An investigation on the adsorptive potential of Palawan natural laterites in the removal of arsenic in simulated groundwater

• Main Authors: Buguis, Ma. Cecilia Bacolor, Fuentes, Benson Gatdula
• Format: text
• Language: English
• Published: Animo Repository 2009
• Subjects: Laterite; Water—Purification—Arsenic removal; Water—Purification—Adsorption; Chemical Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/5163
• Institution: De La Salle University

Arsenic, being a ubiquitous element, continues to pose a major problem in terms of its contamination in groundwaters especially in developing and rural areas. In the Philippines, the Department of Health has set a standard of 10ug/L as the limit to the arsenic content of groundwater (Philippine National Standard for Drinking Water). With this, the need for a cost-effective, accessible, and yet efficient way of groundwater remediation from arsenic then raises interests in the field of research. The study investigates on the adsorptive potential of natural laterites in the removal of arsenic in simulated groundwater. The assessment of the possible high-level concentration of arsenic in selected suspected areas like the Mogpog and Marbel Rivers in Mindoro, Davao, as well as areas in NCR have all revealed arsenic concentrations less than that of the PNSDW Standard. The natural laterite obtained from Palawan was found to have high iron content ranging from 3.83 to 36.32%. Natural Laterite 2 (NL2) has been noted to have the highest among the three samples in terms of iron content. The adsorptive capability of the laterites was studied by batch experiments in the removal of arsenic at varying parameters such as laterite dosage and initial arsenic concentration. It has been observed that the highest arsenic removal occurred when the initial arsenic concentration was set to 0.1 ppm was 96.7%. NL2 had the highest adsorption efficiency of 95.38% at a dosage of 20 g/L. It was also observed that as the laterite dosage increases from 10g/L to 20g/L, there was also a consequent increase in the removal efficiency from 62.55% to 96.7%. Describing the behavior of the adsorption technology, all three laterites suited the Langmuir isotherm model which had a range of correlation values from 0.9963 to 1.0.