硫化物酸溶性计算和应用  

The calculation and application on solubility of sulfides under acid condition

作　　者：匡华成[1] 

机构地区：[1]鞍山市环境监测中心站,辽宁鞍山114003

出　　处：《环保科技》2018年第1期20-23,共4页Environmental Protection and Technology

摘　　要：本文理论上计算硫化物在酸性条件下的溶解所需酸度。对比添加氯化亚锡、抗坏血酸和未添加时的实验结果,以期为硫化物分析条件的选择做出参考。结论:H_2S和水溶性S^(2-)化合物试验酸度下能够完全溶解,严重污染事故时也可以实现完全检测,这类硫化物定义为酸易溶性硫化物。FeS、ZnS溶解所需酸度最高是0.088 mol/L,磷酸系统能满足实验要求。难溶性SnS、CdS、PbS试验中所需酸度较高,硫化物含量在0.001 mol/L时,实验酸度要求高于11 mol/L、13.7 mol/L、19.1 mol/L。CuS、HgS黑、HgS红在实验酸度下无法溶解。在还原剂氯化亚锡和抗坏血酸存在的情况下,由于原电池反应,金属硫化物能够完全溶解而解析出来,硫化物检出数值比未添加时要大。土壤介质中的S单质也可能转化为S^(2-)解析出来,定量分析中需考虑上述因素。This paper theoretically calculates the acidity required for dissolution of sulfides under acidic conditions. Comparisons were carried out among groups adding stannous chloride and that adding ascorbic acid as well as non-adding groups in the experiment in order to provide reference for selecting analyzing conditions. The results show that H_2S and water-soluble S^（2-）compounds are completely soluble under the test acidity and are fully detectable even in the event of a severe pollution. Such sulfides are defined as acid-soluble sulfides. The highest acidity required for the dissolution of Fe S and Zn S is 0. 088 mol/L,and the phosphoric acid system can meet the experimental requirements. Insoluble Sn S,Cd S,Pb S need higher acidity for dissolution. When concentration of sulfides is 0. 001 mol/L,the acidity required is expected to be more than 11 mol/L,13.7 mol/L,19.1 mol/L.Cu S,Hg S black,Hg S red cannot dissolve under experimental acidity. In the presence of the reducing agents,the metal sulfides can be completely dissolved and resolved as a result of the galvanic interaction,with the sulfides concentration detected being larger than that without reducing agents. The S element in soil media may also be converted to S^（2-） and dissolved,and this fact needs to be considered in the quantitative analysis.

关 键 词：硫化物溶解性 溶度积 热力学 原电池 

分 类 号：X833[环境科学与工程—环境工程]