Disposal of Biological Waste

Disposal of Biological WasteA Case Study of a Salmon Processing Plants Need to Reduce the Biological Content of its Industrial Waste. By Mike Mix

Pacific National Processing Pacific National Processing (PNP) is a Salmon processing plant on the west coast of Vancouver Island. This plant processes approximately 16,000 tons of farmed Salmon every year for distribution around the world.

Biological WasteAs a result of the high volume of Salmon processing, there is a significant amount of biological waste to dispose of. PNP produces as much as 160 cubic meters of waste water a day. This waste water primarily consists of blood which potentially contains pathogens harmful to the environment.

Biological Waste Cont.Prior to 2011, this waste water was released directly into the marine environment through the towns sewage system with minimal treatment. This surplus of biological content created an imbalance in the ecosystem resulting in a phenomenon call eutrophication. Eutrophication is when algae grows uncontrollably as a result of infinite availability of nitrates. This algae promotes the growth of bacteria to the point that the bacteria consume all the available oxygen in the environment.

(Wheatley River Improvement Group, 2013)

Harmful PathogensThe waste water produced from processing also has the potential to distribute harmful pathogens into the marine environment. The pathogen of greatest concern to PNP is IHN. IHN has a 100% fatality rate in Atlantic Salmon, which is the type of Salmon that is raised in their fish farms.

What Can Be Done?PNP has identified the need to kill all harmful pathogens and reduce the biological content of their waste water. (Photo of PNP Shipping Area)

Possible SolutionChlorination System

Chlorination SystemThe first option researched by PNP was the chlorination system. The chlorination system is a simple and cheap solution for waste water treatment. The process consists of injecting chlorine into a tank containing waste water. The tank gravity feeds into the next tank where a dechlorination solution is injected lowering the chlorine content of the water. Once the chlorine is removed the waste water is sent to the city sewage for disposal in the marine environment.

ProsThe Chlorine system effectively removes 100% of harmful bacteria.

The Chlorine system does not have a harmful effect on the environment

The Chlorine system is cheap and easy to maintain

ConsThe Chlorine system does not reduce the biological content of the water

Excessive nitrates are still introduced into the marine environment causing an imbalance in the ecosystem.

Has PNP Resolved the Issue?The chlorination system provides waste water treatment that effectively removes 100% of harmful pathogens without causing harm to the natural environment. However, PNP requires their waste water treatment facility to also reduce the biological content. Is the chlorination system a solution to their problems?

NOThe chlorination system does not remove the nitrates from the waste water and does not prevent the harmful phenomenon of Eutrophication. With a surplus in nitrates still present algae is allowed to grow without restriction. This prevents the growth of other vegetation and encourages the growth of bacteria. The bacteria multiply until their population consumes the oxygen available in the water. Throughout the entire process the balance of ecosystem is disrupted.

What Else Can be Done?Picture of Mainstream Fish Farm. This photo was taken from a sea plane searching for warning signs of Eutrophication

14

MASSAnother option available to PNP is the Micro Air Separation System (MASS). The MASS is an excellent example of how society utilizes chemicals and technology to ensure environmental sustainability while industries strive to meet the demands of production.

MASSThe MASS waste water treatment system uses a combination of mechanical and chemical processes to remove suspended solids (blood) from the waste water. Before and after results are shown below.

MASSIn order to effectively remove these suspended solids, the waste water must go through a series of mechanical and chemical processes as shown below.

FilteringThe first of these processes is mechanical filtering by means of a rotary screen. This screen removes all solids from the waste water so that they do not interfere with later processes of the treatment plant.

MASS-EQ Tank and Mixer

The screened waste water is sent to an equalization tank shown below. The content of PNPs waste water varies drastically throughout the day from salt water, blood, waste water from sanitation, and even rain water collected from PNPs shipping yard.

EQ Tank and Mixer

This above ground tank is equipped with a mechanical mixer that blends the contents of the waste water. This ensures that the waste water treatment plant will be treating a consistent level of waste and maximizing the systems efficency.

The Chemical ProcessOnce the waste water has been blended in the equalization tank it is ready to begin the treatment process. This process begins with the introduction Ferric Chloride. Next is the introduction of Polymer and then Caustic Soda is introduced. These chemicals react with the waste water to form the bi-products of water and a solid waste. This waste is separated from the waste water by the injection of micro bubbles which floats the solid waste for easy removal.

