并流加料沉淀法处理含铜锌废水同时形成类水滑石污泥

分别采用传统沉淀法和并流加料沉淀法处理含铜锌废水,考察了废水进样速率、废水pH、搅拌速率对重金属离子残留质量浓度的影响。采用FTIR、XRD和SEM表征了所得污泥的物相和形貌。实验结果表明:并流加料沉淀法所得滤液中Zn~(2+)、Cu~(2+)和Al3+的质量浓度远低于传统沉淀法;在废水进样速率1.0 mL/min、废水pH 9、搅拌速率500 r/min的最佳工艺条件下,滤液中Cu~(2+)和Zn~(2+)基本没有残留,Al3+质量浓度仅为0.2 mg/L,达到工业排放标准;所得污泥结晶度良好,为类水滑石Cu_3Zn_3Al_2(OH)_(16)CO_3·4H_2O(PDF#37-0629)结构。

Treatment of Cu,Zn-containing wastewater and formation of layered double hydroxide by double-jet precipitation process

The Cu,Zn-containing wastewater was treated by traditional precipitation （TP） process and double-jet precipitation （DJP） process respectively. The effects of wastewater feeding rate,wastewater pH and stirring rate on mass concentration of residual heavy metal ions were investigated. The sludge was characterized by FTIR,XRD and SEM. The experimental results showed that：The mass concentration of Zn²⁺,Cu²⁺ and Al³⁺ in the filtrate by DJP process was far lower than that by TP process;Under the optimum process conditions of wastewater feeding rate 1.0 mL/min,wastewater pH 9 and stirring speed 500 r/min,there was almost no Zn²⁺ and Cu²⁺ residual in the filtrate,Al³⁺ mass concentration was only 0.2 mg/L,which met the national discharge standard for industry;The obtained sludge had good crystallinity and typical structure of layered double hydroxide Cu₃Zn₃Al₂（OH）₁₆CO₃·4H₂O （PDF #37-0629）.