Ammonia Removal from High Strength Wastewater using a Hybrid Electro-Oxidation and Electro-Coagulation Process

城市固体废物(MSW)垃圾填埋场产生的高浓度废水，也称为渗滤液，对传统污水处理设施的处理构成了巨大的挑战。渗滤液中含有大量的有机物、无机常量组分、重金属和许多其他有害物质。渗滤液中高浓度的氨氮(AN)对邻近的地表水和地下水来源构成很大的毒性风险，必须对这些渗滤液进行适当处理，以达到当地的安全处置或再利用标准。电氧化(EO)和电絮凝(EC)等电化学高级氧化工艺(EAOP)是一种处理垃圾填埋场渗滤液的有效方法。在EO中，电流的直接作用被用来氧化或还原电极上的物种，从而将有毒和/或难生物降解的污染物转化为更无害的化学物质。另一方面，EC涉及通过在阳极上电溶解金属离子(铝或铁)来原位生成混凝剂。这些混凝剂迅速形成大颗粒絮体，进而化学吸附废水中的污染物。将这两个EAOP组合成一个电解槽，有望展示出从高浓度渗滤液中去除AN的极佳潜力。由于这些工艺不需要添加任何来自外部来源的化学品，它们可以被认为是“清洁”技术。该项目的结果将显著增加公司、GHD和整个加拿大的价值。实际上，该项目旨在为高强度渗滤液的处理开发实用的解决方案，并保护我们的环境质量。虽然现有的处理技术可以很容易地去除渗滤液中的有机负荷，但氨的去除是一个巨大的挑战。建议的EO-EC混合系统预计将减少很大一部分来自高浓度渗滤液的氨和有机负荷。该工艺还将消除对化学投入的需要，并将使小型地区能够设计紧凑型反应堆来处理高浓度废水。

High-strength wastewater generated from municipal solid wastes (MSW) landfills, also known as leachates,poses a significant challenge for treatment via conventional wastewater treatment facilities. Leachate containshigh amounts of organic matter, inorganic macro-components, heavy metals, and many other hazardouschemicals. High concentrations of ammonia nitrogen (AN) in leachates poses a substantial toxicity risk toadjacent surface and groundwater sources and necessitates proper treatment of these leachates to meet localstandards for safe disposal or reuse. Electrochemical advanced oxidation processes (EAOP) likeelectro-oxidation (EO) and electro-coagulation (EC) could serve as a useful means to treat leachates originatingfrom MSW landfills. In EO, the direct action of electric current is used to oxidize or reduce species exclusivelyat the electrodes, which convert toxic and/or biorefractory pollutants into more benign chemicals. On the otherhand, EC involves the generation of coagulants in situ by electrically dissolving metal ions (aluminum or iron)at the anodes. These coagulants quickly form large particulate flocs, which in turn chemically adsorb pollutantsfrom wastewater. The combination of these two EAOPs into a single electrolytic cell is expected todemonstrate excellent potential for the removal of AN from high strength leachates. Since these processes donot require the addition of any chemicals from external sources, they can be considered as "clean" technology.The outcomes of this project will significantly add value for the company, GHD, and Canada in general. Ineffect, this project aims to develop practical solutions for the treatment of high-strength leachate and preservethe quality of our environment. Although existing treatment technologies easily remove the organic load fromleachate, the removal of ammonia presents a significant challenge. The proposed hybrid EO-EC system isexpected to reduce a substantial portion of the ammonia and organic load from high strength leachate. Theprocess will also eliminate the need for chemical inputs and will enable the design of compact reactors in asmall area to treat high-strength wastewater.