Production Experiment On Removal Of Ammonia Nitrogen In Low Temperature Water By BEAC And UV/Chlorine Combination Process

Ammonia nitrogen is a common pollutant in water in China,which is difficult to remove,especially in low temperature water,and it had already been widely concerned.The water in Mudanjiang was also polluted by ammonia nitrogen,especially in winter.In order to guarantee the concentration of ammonia nitrogen in water to meet the standard of?Standards for drinking water quality?(GB5749-2006)in china,it is necessary to study the treatment process of ammonia nitrogen in low temperature water.in this experiment,BEAC and UV / chlorine combination process are used to control the concentration of ammonia nitrogen in low temperature water.In this experiment,the removal efficiency of ammonia nitrogen was compared with the biological activated carbon technology and the ordinary bioactivated carbon technology while under different ammonia nitrogen concentration.The result showed that the removal efficiency of ammonia nitrogen in BEAC process was affected by filtration rate,backwashing mode,ozone dosage and dosing methods,when the filtration rate is 4.47m/h,the removal efficiency is good,and the hydraulic retention time is less than 30 min,backing washing with 8L/(m~2·s)for 10 mins could achieve the best removal of ammonia nitrogen,when the dosage of ozone is 1.5mg/L,the removal efficiency of ammonia nitrogen by biological activated carbon filter was the best,when backwashing with dosage 2mg/L in tower 1,1mg/L in tower 2,the removal efficiency of ammonia nitrogen was better,and the removal rate of organic matter was the maximum.In order to investigate the change of adsorption index of activated carbon,the change of adsorption capacity during the operation of BEAC process was studied,iodine value,methylene blue value,tannin value and humic acid value were determined,these four adsorption properties decreased gradually during the long-term operation of BEAC.The microbial characteristics of BEAC process are characterized by two aspects: biomass and high throughput,the biomass presents a trend that increased first and then decreased in the running process,the average biomass could be as high as 8.57 × 106cfu/g.In the high throughput sequencing,the abundance and biomass of the two dominant bacteria were the same,and the abundance of Acinetobacter was 5.92% while Pseudomonas was 11.77%.In order to study the removal efficiency of ammonia nitrogen under low temperature conditions,the removal efficiency of ammonia nitrogen under different chlorine to nitrogen ratio was compared between the breakpoint chlorination process and the UV / chlorine coupling process,combined with residual chlorine,the disinfection efficiency of these two processes was also investigated.The breakpoint of breakpoint chlorination occurred when the ratio of chlorine to nitrogen was 9:1,but there was no obvious breakpoint in the UV / chloride coupling process,when chlorine to nitrogen ratio was 5:1,the concentration of ammonia nitrogen in effluent was lower than 0.5mg/L.Increasing chlorine to nitrogen ratio,UV light intensity and UV exposure time can improve the removal efficiency of ammonia nitrogen in the process of UV / chlorine coupling.The UV / chlorine coupling process had significant effects on the control of chloroform,chloral hydrate and dichloro acetonitrile.On the basis of the above research,the removal efficiency of ammonia nitrogen under different influent ammonia nitrogen by BEAC process and ultraviolet / chlorine combination process was studied,and the effects of ozone dosage and chlorine to nitrogen ratio on the removal efficiency of ammonia nitrogen in these two process were investigated,the results showed that BEAC and UV / chlorine combination process had good treatment effect and application prospect in treating ammonia nitrogen in low temperature water.