摘要
以A/O工艺排出的富磷剩余污泥为对象,通过两组厌氧消化反应器(1组目标,1组对照),对比研究了Mg(OH)2作为pH值调节剂对污泥厌氧消化过程氮磷释放的影响。结果表明,Mg(OH)2在促进污泥水解的同时,可以有效降低消化液中NH4+-N、PO34--P质量浓度。经过21 d消化,目标反应器中VSS比对照试验多削减10%,但上清液中NH4+-N、PO4--P质量浓度仅为对照的25%、10%。消化后污泥中灰分增加,导致污泥浓缩与脱水性能显著提高。
This paper is engaged in the study of the effects of Mg（OH）2 on the anaerobic digestion of phosphorus-rich waste activated sludge（PRWAS） based on the two parallel anaerobic digestion reactors（R1 and R2）.The sludge sample used in this paper was taken from an aeration tank in a sewage treating plant in Shanghai,in which almost a hundred-percent water to be treated were originated from the domestic sewage and then to be enhanced by Bio-Phosphorus Removal.The results of our study indicate that the pH of the digestive juice in R2 can be steadily kept within the range of 8.5 to 9.0 throughout the experiment process when the added concentration of Mg（OH）2 is to be kept within 400 mg/L.And,in turn,it is made to fit the use of Mg（OH）2 as pH controlled medium for anaerobic digestion of such sludge.Further investigations prove that the hydrolysis of the activated sludge got improved by adding Mg（OH）2 because it was possible to accelerate the hydrolysis under the alkaline condition.Nevertheless,the concentration of NH＋4-N and PO-4-P remains to get lowered obviously due to the most part of NH＋4-N and PO3-4-P can be removed by crystallizing MAP（MgNH4PO4·6H2O） efficiently,in which Mg2＋ comes from the dissolution of Mg（OH）2.Although the VSS tends to drop in R2 more remarkably than that in R1,the concentrations of NH＋4-N、PO4-P in R2 are likely only to drop to 25% and 10% of their original in R1 by the end of the experiments.Therefore,whether in R1 or in R2,the concentration of ash content tends to increase obviously in the course of experiment.Meanwhile,the ash content in R1 tends to increase more than that in R2 due to the struvite precipitation of Mg2＋,NH＋4-N and PO-4-P,which may account for the improved capacity of thickening and dehydration of the digested waste activated sludge.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2012年第1期94-97,共4页
Journal of Safety and Environment
基金
上海市科委科研计划项目(10231201102)
上海市教委重点学科"城市安全工程"项目(J51502)
上海应用技术学院重点培育基金项目(KJ2011-07)
关键词
环境工程学
MG(OH)2
富磷剩余污泥
厌氧消化
pH值
environmental engineering
Mg（OH）2
phosphorus-rich waste activated sludge
anaerobic digestion
pH
