初始pH对表面活性剂/嗜酸性硫杆菌处理电镀污泥脱水及去除铜的影响

Effect of initial pH on dewatering of electroplating sludge and removal of Cu therefrom by treatment with thiobacillus acidophilus in presence of surfactant

以电镀污泥脱水及去除Cu为目标,通过摇瓶试验,对初始pH为3~9的电镀污泥进行为期7 d的表面活性剂/嗜酸性硫杆菌处理。结果表明,烷基糖苷(APG-10)的处理效果要优于十二烷基二甲基甜菜碱(BS-12)和鼠李糖脂。对于APG-10组,随着初始pH的上升,污泥中Cu的去除率先增大后减小,在初始pH为5时Cu的去除率达到最高的93.06%;残渣态Cu含量先上升后下降,氧化态Cu含量先下降后上升,可交换态、还原态Cu含量则几乎一直下降;当初始pH为5时,Cu的生物有效性最低、污泥的稳定性最强,残渣态Cu含量增加41.81%,可交换态、还原态及氧化态Cu含量分别减少15.95%、5.44%和24.13%,污泥比阻由pH为7时的1.56×10^(12) m/kg降至3.11×10^(11) m/kg,污泥由中等难度脱水状态转化为易脱水状态。

With the goal of dewatering the electroplating sludge and removing Cu from it,the shake flask test for surfactant/thiobacillus acidophilus treatment was conducted at an initial pH of 3 to 9 for seven days.The results showed that the treatment effectiveness of alkyl polyglycoside(APG-10)was better than that of dodecyl dimethyl betaine(BS-12)and rhamnolipid.As the initial pH was increased,the removal efficiency of Cu in the sludge of the APG-10 group was increased initially and then decreased,and reached the highest value 93.06%at an initial pH of 5;the content of residual Cu increased initially and then decreased,the content of oxidized Cu decreased initially and then increased,and the contents of exchangeable and reduced Cu kept to reduce.When the initial pH was 5,Cu had the lowest bioavailability and the sludge had the highest stability,and the content of residue Cu increased by 41.81%,and the contents of exchangeable,reduced,and oxidized Cu decreased by 15.95%,5.44%,and 24.13%,respectively.The specific resistance of sludge was decreased from 1.56×10^(12) m/kg(at pH 7)to 3.11×10^(11) m/kg,and the sludge was transformed from a moderately-difficult-to-dewater state to an easy-to-dewater state.