A method for treating landfill leachate concentrate by membrane method

Abstract

The invention discloses a treatment method of a concentrated solution produced from landfill leachate by a membrane method. The treatment method comprises the following steps of enabling the concentrated solution produced from the landfill leachate by the membrane method to sequentially pass through a composite softening coagulation and sedimentation pond, an ozone oxidation reactor, a hydrolyzing pond and an anaerobic MBR pond, and enabling effluent water from the anaerobic MBR pond to enter a nanofiltratoin system; enabling a permeation solution obtained through treatment of the effluent water in the nanofiltratoin system to be treated by a pressure contact oxidation reactor, and directly discharging the treated permeation solution, or after filtering the treated permeation solution by a multi-medium filter, discharging the filtered permeation solution; mixing a concentrated solution obtained after treatment by the nanofiltratoin system with the landfill leachate so as to obtain a mixed solution; and performing concentration treatment on the mixed solution by a biochemical method, an MBR method and the membrane method so as to obtain a concentrated solution, enabling the concentrated solution to enter the composite softening coagulation and sedimentation pond, and performing subsequent operations. The treatment method disclosed by the invention not only is suitable for treatment of the concentrated solution produced from the landfill leachate by membrane filtration, but also is suitable for treatment of other membrane concentrated solutions containing high concentration of organic compounds which are difficult to degrade.

Description

technical field [0001] 本发明涉及垃圾渗滤液处理方法,具体地说,涉及一种针对垃圾渗滤液经过反渗透膜、纳滤膜或其它过滤膜法处理所产生的浓缩液进行处理的方法。 Background technique [0002] 2008年国家颁布了《生活垃圾填埋场污染控制标准》(GB16889-2008),对垃圾渗滤液的处理提出了更高的要求,如今处理垃圾渗滤液多采用NF、RO膜处理工艺。垃圾渗滤液膜滤浓缩液是垃圾渗滤液经过生物降解后经NF膜(或RO膜)截留的残液,一般不具有可生化性,主要成份为腐殖质类物质,呈棕黑色,COD很高,并且含有大量的无机离子,TDS在20000~60000mg / L之间,COD通常在1000~5000mg / L之间,氨氮浓度在100~1000mg / L,电导率为40000~50000us / cm。 [0003] 膜滤浓缩液的体积占垃圾渗滤液原液体积的20%~30%。由于浓缩液含有各种难降解的有机和无机污染物,直接排放可能会对土壤、地表水、海洋等产生污染;若排入市政污水处理系统,过高的总溶解性固体对活性污泥的生长也不利。因此对于减少浓缩液的产量、浓缩液继续处理的研究很有必要。 [0004] 目前所采用主要的处理方法有:回灌、蒸发烘干、固化、焚烧等。将膜法浓缩液回灌到垃圾填埋场、垃圾储坑或垃圾渗滤液储存池,长期循环会导致渗滤液中盐和有机物的累积,从而导致生化处理系统效果变差,增加膜法系统运行的负担及费用。蒸发烘干是将膜法浓缩液中可溶性固体与水分离,对蒸发器抗腐蚀性要求高,并且能耗大,运行成本较高。此外,膜法浓缩液中的部分有机物易挥发,蒸发过程处理不当易引起二次污染。固化处理是利用飞灰或污水处理产生的污泥对膜法浓缩液进行固化处理,然后将干化的剩余物运往垃圾填埋场进行无害化填埋。由于固化后的垃圾处理使得处理成本加大,在对膜法浓缩液处理过程中需要结合垃圾场实际情况进行考虑和经济分析。高级氧化技术是目前处理垃圾渗滤液浓缩液比较合适的处理技术,高级氧化技术降解有机物的速度非常快,如O 3 / UV系统和O 3 / H 2 o 2 系统氧化降解过程,且氧化过程中的中间产物均可以继续同羟基自由基反应,直至最后完全被氧化成二氧化碳和水。 [0005] 但是,由于垃圾渗滤液膜浓缩液污染物浓度过高,如果采用单一的化学氧化法...

AI Technical Summary

Problems solved by technology

[0005] However, due to the high concentration of pollutants in the landfill leachate membrane concentrate, if a single chemical oxidation method is used, its operating cost is too high

If a biological treatment process with low operating costs is used, the biodegradability of the pollutants is very low

If the membrane treatment process is adopted, the problem of membrane fouling is difficult to solve

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