To obtain the pyrolysis characteristics and kinetics of preparation process of sludge-based activated carbon by ZnCl2 activation method （i.e.the pyrolysis process of the sludge with ZnCl2 activation）,the characteris...To obtain the pyrolysis characteristics and kinetics of preparation process of sludge-based activated carbon by ZnCl2 activation method （i.e.the pyrolysis process of the sludge with ZnCl2 activation）,the characteristic of mass loss and gas products generated during pyrolysis of the sludge with ZnCl2 activation were analyzed by thermogravimetric analysis coupled with Fourier Transform Infrared Spectroscopy （TG-FTIR）.The kinetic parameters were calculated by the Coats-Redfem method and the mechanism models were established.The role of ZnCl2 in the pyrolysis process of the sludge with ZnCl2 activation was also illustrated through the comparison of the pyrolysis characteristics and kinetics of the sludge with and without ZnCl2 activation.The results showed that the pyrolysis process of the sludge with ZnCl2 activation can be divided into four stages including the dehydration of sludge and initial depolymerization of a small portion of organics matters,the decomposition of large molecular organic matters into small molecular intermediates,the further degradation of intermediates and volatilization of ZnCl2,and the decomposition of inorganic minerals and undecomposed organic matters.CO2,CO,CH4,H2O,some aldehydes and carboxylic acids are the major pyrolysis gaseous products.The activation energies and pre-exponential factors are in the range of 28.84-206.42 kJ/mol and 9885.16-8.08× 1011 min-1,respectively.During the pyrolysis of sludge,ZnC12 not only can function as a dehydration agent and inhibit the formation of tar,but also can peptize the organic matters in the sludge,making them easier to be decomposed.展开更多
This work experimentally examined the optimal proportioning of sludge curing agent for dewatered sludge curing on solidified sludge,two components sludge curing agent consisted of cement and slag,and three components ...This work experimentally examined the optimal proportioning of sludge curing agent for dewatered sludge curing on solidified sludge,two components sludge curing agent consisted of cement and slag,and three components consisted of cement,slag and inorganic salt. The results showed that,increasing of curing ages could increase unconfined compressive strength and reduce moisture content for solidified sludge. For the test of two components,the biggest unconfined compressive strength of the solidified sludge achieved to 543. 72 kPa and the minimum moisture content achieved to 3. 56% of 21 d. The optimum proportion of the sludge curing agent of two components is sludge: cement: slag = 1 ∶ 0. 05 ∶ 0. 2 which selected by Design-expert. It could rapidly increasing the unconfined compressive strength of solidified sludge when added three components sludge curing agent( sludge: cement: slag: MgSO4= 1 ∶ 0. 05 ∶ 0. 2 ∶ 0. 03) on sludge curing. The results showed that,curing ages of 7 d,the unconfined compressive strength could achieve to 126. 74 kPa,which was more than 11 times comparison with the solidified sludge curing by two components curing agent. Two or three components sludge curing agent all could stabilize the heavy metals on solidified sludge and the leaching of heavy metals was below the government standard,while the stability of the heavy metals was superior for three components sludge curing agent.展开更多
Using the method of life cycle assessment (LCA), the paper studies systematically on municipal solid waste incineration and ecological engineering treatment in Guanghan City. The results showed that the environmental...Using the method of life cycle assessment (LCA), the paper studies systematically on municipal solid waste incineration and ecological engineering treatment in Guanghan City. The results showed that the environmental impact potentials of incineration and ecological engineering treatment is 4\^89×10 -2 and 1\^23×10 -2 respectively ; the net energy consumption is -3\^44×10 2 MJ/ton and -2\^90×10 1 MJ/ton, respectively; the net treatment cost is 84.76 RMB Yuan/ton and 32\^52 RMB Yuan/ton, respectively. Comparing with sole incineration, ecological engineering integrates the advantages of incineration and composing, which not only can reduce the amount of waste for incineration and decrease the second environmental pollution, but also can produce high quality compound fertilizer by adding certain amount of chemical fertilizer into compost. It is proved that ecological engineering treatment is an environmental sustainable and economic afforadably method.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.51008106)
