3 is analysed. Wetland performance for groundwater showed very

    low effluent concentrations for benzene, ethylbenzene, m & p-xylene and o-xylene with 3ug/l, 3ug/l,

    6ug/l and3ug/l respectively. Hydrocarbon ranges C6-9, C10-14, C15-28 and C29-36 achieved removal

    efficiencies of 80%, 94%, 95% and 74% respectively. Similar results could be seen for the pond water

    treatment also. Toluene was a problematic compound in both groundwater and pond water trials

    showing different behaviour to other hydrocarbons. The groundwater trial showed toluene removal

    of 66% although effluent concentrations were still reasonably high. Initial results from the pond

    water trial show toluene concentrations increasing, however this may be due to adsorbed materials

    being released back into the system.

  • 4 | P a g e

    Acknowledgements

    Firstly I would like to thank my industry supervisor Shoba Senasinghe, HSEQ coordinator, for giving

    me the opportunity to be placed at Coogee Chemicals while challenging me to push myself as a

    student entering the workforce, forcing me to plan, think things through and organise, while

    exposing me to industry practices.

    My thanks also extend to Brian Gardner, Director and Manager of HSEQ, Sustainability and

    Manufacturing for considering student projects in the scope of operations at Coogee Chemicals

    which allowed me to finish my degree and kick start my career.

    I would also like to thank Dr. Martin Anda for suggesting myself for the wetland project at Coogee

    and also for providing me and other students with many opportunities throughout their studies in

    environmental engineering and similar fields. If only more students realised the importance of taking

    these opportunities! Additional thanks to Gareth Lee for being so organised that I was able to start

    my internship hastily given a small amount of time to organise contracts etcetera while being

    involved with many students internships.

  • 5 | P a g e

    Introduction

    The internship is a requirement in the degree of Environmental Engineering (BE), a course apart of

    the School of Engineering and Energy. The internship was a full time work placement and is designed

    so that the student gains exposure to engineering projects while bringing together all aspects of the

    student’s knowledge and university training. The ENG450 unit itself is classed as a full time load.

    This report presents the results of the wetland trial to date and outlines additional activities of

    importance relating to the field of environmental engineering works that the intern took place in

    during the internship. Coogee Chemicals is seeking options for the treatment of wastewater

    generated through operations at their Kwinana site to establish acceptable discharge criteria for DEC

    approval. Coogee has considered wetlands as a treatment option because of the environmentally

    sustainable approach to wastewater treatment and ability to handle varying loads. Other advantages

    include

    Simple operation

    No waste product

    Low capital

    Low energy treatment

    The biodegradation process using microorganisms, such as that in wetlands, is a known treatment

    technology or process that can treat hydrocarbons, since they are able to biotransform and/or

    biodegrade pollutants (Mazzeo et al, 2010). Another option being considered is Dissolved Air

    Flotation (DAF) which has its own advantages and disadvantages, but treatment wetlands are

    currently the priority of the research efforts at the time of the internship.

  • 6 | P a g e

    Background

    Company

    Coogee Chemicals is a chemical manufacturing, storage and distribution company with its head

    office in Kwinana, Western Australia. Coogee Chemicals has operations and joint ventures at several

    other locations such as Mt Isa (QLD), Laverton (VIC), Townsville (QLD), Port Hedland (WA), Kemerton

    (WA) and Pasir Gudang (Malaysia).

    The Kwinana site is involved with the manufacturing of chemicals such as aluminium sulphate,

    metham sodium, sulphur pellets and sulphur bentonite, sodium aluminate, sodium silicate, sulphuric

    acid 98% and xanthates. One of the major operations at the Kwinana site is the storage and

    distribution of fuels. These include unleaded petrol, premium unleaded petrol and diesel, the same

    applies with solvents being stored and distributed. There is a dedicated pipeline from the nearby BP

    refinery to Coogee Chemicals Terminals and also ships that deliver millions of litres of fuel which is

    then stored on site. There are over 40 large tanks in the 'South' areas alone at the Kwinana site.

    This large amount of storage gives Coogee Chemicals Kwinana site the ‘Tank Farm’ typecast implying

    heavy industry happenings. There are environmental consequences related to this type of industry

    such as emissions to air, water and land - in this case generation of waste water containing

    hydrocarbons.

    Problem

    Coogee Chemicals are seeking options for the treatment of wastewater generated through

    operations at their Kwinana site to establish acceptable discharge criteria for DEC approval. The

    source of hydrocarbon contaminates is outlined in the 'Hydrocarbon Source' section of this report.

    Within the Kwinana site there are three main effluent streams that are being considered for

    treatment using a wetland system. These are named South 1, South 2 and South 3 or S1, S2 and S3

    respectively. These names refer to zones within the Kwinana site, each of these three zones has its

    own sullage tank and oil-water separator system with evaporation pond (Figures 1 and 2).

  • 7 | P a g e

    Figure 1: South 1 and South 2 areas, the encased areas contain the pond and oil-water separator

    Water from bunded areas, pump areas, gantry floors, line and tank washings is collected in sullage

    tanks in each area (S1, S2, S3). This water is allowed to settle where it then enters oil-water

    separators where the floats are skimmed and the treated water is sent to the pond(s). The water to

    be treated in this trial is in fact the water that enters these ponds. Coogee needs a treatment option

    to put in place as these ponds are not being used as per the initial design criteria and may be

    inadequate with respect to surge loading and oil-water separator failures which can lead to high

    concentration of pollutants. The water for these ponds is collected in sullage tanks which receive

    water from several sources, then is treated in oil-water separators then travels to an evaporation

    pond. This is true for all three zones, however South 3 has a larger scale operation with 2 separate

    parallel plate separators and large sullage tank and pond (Figure 2).

    S2 S1

  • 8 | P a g e

    Figure 2: South 3 area

    South 1 effluent flows typically contain Hydrocarbons, Caustic, Solvents, Ethanol and Detergents.

    There are tanks containing solvents and a loading gantry in this area.

    South 2 effluent flows typically contain Hydrocarbons, Solvents, Detergents and additives (such as

    Toluene & Naphthalene). There are tanks containing solvents and petrol in this area.

    South 3 effluent typically contains hydrocarbons, BTEX, detergents and diesel. It is expected that

    there will be no free oil or phase separated hydrocarbons from the outlet of the API separator, only

    oil in smaller forms such as emulsified oil, dissolved oil and mechanical dispersions.

    Objective

    Coogee Chemicals are seeking options for the treatment of wastewater generated through

    operations at their Kwinana site to establish acceptable discharge criteria for DEC approval.

    S3

    Pond

    G

    O

  • 9 | P a g e

    Scope

    The focus of the internship was to use pilot scale wetland systems for assessing the feasibility of

    using this type of water treatment process for hydrocarbon and chemical contaminated wastewater

    generated on site.

    South 3 produces the largest amount of waste water, and subsequently has the largest sullage /oil

    separator/ pond system of the three zones. Initially focus was on this area as it was of interest to

    Coogee Chemicals as it is the most active area and the volume of contaminated water is large.

    Subsequently more data was obtained for this area as the treatment systems were constructed

    earlier and trailed longer.

    Aims

    Before the internship commenced a number of goals for the intern were outlined by Coogee

    Chemicals;

    Familiarisation with ground water monitoring, testing, chain of custody and bore operation.

