Effects Of Inorganic Carbon And Nitrogen And Phosphorus Precursors On Gas Production Efficiency Of Phosphate Reduction Systems

Microbial phosphorus removal is an important means of wastewater phosphorus removal,The aerobic absorption and anaerobic release of phosphorus by phosphorus accumulating bacteria are widely used.This method of phosphorus removal is relatively traditional,and as technology advances,Human beings discovered biological phosphorus removal pathway and broke through related technology,Then the phosphate reduction dephosphorization technology is gradually developed and utilized.Phosphate reduction method has the advantages of economy,high efficiency,no need to add chemical agents,low content of phosphorus in sludge,and easy to recycle phosphorus resources.The external factors influencing the reduction product phosphine have been discussed,and a lot of work has been done on the environment in which phosphine is produced.However,the effects of organic and inorganic nutrient sources on the production of phosphine are rarely reported.The purpose of this study was to investigate the effect of adding organic and inorganic nitrogen and phosphorus nutrients on phosphate-producing efficiency of phosphate-rich reducing bacteria in sludge and pure phosphate-reducing bacteria.In order to improve the success rate of screening phosphate reducing bacteria and obtain sludge with phosphate reducing function,The activated sludge was domesticated and cultured in stages for 90 days.The removal rate of COD?Chemical oxygen demand?and phosphate was85.36%and 27.46%respectively.After enrichment of screened strains,The result of qualitative analysis of the gas produced is phosphine.The results showed that the experiment of acclimatization of sludge and the enrichment of strain were successful.The influence of organic phosphorus source and inorganic phosphorus source on gas production efficiency of phosphate reduction system was discussed by changing the type of phosphorus source.In this experiment,soybean lecithin,bone meal,dipotassium hydrogen phosphate,sodium phosphite,potassium hexametaphosphate and sodium hypophosphite were selected.Sodium hypophosphite from inorganic phosphorus has the highest gas production efficiency.The gas production effect of organophosphorus source is poor,The yield of phosphine from sodium hypophosphite and bone meal was better than that from single organophosphate source or single inorganic phosphorus source.The concentration of CO₂in the environment was not controlled during the above experiment.In order to explore the effect of this variable on the gas production efficiency of phosphate reduction system,different concentrations of CO₂were introduced to explore.The results show:CO₂concentration has no effect on gas production efficiency of phosphate reduction system.The amount of phosphine produced did not change significantly.The influence of organic nitrogen source and inorganic nitrogen source on gas production efficiency of phosphate reduction system was discussed by changing the type of nitrogen source.Peptone,ammonium chloride and potassium nitrate were selected as nitrogen sources,and it was found that the gas production efficiency was the best when ammonium chloride was the nitrogen source by measuring the gas production volume.When peptone and ammonium chloride were nitrogen sources,the optimum ratio of nitrogen to phosphorus was4:1.Potassium nitrate inhibited the production of phosphine,and the higher the concentration,the stronger the inhibition.The phosphine yield of peptone mixed with ammonium chloride as a nitrogen source is better than that of a single peptone or ammonium chloride as a nitrogen source.