Fermentative Liquid Produced From Municipal Treatment Plant Excess Sludge As The Carbon Sources Of Biological Nitrogen And Phosphorus Removal

Treat the volatile fatty acids(VFAs)from municipal wastewater treatment plant excesssludge anaerobic digestion as carbon source of wastewater biological nitrogen andphosphorus removal can be an important way to realize the resource and reduction ofexcess sludge, volatile fatty acids in the fermented liquid can be used as the carbon sourceto satisfy the shortage of municipal wastewater treatment plant biological,which usebiological nutrient removal (BNR) to removes TN and TP from wastewater. This articlebased on the preliminary research achievements, a pilot-scale self-mixing anaerobicfermentation column reactor (with an available volume of125m3) was carried out in BaiDang wastewater treatment plant New District of Su Zhou. We will study the factors ofexcess sludge anaerobic fermentation and acidfication and the feasibility of producingacids as the carbon source.This paper main study the influences of temperature on the excess sludge anaerobicfermentation and acidification in the pilot scale reactor and the influences of pH on theexcess sludge anaerobic fermentation and acidification. Further more, we study the acidliquid served as carbon source in the biological nitrogen and phosphorus removal,exploring the feasibility of the fermentation acid liquid as carbon source. Main results ofthis dissertation were shown as follows:①When the pH is7.0and the sludge retention time is15d, we monitor the conditionof excess sludge anaerobic fermentation and acidification in the pilot scale reactor,reserching the influence of temperature on the excess sludge anaerobic fermentation andacidification. The results show that: when the temperature reach the37℃, the hydrolysisefficiency reach the maximum, meanwhile, the production of violate fatty acids reach themaximun of192.9mg/L.②Under the condition of temperature is25℃, sludge retention time is10d, theamount of sludge treatment is120L/d, we adjust the pH of excess sludge, investigating theeffect of pH pretreatment on excess sludge anaerobic fermentation and acidificitation, Theresults show that: the sludge hydrolysis efficiency reach the maximun under the pH11.0;the production of acid liquid reach the maximun of103.6mg/L under the pH10.0; therelease of ammonia nitrogen and soluble phosphate reach the maximun of136.7mg/L与67.3mg/L under the pH10.0.③Through adding fermentation liquid into the sequencing batch reactor as carbon source, which the adding ratio of fermentation liquid is1/10、、1/20与1/40of the reactor effective volume, investigating the best adding ratio of the fermentation liquid, getting the best adding ratio.④Through adding fermentation liquid and acetic acid into the sequencing batch reactor as carbon source, adding the same ratio of the reactor effective volume, comparisoning fermentation liquid with acetic acid as the carbon source, investigating the feasibility of the fermentation liquid as biological nutrient and phosphorus removal carbon source, The results show that:the efficiency of biological nutrient and phosphorus removal is better than acetic acid which treating fermentation liquid as carbon source.