低成本焦化厂混凝出水氧化脱色工艺的研究

Study on the oxidation decoloration technology and the mechanism of the coking-plant coagulated efflux at low cost

针对焦化废水经萃取脱酚—生化处理—化学混凝三级处理后的出水水质,提出了化学氧化脱色工艺,研究了有机氯氧化剂浓度、pH值、温度、时间等因素对脱色的影响。确定工艺流程为混凝出水不调pH、不加热,直接投加一定量的有机氯氧化剂,反应进行3h后,过滤。采用GC-MS方法分析了水样中的有机物成分,结果表明焦化废水经三级处理后仍然含有各种生色团和助色团的有机化合物如3-甲基-1,3,6-庚三烯、5-降冰片烯-2-羧酸、2-羟基-苯并呋喃、苯酚、2-氯-2-降冰片烯、1-甲磺酰基-4-甲基苯、3-甲基苯并噻吩、萘-1,8-二胺等,是形成高色度水质的主要原因。

Aiming at the effluent water quality of the coking wastewater which is treatment by the 3-stage treatment （extraction-biochemical treatment-chemical coagulation）, the decoloration technology of chemical oxidation is put forward. The effects of the concentration, pH value, temperature, time etc. of organochlorine oxidant on the decoloration have been studied. It is indicated that the technological flow should be： For the coagulation effluent water, no pH adjustment is needed and no heating is needed. A certain amount of organochlorine oxidant can be added to it directly, and the reaction time is 3 h. Afterward it is filtrated. The organic composition in the water sample is analyzed by GC-MS. The results show that after the coking wastewater is treated by the 3-stage treatment, it still consists of organisms of chromophore and auxochrome, such as 3-methyl-1,3,6 -heptantriente, 5-norbornene-2-carboxylic acid, 2- hydroxylbenzofuran, phenol, 2-chlorine-2-norbornene, 1-methylsulfonyl-4-methylbenzene, 3-methylbenzofuran, naphthalene-1, 8-diamine and so on. They are the main reasons for forming water quality with high chromaticity.