Combustion of herb residues(HRs)for heat recovery is a good way for their utilization,but there exists such a problem as high concentration NOx emission in flue gas.The alcohol extracted herb residue(AEHR),one special...Combustion of herb residues(HRs)for heat recovery is a good way for their utilization,but there exists such a problem as high concentration NOx emission in flue gas.The alcohol extracted herb residue(AEHR),one special type of HRs,was chosen as the object and was subjected to immediate combustion in a fluidized bed reactor to investigate the characteristics of its resulting NOx emission.The results showed that,most of the NOx in the flue gas was produced from the char nitrogen(C-N);as the fuel water content increased,the NOx emission concentration exhibited a trend of first decreasing and then increasing;and a properly low combustion temperature inhibited the NOx emission upon the premise of ensuring full combustion.Air staging combustion was adopted to effectively control NOx:the NOx emission concentration in the flue gas was reduced to 296 mg⋅m3 and the NOx emission reduction rate reached 46.51%compared to conventional combustion.Co-combustion by blending wasted activated coke(WAC)into the AEHR helped both stabilize the combustion state and reduce further the NOx emission.When the blending ratio of WAC fell within a proper range of 20-30%,the NOx emission concentration in the flue gas was as low as 231.4 mg⋅m3.In addition to the dilution effect of the combustion flue gas of the blended WAC,the local reducing atmosphere caused by its incomplete combustion as well as its strong absorbability and catalytical effect was accountable for the further decrease of the NOx emission concentration.展开更多
Herb residue vermicompost is thought to have high agriculture value,while its effects on soil microbial activities have not been fully understood.Here,soil microbial biomass,respiration and enzyme activities in soil p...Herb residue vermicompost is thought to have high agriculture value,while its effects on soil microbial activities have not been fully understood.Here,soil microbial biomass,respiration and enzyme activities in soil planted with maize were compared among treatments amended with herb residue vermicompost at rates of 25,50,75 and 100 g kg^(-1),chemical NPK fertilizer and no fertilizer(the control).Our results showed that soil microbial biomass carbon,respiration,and alkaline phosphatase,urease,and invertase activities were greater in soil amended with herb residue vermicompost than the unfertilized control(P<0.05).Compared with chemical fertilizer,herb residue vermicompost increased soil urease and alkaline phosphatase activities at each application rate,promoted soil respiration and microbial biomass carbon at the application rates of 50,75 and 100 g kg^(-1),and increased soil inverse activity at the application rates of 75 and 100 g kg^(-1).In conclusion,herb residue vermicompost supported greater soil microbial biomass,respiration and enzyme activities than conventional NPK fertilizer,and the effect was larger when higher rates of herb residue vermicompost were added.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2019YFC1906805).
文摘Combustion of herb residues(HRs)for heat recovery is a good way for their utilization,but there exists such a problem as high concentration NOx emission in flue gas.The alcohol extracted herb residue(AEHR),one special type of HRs,was chosen as the object and was subjected to immediate combustion in a fluidized bed reactor to investigate the characteristics of its resulting NOx emission.The results showed that,most of the NOx in the flue gas was produced from the char nitrogen(C-N);as the fuel water content increased,the NOx emission concentration exhibited a trend of first decreasing and then increasing;and a properly low combustion temperature inhibited the NOx emission upon the premise of ensuring full combustion.Air staging combustion was adopted to effectively control NOx:the NOx emission concentration in the flue gas was reduced to 296 mg⋅m3 and the NOx emission reduction rate reached 46.51%compared to conventional combustion.Co-combustion by blending wasted activated coke(WAC)into the AEHR helped both stabilize the combustion state and reduce further the NOx emission.When the blending ratio of WAC fell within a proper range of 20-30%,the NOx emission concentration in the flue gas was as low as 231.4 mg⋅m3.In addition to the dilution effect of the combustion flue gas of the blended WAC,the local reducing atmosphere caused by its incomplete combustion as well as its strong absorbability and catalytical effect was accountable for the further decrease of the NOx emission concentration.
基金was supported by the Natural Science Foundation of Shandong Province,China(ZR201801300002,ZR2016DM17,ZR2018ZB0523ZR2019PD004)+2 种基金the Natural Science Foundation of China(31700447 and 41201305)Science and Technology Fundamental Resources Investigation Program of China(2018FY100300)National Key Research and Development Program of China(2016YFD0201301 and 2016YFD0201200).
文摘Herb residue vermicompost is thought to have high agriculture value,while its effects on soil microbial activities have not been fully understood.Here,soil microbial biomass,respiration and enzyme activities in soil planted with maize were compared among treatments amended with herb residue vermicompost at rates of 25,50,75 and 100 g kg^(-1),chemical NPK fertilizer and no fertilizer(the control).Our results showed that soil microbial biomass carbon,respiration,and alkaline phosphatase,urease,and invertase activities were greater in soil amended with herb residue vermicompost than the unfertilized control(P<0.05).Compared with chemical fertilizer,herb residue vermicompost increased soil urease and alkaline phosphatase activities at each application rate,promoted soil respiration and microbial biomass carbon at the application rates of 50,75 and 100 g kg^(-1),and increased soil inverse activity at the application rates of 75 and 100 g kg^(-1).In conclusion,herb residue vermicompost supported greater soil microbial biomass,respiration and enzyme activities than conventional NPK fertilizer,and the effect was larger when higher rates of herb residue vermicompost were added.