Analysis of Nano-Silicon Dioxide Modified Waste Building Brick Materials in the Application of Adsorption and Removal of Water Pollutants

Abstract

This study is to investigate the effect of nano-silicon dioxide (SiO2) modified waste building bricks (WBBs) in adsorbing pollutants in water. The Stober method is adopted to complete the preparation of nano-SiO2. Afterwards, the prepared SiO2 is modified with 3-(methacryloyl chloride) propyltrimethoxysilane (MPS). The modified SiO2 (MPS-SiO2) is loaded on the surface of the construction waste bricks to analyze the characterization of the modified construction waste bricks and their adsorption to nitrogen (N) and phosphorus (P) in wastewater. Both the energy spectrum and infrared spectrum of the MPS-SiO2 show the characteristic peaks of MPS. It shows that the modification of nano-SiO2 by MPS is feasible. The scanning electron microscope (SEM) image of MPS-SiO2 WBBs has not changed much from before the treatment, but the infrared spectrum of MPS-SiO2 shows the characteristic peak of MPS. Such results indicate that MPS-SiO2 can be successfully loaded to the surface of waste building bricks. Temperature, initial concentration, and pH of waste liquid have a great influence on the adsorption of MPS-SiO2 WBBs to P and N wastewater. MPS-SiO2 building waste bricks are most suitable for treating phosphorus wastewater with an initial pH of 2 and an initial concentration of 50~150 mg/L. The treatment effect of ammonia nitrogen wastewater with a concentration greater than 50 mg/L is not good. The treatment effect of ammonia nitrogen wastewater with an initial pH of 4~7 is better. The waste building brick materials modified by nano-SiO2 have a good prospect in the treatment of water pollution, and are worthy of further in-depth exploration.