摘要
采用次氯酸钠对城市污水厂二级生物处理出水进行消毒试验,从氨氮浓度、pH、消毒时间、水温这4个方面,分析其对次氯酸钠消毒效果的影响。当氨氮浓度≤0.2 mg/L时,次氯酸钠最佳投加量为15 mg/L;氨氮浓度为0.2~0.4 mg/L时,次氯酸钠最佳投加量为8 mg/L;氨氮浓度约0.6 mg/L时,次氯酸钠最佳投加量为6 mg/L;氨氮浓度为0.8~1.2 mg/L时,次氯酸钠最佳投加量为5 mg/L。当pH值为5. 0~6.0时,10 mg/L的次氯酸钠投加量即可使出水达标,若pH值为8.0~9.0时,必须加大次氯酸钠的投加量至15 mg/L。冬季气温较低时,尾水消毒要考虑延长消毒接触时间。夏季水温较高,可以相应减少加氯量。一般消毒接触时间为15~30 min时消毒效果最佳。
Sodium hypochlorite was used to disinfect secondary effluent of wastewater treatment plant.Factors affecting disinfection effect of sodium hypochlorite were analyzed from four aspects: ammonia nitrogen, pH, disinfection time and water temperature.When the concentration of ammonia nitrogen was less than 0.2 mg/L, the optimal dosage of sodium hypochlorite was 15 mg/L.When it was in range of 0.2 ~ 0.4 mg/L, the optimal dosage was 8 mg/L.When the concentration of ammonia nitrogen was about 0.6 mg/L, the best sodium hypochlorite dosage was of 6 mg/L.When the concentration of ammonia nitrogen was in range of 0.8~1.2 mg/L, the optimal dosage of sodium hypochlorite was 5 mg/L.When pH value was in the range of 5.0 ~6.0,with the dosage of 10 mg/L sodium hypochlorite,the effluent could reach the standard,and if pH value was in range of 8.0~9.0,the dosage of sodium hypochlorite must be increased to 15 mg/L.The temperature in winter was low, the disinfection contact time should be extended, and the higher temperature in summer could reduce chlorination.Generally, the best disinfection contact time was 15 ~30 min.
引文
[1]郑晓英,王靖宇,李魁晓,等.次氯酸钠、臭氧及其组合再生水消毒技术研究[J].环境工程,2017,35(11):23-27.
[2]程丽华,李璐瑶,毕学军,等.次氯酸钠对二级出水的消毒效果及对水质的影响[J].中国给水排水,2013(21):104-106.
[3]张金松,卢小艳.饮用水消毒工艺及副产物控制技术发展[J].给水排水,2016,42(9):1-3.
[4] DRAKOPOULOU S,TERZAKIS S,FOUNTOULAKIS M S,et al.Ultrasound-induced inactivation of gram-negative and gram-positive bacteriain secondary treated municipal wastewater[J]. Ultrason Sonochem,2009,16(5):629-634.
[5] HUA G, RECKHOW D A. Comparison of disinfection byproduct formation from chlorine and alternative disinfectants[J]. Water Research, 2007, 41(8):1667-1678.
[6]严煦世,范瑾初.给水工程[M].北京:中国建筑工业出版社,2002.
[7] OGUZ E, KESKINLER B, CELIK C. Investigation on the removal of COD from colored aqueous solutions with O, HO, HCO andPAC[J]. Ozone Science&Engineering,2015,37(1):62-70.
[8] CHEN T Y, KAO C M, HONG A, et al. Application of ozone on the decolorization of reactive dyes-Orange-13 and Blue-19[J].Desalination, 2009,249(3):1238-1242.
[9] LIANG Y, ZHANG Z, YANG X, et al. Effect of suspended solids on the sequential disinfection of secondary effluent by UV irradiation and chlorination[J]. Journal of Environmental Engineering,2013,139(12):1482-1487.
[10]王虹.城市污水处理厂消毒工艺的研究[D].天津:天津大学,2005.
[11]国家环境保护总局,《水和废水监测分析方法》编委会.水和废水的监测分析方法(增补版)[M].4版.北京:中国环境科学出版社,2002.
[12]污水综合排放标准:GB 8978—1996[S].
[13]水质化学需氧量的测定重铬酸盐法:GB 11914—1989[S].
[14]水质铵的测定纳氏试剂比色法:GB 7479—1787[S].
[15]水质悬浮物的测定重量法:GB 11901—1989[S].
[16]水质色度的测定:GB 11903—1989[S].