Nickel-containing wastewater treatment technology

Abstract

The invention discloses nickel-containing wastewater treatment technology, which comprises the following steps: using sodium hydroxide or ammonia water to adjust the pH value of nickel-containing wastewater to between 5.5 and 9.5; adding dimethylglyoxime into the nickel-containing wastewater under the stirring at normal temperature for a nickel deposition reaction, wherein the molar ratio of the dimethylglyoxime to Ni in a filtrate is 2.2:1-2.4: 1; filtering after the reaction is performed for 20 to 60 minutes; washing a filter cake by hot water with a temperature between 40 and 90 DEG C, and then obtaining a pure nickel chelate through the filtration; using hydrochloric acid, sulfuric acid or nitric acid to dissolve the nickel chelate according to product requirements; and obtaining corresponding nickel salt solution and the dimethylglyoxime after the filtration; recovering the dimethylglyoxime from an acid-dissolved filtrate; removing residual Fe through neutralization; heating hydrolysis and filtration, and then evaporating, washing, crystallizing the filtrate and drying the crystal to obtain a product; merging the filtrates in step two and recovering the dimethylglyoxime; and using the recovered dimethylglyoxime for the nickel deposition reaction. The nickel-containing wastewater treatment technology can ensure that the nickel-containing wastewater reaches the standard after the treatment and the content of the residual Ni is less than 1mg / L, can also completely recover nickel, and has low treatment cost and less equipment investment.

Description

technical field [0001] The invention relates to a process for treating nickel-containing wastewater. Background technique [0002] Although nickel and its salts have low toxicity, as an element with biological effects, nickel can activate or inhibit a series of enzymes (such as arginase, carboxylase, etc.) to cause its toxic effects. Animals eating nickel salt can cause stomatitis, gingivitis and acute gastroenteritis, and damage the heart muscle and liver. Experiments have shown that the lethal dose of nickel to rabbits is 7-8 mg / kg. Nickel and its compounds can irritate human skin, mucous membranes and respiratory tract, and can cause dermatitis, bronchitis, and even pneumonia. It has been proved by animal experiments and crowd observation that nickel has a accumulation effect, and the accumulation is the most in the kidney, spleen, and liver, which can induce nasopharyngeal cancer and lung cancer. At the same time, nickel also has adverse effects on plant growth (the cr...

AI Technical Summary

Problems solved by technology

[0016] Including reverse osmosis, membrane extraction, ultrafiltration, etc., because the membrane separation needs to operate normally when the wastewater to be treated reaches a certain index, the suspended solids, organic matter, colloidal substances, etc. in the wastewater are detrimental to the life of the membrane. Influence, the raw water must adopt certain pretreatment measures before entering the reverse osmosis membrane device. At the same time, the membrane treatment process requires high pressure, which requires a large investment in primary equipment and high maintenance and operation costs.