Dual electrochemical treatment method and device for reverse osmosis concentrated solution of landfill leachate

Abstract

The invention belongs to the field of environmental engineering, and particularly provides a dual electrochemical treatment method of a landfill leachate reverse osmosis concentrated solution, which comprises the following two steps: (1) introducing the landfill leachate reverse osmosis concentrated solution into an electric flocculation unit to carry out electric flocculation treatment on the landfill leachate; (2) introducing the reverse osmosis concentrated solution of the landfill leachate subjected to electric flocculation into an electrooxidation-electric flocculation unit and simultaneously carrying out electrooxidation-electric flocculation treatment; the electric flocculation unit and the electrooxidation-electric flocculation unit comprise two or more anodes and cathodes which are connected in series, and the cathode of the electrooxidation-electric flocculation unit is aluminum. The invention further provides a corresponding treatment device for the landfill leachate reverse osmosis concentrated solution. Under the conditions of short time, low energy consumption and no addition of any chemical reagent, high-concentration COD (Chemical Oxygen Demand) can be removed, the biodegradability of the ROLC is greatly improved, and toxic Pb can be effectively prevented from being dissolved from the Ti / PbO2 anode.

Description

technical field [0001] The invention belongs to the field of environmental engineering, and particularly relates to double electrochemical treatment of landfill leachate reverse osmosis concentrate. Background technique [0002] Landfill leachate comes from sanitary landfills and waste incineration plants, and is a pollutant containing high concentrations of organic matter, inorganic salts and heavy metals. By 2025, global landfill leachate production is expected to exceed 330 million tons (Abunama et al., 2018; Costa et al., 2019). In addition, the aging of landfills can produce more difficult-to-treat leachate that cannot be treated by traditional biological methods (Renou et al., 2008). In the "Standards for Pollution Control of Domestic Waste Landfills" (GB16889-2008) promulgated and implemented in China in 2008, the biochemical oxygen demand (BOD) in landfill leachate 5 ), chemical oxygen demand (COD), ammonia nitrogen, total nitrogen (TN), heavy metals and other indi...

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Problems solved by technology

However, limitations of AOP include: (1) the need for continuous input of chemical reagents, such as pH adjusters and hydrogen peroxide, and (2) incomplete oxidation of compounds that may lead to toxic by-products (Gautam et al., 2019)

Although BDD has a high oxygen evolution overpotential, it can generate hydroxyl radicals for rapid pollutant degradation ( et al.,2005), but they are poorly conductive and produce toxic chlorinated by-products such as chlorate and perchlorate ( et al., 2010)

Ti / PbO 2 With good electrical conductivity and oxygen overpotential, it is another widely used anode, but the toxicity of lead (Pb) precipitation affects its applicability (Panizza and Cerisola, 2009)

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