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ENVT5001: Microbes Case Study - Role of Microbesin Reducing N2O Emission from Waste-Water Treatment Plants Assessment Answer
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Internal Code: 6CIGI
Code: ENVT5001
Microbes Case Study Assessment Answer
Assignment Task: ENVT5001 Nitrous oxide (N2O) is a potent greenhouse gas which is produced at various points throughout the microbial nitrogen cycle. Biological nitrogen removal during wastewater treatment employs microbially driven nitrification and denitrification processes to reduce wastewater ammonia (NH3) concentrations, however, it produces unwanted N2O emissions. Manipulating the microbes involved in wastewater treatment is, therefore, a potential way of reducing N2O emissions. In this case study, N2O production from conventional wastewater treatment and anaerobic ammonia oxidising (Anammox) wastewater treatment designs were examined along with strategies for mitigation, and recommendations are made for optimal strategies to reduce emissions. Conventional wastewater treatment which separately nitrify NH3 to NO3 aerobically, and then denitrifies NO3 to N2 produces most N2O (60-80%) during nitrification due to low oxygen concentrations. Increasing aeration during nitrification and the addition of methanol as an external carbon source along with copper ions are strategies used to reduce N2O emissions. Anammox treatment designs which partially nitrify NH3 to NO2 and then produce N2 via the reaction of NH4 and NO2 almost entirely produce N2O during partial nitrification, and on similar levels to conventional wastewater treatment. Anammox systems which separate nitrification and the anammox reaction produce approximately 97.5% of N2O emissions from the nitrification stage, which can be reduced by limiting feeding rates to prevent NO2 concentration spikes and pH rises above 7.0. Single stage systems which combine the processes can significantly reduce N2O emissions by high-frequency intermittent aeration of the reactor. Engineering bacterial communities by selecting and culturing those which preferentially perform nitrification and denitrification reactions under adverse conditions which facilitate N2O production is a potential long-term low cost mitigation strategy which requires further research. ENVT5001 Recommendations are that during conventional wastewater treatment automated management could strictly monitor dissolved oxygen concentrations and ensures sufficient aeration to at least 2 mg O2/L to promote complete nitrification. In addition copper ions in the form of CuNO3 should be added just prior to denitrification to significantly reduce N2O emission from denitrification. Two-stage anammox treatment designs should be phased out in favour of single-stage designs, since reducing N2O emission from partial nitrification is comparatively limited. Nitrifying and denitrifying bacterial communities from existing wastewater treatment systems should be sampled and sequenced in order to determine the species which show the greatest expression of nitrite oxidising and N2O reducing genes, so they might be cultured and used to enhance the mitigation of N2O production. ENVT5001This ENVT5001: Biotechnology Assessment has been solved by our Biotechnology experts at onlineassignmentbank. Our Assignment Writing Experts are efficient to provide a fresh solution to this question. We are serving more than 10000+ Students in Australia, UK & US by helping them to score HD in their academics. Our Experts are well trained to follow all marking rubrics & referencing style.