Treatment method and device for stainless steel electrolytic polishing wastewater

Abstract

The invention discloses a treatment method and device for stainless steel electrolytic polishing wastewater. The method comprises the following steps: detecting the pH value of the wastewater, performing classification according to different pH values, and putting the classified wastewater into different coagulation sedimentation systems; selecting an acidic sedimentation device + an alkaline coagulation sedimentation device for the electrolytic wastewater with original wastewater water quality acidity pH of < 0.8; selecting a two-stage alkaline coagulation sedimentation device for the electrolytic wastewater with original wastewater water quality acidity pH of > 1.2; and performing solid-liquid separation in the coagulation sedimentation system, performing advanced treatment on the treated wastewater by using an reverse osmosis (RO) system, and performing discharge or performing recycling. The treatment method and device for the stainless steel electrolytic polishing wastewater provided by the invention have scientific and reasonable design, effectively treat the stainless steel electrolytic polishing wastewater, realizes recycling, rationally select the combined process and a coagulating agent according to different wastewater characteristics, emission limit values and resource requirements, and achieve a plurality of targets such as reasonable investment, simple and convenient management, high environmental benefits and low costs.

Description

technical field [0001] The invention relates to the technical field of electrolytic wastewater treatment, specifically, a stainless steel electrolytic polishing wastewater treatment method and device for purifying stainless steel electrolytic wastewater through a combined process and realizing effective pollution control and resource utilization. Background technique [0002] With the continuous improvement of the market's product quality requirements, the proportion of electropolishing of stainless steel products is increasing day by day. Its main process is degreasing-water washing-rust removal-water washing-electropolishing passivation-pickling-water washing-air drying -Packaging, these processes will produce wastewater with high concentrations of phosphorus and heavy metals such as nickel, chromium, copper and other pollutants. The direct discharge of these wastewater will cause water pollution, soil pollution, damage to regional ecosystems, and even endanger the health o...

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Problems solved by technology

[0002] With the continuous improvement of the market's product quality requirements, the proportion of electropolishing of stainless steel products is increasing day by day. Its main process is degreasing-water washing-rust removal-water washing-electropolishing passivation-pickling-water washing-air drying -Packaging, these processes will produce wastewater with high concentrations of phosphorus and heavy metals such as nickel, chromium, copper and other pollutants. The direct discharge of these wastewater will cause water pollution, soil pollution, damage to regional ecosystems, and even endanger the health of surrounding residents, etc. Therefore, it is of great significance to effectively treat electropolishing wastewater.

[0003] The stainless steel electrolyte is mainly composed of sulfuric acid, phosphoric acid, and glycerin in a certain proportion. In addition, according to production needs, there are also chemicals such as chromic anhydride, gelatin, and sodium fluoride. Therefore, the wastewater discharged from cleaning is rich in phosphorus, nickel, chromium, copper, etc. Pollutants, among which phosphorus has the highest concentration and is difficult to purify. It is difficult to achieve standard purification in one step. It is necessary to develop an efficient and reliable combined process to effectively treat it and reduce pollutant emissions.

[0004] At present, the most reported treatment process is "single-stage coagulation sedimentation + reverse osmosis". The treatment of heavy metals in the effluent of this process can stably meet the standard, but the rate of phosphorus compliance is low, and the reverse osmosis membrane is often clogged. In actual industrial applications , has not really achieved the purpose of effectively treating electropolishing wastewater

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