The Research Of Combined Extraction Separation-fenton Oxidation-coagulation Sedimentation Treatment On H Acid Wastewater

H acid was an important intermediate of reactive dye,and demand has surged in recent years.H acid production wastewater has the characteristics of high COD,high chroma and high salinity,so the treatment was difficult and the treatment cost was high.If it can not be properly handled,it will bring huge environmental risks.Therefore,it was urgent to develop a efficient and stable treatment process.In this paper,the wastewater from a factory in Shandong was studied.Advanced oxidation with coagulative technology was used as method of H acid wastewater treatment and extraction separation.A new process for the treatment of H-acid wastewater was established and the expected target was achieved.In view of the fact that the H acid wastewater still contained a large amount of industrial raw materials,the subject first adopt the extraction separation and recovery means.The complexation extraction and liquid membrane extraction processes were established separately.Experimental results of complexation extraction showed complexing extraction method could remove 90% of COD,and recycled the H acid and naphthalene from the wastewater efficiently;Complexation extraction experiment showed that the optimized proportion of extractant,auxiliarie and diluent was 3:5:2,reaction time was 5 min,reaction temperature was at 45 ?,the separation time was 5-10 min.We adopted three-stage counter current extraction process,the COD removal rate can reach 90%.After that,the organic phase extracted by hot alkali,extraction time was 5 min,separation time was 10 min.The reverse extraction result was anti-extract concentration reached 3.6 times and the anti-extraction efficiency was close to 100%,the organic phase can be reused after the reprocess,and the anti-extractive absorption of H acid can be returned to the production line,and can be used to adjust the alkalinity of part of the process.Experimental results of liquid membrane extraction showed The optimal operating conditions and optimal emulsion ratio was that the Na OH mass fraction of the reagents of the internal phase was 1%,the external water phase was p H=1,the flow carrier TOA was 8 ml,the surface active agent Span-80 and isooctanol volume fraction was 3 ml,the ratio of the oil and internal ratio was to 1:0.5,and the ratio of oil and wastewater was 1:1.The result of liquid membrane separation of acid wastewater under the optimum conditions: the first grade treatment COD dropped from 10000 mg/L to 3600 mg/L,and the removal rate was 69.3%.After two stage treatment,COD could drop to 1263 mg/L and the removal rate reached 89.3%.For the recycling of emulsion liquid membrane,the breakage rate was about 20%,the stability of the recycled liquid film was not enough,and the complex extraction was selected as the extraction treatment method according to the difficulty of the practical application in the factory.Secondly,treatment was studied by the Fenton oxidation with the oxygen.The remaining COD extracted from the wastewater was treated,and the influencing factors were studied.Lastly,the effect of extraction Fenton coagulation combined treatment on wastewater was investigated,and the economic benefit was analyzed.A modified Fenton method was used to deal with the raffinate of COD concentration of 1000 mg/L.The experimental results showed that 1 ml of hydrogen peroxide(H 2 O 2,30%)and 100 mg of ferric sulfate heptahydrate(Fe SO 4 ·7H 2 O)were added to 100 ml raffinate.The COD Cr concentration was reduced to 350 mg/L.With the add 0.25 ml of saturated ferric chloride,the p H of the solution was adjusted to 7,coagulation sedimentation period was 10 min,then the COD Cr concentration was reduced to 100 mg/L.The optimum conditions are: the optimum dosage of hydrogen peroxide is between 1%~1.3%;ferrous ion concentration is 5%,and initial p H selects 3.5~4.5.The research results of the treatment of the acid wastewater can provide reference for the design and transformation of the treatment for the acid wastewater,and provide technical support and accumulate practices for the harmless treatment of the wastewater.