Electrical generating facilities produce 100 million tons of ash byproducts such as bottom ash (BA) annually, by coal combustion, that are retained at the power plant sites adding to the cost of managing wastes at the plants. Repeated application of livestock and poultry manure on small parcels of land can contribute to environmental problems such as impaired water quality due to nitrate (NO3 -N) leaching into the groundwater and Phosphorus (P) runoff into surface water bodies. Alternative uses of BA and manure such as soil amendment for landscapes or potting soil need to be explored. Before an alternative is adopted at a large scale, it must be evaluated for its effectiveness and environmental integrity.

In a study conducted to evaluate the utilization of various blends of acidic BA (BA is usually alkaline but batches may be acidic due to high contents of sulfur and iron compounds) alkaline composted dairy manure (CM) as a soil amendment material. Five blends of BA and CM (0:100%), (30:70%), (50:50%), (70:30%) and (100:0%) were packed in 91.4-cm tall and 20.3-cm inside diameter acrylic columns. Two water application methods, a flow through and a constant head water table were used to investigate the leaching of Total Nitrogen (N), P, Potassium (K), NO3-N, ammonium-nitrogen ( NH4-N), total solids (TS) and volatile solids (VS), chemical oxygen demand (COD) as well as trace metals from these blends. It was concluded that higher CM content in the blend resulted in significantly higher leachate concentrations of these chemical and physical constituents. For the constant head water table regime concentrations of all chemicals were significantly lower in standing water as compared to those in the leachate. These findings suggested that further studies of BA and CM blends with lower CM content (5, 10 and 20%) be conducted to evaluate these mixtures as soil amendment material.

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