42 results about "Sodium citrate citric acid" patented technology

The invention discloses a composite zinc removing agent for treating wastewater containing zinc, belonging to the field of sewage treatment in environmental protection. The composite zinc removing agent is prepared by compounding organic matters and inorganic matters, wherein the organic matters comprise one or two of sodium citrate, tricalcium citrate, sodium oxalate, potassium oxalate and hydroxyethylidene bisphosphonate, and the inorganic matters comprise two or more of sodium sulfide, magnesium sulfide, ferrous sulfate and aluminum sulfate; in terms of mass ration, the sodium citrate accounts for 20 to 80 percent, the tricalcium citrate accounts for 20 to 80 percent, the sodium oxalate accounts for 20 to 80 percent, the potassium oxalate accounts for 20 to 80 percent, the hydroxyethylidene bisphosphonate accounts for 20 to 80 percent, the sodium sulfide accounts for 10 to 40 percent, the magnesium sulfide accounts for 10 to 40 percent, the ferrous sulfate accounts for 10 to 40 percent, and the aluminum sulfate accounts for 10 to 40 percents; and the composite zinc removing agent prepared according to the proportion is added into the wastewater containing the zinc under the condition that a pH value is between 4.0 and 6.0, the wastewater is stirred for 10 to 30 minutes and is subjected to air flotation treatment, a layer of residue floating on the surface of the wastewater is finally scraped by using a scraping machine, and yielding water can be lower the national discharge standard I. The composite zinc removing agent has the characteristics of simple process flow, lower running cost, no sludge generation, high zinc removing effect and the like.