Enrichment Of Cu²⁺ From Nonferrous Metal Smelting Wastewater Using Fixed Bed Filled With 13x Zeolite Composite And The Recycling Of Copper

Heavy metal pollutants in the water environment mainly come from non-ferrous smelting.The fixed bed is filled with the self-developed particulate 13 X Zeolite Composite material to achieve rapid and efficient enrichment of Cu²⁺ in wastewater.The suitable parameters for fixed bed operation were determined,the performance and mechanism of Cu²⁺ enrichment in composite materials were investigated,and the effects of wastewater quality,coexisting heavy metal ions,and common anions / cations on Cu²⁺ enrichment in composite bed were investigated.In addition,the method of recovering and enriching the copper resources in the composite after saturation was studied.The research results are as follows:?1?The enrichment of Cu²⁺ in the fixed bed of composite material was better under the conditions of particle size 20-40 mesh,p H?5.0,filling height of 50 cm and inlet flow rate of 150 m L/min.The enrichment rate of Cu²⁺ by fixed bed was increased with the increase of Cu²⁺ concentration and the saturation concentration is 1.69 mmol/g.?2?The characterization and desorption results of Cu²⁺ enriched composites show that the main mechanisms of Cu²⁺ enriched by composites were ion exchange adsorption,coordination,surface precipitation and chemical precipitation,of which ion exchange adsorption occurs first,followed by other mechanisms.The results showed that the Cu²⁺ enriched by coordination takes up about 49% of the total enrichment,and the Cu²⁺ enriched by surface/chemical precipitation takes up about 29% of the total enrichment.?3?The types and concentrations of coexisting heavy metal ions will affect the Cu²⁺ penetration time and equilibrium adsorption/enrichment amount in the wastewater coexisting with Pb²⁺,Cd²⁺ and Zn²⁺.The order of influence capacity of Pb²⁺,Cd²⁺ and Zn²⁺ on the equilibrium adsorption/enrichment of Cu²⁺ was Pb²⁺>Cd²⁺>Zn²⁺ and the higher the concentration of co-existing heavy metal ions,the shorter the Cu²⁺ penetration time.?4?The coexistence of common anions/cations will affect the Cu²⁺ penetration time and equilibrium adsorption/enrichment,among which Na+ only makes the Cu²⁺ penetration time shorter,but has little impact on the equilibrium adsorption/enrichment.The competition of Ca2+ for adsorption sites in the composite leads to a decrease of the enrichment of Cu²⁺ when Ca2+ coexists with Cu²⁺.SO42-can reduce the equilibrium adsorption/enrichment of Cu²⁺.The higher the concentration of SO42-,the greater the degree of reduction.?5?Hydrochloric acid was selected as the leaching acid to recover copper resources from the enriched Cu²⁺ saturated materials.The results showed that the leaching rate of copper reached 99.8% when the concentration of hydrochloric acid was 3.0mol/L and the leaching time was 2 h.The reduced iron powder was selected as the reducing agent to recover copper from the leaching solution.When the dosage of reduced iron powder was 8 g/L?the leaching solution?,about 96% of Cu²⁺ in the leaching solution was reduced to sponge copper,which effectively realized the recovery of copper resources.