间甲基苯甲酸生产高盐高COD高氨氮废水蒸发浓盐渣资源化

           间甲基苯甲酸（C₈H₈O₂）是重要有机中间体，广泛用于制药、染料、高分子材料合成等领域。其生产产生的废水含COD 8000-12000mg/L、氨氮 300-500mg/L、全盐量 8%-12%，主要成分包括间甲基苯甲酸（C₈H₈O₂）、氯化铵（NH₄Cl）、氯化钠（NaCl）及少量苯系衍生物。

经蒸发器蒸发脱水后，得到灰白色蒸发浓盐渣，成分及占比为：氯化钠（NaCl）45%-55%、氯化铵（NH₄Cl）25%-35%、间甲基苯甲酸（C₈H₈O₂）8%-12%、其他杂质2%-8%。

通过浓缩、萃取、结晶、提纯等工艺，实现资源化回收：有机物料间甲基苯甲酸（C₈H₈O₂）提纯至工业级，回用于自身生产或作为医药、染料中间体；无机盐氯化铵（NH₄Cl）、氯化钠（NaCl）精制后，分别用作农业肥料、工业融雪剂及化工原料。仅少量无利用价值杂质按危废规范处置，真正实现“变废为宝”，大幅降低危废处置成本，兼顾环保达标与经济效益提升。

Resource Utilization of Evaporated Concentrated Salt Residue from High-Salt, High-COD and High-Ammonia Nitrogen Wastewater in m-Toluic Acid Production

m-Toluic acid (C₈H₈O₂) is an important organic intermediate, widely used in pharmaceuticals, dyes, polymer material synthesis and other fields. The wastewater from its production contains COD 8000-12000mg/L, ammonia nitrogen 300-500mg/L and total salt 8%-12%, mainly including m-toluic acid (C₈H₈O₂), ammonium chloride (NH₄Cl), sodium chloride (NaCl) and a small amount of benzene derivatives.

After evaporation and dehydration by evaporator, grayish-white evaporated concentrated salt residue is obtained, with components and proportions: sodium chloride (NaCl) 45%-55%, ammonium chloride (NH₄Cl) 25%-35%, m-toluic acid (C₈H₈O₂) 8%-12%, and other impurities 2%-8%.

Through concentration, extraction, crystallization, purification and other processes, resource recovery is realized: the organic material m-toluic acid (C₈H₈O₂) is purified to industrial grade and reused in its own production or as an intermediate for pharmaceuticals and dyes; the inorganic salts ammonium chloride (NH₄Cl) and sodium chloride (NaCl) are refined and used as agricultural fertilizers, industrial deicing agents and chemical raw materials respectively. Only a small amount of useless impurities are disposed of in accordance with hazardous waste regulations, truly realizing "turning waste into treasure", greatly reducing hazardous waste disposal costs, and balancing environmental protection compliance and economic benefit improvement.