What hypothesis will be tested:Rendering industry releases highly polluted wastewater with COD more than 2 g L^-1, ammonium 30 mg L^-1 and odor threshold units greater than 1000 threshold odor number (TON). These ammonium contents remain in effluent after preliminary treatment. Deammonification process faces many challenges like high COD/N ratio and longer doubling time of nitrosomonas and nitrobacter. Basis of these challenges it is hypothesized that up flow anaerobic sludge blanket (UASB) effluent will be treated in oxic zone for nitrification at DO between 0.5 -1 mg L^-1 than forward to strict anaerobic zone at 30-35^oC, pretreatment with UASB will facilitate to reduce COD/N ratio.  In this study sodium chlorate may stop nitrification which will results in more nitrite production than nitrate. This will facilitate the production of direct nitrogen from nitrite. As biological process capable of anaerobic transformation of NH₄⁺ to nitrogen gas with NO₂ as electron acceptor. Third hypothesis is to explore effectiveness of nitrifying bacterial in microbial fuel cell for bioelectricity production. 

Why is it important:Free ammonia is toxic to fishes if released in to fresh water bodies and it exert significant nitrification oxygen demand with severely depleting the dissolved oxygen. Transfer of ammonium to ammonia is depends upon pH. Mostly wastewater receiving channels are already polluted and releases odor when ammonium-N is present. It is already reported that some cattles died after drinking such wastewater.

What has already been done: Nitrification potential to form nitrite can be facilitated by ammonium sulphate and further oxidation to nitrate formation can be controlled by sodium chlorate in soil water solution (Hoffman, 2007). In mangroves a study conducted to decrease nitrification by using polybrominatd diphenyl ether (Chen, 2016). To clarify the heterotrophic and autotrophic bacteria in nitrification process in soil with ¹⁵N-ammonium isotopic pool dilution with acetylene as inhibitor was tested to stop autotrophic nitrification and sodium chlorate used to stop the heterotrophic nitrification (Wang, 2014). Allylthiourea had been known to stop nitrification process to enhance the algae growth with due preference of ammonium than nitrite and nitrate (Krustok, 2016). In this proposed research only sodium chlorate will be used in oxi zone during nitrogen removal from wastewater. In previous study sodium chlorate is known to stop nitrate formation in soil.

Methodology:This proposed research project will have three experimental setup (fig 1) and each will consists of UASB, oxic and anaerobic sections. Setup 1 will be operated as control at ambient temperature, setup 2 will run with sodium chlorate and 3 without sodium chlorate. Setup 2 & 3 will operate at temperature 30-35^oC whereas Electrodes will be installed in UASB and anaerobic part of each setup. UASB will be used to reduce total and soluble COD for desirable COD/N ratio before feeding to oxic zone. In setup 2 sodium chlorate is added at oxic zone and its effluent forwarded to anaerobic zone where nitrite will transform into nitrogen gas. Setup 3 oxic zone ammonium is forcedto transform into nitrate and nitrite and later it will denitrify in anaerobic zone. In setup 3 no sodium chlorate will be added. In oxic zone DO will be set from range 0.5 to 1 mg L^-1 along with COD/N ratio 0.2-0.5. Installed anode electrodes in anaerobic part will be connected with cathode to monitor the electron flow. This will act as microbial fuel cell. In three experimental setup six microbial fuel cell will be working. Voltage prodcution potential of heterotrophs (UASB) and nitrifying anammox bacteria will be measured and compared. 

Expected results:This proposed setup will be successful to reduce high COD load from rendering wastewater, better handling of ammoinium nitrogen through anammox system as proposed above paragraph. Treated water will have less odorous compounds and improve the existing condition.  In this study impact of anammox procedure in nitrogen removal and on bioelectricity generation will also be explored along with and without sodium chlorate in oxic zone. Nitrogen would be removed from wastewater without extra energy input and no carbon dioxide will be released to climate.

Data analysis: Obtained results (CODt, CODs, ammonium-N, nitrate-N, nitrite-N, alkalinity, COD/N, DO, TS, TSS,  and VSS) from each setup will be analyzed. Statistical tools such as ANOVA and t-test will be used to study the significance between three setup. Microbial fuel cell will be analyzed for their efficiency among six by using volts, ampare, columbic efficiency and resistance of the circuit. Species identification by using PCR-DGGE.

Significance to the funder: This proposed study is an applied research and after successful results a proto type system will be installed at rendering plant. This research activity will help to develop more understanding between university and industry. At the moment rendering or poultry feed industry releases highly polluted wastewater which going to stream without any treatment. I think this is an only industry which has not been focused yet in Pakistan. Moreover the methodology will help to reduce carbon dioxide emission during wastewater treatment.