Biodiesel, an environmentally friendly biofuel with similar flow and combustion properties as petroleum-based diesel and low emission profile, which is commonly prepared from triglyceride （TG） sources such as vegeta...Biodiesel, an environmentally friendly biofuel with similar flow and combustion properties as petroleum-based diesel and low emission profile, which is commonly prepared from triglyceride （TG） sources such as vegetable oils, animal fats, and waste greases, holds good promises as an alternative to diesel fuel. Alternate fuels for diesel engines have become increasingly important due to diminishing petroleum reserves and awareness of the increased environmental consequences of emissions from petroleum-fuelled engines, as the world is confronted with an energy crisis. Currently, the production of methyl or ethyl esters from edible oils is much more expensive than that of diesel fuels due to the relatively high costs of vegetable oils （about four times the cost of diesel in China）. Methyl esters produced from such oils can be expected to compete economically with diesel fuels, and there is a need to explore low cost alternate feedstocks for the production of biodiesel. Rapeseed is little sensitive to crop input levels, allowing reduction of tillage, irrigation, and weed control. Significant yield increases will be attained using new hybrids and better crop management. Rapeseed cultures in seasonal set-aside lands such as Dongting Lake surroundings can significantly decreases the amount of subsides spent for agricultural overproduction in China, which leads to an increase in farmer incomes as well as the creation of new employment. This significantly lowers production costs, reduces environmental impact, and increases final energy gains. Our rapeseed oil is good source for biodiesel with respect to high oil content and proper fatty acid composition.展开更多
[Objective] This study aimed to provide the basis for scientific and rea- sonable application of nitrogen fertilizer and control Of agricultural non-point source pollution in vegetable-growing area at Chaihe catchment...[Objective] This study aimed to provide the basis for scientific and rea- sonable application of nitrogen fertilizer and control Of agricultural non-point source pollution in vegetable-growing area at Chaihe catchment of Dianchi Lake. [Method] A pot experiment was carried out to compare the loss of nitrogen via ammonia volatilization and nitrogen leaching after application of biochar coated urea （BCU） and common urea （Urea） with different nitrogen rates （0 mg N/kg soil, 400 mg N/kg soil, 320 mg N/kg soil and 280 mg N/kg soil）. [Result] The results indicated that the amount of nitrogen loss was proportional to nitrogen applied rate. Leaching nitrogen was higher than ammonia volatilization. Compare with Urea treatments, ammonia volatilization and nitrogen leaching losses were significantly lower in BCU treatments at the same nitrogen application rate. At the nitrogen application rate of 320 and 280 mg N/kg soil, nitrogen loss, ammonia volatilization and leaching nitrogen was 43.5%-45.5%, 3.7%-21.7% and 49.8%-52.1% lower in BCU treatments than in Ure- a treatments, respectively. [Conclusion] The application of BCU could minimize nitro- gen loss by reducing nitrate leaching loss. It can be concluded that the low nitrogen application rate combined with BCU have a practical influence on controlling the risk of nitrogen pollution in Dianchi Lake.展开更多
文摘Biodiesel, an environmentally friendly biofuel with similar flow and combustion properties as petroleum-based diesel and low emission profile, which is commonly prepared from triglyceride （TG） sources such as vegetable oils, animal fats, and waste greases, holds good promises as an alternative to diesel fuel. Alternate fuels for diesel engines have become increasingly important due to diminishing petroleum reserves and awareness of the increased environmental consequences of emissions from petroleum-fuelled engines, as the world is confronted with an energy crisis. Currently, the production of methyl or ethyl esters from edible oils is much more expensive than that of diesel fuels due to the relatively high costs of vegetable oils （about four times the cost of diesel in China）. Methyl esters produced from such oils can be expected to compete economically with diesel fuels, and there is a need to explore low cost alternate feedstocks for the production of biodiesel. Rapeseed is little sensitive to crop input levels, allowing reduction of tillage, irrigation, and weed control. Significant yield increases will be attained using new hybrids and better crop management. Rapeseed cultures in seasonal set-aside lands such as Dongting Lake surroundings can significantly decreases the amount of subsides spent for agricultural overproduction in China, which leads to an increase in farmer incomes as well as the creation of new employment. This significantly lowers production costs, reduces environmental impact, and increases final energy gains. Our rapeseed oil is good source for biodiesel with respect to high oil content and proper fatty acid composition.
基金Supported by Major Science and Technology Program for Water Pollution Control and Treatment of China(2012ZX07102-003)~~
文摘[Objective] This study aimed to provide the basis for scientific and rea- sonable application of nitrogen fertilizer and control Of agricultural non-point source pollution in vegetable-growing area at Chaihe catchment of Dianchi Lake. [Method] A pot experiment was carried out to compare the loss of nitrogen via ammonia volatilization and nitrogen leaching after application of biochar coated urea （BCU） and common urea （Urea） with different nitrogen rates （0 mg N/kg soil, 400 mg N/kg soil, 320 mg N/kg soil and 280 mg N/kg soil）. [Result] The results indicated that the amount of nitrogen loss was proportional to nitrogen applied rate. Leaching nitrogen was higher than ammonia volatilization. Compare with Urea treatments, ammonia volatilization and nitrogen leaching losses were significantly lower in BCU treatments at the same nitrogen application rate. At the nitrogen application rate of 320 and 280 mg N/kg soil, nitrogen loss, ammonia volatilization and leaching nitrogen was 43.5%-45.5%, 3.7%-21.7% and 49.8%-52.1% lower in BCU treatments than in Ure- a treatments, respectively. [Conclusion] The application of BCU could minimize nitro- gen loss by reducing nitrate leaching loss. It can be concluded that the low nitrogen application rate combined with BCU have a practical influence on controlling the risk of nitrogen pollution in Dianchi Lake.
