| As an environmental functional material,biochar can be used in soil improvement,remediation of soil contaminated by heavy metal and organic pollutant.In order to study the effects of biochar on soil fertility,pollutant remediation and soil enzyme activity,the adsorption experiment,soil culture experiment and plant culture experiment were carried out.First,we explored the effects of reed biochar on the remediation of soil contaminated by glyphosate,Cd and As.The effects of reed biochar on soil physical and chemical properties(pH,CEC,organic matter),soil enzyme activity(urease,catalase,FDA hydrolase)and contents of TCLP-Cd and TCLP-As were compared.The adsorption experiment of glyphosate and the residue in soil were also studied.In order to study the effects of nitrogen fertilizer on the restoration of biochar,the changes of physical and chemical properties and content of TCLP-Cd and TCLP-As were also studied.Pot experiment was conducted to evaluate the restoration effect of reed biochar.The main research contents were described as follows:(1)Remediation of contaminated soil by reed biochar.The pH,CEC and organic matter were increased by reed biochar.After cultivating 11 weeks,compared with CK,the pH of soil with high and low pollution levels was increased by 13.29% and 13.26% respectively,the CEC was increased by 7.17% and 7.66% respectively,the organic matter was increased by 3.62% and 6.20% respectively.The soil urease activity,catalase activity,FDA hydrolase activity were increased by reed biochar.After cultivating 11 weeks,compared with CK,the urease activity was increased by 19.99% and 9.37% respectively,the catalase activity was increased by 27.45% and 20.30% respectively,the FDA hydrolase activity was increased by 4.77% and 6.24% respectively.Reed biochar was beneficial to Cd immobilization,but had an activation effect on As.After cultivating 11 weeks,compared with CK,the TCLP-Cd was reduced by 28.57%% and 20.00% respectively,the TCLP-As was increased by 10.98% and 2.89% respectivelyThe adsorption of glyphosate on the soils can correspond to the Freundlich adsorption empirical equation,The maximum adsorption capacity of soil to glyphosate was 2529.772 mg/kg.The adsorption capacity of reed biochar to glyphosate was less than that of soil.The adsorption of glyphosate on soil was reduced by reed biochar to some extent.The glyphosate content of soil with 5% reed biochar was less than that of soil(0% reed biochar).(2)Pot experimentThe output and biomass of greengrocery were increased by reed biochar.Compared with CK,the output and biomass with high pollution level was increased by 381.65% and 336.11% respectively,the output and biomass with low pollution level was increased by 52.94%?55.31% respectively.Biochar can provide nutrients for the growth of greengrocery,and can also change the physical and chemical properties of soil,thus promoted the growth of greengrocery.The transport coefficient of arsenic in all treatment groups were less than 1,and the transport coefficient of cadmium in BC1 and CK1 were less than 1.Compared with CK,the content of cadmium in the upper and underground parts of greengrocery were reduced by the application of reed biochar,but the content of arsenic were increased.(3)The effects of nitrogen fertilizer on the restoration of biocharAfter cultivating 11 weeks,compared with(BC1,BC2),the pH of soil with high and low pollution levels be reduced by 1.97% and 2.12% respectively,the CEC was reduced by 2.08% and 0.08% respectively,the organic matter was reduced by 0.50% and 2.28% respectively.Nitrogen fertilizer increased the content of cadmium in soil and reduced arsenic content in soil.After cultivating 11 weeks,compared with(BC1,BC2),the TCLP-Cd was increased by 2.92% and 3.79% respectively,the TCLP-As was reduced by 2.72% and 0.38% respectively. |
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