Applied Mechanics and Materials Vols. 409-410

Abstract: The study of the development of ecosystem is a very important problem in ecology. With the development of ecology, the study of ecosystem is gradually from description of natural phenomena to the understanding of mechanism of ecosystem development. Thermodynamics is full of highly scientific and universal theory, and thereby thermodynamic theories can provide the foundations for understanding ecosystem development rule. In this paper, we review the application and development of thermodynamic theories for the development of ecosystem. The limitations and future developments of these theories are also addressed.

Abstract: City-river ecological governance was the most important and difficult point of river engineering. Engineering design should be considered on the basis of local conditions and followed the principles of ecological engineering. This paper presented some new ideas of city-river ecological treatment. Then, a comparison was made among different treatment process of wetland ecosystems. Through the study of relevant technique, we expected to provide technical support and references for city-river ecological engineering.

Abstract: To treat the waste seawater from shrimp farms, TiO₂ powder photocatalysis and ceramic membrane filtration technologies were integrated to form a photocatalytic membrane reactor (PMR). PMR performance was investigated and real waste water sample was treated under the optimum operation conditions. Results indicated that TiO₂ powder with mean particle size of 0.27 μm could be separated successfully with α-Al₂O₃ membrane with pore size of 0.05 μm, the permeation flux was 432 Lhr^-1m^-2 under pressure of 0.05 MPa. Wastewater was treated with three different catalysts involving 2 g of TiO₂ powder, 2 g of TiO₂ powder combined with 5 ml of H₂O₂ (30%), and 2 g of TiO₂ powder combined with 5 ml of Fenton agent for per liter of wastewater, the corresponding COD_Cr removal rates were 15.67 %, 25.19 % and 40.67 % separately.

Abstract: With the rapid economic development, energy and environmental issues of the energy and chemical industry base in northern shaanxi have become increasingly prominent. As an important power, market forces are bringing into play a more and more important role in environmental protection. Under this background, this paper attempts to explore operational model of pollution control of middle-and-small-sized enterprises (MSEs) in the energy and chemical industry base in northern shaanxi. Environmental protect was brought into the operation process of the market mechanism, government's environmental management cost has been greatly reduced.

Abstract: According to many uncertain problems of river eutrophication, a Bayesian hierarchical model was established to predict water quality. We applied the hierarchical method to assess river water quality in an agricultural watershed in eastern China. The procedure followed was developing a hierarchical model relating eutrophication response - the level of chlorophyll (Chla). Through Principal Component Analysis (PCA), five factors strong related with Chla were selected to establish Bayesian hierarchical model to predict the water quality. Results showed that Bayesian hierarchical model was very realistic. Furthermore, in Bayesian perspective, predictions expressed as probabilities, rather than a single value, involving more uncertainty information, can be essential to environmental management and decision-making.

Abstract: Acid mine drainages treatment technology is a hot issue in the mining industry. It summarizes the causes, the reaction mechanism and impact on the environment of acid mine drainage, and introduces the monitoring indicators of acid mine drainage. Further it focuses on the acid mine drainages terminal treatment technologies that including neutralization, sulfide precipitation, microbiological method, constructed wetlands, membrane method and the iron-carbon micro electrolysis, with the analysis of its theories, advantages, disadvantages and practical application. Meanwhile it introduces the major source control technologies, and further proposes the development tendency that is from terminal treatment technology to the combination of source control and terminal treatment technology. And its a focus and hotspot in the research of the acid mine drainage in China's future.

Abstract: The study aims to find a new and effective way to treat petroleum city's contaminated land, and promote the sustainable development of resource-based cities. Qianjiang City combined petroleum-contaminated land remediation with National Mine Park construction, took three modes to treat different degrees of contaminated soils in the Mine Park. Finding out that the petroleum-contaminated treatment site can become Mine Park popular science education base, while Mine Park construction could provide scientific research places and more funds for treatment project. It is conducive to resource-exhausted city to achieve Economic Transition. Combining petroleum-contaminated land treatment and Mine Park construction is a new practical and effective treatment model to restore the ecological environment in petroleum city.

Abstract: Luziping phosphate mining area is the representative of phosphate mining field in Western Hubei. On the base of stern the status of mine eco-environment status in Luziping phosphate mining area, this paper put forward governance measure to recover land to holt and arable land. The research will point out directions and measure for reclamation of other similar areas.

Abstract: To discussion acid inhibition of municipal solid waste in the process of the anaerobic digestion, four biodegradable single substrates of soybean, fat meat, rice and celery cane were considered in this paper. A series of anaerobic co-digestion tests were performed on the four substrates at the load of 1.0 gVS/(Ld) and anaerobic activated sludge. The results show that the acid inhibition was occurred at the load of 1.0 gVS/(Ld) for the soybean and rice; the corresponding pH values at the lowest acidification points were 5.03 and 3.73, respectively. There was no acid inhibition during the whole digestion period for the celery cane at the tested loads.

Abstract: The biological hydrogen production by the sugar wastewater is an effective way to achieve the reclamation. In this paper, the effect of substrate concentration on the hydrogen production is discussed through employing the self-made continuous flow anaerobic fermentation hydrogen production reactor, taking the sludge in urban sewage treatment plant as the inoculated sludge and the simulated sugar wastewater as the substrate. The experimental results show that the best hydrogen production effect can be obtained when the temperature is (37±1) °C, HRT is 7h, the water alkalinity is around 530mg/L and the substrate concentration is 5000mg/L, namely the organic load is 60kgCOD/(m3·d). The volumes of gas production and hydrogen production both reach the maximum. The average values are respectively 36.2L/d and 21.8L/d. The obtained hydrogen production rate is 0.93kgCOD/(m3·d). During the whole process, the proportion of volatile acid composition remains stable, which is the butyric acid-type fermentation. When the concentration of COD is increased to 6000-8000mg/L, the ability of hydrogen production of system will be significantly dropped due to the increase of pH of system. The hydrogen production performance can be restored through artificially and timely lowering the water alkalinity. However, the hydrogen production rate will be decreased compared to the previous situation.