| Landfill leachate is a kind of organic wastewater with high concentration and difficult to be degraded and highly polluting.With the increasingly strict environmental protection requirements in China and the improvement of landfill leachate discharge standards,the traditional biochemical treatment process often fails to achieve water seepage.The discharge requirements of the filtrate pollution control standard?GB16889-2008?,therefore,it is necessary to furtherly deepen the landfill leachate.Photochemical oxidation technology has received increasing attention because of its advantages of low pollution and high efficiency.However,photochemical oxidation technology still has shortcomings in engineering applications,mainly due to high energy consumption and high water quality requirements.Therefore,the combined treatment process of coagulation and photochemical oxidation,and a complete set of equipment was designed in this paper for the advanced treatment of landfill leachate,the treatment effect of the process on landfill leachate was carried out.The optimal process conditions of the coagulational reaction process and photochemical oxidation reaction process were compared.The main research results of the related advanced oxidation process were compared.The main research conclusions are as follows:?1?A coagulation-photochemical oxidation?UV/O3/H2O2?combination treatment process was designed for the performance characteristics of landfill leachate.The key to this combined treatment process is the combined application of a coagulation reaction unit and a photochemical reaction unit.As a pre-treatment unit,the coagulation reaction mainly removes COD,chromaticity and turbidity in landfill leachate,which creates favorable conditions for photochemical reactions;photochemical oxidation?UV/O3/H2O2?unit further oxidizes pollutants in wastewater.While effectively reducing pollutants?such as COD value,ammonia nitrogen and color?,the biodegradability of wastewater is improved,which provides favorable conditions for further biochemical treatment.?2?According to the established coagulation-photochemical oxidation combined treatment process,the key process equipment and accessories such as the coagulation reactor and photochemical oxidation reactor in the combined treatment process were designed,and the corresponding complete experimental equipment was fabricated and built.When the experimental equipment is continuously operated,the daily treatment volume of the landfill leachate is 1.2 tons.?3?Experimental research on the deep treatment of landfill leachate coagulation-photochemical oxidation combined process was carried out by using the experimental equipment.The optimum process conditions of the coagulation reaction stage and photochemical oxidation reaction stage in the combined treatment process were explored in stages.The experimental results of advanced treatment of landfill leachate showed that the COD,UV254,ammonia nitrogen and chromaticity indexes of landfill leachate were 1560mg/L,17AU/cm and 421mg/L,respectively.250 times,reduced to176 mg/L,1.4 AU/cm,162 mg/L and 6 times after treatment,the removal rate reached 88.7%,91.7%,61.5%and 97.9%,respectively,the removal effect is significant.In addition,the effluent biodegradability index B/C value of the combined process is increased from 0.058 to 0.347,and the biodegradability is significantly improved to meet the subsequent biological treatment requirements.?4?For comparison,the effects of single treatment processes such as O3,H2O2 and direct photolysis and their combined processes on landfill leachate treatment were compared in this paper.The comparison results show that the treatment effect and efficiency of coagulation-photochemical combined treatment process in wastewater treatment And equipment maintenance and operating costs,etc.,have obvious advantages. |
PDF Full Text Request