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Reference Document on Best Available Techniques in Common Waste Water and Waste
Gas Treatment/Management Systems in the Chemical Sector (CWW BREF)
Aivi SissaTallinn – Estonia
27 – 28 March 2007
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Introduction
• It was finalised late 2001
• Developed to apply to the chemical industry...contains valuable information for other
sectors
• It is a horizontal BREF
Borderline between vertical and horizontal chemical BREFs
Waste water example
Chemicalreaction
Work-up
Productisolation
Recovery
Product
PRODUCTION
CONTROL
Recipient
Waste waterVERTICAL
CHEMICAL BREFs
CWW BREF
Waste water treatment
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Chemical industryThe chemical industry covers a wide range of enterprises:
• One-process-few-products enterprises with one or just a few waste water/waste gas streams
• Multi-production-mix enterprises with many complex waste water/waste gas streams
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Vertical chemical BREFs
• Chlor-alkali (CAK)• Large Volume Inorganic Chemicals –
Ammonia, Acids and Fertilisers (LVIC-AAF)• Large Volume Inorganic Chemicals – Solid
and Others (LVIC-S)• Large Volume Organic Chemicals (LVOC)• Polymers (POL)
• Speciality Inorganic Chemicals (SIC)• Organic Fine Chemicals (OFC)
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Scope• Environmental management techniques
• Generally applicable process-integrated measures (i.e. applicable with an identical purpose in distinct production processes)
• End-of-pipe treatment applied on chemical sites to WW, WG and waste water sludge
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Structure of the document
• CH1: General description
• CH2: Waste water/waste gas management
• CH3: Applied treatment technology
• CH4: Best available techniques
• CH5: Emerging techniques
• CH6: Concluding remarks
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Best available techniques
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BAT – horizontal approach
• The options for emissions prevention/control are assessed independently of the particular production process(es)
• BAT embrace the most effective and suitable measures for achieving a high general level of protection of the environment as a whole against emissions
• BAT are determined more broadly and include more than just technology
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Implementation of BAT• Implementation of BAT in existing
installations:– BAT can be integrated when major alterations
are planned– BAT can be implemented in a step-by-step
construction programme over a period of time
• Implementation of BAT in new plants is not normally a problem
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General BAT
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Waste water/waste gas management
General Environmental Management
• proper and consistent execution of a recognised EMS
• use of management tools
ENVIRONMENTAL MANAGEMENT
SYSTEM
MANAGEMENT TOOLS
Operational management
tools
Inventory management
tools
Strategic management
tools
Safety and emergency
tools
Site inventory
Stream inventory
WG emission qualification
Reduction of water usage and discharge
WEA
EMFA
Monitoring
Internal targets
Choice of treatment options
WW/WG control systems
Choice of collection system
Implementation of control option
Quality control
Risk assessment
Bench marking
LCA
Pollution incident response
Fire fighting
Management techniques
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Process-integrated measures
• General need for prevention/reduction of the amount of WW and WG and/or contamination within a production line
These are generally production- or process-specific and their applicability requires special assessment
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Waste water/waste gas collection
• Ducting and segregating waste water streams to their appropriate treatment system
• Routing waste gases to treatment systems. These are emission source enclosure, vents and pipes
BAT for process-integrated measures
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BAT for waste water treatment
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Waste water – key issues• Emissions to water can arise from, e.g.,
chemical synthesis, WGT (wet scrubbers) and rain water from contaminated areas
• The majority of process water (70 – 90%) has a low pollution load (e.g. cleaning water, vacuum, exhaust air clean-up, pumps)
• The remaining (10 – 30%) contains up to 90% of the pollution load
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WW techniques that fit into the scope
