Method for removing niobium from sewage

Abstract

The invention discloses a method for processing sewage containing niobium. The method comprises the steps that (1) flocculation precipitation is conducted on waste water containing niobium with polyaluminium chloride and polyacrylamide; (2) 8-10mg / L sodium sulfide solution and 10-15mg / L sodium phosphate solution are sequentially added to the precipitated waste water; pH is adjusted to 3.0-6.5; sufficient stirring is conducted at 100-450r / min to allow the reaction to be complete; (3) the waste water is precipitated for 15-20min in a precipitation tank, and then mud and water are separated; (4) effluent is lifted by a pump to an absorption tower, with a water flow mode of upward flow; and (5) the effluent waste water is the sewage with niobium completely removed, and the effluent is lower than a national Grade I emission standard. The method has the advantages that the method is conducted at a room temperature and is noise-free; used chemical agents are nontoxic, harmless and non-volatile; no new 'three wastes' are generated in a treatment process; heavy metal can be recycled; the raw materials are easy to obtain; the cost is lower; the niobium removal efficiency can reach above 99.9%.

Description

technical field [0001] The invention relates to a method for treating niobium-containing sewage, in particular to the removal of niobium in wastewater from industries such as electroplating, automobiles, aviation, pigments, paints, and printing, and belongs to the field of wastewater treatment in environmental protection. Background technique [0002] In recent years, niobium has been widely used in electroplating, automobiles, aviation, pigments, paints, printing and other industries. Niobium-containing wastewater discharged from factories is the main source of niobium pollution in water bodies. For example, the wastewater discharged from the electroplating industry and military production (with a niobium content of about 0.065mg / L) and the wastewater discharged from processes such as sulfuric acid ore production of sulfuric acid and phosphate rock production of phosphate fertilizers (with a niobium content of up to 0.089mg / L) and other water bodies Pollution is particularl...

AI Technical Summary

Problems solved by technology

Although it has many advantages such as simple process, convenient operation, economical and practical, its sedimentation residue is difficult to handle and will cause secondary pollution

(2) The electrolysis method uses platinum group oxides or PbO 2 Use it as an anode to destroy cyanide, and then flocculate, precipitate, and filter niobium ions under the condition of pH=11 to remove niobium. This method consumes a lot of energy, so it has not been widely used in the treatment of niobium-containing wastewater.

However, this method is limited by the adsorption capacity of the resin, so it is suitable for treating wastewater with low concentration of niobium, and the resin is easy to be poisoned, and the treatment cost is high