亚铁－过氧化氢氧化法处理染料中间体H酸生产废液的研究

Application of ferrous-hydrogen peroxide for treatment of H-acid manufacturing process wastewater

Ｈ酸生产过程中排出的废液中含有大量萘的衍生物，对生物具有毒性，是目前最难处理的废水之一。本研究采用亚铁－过氧化氢氧化法对该废液进行处理，以改善它的可生化性能，降低水中有机物的溶解性，提高混凝处理效率。结果表明，最佳ｐＨ值为２～４，亚铁的适宜投加量为２００ｍｇ／Ｌ，当Ｈ２Ｏ２投加量为３０ｇ／Ｌ时，ＣＯＤ去除率为５０％，废水已具有可生化性。经亚铁－过氧化氢氧化处理（Ｈ２Ｏ２的投加量为３ｇ／Ｌ）后的废液，再用ＦｅＣｌ３进行两级混凝处理（ＦｅＣｌ３的量分别为１５和５ｇ／Ｌ），ＣＯＤ的去除率达９０％，Ｈ酸氧化过程中，ＨＯ先和萘环上的钝化基团发生置换反应，使萘环活化，进一步氧化，萘环裂解，最终转化为无机物。研究结果对提高该种废水生物处理效率有实用意义。

Amino-8-naphthol-3,6-disulfonic acid(H-acid) is widely used Chemical industries for direct. acid, reactive and azoic dye synthesis. The wastewater from H-acid manufacturing process is rich in various substitution derivatives of naphthalene and is one of most difficultlytreated wastewater. A pretreatment method for its biological treatment using combined ferrous ion peroxide oxidation and coagulation-flocculation processes has been studied. The optimum PH value for COD removal is below 4. The suitable ferrous ion dosage is 200mg/L. COD removal of H-acid wastewater is about 50% and the wastewater is biodegradable when hydrogen peroxide dosage is 30g/L. Ferrous ion-peroxide oxidation process can also improve the efficiency of coagulation treatment. The overall COD removal can achieve 90% or more when the concentration of ferrous ion is 200mg/L, the dosage of hydrogen peroxide is 3g/L, and the ferric chloride dosage of two stadge coagulation treatment is 15g/L and 5g/L respectively. The groups on naphthalene ring, such as-NO2, SO-3 etc. are substituted by hydroxyl free radical, then the ring is broken down during oxidation process of H-acid.