5-甲基-2-巯基苯甲酸(MSD)的合成及其钠盐处理镍废水的研究

以对甲基苯硫酚(MP)与草酰氯在无水三氯化铝催化作用下合成了5-甲基-2-巯基苯甲酸(MSD),并考察了各操作参数对MSD收率的影响和MSD钠盐处理镍废水的情况.研究结果表明:MP、草酰氯和无水三氯化铝的物质的量比为1.0∶1.1∶2.2,反应温度为20℃,反应时间为2 h时MSD的收率最高;在pH=9,MSD钠盐实际用量为理论用量的1.2倍时,处理镍含量为625 mg/L的镍废水,镍离子质量浓度下降至0.87 mg/L,完全达到国家排放标准.同时镍螯合沉淀物经10 mol/L的盐酸解螯合,解螯合率达到98.8%.

Synthesis of 5-Methyl-2-Mercaptobenzoic Acid(MSD) and the Application of MSD Sodium Salt in Nickel Wastewater Treatment

5-Methyl-2-mercaptobenzoic acid(MSD) was synthetized with p-toluenethiol and oxalyl chloride over aluminium chloride,and the influence of all kinds of operation parameters on the yield of MSD and the influence of MSD sodium salt on the nickel wastewater treatment was studied.The experimental results show that the optimum parameters of the yield of MSD are as follows:the molar ratio of MP,oxalyl chloride and aluminium chloride is 1.0∶ 1.1∶ 2.2,reaction temperature is 20 ℃,reaction time is 2 h.When the nickel wastewater with 625 mg/L nickel ions was treated,controlling pH at 9 and adding MSD sodium salt 1.2 times the theoretical amount could reduce the nickel content to 0.87 mg/L,which meets the national discharge standard.The chelating precipitant was eluted by 10 mol/L hydrochloric acid,resulting in a desorption yield of 98.8%.