过二硫酸盐降解碱液吸收的甲硫醇恶臭

甲硫醇(CH3SH)是一种高毒、高腐蚀性的酸性气体,是恶臭的重要组成部分.碱液吸收是最常用的CH3SH处理方法之一,但吸收液需要进一步处理.过二硫酸盐(persulfate,PS)作为氧化剂用于降解碱液吸收的CH3SH尚鲜见报道.为此,建立一连续循环的吸收降解体系,进行CH3SH的碱液吸收及PS降解实验,并探讨了PS在碱性条件下的稳定性,及反应条件对CH3SH吸收和降解动力学的影响.结果表明,PS在碱液中的稳定性较好,能够有效地降解碱液吸收的CH3S-;随着PS浓度的增加,CH3SH的吸收速率呈先增加后减小的趋势,CH3S-的降解速率不断增大;随着pH的增加,CH3SH的吸收和降解效果均明显增加.在pH为12,CH3SH进气浓度80 mg·m-3,进气速率1.5 L·min-1,PS浓度为1.4 g·L-1时,碱液吸收的CH3S-90%被降解.

Degradation of the Absorbed Methyl Mercaptan by Persulfate in Alkaline Solution

Methyl mercaptan (CH₃SH) is considered to be an important contributor to odors. It is a toxic, corrosive and acid gas. The absorption of CH₃SH by alkaline solution is one of the most widely used processes,but the remained solution should be further treated. The degradation of dissolved CH₃S^- by persulfate (PS) oxidation has not been reported. CH₃SH is absorbed in alkaline solution and degraded by PS oxidation using a recycling continuous system for absorption and degradation. The stability of PS under alkaline conditions is discussed. The influence of different reaction conditions on the absorption rate and degradation rate is also studied. It was observed that PS was relatively stability under alkaline conditions and the dissolved CH₃S^- could be degraded effectively by PS. The absorption rate of CH₃SH first increased and then decreased with the increasing concentration of PS. The degradation rate of CH₃S^- increased with the increasing concentration of PS. It was also observed that the efficiency between absorption and degradation had been significantly increased with the increasing of pH. In the conditions of pH=12, fixed CH₃SH concentration of 80 mg·m^-3 with a fixed gas flow rate of 1.5 L·min^-1, 1.4 g·L^-1 PS, 90% of the dissolved CH₃S^- can be degraded.