[Integrating technologies for urban communities' municipal solid waste minimization].

Municipal solid waste management of urban communities has difficulties of insufficient source separation and food waste's high moisture content, an integrating technology of manual separation, simple compression of food waste, reclaim of food waste and composting leachate was studied. Manual separating rate was 36.8 kg/h, and would increase when the worker became sophisticated. Community separated food waste had high organic matter content of 44.493%, nutrients N, P, K contents of 2.586%, 0.649% and 1.274%, C/N ratio of 17.427, but 0.07-0.82 times lower heavy metals contents compared to centralized separation of mixed municipal solid waste. Moisture content of food waste was still 78.7%, high enough to have negative impacts of composting processes. Composting leachate processing with biological stabilization and dilution showed a fertilizer efficiency, and dry weight of impatiens irrigated with composting leachate was 1.46-2.49 times of tap water irrigation. Integrating technology based on community's manual separation could decrease 52.6% municipal solid waste.

[Bad tourist behaviors and their environmental impacts on Xixi National Wetland Park in Hangzhou].

By the methods of site investigation, data collection and correlation analysis, the bad tourist behaviors and their environmental impacts on Xixi National Wetland Park in 2006 were studied. The occurrence probabilities of three bad tourist behaviors, i.e., picking, trampling, and littering were 6.5%, 10.3% and 12.6%, respectively. Picking probability was primarily related to the vegetation types along walkways, while the scale of heavy trampling was negatively correlated with tour distance from the entrance. Waste production by each tourist was 782 g x d(-1) on average. The waste from littering amounted for 13.6% of the total. Tourist flow fluctuations of daily, weekly, and monthly perspectives for the study area showed high seasonality and successive days of overloaded tourist flows during peak seasons, which caused an increase of bad tourist behaviors. However, the water quality in the Park was not affected because of the improvement of dredging facilities.

[Adaptive optimized technologies for ecological sanitation and their complex ecological benefits].

Aiming at the ecological characters of the cities in central and west China, several ecological sanitary (ecosan) technologies with different adaptability were integrated, and five adaptive optimized technologies were established. The environmental effects, resources recyclable potential, economic benefits, management difficulties, and public acceptance of each of the technologies were studied, with the possible complex eco-benefits of the technical improvement assessed. The results showed that decentralized ecosan technologies had the advantages of conserving water, recycling nutrients and saving cost, but also had the problems in management and public acceptance. Centralized ecosan technologies had the advantages in management and public acceptance, but were short in high cost and low recycling potential. If the sanitary system was improved through applying ecosan technologies, the greenhouse gases emission (CO2 equivalent) and water pollution (calculated as BOD5) could be reduced by 70% and 30%, respectively, while recycled nutrients (the sum of N, P, K) could be increased by 15 times. The optimized system could supply 3% of domestic energy, 10% of domestic water, and 15% of food demand, and the total cost could be reduced by 56% when the resource-recycling benefits were taken into account.

[Evaluation method and index system of eco-city development: a case study in Dafeng City of Jiangsu Province, China].

City is a kind of social-economic-natural complex ecosystem. How to realize the urban sustainable development is one of the important issues in the world. Eco-city is one of the ideal patterns for urban sustainable development, while the evaluation method and related indices of eco-city development are the main basis in measuring the effect of urban ecological planning, construction, and management. Taking the Dafeng City of Jiangsu Province as a case, the eco-city index system consisting of 58 indices of 4 categories including economic development, ecological construction, environment protection and social progress was established, and the construction effect was evaluated at different urban development phases by using Full Permutation Polygon Synthesis Illustration method. The results indicated that in 2004, the comprehensive index of Dafeng eco-city was 0.24, and the sustainable development ability was belonged to class IV, i.e., be worse, but in 2010, 2015 and 2020, it would reach to 0.45, 0.66 and 0.85, and the sustainable development ability would belong to class III, II and I, i.e., be moderate, better and excellent, respectively. This research could be a reference for decision-making of eco-city development.

[Application of inverse distance weighted interpolation method in contaminated site assessment].

