Organic matter removal from water by adsorption onto a composite carbon–silica

BACKGROUND

Water is one of the most valuable substances in the world. Organic matter is becoming increasingly important in drinking water treatment where it affects the quality of water. Removal of organic matter from drinking water by adsorption onto modified activated carbon (AC) is a widespread water treatment technology.

RESULTS

The AC surface was coated with silica to improve its physicochemical properties. These properties of AC were characterized by N₂ adsorption desorption measurements, X-ray diffraction, infrared and Raman spectroscopy, and measurements of pH of the point zero charge. AC–silica exhibited a meso-microporous surface. ACs were tested for organic matter removal in aqueous solution. The results showed that the silica was introduced successfully into microporous carbon materials and high adsorption capacity of AC–silica was obtained. Fourier transform infrared spectra confirmed that organic matter diffused into the carbon surface and was adsorbed mostly by physisorption and partially by chemisorption, with alteration of the carbon structure. AC–silica composite was more efficient in the removal of chemical oxygen demand and heavy metals than AC. Total organic matter was removed by adsorption, and AC-supported silica was superior (∼100%) to raw AC (∼50.36%), and could be explored to remove contaminants from wastewater.

CONCLUSION

Modified AC allowed a high capacity for organic matter removal from water. This opens new perspectives in the field of adsorbent materials, in order to prepare very efficient carbon adsorbents for environmental organic matter remediation. © 2025 Society of Chemical Industry (SCI).