3-巯基丙酸生产高盐高COD高氨氮废水蒸发浓盐渣资源化

           3-巯基丙酸（3-MPA，HSCH₂CH₂COOH）是重要化工原料，广泛用于医药中间体、PVC稳定剂、高分子材料改性剂等领域。其生产产生高盐高COD高氨氮废水，主要成分为COD 8000-12000mg/L、氨氮（NH₃-N）500-800mg/L、氯化钠（NaCl）15%-20%、硫酸钠（Na₂SO₄）8%-12%及少量3-巯基丙酸杂质。

废水经蒸发器蒸发脱水后，得到灰白色蒸发浓盐渣（含水率5%左右），成分占比：NaCl 32%、Na₂SO₄ 19.74%、有机杂质（以TOC计）1.77%、NH₄⁺ 0.69%，其余为少量金属杂质。

通过浓缩、萃取、结晶、提纯等工艺，回收高价值物料：有机相萃取回收3-巯基丙酸（HSCH₂CH₂COOH），用于再生产或合成酯类稳定剂；无机盐回收氯化钠（NaCl）、硫酸钠（Na₂SO₄），均达到工业级标准，分别用于化工配料、建材助磨剂等。无利用价值少量杂质按危险废物规范处置，真正实现“变废为宝”，大幅降低处置成本，兼具显著环保效益与经济效益。

Resource Utilization of Evaporated Concentrated Salt Residue from High-Salt, High-COD and High-Ammonia Nitrogen Wastewater in 3-Mercaptopropionic Acid Production

3-Mercaptopropionic acid (3-MPA, HSCH₂CH₂COOH) is an important chemical raw material, widely used in pharmaceutical intermediates, PVC stabilizers, polymer material modifiers and other fields. Its production generates high-salt, high-COD and high-ammonia nitrogen wastewater, mainly containing COD 8000-12000mg/L, ammonia nitrogen (NH₃-N) 500-800mg/L, sodium chloride (NaCl) 15%-20%, sodium sulfate (Na₂SO₄) 8%-12% and a small amount of 3-mercaptopropionic acid impurities.

After the wastewater is evaporated and dehydrated by an evaporator, grayish-white evaporated concentrated salt residue (moisture content about 5%) is obtained, with the component ratio: NaCl 32%, Na₂SO₄ 19.74%, organic impurities (calculated as TOC) 1.77%, NH₄⁺ 0.69%, and the rest are a small amount of metal impurities. Through processes such as concentration, extraction, crystallization and purification, high-value materials are recovered: 3-mercaptopropionic acid (HSCH₂CH₂COOH) is recovered by organic phase extraction for re-production or synthesis of ester stabilizers; inorganic salts sodium chloride (NaCl) and sodium sulfate (Na₂SO₄) are recovered, both meeting industrial standards, used for chemical batching, building material grinding aids, etc. A small amount of useless impurities are disposed of as hazardous waste in accordance with regulations, truly realizing "turning waste into treasure", greatly reducing disposal costs, and having significant environmental and economic benefits.