微波改性膨润土吸附-PAM混凝联用技术处理冶炼废水中的重金属

REMOVAL OF HEAVY METALS IN SMELTERY WASTEWATER BY THE COMBINED TECHNIQUE OF ABSORPTION WITH MICROWAVE MODIFIED BENTONITE AND COAGULATION WITH PAM

采用微波对膨润土进行改性,研究微波改性膨润土吸附与聚丙烯酰胺(PAM)混凝联用技术处理实际冶炼废水中的重金属。结果表明,单独微波改性膨润土吸附试验中,当投加量为25 g/L,废水中的锰、锌、镉和铅的去除率分别可达71.9%、89.7%、78.5%和93.1%;采用微波改性膨润土吸附与PAM混凝联用技术时,重金属的去除率均有上升,沉降效果明显改善。当微波改性膨润土投加量为25 g/L,PAM投加量为2 mg/L,吸附时间为50 min,废水pH=8时,对锰、锌、镉和铅的去除率分别可达98.9%、99.6%、99.7%和98.3%,出水中的锌、镉和铅的排放浓度可达到国家相关水质标准。

The bentonite was modified by microwave technique,and then the removal efficiency of the heavy metal in smeltery wastewater by the combined technique of absorption with microwave modified bentonite（MD） and coagulation with（PAM） was studied.The results show that：（1） In the absorption experiment by MD alone,when the modified bentonite dosage was 25 g/L,the removal rate of manganese,zinc,cadmium and lead in smeltery wastewater were 71.9%,89.7%,78.5% and 93.1%,respectively;（2） Using the combined technique of absorption by MD and coagulation by PAM,the removal efficiency of the four metals all increased,and the settlement of adsorbent was obviously improved;（3）The removal rate of manganese,zinc,cadmium and lead in smeltery wastewater were 98.9%,99.6%,99.7% and 98.3%,respectively,when the MB dosage was 25 g/L,the PAM dosage was 2 mg/L,the pH value was 8 and absorption time was 50 min.The emission concentrations of manganese,zinc,cadmium and lead reach the national relevant water quality standards.