Efficient treatment method for electroplating nickel-containing waste water

Abstract

The invention discloses an efficient treatment method for electroplating nickel-containing waste water.The method comprises the following steps that 1, under the acidic condition, the electroplating nickel-containing waste water is subjected to a microelectrolysis reaction in a microelectrolysis reactor till the pH value of the electroplating nickel-containing waste water ranges from 4.0 to 5.0; 2, an oxidizing agent is added, and the electroplating nickel-containing waste water is subjected to secondary microelectrolysis in the microelectrolysis reactor continuously; 3, an alkaline solution is added, and the pH value of the electroplating nickel-containing waste water ranges from 9.5 to 11.0; 4, coagulant and flocculant are added to the electroplating nickel-containing waste water in sequence for coagulating sedimentation, and final supernate is treated waste water capable of being discharged.The efficient treatment method for the electroplating nickel-containing waste water is easy to operate and stable in effect, chemicals such as a heavy metal chelating agent and sodium sulfide which are bad for the environment do not need to be added, and secondary pollution to environment is avoided; the occupied area is saved, the requirements on reaction conditions are low, the waste water pH can be increased in the reaction process, the alkali quantity needed by follow-up alkali adjustment is decreased, and a product obtained through treatment can be recycled.

Description

technical field [0001] The invention relates to a treatment method for electroplating wastewater, in particular to an efficient treatment method for electroplating nickel-containing wastewater, which belongs to the technical field of wastewater treatment. Background technique [0002] As a common heavy metal ion in electroplating industry wastewater, nickel has greatly promoted the development of my country's economy and society. Although nickel is one of the trace elements necessary for living things, excessive nickel can retard the growth and development of plants, cause poor plant growth, cause harm to plants, and even die. At the same time, nickel can accumulate in plants, and when plants exceeding normal levels enter the food chain, it will affect the health of animals and even humans. Nickel can form nickel carbonyl with carbonyl compounds in water, which is highly toxic and an internationally recognized carcinogen. If electroplating nickel-containing sewage is disch...

AI Technical Summary

Problems solved by technology

Among them, the chemical treatment method includes neutralization precipitation method, sulfide precipitation method and ferrite method. The chemical treatment method has simple process flow, convenient operation and mature technology. It is one of the most commonly used methods, but the chemical treatment method occupies a large area and is It is difficult to meet the standard stably; the ion exchange method has a good effect on recovering valuable nickel in wastewater and improving the recycling rate of water, but its operation process is relatively complicated, and ion exchange resins are often damaged due to the influence of other organic pollutants. The shortening of life affects the treatment effect of the whole system; the adsorption method is a method of removing heavy metal ions by using the unique structure of the adsorbent. Zeolite, activated carbon, humic acid, etc. are often used as adsorbents for the treatment of electroplating nickel-containing wastewater, but currently The adsorbents used in industry are generally expensive, and the regeneration and secondary pollution of adsorbents are also issues that need to be considered; the membrane separation technology applied to electroplating nickel-containing wastewater can effectively remove nickel ions in wastewater, and the equipment is simple and does not need to add chemicals. Reagents and other advantages, but the membrane module is expensive and will produce membrane fouling and membrane clogging during use, and the operating cost is high; biological treatment has broad prospects, but the current understanding of the reaction kinetics between biosorbents and heavy metals It is not enough, and biosorbents with large adsorption capacity are still to be developed, and there is still a long way to go before being widely used in industry.