【摘要】 硫化砷渣源于铜、铅、锌冶炼行业高酸冶炼废水的硫化沉淀处理过程，是典型的含砷危险固体废物。传统的硫化砷渣处置技术成本高、药剂消耗量大、易产生二次污染。为此，本文提出了一种模拟可见光氧化浸出硫化砷渣的新思路，探究了影响砷浸出的工艺条件，考察了砷光氧化浸出的过程特征及机理。结果表明，模拟可见光照能大幅提高砷的浸出效率，可见光照射32 h砷浸出率可达到48.9%，砷的浸出效率与温度、搅拌速度、光照强度、溶解氧含量、反应时间呈正相关性。砷以As（Ⅲ）形式进入液相，硫转化成固体单质S和SO₄^2-。光氧化反应后，残留固相颗粒的粒径变大，团聚性增强，为后续的固液分离提供便利。更多还原

【Abstract】 Arsenic sulfide residue, derived from the sulfide precipitation treatment of highly acidic smelting wastewater in the copper, lead, and zinc metallurgical industries, is a typical arsenic-containing hazardous solid waste. Conventional disposal technologies for arsenic sulfide residue are characterized by high costs, substantial chemical consumption, and a tendency to cause secondary pollution. Therefore, this study proposes a novel approach involving simulated sunlight-driven oxidative leaching of arsenic sulfide residue. The process conditions affecting arsenic leaching were investigated, and the characteristics and mechanisms of the photochemical oxidation leaching of arsenic were examined. The results indicate that simulated visible light can significantly enhance arsenic leaching efficiency. The arsenic leaching efficiency shows positive correlations with temperature, stirring speed, light intensity, dissolved oxygen content, and reaction time. The contribution of visible light（350–780 nm） to arsenic leaching concentration is significantly higher than that of ultraviolet light（200–350 nm） and infrared light（780–1 100 nm）. The contribution of visible light at 400 nm to arsenic leaching concentration is significantly higher than that of other single wavelength light. The optimal process parameters for this article including temperature of 25 ℃, initial pH value of 6, arsenic sulfide concentration of 2%, light intensity of 835 mW/cm², stirring speed of 600 r/min, and optical wavelength range of 350–780 nm. Under these parameters, the arsenic leaching rate is 48.9% after 32 hours of light irradiation. Providing dissolved oxygen content through aeration can increase the leaching efficiency of arsenic. Dissolved oxygen decreases during the reaction process and is accompanied by a decrease in pH value when pH>3. The photoreactive solid phase produces elemental sulfur, which would adhere to the surface of arsenic sulfide, and its particle size gradually increases with the extension of reaction time, and the particle settlement performance is significantly improved. The atomic ratio of solid phase S to As gradually increases during the photoleaching process, and As is more easily leached into the liquid phase than S under visible light. It can be seen that light energy significantly improves the leaching effect of arsenic in liquid phase. After the light reaction, arsenic mainly enters the liquid phase as trivalent arsenic, while sulfur transforms to a higher price state SO₄^2-. Although photooxidation can achieve a high leaching rate, the product elemental sulfur can block light, inhibit photoreaction efficiency, and affect leaching. Further research will be conducted on elemental sulfur separation to improve photooxidation efficiency. As a new treatment technology, photooxidation has been studied for its feasibility in arsenic sulfide oxidation leaching treatment, but there is still a long way to go before it can be truly applied in production practice.更多还原