A lanthanum-impregnated silica gel has been developed for the removal of fluoride, phosphate, and arsenate ions by adsorption. The interaction between silica gel and lanthanum ion was maximum at a final pH of 6. The removal of fluoride and arsenate ions by adsorption on the lanthanum-impregnated
silica gel was more than 99.9% at neutral pH from initial concentration of 0.55 and 0.2 mmol/L, respectively. The removal of phosphate ion was 95% at an initial concentration of 0.5 mmol/L at neutral pH. Arsenite ion was not adsorbed on the material. The rate of adsorption of the anions followed
the first-order reaction and fit in the Lagergren equation. The adsorption of each anion followed the Langmuir isotherm. Other anions such as Cl− Br−, I−, NO3−, and SO42− did not interfere
with the adsorption. A column study was conducted for the removal of these anions at a fixed flow rate of 0.5 mL/min at pH approximately 7. These anions were removed by more than 99.9% at initial first or second fraction, and the column was regenerated at pH 8.5. The method was applied for
the removal of these anions from synthetic and high-tech industrial wastewaters.
Water Environment Research® (WER®) publishes peer-reviewed research papers, research notes, state-of-the-art and critical reviews on original, fundamental and applied research in all scientific and technical areas related to water quality, pollution control, and management. An annual Literature Review provides a review of published books and articles on water quality topics from the previous year. Published as: Sewage Works Journal, 1928 - 1949; Sewage and Industrial Wastes, 1950 - 1959; Journal Water Pollution Control Federation, 1959 - Oct 1989; Research Journal Water Pollution Control Federation, Nov 1989 - 1991; Water Environment Research, 1992 - present.