Combined Removal Of Nitrogen And Phosphorus From Livestock Wastewater By Electrolysis

With the rapid development of China’s livestock breeding and biogas engineering, the quality of people’s living standard and life in China’s rural areas have been greatly improved, but also caused environmental pollution of biogas slurry. The direct discharge ofuntreatedslurrycan cause serious environmental problems,thus effectively deal with scientific biogasis particularly critical.Currently, the main ways of handling livestock slurry are returning to field,natural treatment and factory processing.Due to returning to field and natural treatment is to biogas emissions to farmland, which requires a lot of farmland to consumptive handle slurry,while China’s land resources are more tense but biogas emissions is large, which determines both ways operability on questionable.Many technical problems still exist in the factory processing, including nitrogen and phosphorus pollutants technology complex, expensive and removal effect is very difficult to reach the emission standard.The electrolysis technology for nitrogen and phosphorus removal effect is good, and has the advantages of small occupation area, simple operation of the reactor equipment, strong controllability, no two pollution, known as environmental friendly technology.The livestock wastewater was carried out experimental study on N and P removal in this article, We got optimization parameters for eachprocess from these experimental results.Based on the integration of electrolysis nitrogen and electrolytic removal technology, the key parameters of process operation was optimized and guglielmi integrated nitrogen and phosphorus removal process was developed. Through the removal of nitrogen and phosphorus in the aquaculture wastewater anaerobic effluent, improving the biodegradability of the wastewater and provideing scientific basis for subsequent treatment of sewage and recovery of high concentration of nitrogen and phosphorus resources. The main researeh conclusions are as follow:(1) Base on single factor test, multifactor orthogonal test, and dynamic test for electrolytic removal of nitrogen, we obtain some conclusion. The optimal parameters: electric current density70mA/cm2, initial pH11, electrode space20mm, chloride ion concentration7000mg/L. The order of the role of each factor:initial pH> electric current density> electrode space> chloride ion concentration. The removal rate of ammonia nitrogen using RuO2-IrO2-TiO2/Ti is higher than that using graphite, and the optimal reaction time is150min. Taking graphite and RuO2-IrO2-TiO2/Yi as anode respectively, electroehemical oxidation of total nitrogen accords with the first order kineties.(2) Base on single factor test, multifactor orthogonal test, and dynamic test for electrolytic removal of phosphorus, we obtain some conclusion. The optimal parameters:electric current density35mA/cm-, initial pH6, electrode space20mm, chloride ion concentration7000mg/L. The order of the role of each factor:initial pH> electric current density> electrode space. Cathode materials have very little impact on total phosphorus removal. In order to meet the need of further integration of denitrification and phosphorus removal process, select the RuO2-IrO2-TiO2/Ti electrode as the cathode. And the the optimal reaction time is150min. Taking RuO2-IrO2-TiO2/Ti as electrode, electrochemical oxidation of total phosphorus accords with the first order kineties.(3) Artificial wastewater experiment, which realized the combined Removal of nitrogen and phosphorus, proved the feasibility of the electrolysis technology. The removal effect of NH3-N and TN and TP is good:within230min NH3-N removal rate is94.28%and TN removal rate is94.28%and TP removal rate is96.13%.(4) Real biogas slurry proved that organic pollutant can enhance the basicity of the wastewater so that extended N removal electrolysis time. The removal effect of NH3-N and TN and TP is good:within280min the removal rate of NH3-N, TN, TP and COD to reach99.08%,97.94%,98.01%, and47.14%respectively.