Biological flocculant for processing fluorine and calcium in wastewater and preparation and application methods thereof

Abstract

The invention relates to a biological flocculant for processing fluorine and calcium in wastewater and preparation and application methods thereof. A phosphoric-acid-modified iron-based biological flocculant is obtained through reacting a liquid iron-based biological flocculant with a phosphoric acid solution. The biological flocculant is clean, is free of secondary pollution, can be used for efficiently processing wastewater containing fluorine and calcium, particularly complex multi-metal wastewater containing fluorine and calcium, and can enable the concentration of all heavy metal ions and fluorine and calcium ions to meet the lead and zinc industrial pollutant emission standards (GB25466-2010).

Description

technical field [0001] The invention relates to a biological flocculant for treating fluorine and calcium in waste water and its preparation and application method, which is suitable for the treatment of fluorine-containing and calcium-containing waste water produced in technological processes such as fluorine-containing ore mining, non-ferrous metal smelting, aluminum processing, etc., and belongs to the environment engineering field. Background technique [0002] Fluorine-containing ore mining, non-ferrous metal smelting, chemical industry, glass, electroplating and other industries often contain high concentrations of fluoride ions in wastewater. High-concentration fluoride ions will aggravate the corrosion of production pipeline equipment, endanger production safety, and make it difficult to directly reuse purified water. Moreover, the discharge of high-concentration fluoride-containing wastewater will pollute the environment and seriously threaten the safety of drinking...

AI Technical Summary

Problems solved by technology

Membrane separation and ion exchange methods are complex in operation, high in operation and maintenance costs, and there is a risk of secondary pollution

The operation process of the adsorption method is simple, but it is generally only suitable for treating low-concentration fluorine-containing wastewater. The chemical precipitation method generates CaF by adding calcium salts. 2 Precipitation to achieve the purpose of defluoridation The concentration of fluorine in the treated wastewater can only be reduced to 15-20mg / L, which is difficult to meet the discharge standard, and artificial addition of lime will cause the increase of calcium and alkalinity in the water, and the generated sludge Large amount, slow sludge settling, difficult dehydration and other problems

[0004] Flocculation is a widely used method in water treatment, and iron-based flocculant is the most commonly used flocculant. At present, most of them are prepared by chemical oxidation, but strong oxidants are needed, the dosage is large, the reaction conditions are harsh, and the cost is high. ; When using a catalyst, its toxicity must be considered. The nitrite ion in the product is easy to exceed the standard and cause cancer, and there are by-products, which will cause secondary pollution.

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