    Literature search to wetland treatment of chemicals found within the terminal area

    Review of terminal water flows to enable design

    Design and hands on construction supervision of modular pilot scale wetland

    Characterisation of feed stream to wetland (ex primary separator)

    Selection of plant species

    Operation of the pilot plant to test particular plant species and operation of the wetland with

    various water flows

    Remediation work

    These and a number of additional activities were completed throughout the course of the internship.

    Hydrocarbon Source

    Terminal water flows where reviewed to determine the source of hydrocarbons in the ponds. The

    main hydrocarbon sources are as follows;

    South 3

  • 10 | P a g e

    Tank dewatering (major source)

    Gantry floor washdown

    Pumps + bunded areas

    Pigging (not common in S3)

    Slop containers (bulky boxes)(Remediation)

    Vapour recovery

    South 2

    Pigging

    Tank dewatering

    Gantry washdown

    Bunded areas

    Line washing

    Manifold area + draining

    Tank Cleans

    Pump / bund areas

    South 1

    Line washing

    Pigging

    Manifold area

    Gantry washdown

    Tank cleans / draining

    Bund areas

    Wetlands / Literature Review

    Constructed wetlands are well suited to the discipline of environmental engineering (Dallas et al,

    2007) and are well documented in the field of treating storm water as well as industrial wastewater.

    Much research was undertaken to understand the treatment mechanisms of wetlands and also the

    application of hydrocarbons such as BTEX to these treatment systems. Many design factors can be

    incorporated into the design of treatment wetlands, these vary from study to study to suit the task

  • 11 | P a g e

    at hand. The variables that were the most common or successful in case studies and journal articles

    were chosen based on their applicability to the treatment of hydrocarbons and Coogee Chemicals

    requirements, such as the WA climate, BTEX and hydrocarbon removal and spatial considerations.

    Other topics that relate to the wetland specifically;

    Hydrocarbons

    Vertical Flow (VF) Wetlands

    Dissolved Oxygen

    Wetland Configuration

    Plant Species

    Media

    Nutrient Loading

    Residence Time

    Hydrocarbons

    Wetlands are well documented in their uses in the treatment of industrial wastewater. This is also

    true for hydrocarbon contaminated water and waste water from the petroleum/oil industry

    (Domingos et al, 2011; Nix et al, 1995; Knight, 1999). However the scale that Coogee Chemicals

    would implement a VF flow system will not have been used for targeting hydrocarbons specifically in

    Western Australia. Information that is available on petroleum wastewater treatment wetlands

    indicates that COD is reduced at rates comparable to wetlands treating other types of wastewater

    (Knight, 1999), such as BOD and total nitrogen. This report expresses the concentrations of

    hydrocarbons as micrograms per litre (ug/L)(ppb).

    The breakdown time for aromatic hydrocarbons is longer when more than one benzene ring is

    present (Knight, 1999), therefore, it would be expected that a compound such as naphthalene would

    take longer to break down in the wetland system then BTEX compounds with one benzene ring as it

    contains two benzene rings. Diesel may take even longer due to its high molecular weight, as Knight

    mentions, the breakdown time for aliphatic hydrocarbons is longer for compounds of higher

    molecular weight. The processes for contaminant removal in treatment wetlands are many.

    Hydrocarbons and associated industry chemical treatment paths include (Knight, 1999).

  • 12 | P a g e

    Volatilization,

    Partitioning to sediments, biofilms, and humics;

    Mass transfer (sorption);

    Biodegradation;

    Photodegradation

    Plant and animal uptake

    Vertical Flow (VF) Wetlands

    The pilot scale wetland will be a stepping stone in the design phase of a treatment wetland within

    the terminal at Kwinana. Space constraint is an issue within the busy terminal; therefore a vertical

    flow wetland is desirable by Coogee Chemicals for its spatial advantages. The space used for a

    horizontal flow system with the same treatment capacity may not be feasible. Vertical flow wetlands

    have increased in popularity (Kadlec & Wallace, 2009) with a large number of studies using VF

    wetlands, see References. Another advantage in the use of vertical flow wetlands is that they tend to

    have higher dissolved oxygen (DO) levels then other sub-surface and surface flow wetlands,

    especially when given the chance to drain and fill (Eke & Scholz, 2008; Vymazal, 2010). Many studies

    had used the vertical flow type to allow ‘tidal’ flow, which is continual wetting and drying of the

    substrate to allow for oxygen infiltration. The trial at Coogee will operate as a fill/draw/rest system

    to allow oxygen replenishment, bioaccumulation control, clogging prevention and intermittent

    drying as the plants used are Western Australian native so may prefer not to be constantly saturated

    but also handle dry spells.

    Dissolved Oxygen

    Having high DO levels is important in the treatment of hydrocarbons in wetlands. It is believed that

    DO levels increase volatilization and aerobic biodegradation of the hydrocarbon compounds

    (Wallace & Kadlec, 2005). Oxygen has been documented in several studies as an important factor for

    hydrocarbon degradation (Eke & Scholz, 2008; Kadlec, 2001; Wallace & Davis, 2009). It is generally

    considered that the anaerobic degradation of petroleum hydrocarbons is negligible compared with

    aerobic processes (Leahy and Colwell, 1990). For this reason several options were considered to

    increase the oxygen levels in the VF wetland(s), the three most viable options are cascade aeration,

    forced aeration and fill/draw batch system loading (allows replenishment of oxygen through soil

    column). Fill/draw aeration was chosen for this trial, with an air distribution system added to allow

    for future testing of forced aeration if desired. As oxygen may be a limiting factor for this waste

    streams treatment efficiency, forced aeration would be used within the wetland cell itself, as

  • 13 | P a g e

    aerating before entering the wetland would only allow the water to reach its oxygen saturation

    point, with minimal amounts of oxygen being replenished in the allocated retention time due to

    diffusion and similar ‘slow’ processes. Eke & Scholz mentioned dissolved oxygen levels should be

    around 2mg/L in the wetland itself; any higher would be a waste of energy used for pumping, as

    higher levels (above 2mg/L) may not lead to greater treatment efficiency (Eke & Scholz, 2008).

    (Bedessem, 2007) is an example of water from an oil water separator was oxygenated using

    compressed air and DO levels reached 6mg/L from 0.5mg/L, this would allow for more oxygen to be

    available to bacteria for biodegradation. If opportunity came for the addition of forced aeration it

    would provide a comparison between the effectiveness of having aeration or not, in this trail forced

    aeration was not practised but can be easily added in the future. Additionally, forced aeration will be

    more expensive if scaled up to a larger scale.

    Wetland Configuration

    Wetland configuration was chosen based on the characteristics of the influent. Two VF wetlands in

    series have been proposed for several reasons. A common site in treatment wetlands is to have one

    aerobic followed by an anaerobic wetland, to replicate nitrification / denitrification, respectively, for

    the removal of nitrogen (Domingos et al, 2007; Cooper, 1999). However the waste stream at Coogee

    is not characterised with high nutrient levels as with many journal paper examples. Therefore it

    would not be useful to have an oxygen deficient wetland in the treatment of this waste stream.