WASTE WATER TECHNIQUES
Process-integrated measures
End-of-pipe treatment
Individual treatment
Central treatment
RECIPIENT
PretreatmentFinal treatment
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BAT for waste water treatment
• Four different strategies:– central final treatment in a biological WWTP on site– central final treatment in a municipal WWTP– central final treatment of inorganic waste water in a
chemical/mechanical WWTP– decentralised treatment(s)
All four strategies are considered as BAT when properly applied to the actual waste water situation
The approach to reaching specific BAT conclusions follows the pathway of pollutants
OrganicInorganic
ABATEMENTTECHNIQUES
(non biodegradable)OxidationReductionHydrolysis
Air oxidationIncineration
RECOVERYTECHNIQUES
NF / ROAdsorption
Extraction/DistillationEvaporation
Stripping/gas treatment
Uncontaminated (e.g. rainwater)
Heavy metals
Free oilHydrocarbons
Salts and/or acids Salts
and/or acids
ABATEMENTTECHNIQUES
(biodegradable)Biological treatment
Pollutants unsuitable
for biological treatment
Waste water sewerage system
Biodegradable substances
Waste water
Refractory or toxic organic
Contaminated
Receiving water
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BAT AELs for the final discharge into receiving water
ParameterPerformance
rates(%)
Emission levels(mg/l)
TSS 10 – 20
COD 76 – 96 30 – 250
Total inorganic N 5 – 25
Total P 0.5 – 1.5
Heavy metals No decision – split view
AOX No decision – split view
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BAT for waste gas treatment
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Waste gas – key issues
• Only rarely can waste gas streams with different characteristics be treated simultaneously
• Waste gas streams can roughly be divided into ducted and non-ducted (diffuse, fugitive) emissions
• The flow rate to be treated is a major parameter in the selection of abatement options
• Recovery techniques are generally used for valuable products
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WG techniques that fit into the scope
WASTE GAS TECHNIQUES
Ducted emissions
Process-integrated measures
End-of-pipe treatment
Fugitive and diffuse emissions
Capture
Individual treatment
Central treatment
Group treatment
STACK
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• low temperature sources
• high temperature sources
BAT for waste gas treatment
The approach to reaching specific BAT conclusions follows the pathway of pollutants
According to treatment, the sources for waste gases are distinguished as:
Decision pathway for WGT: basis for BAT conclusions
Low temperature:production,
handling andwork-up gases
High temperature:Combustion gases
Inorganicvolatiles
Dust DustNOx
SOx HCl, HF
Substancerecovery
Energyrecovery
Recovery techniquesMembrane separation
CondensationAdsorption
Wet scrubbersSeparatorsCyclones
Electrostatic precipitatorsFabric filters
Abatement techniquesBiofiltration
BioscrubbingBiotrickling
Oxidation (thermal and catalytic)Flaring
SeparatorsCyclones
Electrostatic precipitatorsFiltrationSorption
SNCR / SCR
VOC
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BAT AELs for waste gas treatment
Low-temperatures waste gases
There are no BAT AELs for low-temperature waste gases in the CWW BREF. These are reported in the corresponding vertical BREFs
However, the BAT chapter of the CWW BREF reports performance levels related to the application of techniques
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BAT AELs for waste gas treatment
High temperature waste gases
ParameterEmission levels
(mg/Nm3)
Dust <5 – 15
HCl <10
HF <1
SO2 <40 – 150
NOx (gas boilers/heaters) 20 – 150
NOx (liquid boilers/heaters) 55 – 300
NH3 4 <5
Dioxins 0.1 ng/Nm TEQ
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Emerging techniques
• Techniques not yet applied on a commercial basis or outside pilot plant operation. These could be applicable in the future at large scale operation
• Assessment needed during the review of the BREF
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Concluding remarks
• High level of consensus achieved
• There is a lack of information on:– performance data in combination with
operational data (e.g. cross-media and energy issues)
– costs
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Revision of the CWW BREF
• Planned to start late 2007/early 2008
• Currently preparing a comparative analysis of the first series of chemical BREFs:
– to set guidelines/recommendations which will help the Technical Working Group (TWG) with the preparation of the review of the CWW BREF as well as during the review process
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QUESTIONS?