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

从城市固体废物（MSW）填埋场产生的高浓度废水（也称为渗滤液）对通过常规废水处理设施进行处理提出了重大挑战。渗滤液含有大量的有机物、无机宏量组分、重金属和许多其他有害化学物质。渗滤液中高浓度的氨氮（AN）对邻近的地表水和地下水源造成了很大的毒性风险，需要对这些渗滤液进行适当的处理以满足当地的安全处置或再利用标准。电氧化（EO）和电凝聚（EC）等电化学高级氧化技术（EAOP）可作为处理垃圾渗滤液的有效手段。在EO中，电流的直接作用用于氧化或还原电极处的物质，将有毒和/或生物难降解的污染物转化为更良性的化学物质。另一方面，EC涉及通过在阳极处电溶解金属离子（铝或铁）来原位生成凝结剂。这些混凝剂迅速形成大颗粒絮凝物，进而化学吸附废水中的污染物。这两种EAOP组合成一个单一的电解池，预计展示了良好的潜力，从高强度的渗滤液中去除AN。由于这些工艺不需要添加任何外部来源的化学品，因此可以将其视为“清洁”技术。该项目的成果将显著增加公司、GHD和加拿大的整体价值。该项目旨在为高浓度渗滤液的处理开发实用的解决方案，并改善我们的环境质量。虽然现有的处理技术很容易去除渗滤液中的有机负荷，但氨的去除提出了一个重大挑战。建议的混合EO-EC系统有望减少高浓度渗滤液的氨和有机负荷的很大一部分。该工艺还将消除对化学品投入的需求，并将使小型反应器的设计能够在小面积内处理高浓度废水。

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.