There are many difficulties in ascertaining the area that needs to be remedied in contaminated site. This paper integrated the experts' judgments with grids as the sampling strategy in an abandoned pesticide plant in northern China, and applied a geostatistical method, inverse distance weighted interpolation (IDW), to simulate the pollutants- and risk spatial distribution. Based on soil environmental benchmark, two scenarios were designed for ascertaining the polluted area. The results showed that the area needed to be remedied and determined by IDW was somewhat larger, according to the national environmental 2nd standard for agricultural soils, but the area and cost needed for remedy were smaller and more economic and reasonable, based on the health risk threshold level and IDW method. A combination of IDW and health risk assessment in ascertaining polluted area would be a new way for site assessment and soil remediation in the future.

[Niche assessment of China provincial social-economic-natural complex ecosystems in 2003].

Using the approaches of evaluating sustainable development and livable cities for references, a set of indicator systems were established to assess the ecological niche of complex ecosystem. The integrated ecological niche of complex ecosystem included 4 sub-niches of natural resources, environment, economy and society, and these sub-niches comprised many single-item indicators. How to apply the polygon synthesis indicators approach to calculate the integrated ecological niche and 4 sub-niches was introduced, and a quantitative assessment on the ecological niches of complex ecosystems in 31 provinces, autonomous regions, and municipalities directly under Central Government of China in 2003 was made. The results showed that Yunnan, Hainan and Guangxi had a higher sub-niche of natural resources, Hainan, Fujian and Hubei had a higher sub-niche of environment, Shanghai, Beijing and Zhejiang had a higher sub-niche of economy, and Shanghai, Beijing and Tianjin had a higher sub-niche of society. The integrated ecological niche in Guangdong, Fujian and Hainan was the highest.

[Ecological risk assessment and its research progress].

Ecological risk is a hotspot in the present environmental management study, which mainly focuses on the chemical, physical, and biological stressors that may damage ecosystem or its components. Ecological risk assessment (ERA) has a great significance for making scientific environmental management strategies. In order to lessen the damage of ecosystem or its parts, and to manage the ecosystem effectively, it is necessary to predict the probability the adverse ecological effects would occur and the consequences. This paper summarized the research methods, tools and trends of ERA, and pointed out the areas that need to be further studied. It was suggested that under the background of urbanization, urban ecological risk should be given more attentions. The prospects of further study were discussed, based on the issues existed in current researches.

Variation of soil fertility and carbon sequestration by planting Hevea brasiliensis in Hainan Island, China.

The development of rubber industry depends on the sustainable management of rubber plantation. To evaluate the environmental effects of planting Hevea brasiliensis on a subsystem of tropical forest ecosystem, the variation of soil fertility and carbon sequestration under rubber plantation within 30-year life period were investigated in Hainan Island. Results showed that (1) with the increase of stand age of rubber plantation, soil fertility decreased all along. From 1954 to 1995, soil organic matter, total N, available K and available P decreased by 48.2%, 54.1%, 56.7% and 64.1%, respectively. (2) If the complete return of litters was considered without additional fertilizer application to the soil of the rubber plantations, the consumption periods for P, N, K, Mg were only 825 years, 329 years, 94 years and 65 years, respectively. To improve soil fertility is essential for rubber plantation development. (3) The C sequestration of rubber trees per hectare accounts for 272.08 t within 30-year life period and 57.91% of them was fixed in litters. In comparison with C sequestration by rain forest (234.305 t/hm2) and by secondary rain forest (150.203 t/hm2), rubber forest has more potentials for C fixation. On the base of above results, the following measures would benefit the maintenance of soil fertility and the development of rubber industry, including applying fertilizer to maintain the balance of soil nutrients, intercropping leguminous plant to improve soil fertility, reducing the collection of litters, optimizing soil properties to improve element P availability such as applying CaCO3. The information gathered from the study can be used as baseline data for the sustainable management of rubber plantation elsewhere.

[Ecological service assessment of human-dominated freshwater ecosystem with a case study in Yangzhou Prefecture, China.

Freshwater ecosystems provide a host of services to humanity. These services are now rapidly being lost, not least because of the inability of making the impacts measurable. To overcome this obstacle, assessment frameworks for freshwater ecosystem services are needed. A simple water equivalent framework to assess the ecological services provided by freshwater ecosystems was developed in this study. It translated the occupation of freshwater ecosystem services into biologically freshwater volumes and then compares this consumption to the freshwater throughput, that is, the ecological capacity available in this region. In this way, we use the example of Yangzhou Prefecture, to account the main categories of human occupation of water ecosystem services. The result showed that there is a huge gap between the consumption and the supply of freshwater ecosystem services. This must encourage local government to make land-use and water management decisions both economically rational and environmentally sound.