    Leahy & Colwell mention that the anaerobic degradation of petroleum hydrocarbons is negligible

    compared with aerobic processes (Leahy and Colwell, 1990). The purpose of having two VF wetlands

    in series - essentially doing the same thing, is to increase DO levels, increase the residence time and

    to allow the system to operate as a batch system. A constantly saturated wetland will have reduced

    DO levels which is not desirable in this case. One will be full while the other is resting, also allowing

    maintenance time for the full scale wetland if constructed. This is not unlike recirculation, with a

    100% recirculation rate, as stated by (Lian-sheng, 2006), when effluent is recirculated, additional

    oxygen for aerobic microbial activities is transferred into wastewater.

    Plant Species

    Appropriate plant species for the wetland have been selected following literature review,

    consultation and using native species appropriate for the West-Australian climate. Plant species play

    several roles in wetlands some physical examples are; roots provide surface area for attached micro-

    organisms, and root growth maintains the hydraulic properties of the substrate. The vegetation

    cover protects the surface from erosion and shading prevents algae growth (Langergraber, 2003).

  • 14 | P a g e

    Additionally, macrophytes release oxygen from roots into the rhizosphere and this oxygen leakage

    stimulates growth of nitrifying bacteria (Brix, 1997). Several plant species where considered for their

    wide and well documented use in similar treatment wetlands such as Phragmites sp., Juncus sp. and

    Schoenoplectus sp (Wallace, 2005; Domingos 2011; Langergraber, 2003). Phragmites is used widely

    in the wetland field and is a typical VF wetland species (Kadlec & Wallace, 2009), however was not

    chosen due to some species not being native and pointy rhizomes which may damage liner for lined

    systems. From consultation with Sergio Domingos it was recommended to use Typha domingensis,

    Schoenoplectus validus, Juncus pallidus or Isolepis sp. Due to availability, research, consultation and

    price Juncus pallidus and Schoenoplectus validus where the ideal plants to be used. A mixture of

    Juncus pallidus, Schoenoplectus validus, Baumea ribiginosa and Baumea articulata where used. The

    number of plants used is not defined in many wetland studies, and the size of studies varies greatly,

    (Shutes, 2003) mentions using 7.5plants/m2 and this may be considered quite low by some, Dr.

    Sergio Domingos also recommended a minimum of 8plants/m2. Approximately 12-14 plants were

    used in the wetlands for this trial.

    Residence Time

    Residence time has been chosen following literature showing the treatment of hydrocarbons in

    constructed wetlands. This is typically at least 1 day (Wallace & Kadlec, 2005). Some examples are;

    Bedessem et al, 2007: 0.61 – 0.76days (aerated)

    Wallace & Kadlec, 2005: 1 day (aerated)

    Eke & Scholz, 2008: 1 day (fill and drain)

    Domingos et al, 2009: 6 days

    Kadlec 2000: 7.5 days

    Typically, a large percentage of benzene is volatilized within the first 24hours (Eke & Scholz, 2008).

    Some of the hydrocarbons in the waste water at Coogee Chemicals have higher (diesel range)

    molecular weights therefore the method used for this trial has been as follows; first cell – 48 hours,

    second cell – 48 hours, giving a total of 4 whole days.

  • 15 | P a g e

    Media

    Substrate for the wetland was chosen using literature review and knowing the typical characteristics

    of the influent to the treatment wetland. Kadlec & Wallace give examples of wetland substrates for

    vertical wetlands, along with several other studies, from Kadlec & Wallace, 2009;

    Table 1: Examples of sizes and types of media used in vertical flow wetlands (Kadlec & Wallace, 2009)

    Typically, as within these studies- sand is used as the bulk media to provide a large surface area for

    microorganisms, followed by medium – large sized gravel at the bottom to allow fast drainage and

    cover effluent collection pipes. Fine sand would increase the surface area, however taking into

    account this system will receive hydrocarbons there is a possibility for clogging (Langergraber, 2001),

    especially if the API separator does not perform to full standard. One option if there is clogging, is to

    remove plants from the first wetland and use larger particle media to increase the porosity and

    allow for easy drying and collecting of surface sludge. Approximately 20-25% of the volume of the

    wetland is pea gravel with the remainder being sand.

  • 16 | P a g e

    Nutrient Loading

    An extra factor that may become prevalent is that the waste stream at Coogee does not have a

    balanced nutrient content, mainly high hydrocarbon levels. The plants and bacteria thrive on having

    nutrients present (Knight, 1999), it may be required to add a nutrient source to increase the

    efficiency of the system – through providing optimal conditions for bacteria and plants. (Eke &

    Scholz, 2008) add nutrients to waste water containing hydrocarbons before entering a wetland

    system to balance nutrient ratios.

    Materials

    Wetland Construction Procedure:

    Prepare PVC pipe distribution manifold (Requires drill & saw)

    Drill holes (perforate) the pipe lengths in a straight line.

    Make sure it is sized to fit in the area of the IBC container (about 1m2)

    Unscrew top bars holding plastic container inside the metal cage.

    Take plastic bulky box out – cut with saw at desired depth (800L mark)

    Place plastic box back into cage

    Cover outlet on inside of the container with mesh material to prevent gravel escaping

    Fill with gravel first

    Place aeration tube and pipe into the box sitting vertically atop the gravel surface

    Spread aeration tubing around area evenly

    Fill with sand

    Plant plants

    Place pipework manifold and cover with sand

  • 17 | P a g e

    Figure 3: Stages of wetland construction clockwise from top left; IBC containers with tops cut off; Gravel on

    the bottom with airline inserted; Sand atop the gravel; Plants and distribution manifold inserted.

    Wetland Materials:

    IBC Container ‘Bulky Box’

    Pipe manifold: 2 corner pieces, 3 T pieces, 6m of 40mm PVC pipe

    Aeration pipe:

    Aeration Tube: 10mm plastic tubing (5m)

    0.2m3 – 0.25m3 gravel

    0.6m3 sand

    Funnel

    Desired Plants

  • 18 | P a g e

    Due to availability and cost of plants some changes were made after the initial wetlands.

    Wetland 1+2

    8 Schoenoplectus validus

    6 Juncus palidus

    Wetland 3 + 4 + 5 + 6

    Mixture of

    Juncus palidus

    Schoenoplectus validus

    Baumea articulata

    Baumea rubiginosa

    Methods and Practices

    In this case the dependant variable is water quality at end of treatment wetland. The Independent

    variables are the changes to the contaminants in the feed water which cannot be given pre

    determined values such as in a controlled experiment. The feed water and effluent water are tested

    each batch for BTEX (benzene, toluene, ethylbenzene and xylene) and TRH (total recoverable

    hydrocarbons).

    The following methods where used for the trial of the wetland systems;

    Configuration - 2 vertical flow wetlands in series. Water is fed to the first wetland, then after the

    residence time is drawn from the first wetland and fed to the second wetland where it stays for the

    residence time.

    Residence time – 2 days in each wetland. Total 4 whole days

    Sampling - The feed water to the first wetland is sampled and the effluent of the second wetland is

    sampled (the start and end of the batch). When sampling is conducted for wetland effluent, a 'flush'

    of some water is released so as to not sample possible stagnant water and get a sample

    representative of water within the wetland. A bucket is then filled with the effluent water to be

    sampled then the sample bottles are filled with the water in the bucket. Sample bottles containing

  • 19 | P a g e

    the water to be tested are kept on ice until sent to external laboratory. The process is very similar for

    sampling of feed water.

