(248ag) Magnetic Adsorbents for Heavy Metal Removal from Sea Water

Magnetic Adsorbents for Heavy Metal Removal from Sea Water

Xinqing Chen¹, Kailin He¹, King Lun Yeung^1,2,*

¹Department of Chemical and Biomolecular Engineering, ²Division of Environment, ³Nano Science and Technology Program, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China

*Corresponding author: kekyeung@ust.hk

Abstract:

The global distribution and impact of heavy metals on marine organisms and human health are of great concern due to their persistent, non-biodegradable and toxic nature. Many of the heavy metals found in coastal water and harbours near populated urban areas are strongly associated with anthropogenic activities. Their ecological impacts on marine environment are well documented and their tendency to bio-accumulate in the food chain poses a real health threat to the population. Long-term consumption of heavy metal tainted foods is known to cause neurological disorder, organ damages and even increased cancer risk. Large scale district cooling projects utilizing seawater is expected to increase heavy metal release (i.e., copper and chromium) into coastal water. A new salt-tolerant, fouling-resistant magnetic adsorbents based on mesoporous silica were successfully designed to selectively remove a target pollutant or class of pollutants from contaminated water. Two particular adsorbents were capable respectively of removing ninety percent of copper and chromium ions from seawater in the presence of other contaminating ions (i.e., Ni , Zn , Cl , SO). The adsorbent can be regenerated by a simple acid wash and the recovered metal ions are of sufficient purity (> 80%) to allow for recovery and reuse.