Advanced Treatment Of Printing And Dyeing Wastewater By Iron-carbon Micro-electrolysis Combined With H₂O₂

With the increase of China’s efforts to protect the environment, some discharge standardswere upgraded, especially the discharge standard of water pollutant for dyeing and finishingoftextile industry (GB4287-2012). The advanced treatment process must be used for printing anddyeing wastewater treatment, reducing the concentration of pollutants in the water further, theeffluent can meet the discharge standard. This study mainly research the advanced treatmentprocess for the effluent of the secondary sedimentation tank in a industrial area wastewatertreatment plant. Based on a variety of advanced treatment processes, this thesis considers thatiron-carbon micro-electrolysis combined with H2O2can appropriate to used for advancedtreatment of printing and dyeing wastewater.The degradation effect of printing and dyeing wastewater via iron-carbon micro-electrolysisand iron-carbon micro-electrolysis combined with H2O2were investigated through experiments inthe laboratory. The experiments in the laboratory showed that the best operational condition ofiron-carbon micro-electrolysis were：the initial pH value was3.5, ratio of carbon to iron was2.5,dosage of iron was27g/L, reaction time was150min. Meanwhile, the best operational condition ofiron-carbon micro-electrolysis combined with H2O2were：the initial pH value was3, ratio ofcarbon to iron was2.5, dosage of iron was27g/L, dosage of H2O2was130mg/L reaction time was120min. Under the best operational condition of iron-carbon micro-electrolysis and iron-carbonmicro-electrolysis combined with H2O2, the removal rates of CODcr were45%and78%,respectively. The combined process is better than iron-carbon micro-electrolysis process.The study used GC-MS to analyzing the organic matter in water with pretreatment of solidphase extraction.The effluent of iron-carbon micro-electrolysis process still had a set amount ofpollutants. Ester substance could not be reduced ffectively，the same as thiazole. The effluent ofiron-carbon micro-electrolysis combined with H2O2process was better，a set amount of pollutantswere degradated.Lipids were almost hydrolyzed to alcohols that was friendly to environment.Amides was degradated partly.Confirming the best operating condition of iron-carbon micro-electrolysis combined with H2O2, and the stability of test running.Then calculate the cost of pilot.The optimal reaction conditions of treating the dyeing wastewater under the condition of thisexperiment were obtained by using single factor test and response surface analysis.The operationalcondition of iron-carbon micro-electrolysis combined with H2O2were:dosage of H2O2was170mg/L, reaction time was eight hours，ratio of carbon to iron was2.5，dosage of iron was27g/L，the initial pH value was3.5，the removal rates of CODcrwere about57%,the cost was2.545yuanper cubic metres. Under the optimal reaction conditions, the pilot plant can achieve stableoperation.Results of the research provide the references to printing and dyeing wastewateradvanced treatment and expande the application range of iron-carbon micro-electrolysis combinedwith H2O2Process.