    Loading - 80litres per batch (80 litres fed to the first wetland). Loading done with a bucket which is

    poured into the distribution system using a funnel.

    Fill/Draw - While one wetland is treating wastewater the other is 'dry'. That is when wetland 2 (W2)

    contains water, wetland 1 (W1) is left to dry for the period that W2 contains water (2days).When W2

    is drained, W1 is fed and while the water is treated for 2days in W1, W2 is left to dry in preparation

    to receive the water from W1.

    In the early stages of the internship the experimental plan was to use the pond water in the South 3

    area (that is treated beforehand through the oil water separator). However once the internship

    commenced this oil-water separator system was not performing and the effluent entering the pond

    was highly contaminated, additionally the hot conditions (February) meant high evaporation and low

    water levels in the pond concentrating the contaminants even further. There were also issues with

    the pump system at the pond. Therefore to get alternative experimental data groundwater

    contaminated with diesel was used. The contamination is from a past diesel spill and is being

    remediated. The water was recovered from the upper water table where the hydrocarbons are likely

    to float to the surface; this was done using a skimmer pump that sits in the sampling bore

    permanently which leads to a storage IBC container. Usually this container is emptied every two -

    three days to continue remediation of the groundwater but this was interrupted for the experiment.

    Once the pump and oil-water separator system was running correctly the initial plan of using pond

    water was continued.

    Two wetlands in series are located in each of South 3, South 2 and South 1. Each of these will be

    treating water from the sullage-oil separator-pond systems located in each area with the exception

    of South 3 which initially received contaminated groundwater for some time before the other

    systems where set up. The Wetland cells are numbered W1-W6 with the following area allocations;

    South 3 - W1 & W2

    South 1 - W3 & W4

    South 2 - W5 & W6

    Wetlands W3, W4, W5, W6 are still in the early stages of trial at the time of reporting.

  • 20 | P a g e

    Results and Discussion

    Groundwater

    As mentioned diesel contaminated groundwater in South 3 was trialled before the pond water could

    be used as an influent stream.

    Results from the first trial are summarised as follows (TRH = Total Recoverable Hydrocarbons);

    Table 2: Summary of results from initial trial

    Parameter Inlet Outlet Reduction Factor

    ug/l ug/l

    TRHC6-9 500 170 0.66

    TRH C10-14 12000 170 0.99

    TRHC15-28 61000 1400 0.98

    TRHC29-36 280 100 0.64

    Benzene 10 5 0.50

    Toluene 210 120 0.43

    Ethylbenzene 10 5 0.50

    m+p xylene 53 10 0.81

    o- Xylene 36 5 0.86

    The TRHC15-28 range has a much higher concentration of 61000ug/l at the inlet (feed water), and

    also TRHC10-14 (this is characteristically the range diesel fuel contains – that is, diesel fuel is made

    mostly of hydrocarbons which contain 10 to 22 carbon atoms (Chevron, 2007)). Figure 4 is from

    Chevron’s Diesel Fuel Technical Review (Chevron, 2007).

  • 21 | P a g e

    Figure 4: Carbon Number Distribution (Chevon, 2007)

    Notice that the lab results correlate to this diesel fuel chart quite well. The C10-28 range has the

    highest mass in the sample taken especially the C15-28 range, this correlates with the mass

    distribution in the chevron analysis chart. This data suggests that the suspicion of diesel

    contamination is most likely true. The toluene has the lowest reduction factor of only 43%; this may

    be due to a number of factors. Firstly there is an initial concentration of 210ug/l which is significantly

    more than the other BTEX components. Additionally the vapour pressure of toluene is interesting

    compared to other BTEX compounds, for example benzene, toluene, ethylbenzene and o-xylene

    have vapour pressures of 76mmHg, 22mmHg, 7mmHg and 5mmHg respectively. This places toluene

    'in the middle' of the BTEX compounds for this characteristic, the same trend can be said for the

    solubility in water (Wolfram Alfa, 2012). The remaining higher concentration of toluene may be

    attributed to the differences in vapour pressure and solubility, for example the toluene may have

    been in solution due to a reasonable solubility, while having a much lower vapour pressure than

    benzene, eliminating volatilization as a treatment method - however this is speculation as no

    references can be found on toluene specifically. Finally, oxygen may be a factor affecting the

    breakdown of toluene as it is known that it is a major factor in the degradation of BTEX compounds

    (Young and Cerniglia, 1995), however this can be dismissed in this case as the TRH values decreased

    significantly.

  • 22 | P a g e

    Figure 5: Groundwater Contaminant Averages

    Figure 5 shows the average concentrations of diesel contaminated groundwater before and after

    entering the wetland system. Data is shown on a logarithmic scale as some of the differences in

    concentration are so large such as the TRHC10-14 and TRHC15-28 range having very high removal

    rates. The highest concentration of any contaminant is that of the TRHC15-28 range (50000ug/l)

    which as explained is expected due to the diesel contamination. Although the reduction of the

    TRHC15-28 range is significant, there is still 2050ug/l concentration in the effluent stream. The

    hydrocarbon molecules are not specified in the lab analysis or in guidelines such as ANZECC 2000

    (NWQMG, 2000). However, a method of determining the suitability of the water for discharge in the

    future may be to have COD analysed for the effluent sample.

    545

    7850

    50000

    450

    6

    255

    5.5

    37 31.5

    105.5

    270

    2050

    100

    3

    77

    3

    6

    3

    1

    10

    100

    1000

    10000

    100000

    Co

    nce

    ntr

    atio

    n (u

    g/L

    ) (p

    pb

    ) South 3 Groundwater Concentration (Logarithmic Scale)

    (AVERAGE)

    Inlet Concentration

    Outlet Concentration

    Standard Deviation

  • 23 | P a g e

    Figure 6: Average Removal Efficiencies

    From the same set of data as Figure 5, Figure 6 is the average removal rates for the groundwater

    contaminates. Recall that the TRHC10-14 and TRHC15-28 ranges had the highest concentrations;

    Figure 6 shows these also have the highest removal rates with 94% and 95% respectively.

    Surprisingly toluene has a higher (66%) removal rate than most of the BTEX compounds. However

    this is because the initial concentrations of benzene and ethlybenzene where already small

    compared to other compounds, 6ug/l and 5.5ug/l respectively.

    Trialling of groundwater was seized once the oil-water separation and pump system was online. Out

    of interest a full suit test was run for the pond water initially to see what contaminant levels where

    present (Table 3). Only one batch of pond water was completed at the time of reporting.

    0.80

    0.94

    0.95

    0.74

    0.50

    0.66

    0.50

    0.86

    0.91

    0.00 0.20 0.40 0.60 0.80 1.00 1.20

    TRHC6-9

    TRH C10-14

    TRHC15-28

    TRHC29-36

    Benzene

    Toluene

    Ethylbenzene

    m+p xylene

    o- Xylene

    Average Reduction Factor

    Removal Efficiencies for Hydrocarbon Contaminants for South 3 Groundwater

  • 24 | P a g e

    Table 3: Full-Suite test for pond water

    Pond Water Hydrocarbons Units

    TRHC6-9 100 ug/l TRH C10-14 2600 ug/l TRHC15-28 3600 ug/l TRHC29-36 330 ug/l Benzene

  • 25 | P a g e

    The contaminant values for the pond water where significantly smaller than expected this may be

    due to the pump system which sprays recirculted water and diluation due to raina and storm water.