Ferric ChlorideFerric chloride is introduced to lower the PH of the waste water. This lowering of PH as well as the introduction of iron contained within the chemical prepares the waste water for the treatment process. The iron provides an element for the nitrates to begin to bind to and the acidity helps separate the nitrates from the water.

PolymerAfter Ferric Chloride is injected a Polymer is added. Polymer acts as the primary coagulant as it binds to the dissolved biological content of the waste water. The picture to the right shows the waste water after this process.

Caustic SodaNext Caustic Soda is added to the waste water. Caustic Soda is a strong base and raises the PH of the wastewater. This chemical is also a flocculent and helps the suspended solids clump together as shown in the picture.

Micro Air Separation SystemNext in the waste water treatment process is the primary MASS system. This system injects micro air bubbles into the chemically treated waste water completing the reaction. These micro air bubbles enhance the chemical reaction by binding to the floc and floating it up for removal.

Skimmer TankA skimmer is used to remove the floating floc from the wastewater. When the floc is removed the primary MASS process is complete and the wastewater is ready for further processing.

Ozone MASSAfter the Primary MASS comes the Ozone MASS. The Ozone MASS is used to disinfect the water. Ozone is used to kill harmful pathogens and oxidize any proteins that remain in the wastewater. This process is done in a pressurized tank to ensure maximum effectiveness of the ozone reaction.

UV DisinfectionAfter being treated by the Ozone MASS, the wastewater is disinfected by passing by UV lamps inserted into the plumbing. This provides the final stage of disinfection. The waste water is now ready to be released into the environment.

What About the Floc?The wastewater treatment facility produces approximately thirty tons of solid floc a week. This floc is rich in nitrogen and other nutrients used to fertilize soil. The floc is transported along with other solid wastes from production to landfills to be decomposed into black dirt.

Has PNP Resolved the Issue?Yes, PNP has resolved their wastewater issue. In 2011 they invested 1.1 million dollars to build a wastewater treatment plant using MASS technology.

BibliographyFisheries and Oceans Canada. (2013, February 27). Acquire and Install Unique Air and Pressurized Ozone Technology at Tofino Fish Processing Plant to Reduce Pathogens and Biological Loading of Processing Wastewater. Retrieved from Fisheries and Oceans Canada: http://www.dfo-mpo.gc.ca/aquaculture/sustainable-durable/rapports-reports/2010-P01-eng.html#tphpThis source is the report done by PNP for the Department of Fisheries and Oceans Canada (DFO). The report describes the need for the waste water treatment plant as well as reports the successes of the system for their review. The report provides a detailed analysis of the methods and procedures used for future processing plants to use as guidelines. The author of this presentation contributed in the processing of this report while employed as the operator of the wastewater system mentioned in the presentation.

BibliographyMuddy River Technologies Inc. (2011, Oct 05). Blood Water Treatment. Retrieved from Slide Share: http://www.slideshare.net/nelsladouceur/blood-water-treatmentThis source is a power point presentation created by Muddy River Technologies INC, the engineering team responsible for the design and construction of the MASS waste water treatment system. This source described the advantages of the MASS system over competing waste water treatment systems. The imagery of the water samples was taken from this source. The author of this source also taught the author of this presentation the processes related to MASS treatment described in this presentation.

BibliographyWarkentin, G. (2011, December 06). Mainstream Upgrade Provides Downstream Benefits for Tofino. Retrieved from Mainstream Canada: http://msc.khamiahosting.com/mainstream-upgrade-provides-downstream-benefits-tofinoThis source is an article featured in the Mainstream Canada company newsletter. This source provided the economical statistics of the wastewater system. This article was intended to inform the residents of Tofino as well as investors to the company that PNP was committed to producing their product responsibly and without harming the local environment.

BibliographyWheatley River Improvement Group. (2013). WheatleyRiver.ca. Retrieved from Wheatley River Improvement Group: http://www.wheatleyriver.ca/current-projects/wrig-pilot-nitrate-study/nitrates-and-their-effect-on-water-quality-a-quick-study/This source provided the detailed information about Eutrophication. It also provided the diagram describing the process of Eutrophication.