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  The Fate of Methylcyclohexane Methanol in Soil and Effect on Enzyme Activity

  William Doggett and Frieda Eivazi

  Methylcyclohexane methanol (MCHM) is the chemical that leaked into the Elk River, in Charlestown, West Virginia on the 9th of January, 2014, causing state of emergency called for use of drinking water contaminated with the chemical. Methylcyclohexane methanol is an organic compound classified as a saturated higher alicyclic primary alcohol. It is commonly used in air fresheners and as frothing agent for coal processing and cleaning. The full toxicity of this chemical to humans was unknown at the time of spill and there is still lack of information on exact toxic effects of the crude MCHM. In a recent study it was determined that the MCHM can cause damage to human DNA and potentially cause cancer and reproductive problems. Soils are ultimate recipient of all kinds of contaminates from different sources. There is a need to study and investigate the properties of the MCHM in water and soil especially with the crude MCHM. If released to soil, MCHM is expected to have very high mobility. Volatilization from moist soil surfaces is expected to be an important fate process. To determine toxicity of this chemical on soil biological properties, we measured beta-glucosidase activities in soil treated with different rates and incubated for periods of one hour to 4-weeks. Results indicated that in short term enzyme activity was inhibited by MCHM.

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  Effect of Silver Nanoparticles on Select Soil Enzyme Activities Involved in Nutrient Cycling

  William Doggett, Frieda Eivazi, Zahra Afrasiabi, and L. Jose

  Soils are being continuously exposed to large amounts of engineered nanoparticles (ENPs), especially silver nanoparticles (AgNPs). These materials can interact with microbial enzyme activity, stability and/or specificity affecting their role in nutrient cycling. Specific enzyme activity measurements have potential to serve as bioindicator in identifying major changes in the soil environment. Present study investigated the effect of AgNPs on soil enzymes known to play a critical role in mineralization of C, N, P and S in the soil. Soil samples were collected from surface layer (0-10 cm) of a Wrengart silt loam series. The study used two sizes (10 and 50 nm) and treatment included two rates (1.6 and 3.2 mg Ag/kg of dry soil) of silver nanoparticles and a control without AgNP application in a randomized complete design, replicated three times. The solution of AgNP was applied to the soil and mixed until homogeneously distributed. Acid Phosphatase, β-Glucosaminadase, β-Glucosidase and Arylsulfatase activities were measured after 1-hr, 1-week, and 1- month of incubation time. All four enzymes showed a decrease in activity after treatment with silver nanoparticles at 1-hr and 1-week incubation period compared to control. In this study there was some difference, though not highly significant, in the effect on enzyme activity between the two sizes used (10nm and 50nm).