Effect of fly ash on growth of mustard and corn.

摘要

Fly ash is generated as a by-product of coal combustion and contains many nutrients, such as Ca, K, Na, Mg, and S, as well as toxic metals such as As, B, Cd, Cr, Hg, and Pb. For this project, the goal is to optimize a phytoremediation technique to stabilize the toxic metals and produce biomass which could have benefit for example as biofuel. The hypothesis was that different amendments would improve the water holding properties of the ash and reduce metals availability and toxicity. Flyash was combined with leaf mulch (1%, 3%, 5%, 10%, 20%), wood mulch (1%, 3%, 5%, 10%, 20%), and soil (1%, 5%, 25%, 75%, 90%) in varying concentrations and distributed into 9 "cone-tainers" for each mixture. Water holding capacity was determined for each amendment and the leachates from the cone-tainers were then analyzed to determine pH, EC (electrical conductivity), and TDS (total dissolved solids) for the different mixtures. Zea mays, Brassica juncea, and poplar were planted and germination times were recorded. Plants were harvested at 7 weeks for Brassica juncea and 8 weeks for Zea mays and biomass and height were recorded. For Brassica juncea and Zea mays, plants grew best in soil amendments. For Brassica, leaf mulch appeared to have a negative effect on growth. Further analysis of metal content using ICP-MS is planned.