Bioventing is conducted on one-dimensional soil columns. A numerical model is developed for simulating the mass exchange, advective and dispersive transport and biodegradation of toluene. The model parameters are esti...Bioventing is conducted on one-dimensional soil columns. A numerical model is developed for simulating the mass exchange, advective and dispersive transport and biodegradation of toluene. The model parameters are estimated independently through laboratory batch experiments, or from literature. Simulations are found to provide reasonable agreement with experimental data. Experimental results show that toluene removal due to biodegradation is more important at the later stage. The total cleanup time when NAPL (non-aqueous phase liquid) phase exists was twice more than that without NAPL. Sensitivity analysis of parameters suggests that model predictions are mainly dependent on mass transfer coefficient and microbial parameters, such as the half-saturation coefficient and maximum specific substrate utilization rate.展开更多
Plastic wastes from milk containers, soft drink bottles, plastic wraps, plastic flatware, etc. have been successfully converted into fuel. Two approaches for the conversion of waste post consumer plastic into fuel hav...Plastic wastes from milk containers, soft drink bottles, plastic wraps, plastic flatware, etc. have been successfully converted into fuel. Two approaches for the conversion of waste post consumer plastic into fuel have been investigated： （1） muffle furnace to reactor liquefaction system; （2） direct liquefaction system. Majority of used plastics are derived from ethylene, propylene, butadiene and benzene. Waste plastics are plastics that are used by the people in their daily life. It is collected from outside and city municipalities. Some of them are coded and rests are non-coded. A developed process discussed in this paper works with most of the waste plastic, both coded and non-coded. The plastics are heated up at 120-380 ℃ temperature to melt. The gaseous vapor is then condensed into liquid fuel.展开更多
The copper consumption by the Chinese cable industry amounted to 354×104 t in 2006, taking over 70 % of the total copper consumption in China in that year. At present, making copper rod directly from recovered sc...The copper consumption by the Chinese cable industry amounted to 354×104 t in 2006, taking over 70 % of the total copper consumption in China in that year. At present, making copper rod directly from recovered scrap copper and saving copper with aluminum have become topics of general interests in the Chinese cable industry. The quality of the copper conductors in the industry is declining, resulting in sharp decrease in the rate of qualified wire and cable products. More and more copper wires are drawn from the rods made directly from scrap copper. The manufacturers know well some of the wires or rods are unqualified products though, they continue to use or produce products not complying with standards in order to make profits. Now the consumption of copper-clad-aluminum and copper-clad-steel is growing gradually. In 2006, the consumption of copper-clad-aluminum in China amounted to ca. 5×104 t. But in some applications, neither the common understanding between buyer and supplier nor the results of feasibility study are achieved in the product orientation and technical/economic feasibility in terms of saving copper with aluminum. This paper presents the status-quo, problems arisen and suggestions in terms of making copper rod directly from recovered scrap copper and saving copper with aluminum, in a view to promote these two topics of general interests to go toward a virtuous circle.展开更多
基金the National Natural Science Foundation of China (No. 20276048).
文摘Bioventing is conducted on one-dimensional soil columns. A numerical model is developed for simulating the mass exchange, advective and dispersive transport and biodegradation of toluene. The model parameters are estimated independently through laboratory batch experiments, or from literature. Simulations are found to provide reasonable agreement with experimental data. Experimental results show that toluene removal due to biodegradation is more important at the later stage. The total cleanup time when NAPL (non-aqueous phase liquid) phase exists was twice more than that without NAPL. Sensitivity analysis of parameters suggests that model predictions are mainly dependent on mass transfer coefficient and microbial parameters, such as the half-saturation coefficient and maximum specific substrate utilization rate.
文摘Plastic wastes from milk containers, soft drink bottles, plastic wraps, plastic flatware, etc. have been successfully converted into fuel. Two approaches for the conversion of waste post consumer plastic into fuel have been investigated： （1） muffle furnace to reactor liquefaction system; （2） direct liquefaction system. Majority of used plastics are derived from ethylene, propylene, butadiene and benzene. Waste plastics are plastics that are used by the people in their daily life. It is collected from outside and city municipalities. Some of them are coded and rests are non-coded. A developed process discussed in this paper works with most of the waste plastic, both coded and non-coded. The plastics are heated up at 120-380 ℃ temperature to melt. The gaseous vapor is then condensed into liquid fuel.
文摘The copper consumption by the Chinese cable industry amounted to 354×104 t in 2006, taking over 70 % of the total copper consumption in China in that year. At present, making copper rod directly from recovered scrap copper and saving copper with aluminum have become topics of general interests in the Chinese cable industry. The quality of the copper conductors in the industry is declining, resulting in sharp decrease in the rate of qualified wire and cable products. More and more copper wires are drawn from the rods made directly from scrap copper. The manufacturers know well some of the wires or rods are unqualified products though, they continue to use or produce products not complying with standards in order to make profits. Now the consumption of copper-clad-aluminum and copper-clad-steel is growing gradually. In 2006, the consumption of copper-clad-aluminum in China amounted to ca. 5×104 t. But in some applications, neither the common understanding between buyer and supplier nor the results of feasibility study are achieved in the product orientation and technical/economic feasibility in terms of saving copper with aluminum. This paper presents the status-quo, problems arisen and suggestions in terms of making copper rod directly from recovered scrap copper and saving copper with aluminum, in a view to promote these two topics of general interests to go toward a virtuous circle.