Scenario simulation of water security in China.

Limited water resources, increasing demand, low use efficiency, and serious pollution result in severe water resource difficult in China. The evaluation of addressing water problems and the search for effective countermeasures that ensure sustainable water use are key to China's sustainable development. The "compound water security" consists of food security, life security, environmental security, and economic security. By establishing a conceptual model, the water security of China has been simulated in terms of four scenarios called BAU (the business-as-usual scenario), TEC (the technology and economics scenario), IVL (the institution, values, and lifestyles scenario) and TSD(toward sustainable development) in this paper. The results indicated that water crises, especially water shortages, are being experienced now and will continue to do so for a relatively long time in China and that it is possible to reach a basic balance between supply and demand of water and grain under the TSD developing pattern by a series of approaches including technological innovation, policy adjustments, and behaviour inducement.

Life cycle assessment of mobile phone housing.

The life cycle assessment of the mobile phone housing in Motorola(China) Electronics Ltd. was carried out, in which materials flows and environmental emissions based on a basic production scheme were analyzed and assessed. In the manufacturing stage, such primary processes as polycarbonate molding and surface painting are included, whereas different surface finishing technologies like normal painting, electroplate, IMD and VDM etc. were assessed. The results showed that housing decoration plays a significant role within the housing life cycle. The most significant environmental impact from housing production is the photochemical ozone formation potential. Environmental impacts of different decoration techniques varied widely, for example, the electroplating technique is more environmentally friendly than VDM. VDM consumes much more energy and raw material. In addition, the results of two alternative scenarios of dematerialization showed that material flow analysis and assessment is very important and valuable in selecting an environmentally friendly process.

Hydrological eco-service of rubber plantations in Hainan Island and its effect on local economic development.

The impacts of economic forest on global environmental change (GEC) are one of the hot issues in environmental study. Based on the 3-year observation data and 40-year climate data, GEC and analysis of the hydrological dynamic characteristics of rubber plantations and estimate of the water balance in the rubber plantations in Hainan Island were made. The results showed that the rainfall intercepted by the canopy of the plantations accounted for 11.45% of the annual rainfall, the total runoff for 23.71%, the total evaporation and transpiration for 63.24%, the soil moisture storage for 1.6%. Analysis of the 40-year rainfall data in the 19 counties of Hainan Island during 1951-1990 showed that the large-scale substitution of the natural vegetation with the rubber plantations had no significant effect on the local rainfall in Hainan Island. The main reasons are (1) 80% of the rainfall in Hainan is brought by typhoons; (2) the proportion of 11.6% rubber plantations in total forest coverage in Hainan is not enough to influence the local rainfall in Hainan Island; and (3) although the rubber plantation is artificial vegetation, it has the similar function to the tropical rain forest. Analysis of the total water resource and total GDP of Hainan in 1997 showed that the economic benefit resulted from the water resource was 1.0 RMB Yuan/m3. The value of hydrological of the rubber plantation in Hainan was 113.9 million RMB Yuan/3 when compared with the tropical rain forest. The paper reaches conclusion that the hydrological eco-service function of rubber plantation has been enhanced after transformed from natural vegetation, which includes the natural service and powerful social service.

Effects of red-yellow soil acidification on seed germination of Chinese pine.

Acid treatments significantly change the physical and chemical properties of red-yellow soil by lowering its pH value and leaching out aluminum(Al) ions that are harmful to the growth of plants. The structure of soil will be damaged, resulting in higher viscosity, higher water retention rate and lower air permeability of the soil. The germination rate of Chinese pine(Pinus tobulacformic Carr.) seeds sowed in soil treated with sulphuric acid(H2SO4) decreased compared to that for untreated soil. The direct cause was the large amount of Al ions leached out because of low pH values(> or = 3.5). The added acid decreased the soil aggregation and increased the number of micro-aggregates(under 250 microns in diameter). Such changes increased the soil's viscosity, which tied the pine needles to the soil after the seeds had germinated and prevented the seedlings from fully developing.