| With the rapid development of the economics,the municipal solid waste becomes a severe problem for it is bringing great pollution and difficult to be disposed. Landfill leachate has been recognized as high hazardous and high contaminated wastewater, which is potentially harmful to surface and ground waters. Leachate is very difficult to treatment due to its high contamination, fluctuations of water quality and flow rate, and uncontrollability. And, due to the greater fluctuations in the quantity and composition of landfill leachate, the treatability of landfill leachate depends on its composition and characteristics, the nature of the organic matter present as well as the age and structure of the landfill. None of the individual biological or physic-chemical techniques is highly effective for the treatment of landfill leachate. Thus, a new effective treatment technology of landfill leachate was explored to improve the removal of organics, accelerate reaction speed and reduce treatment costs.In this dissertation, we mainly aimed at the landfill leachate processed by songjiang Shanghai Auspicious appearance solid waste disposal Co., LTD after the biochemical treatment.The paper introduces the study development on the treatment of landfill leachate at the beginning.Then the advantages and disadvantages of different processing methods were compared.Then magnesium ammonium phosphate method and fenton oxidation method were applied to treat landfill leachate.The paper uses the magnesium ammonium phosphate method as its advanced treatment at first to remove ammonia nitrogen.Through the experiment, the best reaction conditions were selected by analyzing the experiment conclusion and the best reaction condition was found when pH is 10.5,n(Mg2+):n(NH4+-N):n(PO43) is 1.2:1.0:1.0 and mixing time is 15min.At this condition the quality of the ammonia nitrogen concentration can be made of 550mg/L to 20 mg/L and the removal rate of ammonia nitrogen is more than 96%.The effluent can meet the national miscellaneous water discharge standards.At the same time, magnesium ammonium phosphate is a kind of high efficient compound fertilizer with good efficiency and higher economic benefits.After the magnesium ammonium phosphate method the best conditions is choosed to treat a number of landfill leachate.Then the paper uses the fenton oxidation method as the next step to remove CODcr.Through the experiment, the best reaction conditions were selected by analyzing the experiment conclusion and the best reaction condition was found when H2O2 (30%) is 10ml/L,FeSO4·7H2O is 0.02mol/L,pH is 4,temperature is 50°,active carbon is 1.5g and response time is 90min. At this condition the quality of the CODcr concentration is down to 95mg/L and the removal rate of CODcr is 85.35%.So it did't reach national miscellaneous water water quality standards.But it have good bildegradability.So after biological treatment,the effluent can meet the national miscellaneous water quality standards and concentrations of CODcr and BOD5 is 47 mg/L and 9.47 mg/L.Because the sole use of fenton oxidation method,CODcr is not up to national miscellaneous water quality standards.the paper uses ultrasound and fenton oxidation method(US+Fenton) to remove CODcr. Through the experiment, the best reaction conditions were selected by analyzing the experiment conclusion and the best reaction condition was found when H2O2 (30%) is 10ml/L,FeSO4·7H2O is 0.02mol/L,,pH is 4,temperature is 50°,active carbon is 1.5g,response time is 90min,ultrasonic frequency is 28kHz and ultrasound power is 1200W. At this condition the quality of the CODcr concentration is down to 44.72mg/L and the removal rate of CODcr is 93.12%.So it reach national miscellaneous water quality standards.Through the experiment research,there are two ways to make ammonia nitrogen concentration and CODcr concentration reach national miscellaneous water quality standards: magnesium ammonium phosphate method+fenton oxidation method + MBR and magnesium ammonium phosphate method + US/fenton oxidation method. |
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