论文部分内容阅读
为降低实际工程中二硫代氨基甲酸盐(DTC)类螯合剂用药成本,以某电镀厂高浓度含络合Ni电镀漂洗废水作为处理对象,研究了一种有机巯基类螯合剂(简称DDTC)复配Na_2S去除Ni离子的效果与机理,并重点对反应pH、DDTC与Na_2S单独、复配投加量、含Ni初始浓度等几个因素的影响进行探究。实验结果表明:反应pH值对Ni的去除有较大影响,pH=9.0时Na_2S-DDTC对Ni的去除效果最好;Na_2S-DDTC对电镀络合Ni具有很好的捕集功能,优于Na_2S、DDTC单独使用,其中当pH=9.0,nNa_2S/nNi=1.5,ρ(DDTC)=200 mg·L~(-1)时,Ni的剩余浓度为0.062 mg·L~(-1),达到《电镀污染物排放标准》(GB 21900-2008)中关于Ni污染物特别排放限值要求(<0.1 mg·L~(-1));Na_2S-DDTC处理不同初始浓度的含Ni废水具有较宽的应用范围,其中Na_2S对Ni的用量存在nNa_2S/nNi=1.5的化学计量关系,DDTC存在不同的最佳投药量;Na_2S与DDTC复配使用具有一定的协同作用。
In order to reduce the cost of dithiocarbamate (DTC) chelating agent in the actual project, a high-concentration electroplating rinse wastewater containing complexing Ni plating was used as the treatment target. An organic thiol chelator (DDTC ) Effect and mechanism of complexing Na_2S with Ni ions were studied. The effects of reaction pH, DDTC and Na_2S alone, compound dosage, initial concentration of Ni and other factors were explored. The experimental results show that the reaction pH value has a significant effect on the removal of Ni, Na_2S-DDTC has the best removal efficiency for Ni at pH = 9.0. Na_2S-DDTC has better trapping ability for Ni-S DDTC was used alone. The residual concentration of Ni was 0.062 mg · L -1 at pH = 9.0, nNa_2S / nNi = 1.5 and ρ (DDTC) = 200 mg · L -1, (<0.1 mg · L -1) for Ni pollutants in GB 21900-2008; the Ni 2 S-DDTC treatment of Ni-containing wastewater with different initial concentrations has a wide range of The range of application, in which Na_2S on the amount of Ni exists nNa_2S / nNi = 1.5 stoichiometry, DDTC there are different optimal dosage; Na_2S and DDTC with a certain amount of synergies.