摘要
采用城市污水处理厂剩余污泥超声溶胞过程中释放的溶解性有机物(DOM)作为淋洗剂去除污泥中的重金属.分别研究了DOM在不同浓度、pH值、震荡时间以及淋洗次数下对Cd和As去除效率的影响以及淋洗对污泥理化性质的影响,并利用Tessier连续提取法分析了DOM淋洗对污泥中Cd和As形态的改变.研究表明,在DOM浓度为1200mg/L、pH值为6.0、淋洗时间为24h、液固比40:1的最优条件下,单次淋洗后Cd和As的去除率分别为36.12%和23.75%,3次淋洗后Cd和As的去除率可达62.35%和39.45%.3次淋洗后污泥中的有机物和总氮含量升高,然而总磷、总钾含量以及pH值降低,污泥中Cd和As的形态发生了改变,有效态比例明显降低.
The dissolved organic matter(DOM) released from ultrasonic lysis of sludge was used to remove the heavy metals in the waste activated sludge. The effects of DOM on the removal efficiency of cadmium(Cd) and arsenic(As) were investigated under different DOM concentrations, pH, shaking and washing time. The physicochemical properties of sludge before and after DOM leaching were also taken into comparisons. Moreover, changes of Cd and As speciation of sludge were analyzed by using continuous extraction of Tessier. Under optimal conditions: DOM concentration 1200 mg/L, pH 6, leaching time 24 h and the ratio of liquid to solid 40:1, the removal efficiencies of Cd and As were 36.12% and 23.75%(single washing) and improved to 62.35% and 39.45%(triple washing), respectively. The contents of organic matter and total nitrogen in the sludge increased, but the contents of total phosphorus, total potassium and pH decreased after triple leaching. The fractions of cadmium and arsenic distribution in sludge was changed before and after triple washing. Moreover, the available contents of Cd and As in sludge was significantly reduced.
出处
《中国环境科学》
EI
CAS
CSSCI
CSCD
北大核心
2017年第11期4179-4187,共9页
China Environmental Science
基金
国家自然科学基金资助项目(51508178
51521006)
