Study On The Preparation Of And The Property Of Lightweight Geopolymer-loaded Modified Polyurethane Adsorbent Materials

Xanthate lipid heavy metal adsorbent reacts with heavy metal cations to generate insoluble chelate products in order to achieve adsorption of heavy metal ions.However,powdered xanthate adsorbents are criticized for being easy to disperse,difficult to separate and difficult to recover in the treatment of wastewater.In particular,xanthate prepared from polyurethane is not commonly used in water treatment due to its hydrophobicity.Therefore,in this study,a modified polyurethane was prepared,and modified polyurethane lightweight geopolymers(HG-MPs)were obtained by loading with porous lightweight geopolymers.In addition,the performance of the modified polyurethane and the modified polyurethane lightweight geopolymer was investigated to analyze their feasibility in the treatment of heavy metal pollution in water bodies.The main contents of this study include:preparation of modified polyurethane and verification of its performance by characterization and heavy metal adsorption tests;preparation of HG-MPs by adding different mass ratios of modified polyurethane to geopolymers;analysis of the effects of modified polyurethane on the physicochemical properties of geopolymers and investigation of the adsorption performance of HG-MPs on heavy metal ions(Cu²⁺,Pb²⁺)in simulated wastewater.The results of this study are as follows:(1)Modified polyurethane wastes were modified by carbon disulfide+magnesium sulfate to obtain modified polyurethane.The successful modification of polyurethane waste was confirmed by characterization of the modified polyurethane.The adsorption of modified polyurethane waste to simulated wastewater Cu²⁺and Pb²⁺was significantly increased as determined by adsorption tests.(2)The adsorption effect of modified polyurethane on simulated Cu and Pb-containing wastewater was affected by p H,and the presence of hydrogen ions in the wastewater was detrimental to the adsorption of heavy metal ions by the modified polyurethane.Under the optimal water p H condition(p H=6),the peak adsorption of modified polyurethane on Cu²⁺and Pb²⁺in the simulated wastewater was 74.03 mg/g and42.08 mg/g,respectively.(3)The magnitude of the adsorption rate of modified polyurethane on Cu²⁺and Pb²⁺in the simulated wastewater depended on ligand adsorption rather than simple physical adsorption,which further proved that polyurethane by modification.The heavy metal adsorption capacity was obtained by modification of polyurethane.(4)HG-MPs were prepared by loading the modified polyurethane with metakaolin-based polymers,and the addition of the modified polyurethane optimized the spatial structure and physical properties of HG-MPs,resulting in more uniform internal pores.And HG-MPs is a modified polyurethane-geopolymer hybrid structure,and the reorganization of Al-O and Si-O spatial structures occurred during the preparation of HG-MPs materials.(5)The flexural strength of HG-MPs samples decreased with the increase of modified polyurethane addition,but the optimum modified polyurethane addition of 5 wt%could improve the compressive performance of the material(3.0 MPa).the thermal insulation performance of HG-MPs was superior compared with that of ordinary lightweight geopolymers,and the thermal conductivity of HG-MP₂₀ was 0.31 W/m K,which was 27.9%lower than that of the reference sample(HG-P₀)was reduced by27.9%.(6)The adsorption effect of HG-MPs on Cu²⁺and Pb²⁺in simulated wastewater was also influenced by p H,and the heavy metal adsorption effect of HG-MPs composites was better than that of modified polyurethane.Under the optimal water p H conditions(p H=6),the adsorption amounts of HG-MPs on Cu²⁺and Pb²⁺in simulated wastewater were 92.37 mg/g and 68.46 mg/g,respectively,which were 24.77%and 62.69%higher than those of modified polyurethane on Cu²⁺and Pb²⁺in simulated wastewater,respectively.(7)The adsorption equilibrium time of HG-MP₁₅ on Cu²⁺and Pb²⁺in simulated wastewater was 50 min,and the adsorption behaviors of HG-MP₁₅ on Cu²⁺and Pb²⁺in simulated wastewater were consistent with quasi-secondary kinetics.