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Remediation/Pollution Control

Abstract
Sorptive Treatment of Metals and Nitro Explosives in Water Using Biochar - Seok-Young Oh1*, Biochar, a solid byproduct of a pyrolysis process was investigated as a sorbent to remove toxic metals and nitro explosives from natural water and wastewater. It was hypothesized that biochar can sorb dissolved metals and nitro explosives due to its high surface area and strong sorption affinity of aromatic organic compounds. Using a tube furnace under N2, various types biochar were synthesized by changing biomass (poultry litter, sludge, fallen leaves, corn stalk, rice straw, and coffee grounds) and temperature (250, 400, 550, and 700 oC). The physical, chemical, and engineering properties of the biochar were characterized. Through batch experiments, the extent of removal of dissolved metals (Cd, Cu, Pb, Zn, and As) and nitro explosives [2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)] was evaluated using sorption isotherm models. The removal of metals and nitro explosives was as effective as granular activated carbon, widely used as a typical sorbent in remediation processes. Considering the properties of biochar and maximum sorption capacity for each contaminant, factors affecting the sorption of contaminants to biochar were discussed. Our results suggest that biochar may be applied as a sorbent to decrease the concentrations of metals and nitro explosives in natural and engineered systems. Water Pollution Control – J. Kearns, University of Colorado Char filters have been used for thousands of years to remove contaminants from water by adsorption. Today, commercial activated chars are used in municipal drinking water treatment for control of compounds that impart undesirable aesthetics (taste, odor, and appearance) and/or present unacceptable human health risks. In developing communities around the world, however, commercial Activated carbon (AC) is unavailable or cost-prohibitive. In the developed world, the use of commercial AC for treatment of storm water, agricultural, and other non--‐point source run-off, or municipal wastewater tertiary treatment is also often prohibitively expensive. Our work has shown that some Biochars produced by “low--‐tech” methods (e.g. top lit up--‐ draft (TLUD) cookstoves and drum ovens) And for a fraction of the cost of commercial AC can be nearly as effective, or as effective, for sorption of a range of water contaminants. Here we present results of batch studies using biochars produced from a range of feedstocks and processes to sorb chlorine and methyl isoborneol (taste and odor compounds), trihalomethanes (disinfection by--‐products impacting health), sulfamethoxazole (environmentally persistent antibiotic), and 2,4--‐dichlorophenoxyacetic acid (prevalent herbicide) from simulated natural waters. This work can help advance efforts in safe drinking water provision in developing communities, as well as cost--‐effective non--‐point source and wastewater effluent pollution control in developed societies. Prevention of tree wilt and reduction of radioactive Cesium with charcoal and mycorrhizal fungi - Makoto Ogawa Northeast districts of Japan were attacked by intense earthquake and tsunami in 2011, polluting a wide area with radioactive substances emitted from the Fukushima Nuclear Power Plant. Using our knowledge and experiences with charcoal and mycorrhizal fungi, our team joined the recovery efforts focusing on a reforestation project of the coastal forest lost by tsunami. Ogawa started the project raising pine seedling, using charcoal and mycorrhizal fungi, a process which he developed in the 1980s which has been popularized for the rehabilitation of wilting pine and other ornamental trees or the reforestation of seacoast areas. This treatment improves the survival rate and general growth is promoted. It was also recognized that seedlings with certain mycorrhiza have stronger salt resistance than non-mycorrhizal plants. Similar studies have been conducted to combat oak wilt which caused from a fungus, carried by an ambrosia beetle, which kills fine roots on oak and causes a decrease in mycorrhizas. Charcoal treated oak trees recovered from wilt frequently forming mycorrhizas on the regrown roots. Encouraged by previous results, we applied charcoal in a forest ~200 km from Fukushima. In July 2012, the regrowth of fine roots and mycorrhiza formation could be observed. One year after the treatment, the biomass of mycelium and mycorrhiza increased remarkably, and the numbers of fruit body of mycorrhizal fungi in the treated plots were much more than those in without charcoal. This presentation will review a new method in which Cesium in the polluted soil and litter can be reduced with charcoal and mycorrhizal fungi. In this method, the seedlings inoculated with suitable mycorrhizal fungi will be planted on the polluted soil mixed with charcoal. It is expected that Cesium might be concentrated into mycorrhiza, fruit bodies and the plant itself, which can then be collected.
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Date
2013-10-14
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