“A University of Florida ...

“A University of Florida professor has developed a quick, cheap and easy way to filter from water one of the world's most common pollutants: arsenic.

Bin Gao's team used iron-enhanced carbon cooked from hickory chips, called biochar, to remove the toxin. He is an associate professor with the Institute of Food and Agricultural Sciences' in agricultural and biological engineering.

"Because biochar can be produced from various waste biomass, including agricultural residues, this new technology provides an alternative and cost-effective way for arsenic removal," Gao said.

In a study to be printed in the January issue of the journal  Water Research , Gao and his team describe the process: The wood chips were first ground, then heated in nitrogen gas, but not burned. The resulting biochar, which has the consistency of ground coffee, was then treated with a saltwater bath to impregnate it with iron. Tests showed that plain biochar had no effect on arsenic, but the iron-enhanced product effectively removed the poison from water.

Current methods to remove arsenic include precipitation, adding lime or coagulants to water, using membranes to filter it out, or using an ion exchange process. But using a filter for removal is one of the most commonly used methods due to its ease of operation, relatively low cost and high effectiveness.

Gao said water treatment plants could use large biochar filters to extract the arsenic. Homeowners could use a small filter attached to their tap.

Additional investigations are still needed to optimize the process and to develop commercially available filters, he said. Gao's study was partly supported by the National Science Foundation.”

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Materials provided by  University of Florida .

Journal Reference :

1. Xin Hu, Zhuhong Ding, Andrew R. Zimmerman, Shengsen Wang, Bin Gao.  Batch and column sorption of arsenic onto iron-impregnated biochar synthesized through hydrolysis .  Water Research , 2015; 68: 206 DOI: 10.1016/j.watres.2014.10.009
2. University of Florida. "Inexpensive, easy way to filter arsenic from water." ScienceDaily. ScienceDaily, 3 November 2014. .