| Phosphorus is one of the most critical factors that cause water eutrophication.In order to deal with the crisis of water eutrophication,a cost-effective water dephosphorization process is essential.The iron-carbon micro-electrolysis technology utilizes the susceptibility to corrosion of active metallic iron,and the inert carbon can form iron-carbon primary batteries to remove pollutants in water,and is currently widely used in wastewater treatment.In view of the shortcomings of long-term use of traditional iron-carbon micro-electrolysis process,it is easy to passivate compaction,this subject developed iron-carbon micro-electrolytic filler with regular particle size,combined with aeration biolocgical filter(BAF)process to strengthen phosphorus in sewage Remove.In this study,using reduced iron powder and activated carbon powder as the skeleton,new micro-electrolytic fillers were prepared under high temperature conditions to study the best preparation process conditions;analysis of influencing factors of iron-carbon micro-electrolysis,combined with adsorption kinetics and adsorption isotherm studies revealed The adsorption and dephosphorization characteristics of fillers and the analysis of its phosphorus removal mechanism;simulation of aerated biological filter to explore the feasibility of iron-carbon fillers as filter materials in practical applications and their removal efficiency for pollutants.Through the analysis of orthogonal test and single factor test,the best technological conditions for preparing ecological filler are determined:the mass ratio of reducing iron powder and active carbon powder is 3:1,the firing temperature is 600? and the holding time is 20 minutes.The effects of environmental factors such as the dosage of packing,pH of solution,adsorption time,initial concentration and dissolved oxygen concentration on the adsorption characteristics were investigated.The results showed that in 200ml phosphorus solution,4g iron carbon packing,pH=2,adsorption time is 36h,dissolved oxygen concentration is 4-4.5mg/l,the initial concentration is 10mg/L,the phosphorus removal rate can reach 93.2%,and the phosphorus concentration in the effluent can be reduced to 0.68mg/l.Through the analysis of reaction kinetics and adsorption isotherm,it is found that the Langgmuir adsorption isotherm model is more consistent with the single molecular layer adsorption.Based on the analysis of the electrolytic behavior of iron carbon packing,the release rate of iron ions and the concentration of iron ions in wastewater are the key factors for phosphorus removal.The results show that when the initial phosphorus concentration is less than 30mg/L,the removal rate of total phosphorus is more than 90%;when the initial phosphorus concentration is 50mg/L,HRT=6h,dissolved oxygen concentration is 4mg/L,the removal rates of COD,ammonia nitrogen and total phosphorus are 85%,80%and 55%,respectively.The results show that the iron carbon micro electrolysis packing has a high phosphorus removal efficiency,and also has a good removal effect for ammonia nitrogen and COD.The application of the filter material in BAF can strengthen the water phosphorus removal.The research results are of great significance for the practical application of the iron carbon micro electrolysis packing phosphorus removal process. |
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