Study On Treatment Technology Of Multiple Industrial Chemicals Wastewater By IBR And Advanced Treatment Baced On Sponge Iron

In recent years,the number of chemical industrial parks in China has been increasing,and the coming water pollution problem has posed a threat to the ecological environment and human health,which has become a bottleneck restricting the development of chemical industry parks.In this paper,the multiple chemical wastewater treatment in a typical small and medium-sized chemical industry park in Hubei province was studied.The effects of the biological treatment process of the HA-2-stage IBR process on multiple chemical wastewater were studied and evaluated,and microbial community characteristics within the biological treatment system was studied by high-throughput sequencing.At the same time,in view of the problem of unstable effluent water quality and non-compliance of COD,an advanced treatment experiment was conducted on the secondary biological effluent through the zero-valent iron technology based on sponge iron.The main research contents and conclusions are as follows:?1?Study on HA-2-stage IBR Treatment of Multiple Chemical WastewaterThe water quality of multiple chemical wastewater is complex,and the main pollutants are COD,TN,TP and oil,among which there are some difficult biodegradable and toxic substances to biological systems.The HA-2-stage IBR biological treatment process can effectively treat multiple chemical wastewater.The removal rates of COD,NH₄⁺-N and TP were 71.6%,89.0%and 81.9%,respectively.The results of high-throughput sequencing of sludge in the hydrolysis acidification pool showed that at the gate level,Proteobacteria,Bacteroides and Chloroflexi were the dominant strains;at the genus level,Desulfurization,Methylophilus,and Thauera are dominant genera,which are all favorable for the hydrolytic acidification and degradation of organic contaminant.The results of high-throughput sequencing of sludge in the 1st-stage and 2nd-stage IBR pools indicated that the structure of their microbial communities changed significantly prior to acclimation,and the microbial communities in the two-stage IBR pools existed similarities.Compared with pre-acclimation,the diversity of microbiota in 1-st IBR is weakened.In contrast,2nd-stage IBR has increased biodiversity.In terms of species taxonomy,at the level of gates,classes,orders,families,genus and species,the microbial structure and abundance of the two-stage IBR sludge were changed before domestication,and sludge was acclimated to adapt the multiple chemical wastewater.?2?Study on Advanced Treatment Technology of Secondary Biological Effluent Based on Spongy IronThe secondary effluent from multiple chemical wastewater treatment was conducted through the sponge iron-based s-Fe⁰/PAC and s-Fe⁰/H₂O₂ systems,respectively.The effect of s-Fe⁰/PAC system on the secondary biological effluent was affected by the initial pH,s-Fe⁰ dosage,PAC dosage and reaction time.At the initial pH of 3,the s-Fe⁰ dosage of25 g/L,the PAC dosage of 200 mg/L,and the reaction time of 2 h,the removal rate of COD in the s-Fe⁰/PAC system was about 30%.The effect of s-Fe⁰/H₂O₂ system on the secondary biological effluent was affected by the initial pH,the dosage of s-Fe⁰ and the dosage of H₂O₂.The s-Fe⁰/H₂O₂ system could remove the COD from the secondary biological effluent better.At the initial pH of 3,the s-Fe⁰ dosage of 200 g/L,the H₂O₂dosage of 2 mM?64 mg/L?,the removal rate of COD was 77.9%when the reaction time was 1.5 h.The sponge iron was subjected to 7 recycling tests,and the removal efficiency of COD was more stable than 70%.The flocculation precipitation method and conventional Fenton method were used to treat the secondary biological effluent,respectively,and their treatment effects were inferior to the s-Fe⁰/H₂O₂ system.The cost calculation of the s-Fe⁰/H₂O₂ system is less costly than conventional Fenton,and the process step to adjust the pH at the end of the reaction can be omitted.The secondary biological effluent treatment effect was concentrated by UV-vis spectroscopy and3D-EEM:PAC<s-Fe⁰/PAC<s-Fe⁰/H₂O₂.It was confirmed that the s-Fe⁰/H₂O₂ system can be used as a cost-effective advanced method for treatment of secondary biological effluent from multiple chemical wastewater,providing support for practical applications.