| The landfill leachate contains a lot of difficult degradable organic matters and ammonia nitrogen. After early biological treatment, the BOD/COD is even more lower, the residual COD with refractory organic compounds can’t been removed through the biological technology processing. This paper adopts the combination process of UV/H2O2+MBR handling the landfill leachate, and study the organic matter and ammonia nitrogen treatment effect by process; analyzed the change of characteristic of sludge and EPS content, and membrane fouling mechanism in the operation of the MBR; Through the modern analysis technology of GC-MS, analysis the organic compounds in the leachate in qualitative and quantitative analysis of the change of before and after reaction.Experiment is divided into three main stages:in the first phase, research the effect of leachate treatment by UV/H2O2process dealing with, and get the process suitable working conditions through orthogonal test and single factor experiment;in Second phase, by starting and running MBR, research the effect of treatment for the leachate after the advanced oxidation processing effect by MBR process, and analyze the characteristics of sludge, EPS content and the degree of membrane fouling degree. In the third phase, change membrane components and restart the reactor again, treat the leachate with difficult biodegradation of organic matter and ammonia nitrogen in MBR.The experimental result shows that:(1) When the process conditions as hydrogen peroxide dosing quantity for1g (according to the theoretical calculation value of2.1g (H2O2)/g (COD), concrete additive amount), pH in weak acid, reaction time2h, the temperature about30℃, the process treatment effect is good, the concentrate of50%TOC of leachate has been effective degradation, and the removal of ammonia nitrogen is obvious;(2) The MBR has obvious effect of biochemical degradation for the organic matter in water after UV/H2O2process section, keep more than80%removal rate of organic matter; (3) The MBR reactor work under the condition of low sludge loading, the impact on removal efficiency of COD by HRT and organic volume load is not big; in the late stage, microbial endogenous respiration, the sludge concentration and MLVSS/MLSS ratio has decreased, COD removal rate is falling;(4) MBR reactor has activated nitrification for ammonia of nitrogen leachate, ammonia nitrogen removal rate is more than92%, and the resistance ability to high ammonia nitrogen volume load is strong;(5) After running for a long time, the long sludge age, low sludge loading cause changes of the characteristics of sludge; Sludge settleability, ratio of VSS/SS, the filterability all change, mainly caused by microbial endogenous respiration producting inert material and cells secreting EPS; But organic molecular structure of active micro bial does not change obviously, showingthe adaptability of dominant fungi to leachate is strong, and conclude that there has a certain relationship with mild quality of MBR reactor inlet water;(6) Propose secondary dynamic membrane’s point of view, analyze the factors of experiment membrane fouling in each operational of stage, consider the secondary dynamic membrane will retard membrane fouling, correlation of the EPS content and process of flat membrane fouling degree is not high, and conclude that the membrane inside pollution contribute the largest contribution to the pollution of the membrane fouling;(7) When organic matter is relatively too much or microbial endogenous respiration happen, the secretion of EPS material increase, conclude that there has certain relationship with the microbial activity and different degradation properties of organic matter;(8) Landfill leachate processed after the advanced oxidation processing, long chain alkane and aromatic hydrocarbon, such as thecomplex organic compounds were degraded into medium or small molecular organic matters, and create an enabling environment for the stable operation of the MBR reactor. |
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