Date of Award
2008
Degree Type
Thesis
Degree Name
Master of Engineering Science
Program
Civil and Environmental Engineering
Supervisor
Dr. Ernest K. Yanful
Abstract
Groundwater contamination by heavy metals is a major environmental concern in areas where the water supply system draws primarily on groundwater. Several methods of arsenic and chromium ions removal from water are already available. Among all removal methods, adsorption by magnetite nanomaterials is the most promising. In the present study, nano-size magnetite particles were used in the removal of arsenic and chromium species from different water samples, namely, stock solutions of arsenic and chromium, synthetic water, natural groundwater and spiked groundwater obtained from Srinagar, Munshiganj and Sylhet Golapganj in Bangladesh. The intent was to identify or develop a practical method for future groundwater remediation at the site. The results of the study showed 95-99% arsenic and chromium ions removal under controlled pH conditions and magnetite nanoparticles can adsorb arsenic and chromium(VI) more readily in an acidic pH range. Redox potential and pH data identified possible dominating species and oxidation states of arsenic and chromium in solution. The results also showed the limitation of arsenic and chromium removal by nanosized magnetite in the presence of a competing anion such as phosphate. At a fixed adsorbent concentration, arsenic and chromium ions removal decreased with increasing phosphate concentration. Nano-size magnetite particles removed less than 50% arsenic from synthetic water containing more than 3 mg/L phosphate and less than 50% chromium(VI) ion from synthetic water containing more than 5 mg/L phosphate. In natural groundwater containing more than 6 mg/L phosphate, less than 60% arsenic ion removal was achieved. In this case, it is iii anticipated that an optimum design with magnetite nanoparticles may achieve high arsenic ion removal in the field.
Recommended Citation
CHOWDHURY, SAIDUR RAHMAN, "REMOVAL OF ARSENIC AND CHROMIUM FROM WATER USING MAGNETITE NANOPARTICLES" (2008). Digitized Theses. 4742.
https://ir.lib.uwo.ca/digitizedtheses/4742