    Iron has a concentration of 2.2mg/l which leaves visual evidence of red coloured stains on the lining

    of the pond. The nutrients are low also compared to the carbon levels that are present due to the

    hydrocarbons, with Total Nitrogen and Phosphorus being 5.8mg/l and 0.47mg/l respectively.The

    focus is on the hydrocarbon concentrations which are summarised in Figure 7.

    Figure 7: Pond water Contaminant Concentrations

    The results in Figure 7 are from only one batch, however similar trends with the results in the

    groundwater trial can be seen. The concentration of benzene, ethylbenzene, m+p xylene and o-

    xylene are all extremely low at 1ppb, 1ppb, 4ppb and 1ppb respectively. once again toluene is an

    outliying compund in the BTEX group. In fact in this case the toluene concentration increases by

    7ppb. There may be several explanations for this, one is that from previous batches where the

    toluene concentration was comparitively high (groundwater concentrations) the toluene remained

    in the system through means such as sorption - and has been collected by the pondwater as it

    percolates through the system as it (the pondwater) had a low concentration of toluene. Similar to

    the process of diffusion. Another unlikely scenario is that free toluene vapour has travelled from a

    nearby dedicated toluene tank and intercepted the wetland.

    100

    2600 3600

    330

    10 10 10

    20 13

    42

    220

    920

    100

    1

    17

    1

    4

    1 1

    10

    100

    1000

    10000

    Co

    nce

    ntr

    atio

    n (u

    g/L

    ) (p

    pb

    )

    South 3 Pondwater Concentration (Logarithmic Scale)

    Inlet Concentration

    Outlet Concentration

  • 26 | P a g e

    Figure 8: Pond water Removal Efficiencies

    As mentioned toluene has had an increase in concentration, this results in a negative reduction

    factor (Figure 8). The concentration of the other BTEX compounds were not high in the influent

    concentration but still managed to be reduced to very low levels so still have a significant redution

    factor. TRHC10-14 has the highest reduction factor of 92%, similar to the groundwater trial. TRHC15-

    28 has a 74% reduction. With these carbon ranges it is important to remember they also have the

    highest removal amounts, that is these ranges have the highest starting concentrations by far.

    Therefore with high reduction factors it is still possible to have effluent concentrations in the 000's

    of ug/l remaining. Comparativley, the BTEX compounds (besides toluene) have very low

    concentrations in the effluent and also have high reduction factors. This may be due to low

    molecular weights of these compunds as well as their volatility (Zhi-ping et al, 2010).

    One major factor that may be prevalent in both trials is sorption. (Knight, 1999) mentions sorption as

    a treatment factor considering hydrocarbon treatment in wetlands. The high levels of sorption is

    likey due to the large amount of surface area provided by the sand and the 'young' age of the

    wetlands. This theory may be testable in the future by taking a soil sample to see the concentration

    of contaminants still remaining in the sample. Additionally, if sorption was the case then it would be

    expected that the capacity of the wetland to adsorb material would decline over time.

    0.58

    0.92

    0.74

    0.70

    0.90

    -0.70

    0.90

    0.80

    0.92

    -0.80 -0.30 0.20 0.70 1.20

    TRHC6-9

    TRH C10-14

    TRHC15-28

    TRHC29-36

    Benzene

    Toluene

    Ethylbenzene

    m+p xylene

    o- Xylene

    Reduction Factor

    Removal Efficiencies for Hydrocarbon Contaminants for South 3 Pondwater

  • 27 | P a g e

    If the case was that sorption was a major factor and treatment efficiency declined over time due to

    this, then other variables may be considered for the optimisation of treatment efficiency. As

    mentioned aeration is considered a major factor in the breakdown of hydrocarbons (Leahy and

    Colwell, 1990; Wallace & Davis, 2009; Wallace & Kadlec, 2005).There is still remaining hydrocarbons

    at levels of 000's in the TRHC15-28 range, this may be due to oxygen being a limiting factor.

    The aim of the trial was to investigate the concentration of hydrocarbons in the effluent stream of

    the wetland system to see if suitable criteria could be achieved to satisfy DEC regulations for

    discharge if a license were applied for. To check this the National Water Quality Management

    Strategy: Australian and New Zealand Guidelines for Fresh and Marine Water Quality, 2000 and also

    Contaminated Sites Management Series: Assessment Levels for Soil, Sediment and Water, 2010

    where used as reference. Referenced in this paper as (NWQMS, 2000) and (DEC, 2010).

    Both of these are used as the National Water Quality Management Strategy is more specific to

    marine and fresh water receiving environments while (DEC, 2010) guidelines compare and

    summarise several Australian standards and guidelines at once, giving extra guidance on

    contaminants that the NWQMS may not.

    A summary of the relevant information provided in (NWQMS, 2000) is below (Table 4).

  • 28 | P a g e

    Table 4: NWQMS trigger values for fresh and marine waters (NWQMS, 2000)

    Chemical

    Trigger

    values

    Freshwater

    Level of

    Protection

    (%

    species)

    Trigger

    values

    Marine

    water

    Level of

    Protection

    (%

    species)

    99% 95% 90% 99% 95% 90%

    ug/l ug/l ug/l ug/l ug/l ug/l

    Benzene 600 950 1300 500 700 900

    Toluene ID ID ID ID ID ID

    Ethylbenzene ID ID ID ID ID ID

    o-xylene 200 350 470 ID ID ID

    m-xylene ID ID ID ID ID ID

    p-xylene 140 200 250 ID ID ID

    m+p-xylene ID ID ID ID ID ID

    Naphthalene 2.5 16 37 50 70 90

    ID = Insufficient data to derive reliable trigger value.

    Notice many of the contaminants have undefined trigger values, using the (DEC, 2010) guidelines

    can assist in gathering more information. A summary of information is provided in Table 5.

  • 29 | P a g e

    Table 5: Summary table from DEC, (2010) for trigger values of hydrocarbons

    Source

    Document

    ADWG ADWG DoH

    Drinking

    Water

    Health

    Value

    Drinking

    Water

    Aesthetic

    Value

    Non potable

    groundwater

    Chemical ug/l ug/l ug/l

    Benzene 1 - 10

    Toluene 800 25 25

    Ethylbenzene 300 3 3

    xylenes 600 20 20

    ADWG = NHMRC & ARMCANZ (2004). Australian Drinking Water Guidelines.

    DoH (Department of Health) = DoH, (2006) Contaminated Sites Reporting Guideline for Chemicals in

    Groundwater.