文摘To obtain the pyrolysis characteristics and kinetics of preparation process of sludge-based activated carbon by ZnCl2 activation method （i.e.the pyrolysis process of the sludge with ZnCl2 activation）,the characteristic of mass loss and gas products generated during pyrolysis of the sludge with ZnCl2 activation were analyzed by thermogravimetric analysis coupled with Fourier Transform Infrared Spectroscopy （TG-FTIR）.The kinetic parameters were calculated by the Coats-Redfem method and the mechanism models were established.The role of ZnCl2 in the pyrolysis process of the sludge with ZnCl2 activation was also illustrated through the comparison of the pyrolysis characteristics and kinetics of the sludge with and without ZnCl2 activation.The results showed that the pyrolysis process of the sludge with ZnCl2 activation can be divided into four stages including the dehydration of sludge and initial depolymerization of a small portion of organics matters,the decomposition of large molecular organic matters into small molecular intermediates,the further degradation of intermediates and volatilization of ZnCl2,and the decomposition of inorganic minerals and undecomposed organic matters.CO2,CO,CH4,H2O,some aldehydes and carboxylic acids are the major pyrolysis gaseous products.The activation energies and pre-exponential factors are in the range of 28.84-206.42 kJ/mol and 9885.16-8.08× 1011 min-1,respectively.During the pyrolysis of sludge,ZnC12 not only can function as a dehydration agent and inhibit the formation of tar,but also can peptize the organic matters in the sludge,making them easier to be decomposed.
基金Sponsored by the Technology Research Projects of Harbin Science and Technology Bureau(Grant No.2010AA4CS024)the Fundamental Research Funds for the Central Universities(Grant No.HIT.NSRIF.201192)+1 种基金the National Natural Science Key Foundation of China(Grant No.51206036)the State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(Grant No.2013DX04)
文摘This work experimentally examined the optimal proportioning of sludge curing agent for dewatered sludge curing on solidified sludge,two components sludge curing agent consisted of cement and slag,and three components consisted of cement,slag and inorganic salt. The results showed that,increasing of curing ages could increase unconfined compressive strength and reduce moisture content for solidified sludge. For the test of two components,the biggest unconfined compressive strength of the solidified sludge achieved to 543. 72 kPa and the minimum moisture content achieved to 3. 56% of 21 d. The optimum proportion of the sludge curing agent of two components is sludge: cement: slag = 1 ∶ 0. 05 ∶ 0. 2 which selected by Design-expert. It could rapidly increasing the unconfined compressive strength of solidified sludge when added three components sludge curing agent( sludge: cement: slag: MgSO4= 1 ∶ 0. 05 ∶ 0. 2 ∶ 0. 03) on sludge curing. The results showed that,curing ages of 7 d,the unconfined compressive strength could achieve to 126. 74 kPa,which was more than 11 times comparison with the solidified sludge curing by two components curing agent. Two or three components sludge curing agent all could stabilize the heavy metals on solidified sludge and the leaching of heavy metals was below the government standard,while the stability of the heavy metals was superior for three components sludge curing agent.
文摘Using the method of life cycle assessment (LCA), the paper studies systematically on municipal solid waste incineration and ecological engineering treatment in Guanghan City. The results showed that the environmental impact potentials of incineration and ecological engineering treatment is 4\^89×10 -2 and 1\^23×10 -2 respectively ; the net energy consumption is -3\^44×10 2 MJ/ton and -2\^90×10 1 MJ/ton, respectively; the net treatment cost is 84.76 RMB Yuan/ton and 32\^52 RMB Yuan/ton, respectively. Comparing with sole incineration, ecological engineering integrates the advantages of incineration and composing, which not only can reduce the amount of waste for incineration and decrease the second environmental pollution, but also can produce high quality compound fertilizer by adding certain amount of chemical fertilizer into compost. It is proved that ecological engineering treatment is an environmental sustainable and economic afforadably method.
