Study On The Pollutants Removal Performance And Degrade Technology In Wu Coking Waste Water Treatment System

Abstract:coking wastewater containing polycyclic aromatic and heterocyclic compounds, and a lot of poisonous and harmful refractory pollutants in recent years has become a hot research topic in the processing of industrial wastewater. This paper choose coke production is3million/ton in wuhai a coking plant biochemical effluent treatment station as the research object, the site process consists of two parts, the secondary biochemical and deep processing. Oil removal process is respectively: pretreatment pool+aerobic anoxic pool, the secondary sedimentation pool and the high-efficiency clarifier+P-MBR pool+RO device. Experimental study in waste water by means of conventional index determination, in the process of ultraviolet, the three dimensional fluorescence spectrum and GC-MS spectrum scanning methods, water the units of wu jiao process routine indexes and characteristics of PAHs pollutants discharge conditions and the degradation rule was analyzed. In view of the present station depth treatment technology problem of high cost and secondary pollution of heavy, the ferrate green water purifier in the application of advanced treatment of coking wastewater laboratory research. The results show that:(1) With reference to the latest coking industry pollution control standard (GB16171-2012), secondary biochemical effluent treatment station, volatile phenol and cyanide was far below the standards; CODcr and NH3-N average of130.9mg/L respectively, and14.2mg/L, are higher than emissions standards; Check out the content of heavy metals is far lower than the discharge standard (GB8978-1996); Characteristics of the pollutant emissions of PAHs and BaP were0.368ug/L and17ng/L, all up to standard.(2)Disposal of pollutants removal performance of the research results show that the unit water pH are between7and8, chromaticity and turbidity were significantly decline, removal rate of100%and100%respectively. Deep treatment P-the MBR effluent turbidity under0.2NTU, fully meet the requirements of RO water. A/O and P-MBR processing unit for ammonia nitrogen removal rate is over90%. RO is the main unit of sulfate removal, removal rate is more than99%. Each processing unit of TOC and CODcr removal effect for:> aerobic anoxic pool pool> density> P pool-the MBR. A downward trend in the whole process of heavy metals, the process of zinc, high removal rate of Pb, As, for Ni, Cu, no obvious removal effect. Wu features in the coke wastewater pollutants PAHs is mainly composed of1-methyl naphthalene,2-methyl naphthalene, acenaphthene, fluorene, indene, aerobic pool and P-MBR pool of PAHs has obvious reduction effect; Aerobic sludge residue in large amount of PAHs BaP accounted for80%, content of0.39mg/g.(3) By uv and three-dimensional fluorescence on each unit of the water treatment station scan results show that the absorption of ultraviolet spectrum peak mainly in200-300-nm wavelength range, the benzene series has similar characteristic absorption band, water ultraviolet spectrum peak area of each unit with process gradually declining, that happened to the benzene content in the process of degradation and transformation. Three-dimensional fluorescence characteristics of fluorescence peak position mainly in EM/EX:300nm to350nm/200nm to300nm, according to the three dimensional fluorescence spectrum location and the change of the fluorescence intensity, carried out in accordance with the technological process of degree will wu pollutants in waste water composition is changed into easy degradation and biodegradable, difficult to degradation and refractory four categories, the secondary biochemical treatment of the water main is Ⅰ and Ⅱ easy degradation and biodegradable pollutants, accounting for84%of the total. Processing out of the water depth is mainly Ⅲ and Ⅳ refractory to remove pollutants, accounting for23.6%of the total.(4) The laboratory research results show that the coking wastewater treatment under the condition of room temperature fast mixing, potassium ferrate on chromaticity has significant removal effect, the optimization of reaction conditions as follows:pH=3, the response time of19.5min, potassium ferrate dosing quantity is800mg/L, CODCr removal effect is good, but not stable standards; By introducing H2O2significantly promoted potassium ferrate oxidation degradation and decolorization effect of CODcr, optimized reaction conditions for, under the condition of room temperature fast mixing, pH=5,[H2O2]/[Fe (Ⅵ)]=30, potassium ferrate dosing quantity in200-800mg/L range, CODcr all reached the coking industry standards (GB16171-2012). The estimation, using K2FeO4/H2O2tons of water treatment cost compared with the existing technology, the highest can save costs7yuan/ton. PAHs emissions are well control at the same time, the GC-MS scan results showed that the PAHs in water to the degradation of other straight long chain hydrocarbon, use of ferrate and combination of hydrogen peroxide method greatly reduces the environmental risks from coking wastewater.