    Using descriptions in the (EPA, 2000) and (NWQMS, 2000) it is recommended to use values in the

    99% range due to the location of the Kwinana terminal and nearby Cockburn Sound. The values

    outlined in Table 4 for benzene in the 99% range of species protection is 600ug/l for freshwater and

    500ug/l for marine water. Even when using the lower 500ug/l as a reference point the wetland has

    successfully removed benzene concentrations below this level on every occasion. Ethylbenzene

    concentration is not identified for marine or fresh water but is available for values is drinking water

    (health), drinking water (aesthetics) and non-potable groundwater – with values of 300ug/l, 3ug/l

    and 3ug/l respectively. The wetlands removed ethylbenzene to below or equal to 3ug/l on all

    occasions. Xylene concentrations are similarly well below concentrations outlined in all the relevant

    guidelines, including (NWQMS, 2000).Toluene does not have values outlined in (NWQMS, 2000) but

    is outlined in (DEC, 20120) through DoH and ADWG values. The drinking water (health), drinking

    water (aesthetics) and non-potable groundwater values are 800ug/l, 25g/l and 25ug/l respectively.

    800ug/l seems surprisingly high for the health value of drinking water due to health and

    environmental affects (Lausch & Bartkow, 2010). This value should not be an issue as none of the

    samples indicated levels of toluene being close to 800ug/l even before treatment. However the

    average toluene concentration for groundwater after treatment was 77ug/l which is above the non

    potable groundwater guidelines of 25ug/l, while the treated pond water is below this at 17ug/l. This

  • 30 | P a g e

    may indicated that with high influent toluene concentration the effluent concentration will be

    increased, therefore to stay in guideline levels (for non potable groundwater at least) the influent

    toluene concentration would need to be low. As for the remaining hydrocarbon ranges there has

    been no trigger values found in any guideline document as they outline specific pollutants. However

    to measure the Chemical Oxygen Demand of the sample may provide relevant data on the suitability

    for discharge.

    Conclusions

    The South 3 treatment wetlands W1 and W2 successfully removed hydrocarbons from contaminated

    groundwater, with the greatest reduction seen being the range of C15-28 reducing from 50000ug/l

    down to 2050ug/l which is a 95% reduction. BTEX levels where consistently below guideline trigger

    values for both groundwater and pond water trials.

    The high treatment efficiencies seen throughout the trial in S3 may be attributed to sorption. It is

    possible that the large surface area of the sand combined with being a ‘new’ system caused

    significant amounts of contaminant to be adsorbed to surfaces in these early trials. If this is the case

    then treatment efficiency would be expected to decline over time.

    Toluene was a ‘problem’ contaminant throughout all trials as it continually went against the trends

    shown by the other hydrocarbons and BTEX compounds. There is no apparent reason for this

    however toluene was continually higher in concentration then other BTEX compounds, additionally

    the differences in vapour pressure and solubility between toluene and BTEX compounds may be a

    factor.

    At the time of reporting wetlands W3, W4, W5, W6 are in the early stages of trialling, a final report

    will be made for Coogee Chemicals with the results of all the wetland trials.

  • 31 | P a g e

    Further work

    Opportunities exist to expand on the study thus far. As mentioned sorption may decrease over time,

    if this were the case there may be several options to boost the treatment efficiency of the

    wetland(s).

    Aeration – As mentioned oxygen levels are crucial in the breakdown of hydrocarbons. To boost the

    performance of the wetland compressed air could be added to the system itself or to a reservoir

    before entering the system. One option is to have a recirculating system with a separate reservoir

    being aerated to continually provide water with a high DO contact that will come into contact with

    more bacteria.

    Increase Loading – To test the capacity of the wetland to treat hydrocarbons a high loading rate will

    give an understanding of the sizing needed when scaling up to a larger system.

    Inoculation – Using established bacteria populations to inoculate the wetland may improve

    performance by using the appropriate populations for breaking down hydrocarbons. Of course, the

    correct type would need to be sourced from an already established system which is treating

    hydrocarbons.

    Addition of nutrients – The waste stream is high in carbon due to the hydrocarbon content but is

    lacking other nutrients such as nitrogen and phosphorus. Adding of nutrients through fertilizers or

    wastewater from the CSBP plant will balance the nutrient concentration and may provide optimal

    conditions for plants and bacteria.

  • 32 | P a g e

    Reference

    Bedessem, M., Ferro, A., Hiegel, T. (2007). Pilot-Scale Constructed Wetlands for Petroleum-

    Contaminated Groundwater. Water Environment Research. 79 (6), 581-586.

    Becker, P. (Exxon) & Walden, T. 1999.Clarinet-Nicole Natural Attenuation Workshop: Natural

    Attenuation Of Hydrocarbons. Copenhagen, Denmark

    Brix, H. (1997). Do macrophytes play a role in constructed treatment wetlands? Water Sci. Technol.,

    35(5), 11-17.

    Chevron Corporation. 2007. Diesel Fuels Technical Review. Source:

    http://www.chevronwithtechron.com/products/documents/Diesel_Fuel_Tech_Review.pdf

    Cooper, P. (1999). A review of the design and performance of vertical-flow and hybrid reed bed

    treatment systems. Water Science and Technology. (40) 3. pp 1-9.

    DEC, 2010. Contaminated Sites Management Series: Assessment Levels for Soil, Sediment and Water.

    Version 4.

    DoH, (2006) Contaminated Sites Reporting Guideline for Chemicals in Groundwater.

    Domingos, S., Germain, M., Dallas, S. and Ho, G. (2007) Nitrogen removal from industrial wastewater

    by hybrid constructed wetland systems. In: 2nd IWA-ASPIRE Conference and Exhibition, 28 October -

    31 November, Perth, Western Australia.

    Domingos, S., Dallas, S. and Felstead, S. (2011) Vertical flow wetlands for industrial wastewater

    treatment. Water, 38 (3). pp. 103-104.

    Domingos, S. , Boehler, K., Felstead, S., Dallas, S. and Ho, G. (2009) Effect of external carbon sources

    on nitrate removal in constructed wetlands treating industrial wastewater: woodchips and ethanol

    addition.

    In: Nair, J., Furedy, C., Hoysala, C. and Doelle, H., (eds.) Technologies and Management for

    Sustainable Biosystems. Nova Science Publishers, New York, pp. 157-167.

    EPA, 2000. Environmental Protection Authority. Perth’s Coastal Waters Environmental Values and Objectives. The position of the EPA - A working document.

    http://researchrepository.murdoch.edu.au/view/author/Domingos,%20Sergio.htmlhttp://researchrepository.murdoch.edu.au/view/author/Dallas,%20Stewart.htmlhttp://researchrepository.murdoch.edu.au/view/author/Ho,%20Goen.htmlhttp://researchrepository.murdoch.edu.au/view/author/Domingos,%20Sergio.htmlhttp://researchrepository.murdoch.edu.au/view/author/Dallas,%20Stewart.htmlhttp://researchrepository.murdoch.edu.au/4338/http://researchrepository.murdoch.edu.au/4338/

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    Eke, P., Scholz, M. (2008). Benzene removal with vertical-flow constructed treatment wetlands.

    Journal of Chemical Technology and Biotechnology 83:55–63.

    Kadlec, R.; Wallace, S. (2009) Treatment Wetlands, 2nd ed.; CRC Press: Boca Raton, FL, USA.

    Kadlec, R.H. (2001). Feasibility of Wetland Treatment BP-Amoco Casper Refinery Remediation. North

    Logan, Utah: Phytokinetics, Inc.

