Experimental Study On The Absorption And Removal Of Copper Ions Based On RSPRC

Copper is an essential element for the growth and development of animals and humans,as well as an important nutrient element for the growth of plant.In recent years,with the widespread use of copper,a large amount of copper-containing wastewater has been discharged into water bodies,causing water body pollution and threatening human life and health.Therefore,it is urgent to develop water treatment technology for copper wastewater.Adsorption is a typical method for treating copper-containing wastewater,and its core problem is to select an adsorbent with excellent adsorption performance and low cost.Based on the team’s previous research results,the RSPRC particles suitable for adsorption of copper ions were prepared by using steel slag,fly ash and active clay as adsorption substrate,porogens and binder as adjuvant（Residue&Soil Phosphorus Removal Composite）.The adsorption and removal performance of RSPRC particles on copper ions was systematically studied from the aspects of substrate ratio,influence factors,mechanism model,microstructure and modification treatment,in order to achieve the win-win effect of industrial waste resource reuse and copper ion wastewater treatment.The research results showed that the activated clay had the strongest adsorption capacity for copper ions among the three substrates,but the ratio of activated clay to a certain limit caused the mechanical strength of the RSPRC particles after adsorption to decrease;At the temperature of 25°C,according to Langmuir model,the theoretical maximum adsorption capacity of RSPRC particles for copper ions was 2.633 mg/g;In the coexistence of metal cation environment,Mg²⁺,Ca²⁺,and Fe³⁺all inhibited the adsorption of copper ions by RSPRC particles except Na⁺;In the presence of inorganic anions,PO₄^3-and SO₄^2-promoted the adsorption of copper ions by RSPRC particles,but Cl^-had an inhibitory effect.The adsorption kinetics study indicated that the adsorption process of copper ions by RSPRC particles conformed to pseudo-first order kinetic model and pseudo-second order kinetic model.The adsorption process was controlled not only by surface diffusion but also by internal pore diffusion,and the adsorption rate was mainly controlled by the internal pore diffusion step.The study of adsorption thermodynamics indicated that the adsorption of RSPRC particles to copper ions was a spontaneous,endothermic,and entropy process.The higher the ambient temperature,the stronger the adsorption capacity of the adsorbent for copper ions.The characterization results of the samples before and after the adsorbent adsorbed copper ions found that,in addition to physical adsorption,the removal mechanism of copper ions by RSPRC particles also included ion exchange reaction and chemical precipitation,which was due to the fact that RSPRC particles contain metal oxide and silicon oxide.RSPRC particles can adsorb phosphate ions in the solution.The characterization results of samples before and after phosphorylation modification showed that the specific surface area of RSPRC particles increases after adsorbing phosphate.The experimental results indicated that the theoretical maximum adsorption capacity of copper ions after phosphate absorption had been improved to a certain extent.This means that RSPRC particles have the potential to simultaneously remove phosphate ions and copper ions in wastewater,and the phosphorylation modification of RSPRC particles can promote the adsorption of copper ions by RSPRC particles.