Papers by Author: Ming Xin Wang

Abstract: In demonstration and promotion of treatment works for rural domestic sewage, the technical solutions should consider not only the treatment technology’s effectiveness, but also its economy and suitability for specific rural areas, that is, the advanced and applicable technology should be selected. In this paper, a rural domestic sewage technology evaluation system was established with the analytic hierarchy process as the assessment method to evaluate the alternative technology options and made decision. The indicators quantification and standardization and the weight determination were also promoted. Finally, a case study was conducted. The method can be used as decision support analysis tool in demonstration and promotion of treatment works for rural domestic sewage.

Abstract: Life cycle analysis method was used to establish an inventory of a winter wheat production system that employed the Soil Testing and Formulated Fertilization Program in Linqing county, China, after which the net resource conservation and emission reduction benefits were calculated, evaluated and compared to the winter wheat production system in a conventional fertilization area. The results revealed a great reduction in resource consumption and emissions of the winter wheat production system in the program demonstration area. From 2006 to 2010, the life cycle reduction potentials of eutrophication, and acidification potential per ton of winter wheat accounted for 12.09-30.31% and 1.40-4.52% of the relevant environmental impact potential per capita worldwide in 2000, respectively. The Program significantly decreased the environmental burdens of the winter wheat production system, and farmer’s fertilization behavior tended to become rational.

Abstract: Rice had the largest sown area in China, so its nitrogen intensity had a significant impact on rural environment. The Surface Nitrogen Surplus and Nitrogen Productivity were defined and estimated for China’s rice production systems using statistical data collected from 1998 to 2009 at the national and provincial scale, and the temporal and spatial change of the two indicators was analyzed to evaluate the environmental performance of rice nitrogen management. The results showed that the environmental performance of rice nitrogen management in China was improved stably in the last more than ten years. The Surface Nitrogen Surplus of the indica rice in developed southern provinces is the largest, and was slightly less in the central region. However, the Surface Nitrogen Surplus of the japonica rice was much higher in North China Plain than in other dominated rice production region. The nitrogen intensity and its environmental burdens control should focus on the early and late indica rice production systems in South China and southwestern China, the medium indica rice production systems in Eastern China, and the japonica rice production system in North China.

Abstract: Cadmium (Cd) accumulation and distribution in rice plants were investigated with six rice cultivars under different soil Cd levels. The results showed that Cd accumulations in different organs were in the order: root » stem > leaf > grain. The magnitudes of the differences among rice organs in Cd accumulations were larger for soil Cd treatments than for the control. The magnitudes of the variations among rice cultivars in Cd accumulations were the largest in grains, followed by roots, and the smallest in stems and leaves, and these were also larger for soil Cd treatments than for the control. Cd absorbed by rice plants were mostly accumulated in roots (about 80% for the control and more than 90% for soil Cd treatments), and only a very small portion was transferred into grains (about 2% for the control and less than 1% for soil Cd treatments). The magnitudes of the variations among rice cultivars in Cd distributions were larger for soil Cd treatments than for the control.

Abstract: Based on the input-output life cycle assessment method, the embodied energy consumption, air and water emissions of China's international trade in 2007 were estimated. The results showed that the embodied energy consumption of China's international trade in 2007 is up to 229.04 Mt, accounting for 8.62% of total energy consumption. The embodied Chemical Oxygen Demand, Ammonia Nitrogen, Sulfur Dioxide and Dust emissions caused by net exports accounted for 9.85%, 9.11%, 6.71% and 0.78% of the overall emissions in China, respectively. China’s export promoted energy consumptions and pollutant emissions significantly. Therefore, China should adjust its export strategy and structure to reverse the adverse effects on energy and environment caused by exportation.

Abstract: In order to study the variations among rice cultivars in cadmium (Cd) concentration abilities, pot soil experiments were conducted with six rice cultivars of different types at different soil Cd levels, i.e. 0.12 (the control), 5, 10 mg/kg. The results showed that there were great or obvious variations among the rice cultivars in Cd concentration abilities. But the magnitudes of the variations differed with soil Cd levels and plant organs. Generally, the magnitudes of the variations were larger for soil Cd treatment (5 and 10 mg/kg) than for the control. The magnitudes of the differences among the rice cultivars were higher in grains than in other plant organs. With regard to Cd concentrations in different organs of rice plant, they fell fast from root to grain. Bio-concentration factors (BCF) of Cd in rice plants were in the order: root > stem > leaf > grain. On the differences of soil Cd levels, BCF were in the order: the control > 5 mg/kg soil Cd treatment > 10 mg/kg soil Cd treatment.