    Kadlec, R. (2000). The inadequacy of first-order treatment kinetic models; Ecol Eng, 15, pp105–119

    Knight, R. (1999). The Use of Treatment Wetlands for Petroleum Industry Effluents. Environmental

    science & technology, 33(7), 973-980.

    Langergraber, G. (2003). Constructed Wetlands for the Treatment of Organic Pollutants. Journal of

    Soils and Sediments. 3(2).

    Langergraber G. (2001): Development of a simulation tool for subsurface flow constructed wetlands

    (Entwicklung eines Simulationsmodells für bepflanzte Bodenfilter); Wiener Mitteilungen No.169,

    Vienna.

    Leusch, F. & Bartkow, M. 2010. A Short Primer on benzene, toluene, ethylbenzene and xylenes (BTEX)

    in the environment and in hydraulic fracturing fluids. Smart Water Research Centre. Griffith

    University.

    Leahy, J., and Colwell, R. (1990). Microbial degradation of hydrocarbons in the environment.

    Microbiol. Rev. 54 (3):305-315.

    Lian-sheng, H., Hong-liang, L., Bei-dou, X., Ying-bo, Z. (2006) Enhancing treatment efficiency of swine

    wastewater by effluent recirculation in vertical-flow constructed wetland. Journal of Environmental

    Sciences, 18(2): 221-226.

    Logan, B.E. and Wu, J. 2002. Enhanced Toluene Degradation Under Chlorate-Reducing Conditions by Bioaugmentation of Sand Columns with Chlorate- and Toluene-Degrading Enrichments.

    Bioremediation Journal, 6:2, 87-95

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    Mazzeo, D. Levy C. Angelis, D. 2010. BTEX biodegradation by bacteria from effluents of petroleum

    refinery. Science of The Total Environment. 408 (20), p4334-4340.

    Nix, P., Gulley, J. (1995). Kinetic and Empirical Design Criteria for Constructed Wetlands; Poster

    presentation at SETAC World Congress, Vancouver, BC, Canada, November 5-9.

    NHMRC & ARMCANZ (2004). Australian Drinking Water Guidelines.

    NWQMS, 2000. National Water Quality Management Stratergy: Australian and New Zealand

    Guidelines for Fresh and Marine Water Quality. Paper number 4. Volume 1.

    Shutes, R. Brian E., Katima, J., Omari, K., Revitt, D., Mike and Garelick, Hemda (2003) Hydrocarbon

    removal in an experimental gravel bed constructed wetland. Water Science and Technology, 48 (5).

    pp. 275-282.

    Wallace, S., and Kadlec, R. BTEX degradation in a cold-climate wetland system. Water Science &

    Technology, Vol. 51, No. 9, 2005. pp.165-171.

    Wallace, S., and Davis, B. (2009) Engineered Wetland Design and Applications for On-Site

    Bioremediation of PHC Groundwater and Wastewater. Society of Petroleum Engineers. Presentation

    at the SPE international Conference on health , Safety and Environment in Oil and Gas Exploration

    and Production, Nice, France, 15-17 April 2008.

    Wolfram Alfa. 2012.

    http://www.wolframalpha.com/input/?i=toluene&asynchronous=false&equal=Submit

    Vymazal, J. (2010). Constructed Wetlands for Wastewater Treatment. Water. 2, 530-549.

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    Chemicals. Wiey-Liss, New York.

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    Zhi-ping, L. Ke, L. Yan, M. Ming-zhu, L. 2010. Volatilization Mechanism of BTEX on Different

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  • 36 | P a g e

    Appendix 1 - Internship Roles

    Activities Performed

    Many additional tasks where completed during the internship. Work place related subjects and

    undertakings have been studied and completed, some of the main points are as follows.

    Annual Water Sampling

    Hydrocarbon Spill (Presentation)

    Petrochemical Chemistry and Characteristics

    Groundwater Remediation / Natural Attenuation

    Soil Sampling and Remediation Study

    Site Environmental Management Procedure and MSDS

    Stormwater Management

    Oil-Water Separator Study

    Assisting in dust sampling and annual stack testing

    Site inductions have also been completed to familiarise with the site and dangers that come with

    working at a major hazard facility. Some of the competencies included manual handling, emergency

    procedure, permit to work, hot work permit and drug & alcohol policies.

    Other Areas of work: Static electricity + Safety precautions; Oil Plumes - Free Oil, LNAPL, DNAPL;

    Hydrocarbon plumes and Natural Attenuation; DEC license conditions; Industry-Related

    Contamination; Groundwater monitoring; JSEA – Job Safety and Environment Analysis; Use of

    Internal Document System and Purchasing System.

    Annual Water Sampling

    At the Kwinana site, there are known areas of groundwater contamination. The site has been

    classified as “Contaminated - Remediation required” on May 2007 under the Contaminated Site Act

    2003 (Coogee Chemicals Annual Environmental Report, 2012). Therefore, remediation work is

    carried out and monitoring is done constantly – the main information hub however comes from

    annual sampling of groundwater across the entire site. There is an internal procedure - “Bore

    Sampling Procedure” which is followed closely as it is designed in consideration of Australian

  • 37 | P a g e

    Standards AS5667.11:1998 – Guidance on design of sampling programs, sampling techniques and

    the preservation and handling of samples, and AS5667.4:1998 – Guidance on sampling of

    groundwater.

    Figure A: Some of the bottles used for sampling

    The process involves much planning and preparation, including ordering of sample bottles,

    calibration of field pH and conductivity metres, preparation of equipment such as ice, eskys, bailers,

    IP dippers, checking of battery powered pumps and labelling sample bottles, etc. Samples are sent to

    an accredited laboratory. I was involved with this year’s sampling process from planning to sending

    to external laboratory for testing, some of which was done completely independently.

    Groundwater Remediation / Natural Attenuation

    Currently there are two forms of remediation taking place, both of which I have been involved with.

    Both these tasks have written procedures to follow – ‘Bore dipping and manual bailing procedure’.

    The first is manual, which involves using plastic bailers being used to bail water from sampling bores.

    By checking the known contamination areas we can estimate some characteristics of the plume.

    Firstly, there may not be any PSH (Phase Separated Hydrocarbons) present, which is a good sign. This

    can be checked with an interface meter which is capable of detecting PSH. When hydrocarbons are

    present, the bailer can show the amount of PSH present and also allows visual investigation of the

    contaminant. Measurements of the separated layer are taken in millilitres (ml) and recorded, then

  • 38 | P a g e

    the following day or when time permits another recording is done to estimate the recharge rate of

    that particular bore/plume. Severe areas can recharge within hours, while less affected areas may

    take more than a day for any noticeable PSH.

    Figure B: A 1Litre, 1meter plastic bailer

    The other recovery method is using pumps which are designed to target shallow groundwater so

    maximum amounts of PSH can be obtained. These pumps are pneumatic and usually lead to an IBC

    container which when full is emptied into a sump, which will end up entering the oil-water

    separator.

  • 39 | P a g e

    Figure C: A pump inside a sampling bore at S3

    Natural attenuation is also a form of remediation, which is also constantly taking place in the

    surrounding environment. There is much information about natural attenuation regarding fuels and

    oils available. Some regard this as a ‘Doing nothing’ approach, but regardless there is still treatment

    processes occurring such as; dilution & dispersion, sorption, precipitation, volatilization,

    biodegradation.

