Effects Of Weathered Coal Activated By Ultrasonic On Speciations Of Chromium And Enzyme Activity In Soil

Chromium which has the characteristic of easy-accumulating and hard-removing isof mutation and teratogenicity,as one of four pollution elements of environment. Chromiumnot only endangers the quality of soil, the safety of groundwater, the yield of crops,but alsothreatens human and livestock health. Applying chemical amendments is an effective way tomitigate soil heavy metals pollution. humic acid is a kind of natural macromolecules organicmatter,which has the action of improving soil environment and remedating the soil pollutionof heavymetal. This subject studies the effect of humic acid in weathered coal activated byultrasonic on pakchoi cabbage’s absorbing Chromium and soil enzyme activity,aim to providetheoretical evidence for applying humic acid to toxicity area of chromium. The main resultsand conclusions are as follows:(1)Results and conclusions of study that effect of humic acid in weathered coal activatedby ultrasonic on seciation of Chromium and pakchoi cabbage’s absorbing Chromium:Applying20,40,60,80g/kg weathered coal or weathered coal activated by ultrasonic, thecontent of acid extractable, reducible and oxidizable Chromium decreased, and the propertyof movability of Chromium decreased, at the same time,phytoavailability and bioavailabilitytoxicity of Chromium decreased. The content of Chromium in soil increased andthe Chromium uptake of pakchoi cabbages decreased. When applying60g/kg weathered coalactivated by ultrasonic on seciation, the content of Chromium in soil reaches a maximum andthe Chromium uptake of pakchoi cabbages reached the minimum. With the sameaddition,compared with the weathered coal, weathered coal activated by ultrasonic decreasedthe content of acid extractable, reducible and oxidizable Chromium, increase the residue typeof Chromium, decreased the property of movability, phytoavailability and bioavailabilitytoxicity of Chromium, increased the content of Chromium in soil and decreasedthe Chromium uptake of pakchoi cabbages in deeper degree. (2)Under the action of humic acid in weathered coal activated by ultrasonic, the researchtrials conclusion of Cr’s impact on soil enzyme activity as follows: Adding20,40,60,80g/kgweathered coal which is not activated or activated by ultrasonic, all are able to reduce thebiological toxicity of Cr in soil, and improve the activity of soil enzymes (catalase, urease,dehydrogenase). On the condition that the additive amount of weathered coal activated byultrasonic is60-80g/kg, the activity of soil enzyme (catalase, urease, invertase) in Cr singlecontaminated soil is similar with that in blank group. Under the same additive amount ofweathered coal condition, weathered coal activated by ultrasonic can reduce the biologicaltoxicity of Cr in soil and improve the activity of soil enzymes (catalase, urease,dehydrogenase) in higher degree compared with that is not activated. It shows that incomparison with weathered coal not activated, weathered coal activated by ultrasonic canalleviate the inhibitory effect of heavy metals on soil enzyme activities to more extent, andform more NH4+, which is conducive to the conversion of the carbon in the soil and thegrowth of plants. Therefore, applying60-80g/kg weathered coal activated by ultrasonic,caneffectively reduce the poison of heavy metals Cr single pollution in the soil to pakchoi.