Synthetic organic water contaminants in developing communities: an overlooked challenge addressed by adsorption with locally generated char. Journal of Water, Sanitation and Hygiene for Development, Vol 4 No 3 pp 422–436 © IWA Publishing 2014 doi:10.2166/washdev.2014.073
Joshua P. Kearns, Detlef R. U. Knappe and R. Scott Summers
Department of Civil, Environmental, & Architectural Engineering, University of Colorado-Boulder, 1111 Engineering Dr, ECOT 441, UCB 428, Boulder, CO 80309, USA E-mail: joshua.kearns@colorado.edu
Department of Civil, Construction, & Environmental Engineering, North Carolina State University, 2501 Stinson Dr, Campus Box 7908, Raleigh, NC 27695, USA
Chemical contamination of drinking water sources is a worldwide problem. However, few locally managed, sustainable, and low-cost on-site treatment technologies are available in rural, remote, and emergency/disaster relief/humanitarian crisis situations. Char filter-adsorbers have been used to treat drinking water for thousands of years and are still widely used today. Our studies show that some chars produced by traditional means from a range of feedstocks develop favorable sorption properties for uptake of 2,4-dichlorophenoxyacetic acid (2,4-D), a prevalent herbicide and water contaminant.
However, more energy efficient, environmentally sustainable and scalable production of consistent highly sorptive chars can be accomplished with biomass gasification. Our laboratory studies demonstrate that locally produced char adsorbents derived from surplus agricultural and forestry biomass are effective for adsorbing 2,4-D. A year-long study of field-scale application of chars in Thailand is also presented. Based on these studies we present design recommendations for integrating char adsorbers into low-cost, multi-barrier treatment trains for on-site water provision.