    Hydrocarbon Spills (Presentation)

    I gave a short presentation to production staff members and managers on the subject of spills and

    what happens after hydrocarbons have been introduced to the environment. Additionally I

    presented a second time to the fortnightly safety meeting. This gave the opportunity to research

    natural attenuation and some of the effects of hydrocarbons on the environment and human

    interactions, and also some of the more complicated processes that are at work when hydrocarbons

    enter soil and water, discussed in the following paragraph.

    Petrochemical Chemistry and Characteristics

    In order to understand the results of groundwater sampling, wetland trail results and issues that

    come with working in the petrochemical industry, knowledge of the substances themselves is

    required. As the three wetland systems will now receive water from separate water sources each

    contaminated with (mostly) diesel, petrol and solvents, knowledge of the chemical characteristics is

    needed to interpret results.

  • 40 | P a g e

    For example, in South 3 the groundwater is known to be contaminated with diesel so one could

    expect to see diesel range hydrocarbons present when a sample is analysed. The following is from

    Chevron’s Diesel Fuel Technical Review, (Chevron, 2007). This is characteristically the range diesel

    fuel contains – that is, diesel fuel is made mostly of hydrocarbons which contain 10 to 22 carbon

    atoms (Chevron, 2007).

    Figure D: Carbon Number Distribution (Chevon, 2007)

    Notice that the lab results correlate to this diesel fuel chart quite well. The C10-28 range has the

    highest mass in the sample taken especially the C15-28 range, this correlates with the mass

    distribution in the chevron analysis chart.

    As mentioned, natural attenuation has some technical requirements too, and these are helpful tools

    for the petrochemical industry to use in the monitoring of contaminated soils and water. When a

    hydrocarbon spill occurs there is mostly air, soil and groundwater contamination. Volatilization of

    lighter compounds and aromatics such as benzene occur the quickest, while other processes may

    take longer. When hydrocarbon reaches the water table dilution occurs and contaminants become

    susceptible to biodegradation. Oxidation-Reduction reactions are used by bacteria to use the

    hydrocarbon as an energy source. The hydrocarbons act as electron donors while electron acceptors

    are dependent on the surrounding environment and include (in order of energy released); oxygen,

    nitrate, iron oxides, sulphate and carbon dioxide. The reduction of the electron acceptor is what

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    releases energy for the bacteria to utilize. The following are the reactions that take place for BTEX

    hydrocarbons acting as an electron donor with the following acceptors; showing aerobic respiration

    is much more energy efficient for the bacteria as the oxygen is available as an electron acceptor

    (Becker & Walden, 1999).

    Table A: Biodegradation of BTEX in order of electron acceptance (Becker & Walden, 1999)

    For this reason, hydrocarbon plumes will typically be oxygen depleted, with aerobic respiration

    occurring at the outer boundary of the plume where the ground water still contains dissolved

    oxygen.

    Oil-Water Separator

    There are two plate separators sitting parallel with each other located at S3 and one in each S2 and

    S1. These receive water from a large collection sullage ‘Oily Water Tank’ which gravity feeds into the

    separators. Initially the plan for feed water to the wetland (in S3) was to use water from the

    separator outflow, due to the representation of the waste water flows within the terminals.

    However at the time of starting the internship the oil-water separation system was inefficient and

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    effluent had been ‘dirty’, with floats being visible in the separators. Effort had since been put into

    fixing the system and as of 4/5/12 the system was been cleaned and operating correctly.

    The separators themselves are parallel plate separators, which use the specific gravity of oil and light

    products to separate the wastewater allowing suspended solids to settle and compounds with

    specific gravity lower than water to float. For example some of the products on site are BP Premium

    Unleaded Petrol (PULP) with a density of 0.75g/cm3, BP Regular Unleaded Petrol: 0.73g/cm3,

    Solvesso (solvent product containing Naphthalene): 0.898g/cm3 and Mobil Diesel 0.84g/cm3 (from

    MSDS). The term parallel plate comes from the fact that angled plates are used inside the vessel to

    increase the surface area for oil amalgamate and rise, while sediment can still settle, increasing the

    removal efficiency of the system.

    Figure E: The empty oil-water separator showing the parallel plates

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    Figure F: Pipework from the sullage to the two plate separators

    Site Procedure and MSDS

    There are many chemicals and products constantly being transferred and stored on site. Each

    hazardous material has its own Material Safety Data Sheet (MSDS), I focussed on materials I would

    most likely come into contact with when dealing with wastewater for wetland trials or day-to-day

    actions. Some MSDS sheets I have checked;

    BP Premium Unleaded Petrol, 2007

    BP Regular Unleaded Petrol, 2011

    Mobil: Diesel, 2009

    ExxonMobil: Solvesso 150 Fluid, 2010

    Coogee Chemicals: Hydrochloric Acid (32%), 2010

    Coogee Chemicals: Caustic Soda (50%), 2010

    Coogee Chemicals: Aluminium Sulphate Solid, 2009

    There are also many procedures which are used for activities which require quality, safety and

    and/or environmental control. There are different procedures for loading and unloading of different

    product; production, cleaning of tanks etc. and these are all updated when needed. Examples of

    procedures affecting myself include;

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    Bore Sampling Procedure

    Emergency Response Procedure

    Groundwater Bore Decommissioning Procedure

    Bore Dipping and Manual Bailing Procedure

    Permit To Work Procedure

    JSEA – Job Safety Environment Analysis Procedure

    Storm Water Discharge from Contained Areas

    Soil Sampling and Remediation Study

    Coogee Chemicals has a site in Kemerton where there is currently a salt contaminated groundwater

    problem and also acid sulphate soils. An EIP has recently been completed for this site. I travelled to

    the Kemerton Site to assist in taking soil samples and tour the site which is a chlor alkali process.

    Stormwater Management

    The site contains many opportunities for stormwater to become contaminated, and is almost

    entirely composed of hard surfaces. With the first rains of winter came checking of the stormwater

    procedure ‘Storm Water Discharge From Contained Areas’ and auditing to see if it was being put into

    place. Management was also reminded of the procedure and to pass on to the relevant people.

    Currently stormwater accumulates in bunded areas; before this stormwater can be discharged it

    must be tested for pH and conductivity and cannot contain any oil matter. The discharge criteria are

    as follows;

    Table B: Discharge criteria for stormwater (Western Australian Environmental Protection (Unauthorised

    Discharges) Regulations 2004)

    Analyte Discharge Criteria

    Conductivity Maximum 2000 uS/cm

    pH Between 4 and 10

    Colour Translucent and clear

    Odour No Odour

    Oily components No oily matter

    Solids material No solid material

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    If the sample meets discharge criteria then it can be pumped out of the bunded area and retained

    for 1 month in a designated area such as a pond or soak. If the sample does not meet the criteria

    then on site treatment is performed.

    Figure G: A bunded area containing stormwater

    Figure H: One of the stormwater discharge areas

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    Appendix 2 – Site map with sampling bore locations

    Note: Far left circle is S3 diesel location, far right is solvent contamination S2, and the middle is

    petrol contamination. The crossed circles are bore locations.

  • Appendix 3 - Lab results

    Appendix 3 has been removed for copyright reasons


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