Environmental protection treatment method for citric acid chemical plating waste water

Abstract

The present invention provides an environment-protecting processing method for the lemon acid chemical plaiting wastewater, the lemon acid chemical plating wastewater is added with hydrochloric acid and calcium chloride, the vacuum suction-filtering or pressing-filtering is executed after reaction, the pressing-filtering is executed after adding sodium sulfide for sufficient reaction and the filter residue is the sulfide deposition of the nickel and cobalt, the filter residue is recovered as the mineral product; measuring the COD of the filter liquor separated last, the conventional biochemical treatment is executed until the discharge standard is obtained when the COD value does not get to the discharging standard. The method of the invention has the beneficial effects of greatly shortening of the processing period, effectively recycling the costly nickel and cobalt product, better settling the COD discharging problem of the wastewater up to standard, higher economic benefit and social benefit.

Description

technical field

[0001] The invention relates to an environmental protection treatment method for waste liquid, in particular to a method for treating waste water after citric acid electroless plating is performed on electronic materials. Background technique

[0002] In the production process of some electronic materials, citric acid electroless plating is used, such as plating nickel, cobalt and other heavy metals on the surface of electronic materials. Wastewater treatment after electroless plating The current general treatment method in the industry is to oxidize and decompose organic matter such as citric acid through biochemical treatment such as surface cascade gas method, and then put in chemicals through chemical methods to precipitate heavy metals such as nickel and cobalt together with biochemical sludge , and then recover and process the precipitate by pressure filtration. Because heavy metals such as nickel and cobalt form highly stable complexes with citric aci...