2011 Annual Report
Biochars (plant or animal waste heated without air) were produced by heating cotton seed hulls, almond shells, biorefinery waste lignin (woody byproduct), and chicken manure in a hot oven to several different temperatures. They were kept in the oven for 1 to 4 hours. After cooling, these biochars were washed in water or left un-washed and inspected both physically and chemically. We found that the materials kept their density unless the oven was very hot (800° Centigrade). In the hotter oven small channels (pores) developed in the chars which increased the active surface area. However, this was not true for all the starting materials. For example, almond shell char did not develop pores even at 800°. If steam was added to the oven above the chars, the active surface area increased in all cases.
Previous studies had shown that mercury could be removed from air using biochars made from chicken and turkey manure. In new studies, we replaced the air with a gas similar to the one seen in exhausts from coal-fired power plants. The un-washed biochars made from chicken manure worked very well and removed almost all the mercury form the gas. Biochars made from turkey manure also worked well if it was washed. Washing adds additional cost to the process. A manuscript was published with the results.
Biochars made at 350° from cotton seed hulls was effective in removing copper, nickel, cadmium, and lead from a water and soil system. Later studies investigated the importance of chemical composition and function of the surface of the biochars; it was noted that the chars made at low temperature contained more oxygen groups, which are known to attract metal contaminants. Biochar made from chicken manure was also effective in removing metals (except nickel) from the same type of system. Experiments with different types of soils and natural organic matter (found in many soils) showed that the natural organic matter prevented some of the metals to adsorb to the chars. Multiple manuscripts were published with the results.
Work with collaborations showed that biochars left from a process to make bio-oils (by very fast heating of powdered biomass) could later be slowly heated in the presence of steam to make biochars that were better (on average) at removing metals, such as copper, nickel, cadmium, and zinc from water, than the starting biochars. Using electron microscopy, we were able to show that pores were made by the steam and this resulted in more surface area per weight of biochar.
Uchimiya, M., Wartelle, L.H., Lima, I.M., Klasson, K.T. 2010. Sorption of deisopropylatrazine on broiler litter biochars. Journal of Agricultural and Food Chemistry. 58(23):12350-12356.
Uchimiya, M., Klasson, K.T., Wartelle, L.H., Lima, I.M. 2011. Influence of soil properties on heavy metal sequestration by biochar amendment: 1. copper sorption isotherms and the release of cations. Chemosphere. 82(10):1431-1437. Uchimiya,M., Gorb, L., Isayev, O., Qasim, M.M., Leszczynski, J. 2010. One-electron standard reduction potentials of nitroaromatic and cyclic nitramine explosives. Environmental Pollution. 158(10):3048-3053.
Uchimiya, M., Klasson, K.T., Wartelle, L.H., Lima, I.M. 2011. Influence of soil properties on heavy metal sequestration by biochar amendment: 2. copper desorption isotherms. Chemosphere. 82(10):1438-1447.
Uchimiya, M., Wartelle, L.H., Klasson, K.T., Fortier, C.A., Lima, I.M. 2011. Influence of pyrolysis temperature on biochar property and function as heavy metal sorbent in soil. Journal of Agricultural and Food Chemistry. 59:2501-2510.
Klasson, K.T., Lima, I.M., Boihem, L.L., Wartelle, L.H. 2010. Feasibility of mercury removal from simulated flue gas by activated chars made from poultry manures. Journal of Environmental Management. 91(12):2466-2470.
Klasson, K.T., Uchimiya, M., Lima, I.M., Boihem, Jr., L.L. 2011. Feasibility of removing furfurals from sugar solutions using activated biochars made from agricultural residues. BioResources. 6(3):3242-3251.
Lima, I.M., Boateng, A.A., Klasson, K.T. 2010. Physicochemical and adsorptive properties of fast-pyrolysis bio-chars and their steam activated counterparts. Journal of Chemical Technology & Biotechnology. 85(11):1515-1521.
Uchimiya, M., Lima, I.M., Klasson, K.T., Wartelle, L.H. 2010. Contaminant Immobilization and Nutrient Release by Biochar Soil Amendment: Roles of Natural Organic Matter. Chemosphere. 80 (8):935-940.
Uchimiya, M., Chang, S., Klasson, K.T. 2011. Screening biochars for heavy metal retention in soil: role of oxygen functional groups. Journal of Hazardous Materials. 190:432-441.
Klasson, K.T., Taylor, P.A. 2006. Remediation of groundwater contaminated with radioactive compounds. On line web access only at www.eolss.net.
Uchimiya, M. 2010. Reductive transformation of 2,4-dinitrotoluene: roles of iron and natural organic matter. Aquatic Geochemistry. 16(4):547-562.