Jun 2008, Volume 2 Issue 2

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  • ZHANG Kunmin, WEN Zongguo, PENG Liying
    This article reviews the development of current environmental policies in China and the great progress made during 1979–2006. Applying lessons learned from industrialized countries to its own situation, China’s environmental policies have the following main features: (1) to explore command and control measures to their fullest extent, (2) to strive to raise funding for environmental protection, (3) to identify who should take accountability for environmental protection; (4) to encourage strategies of “combination of prevention and control” and “integrated utilization”, (5) to embrace openness in the field of environmental policy and early international cooperation. During the past 30 years, China’s environmental policies have evolved and deepened: status expanded the national basic policies of environmental protection by adding a sustainable development strategy, focus changed from pollution control to a combination of pollution control and ecological protection, method changed from end control to source control, scope changed form point source control to watershed and territory pollution control, and management style changed from primarily using executive power to using legal and economic measures. This article introduces how they are evaluated by the international community and provides the prospects of the policies.
  • DONG Xin, ZENG Siyu, CHEN Jining, ZHAO Dongquan
    In recent years, the urban drainage system in China is facing the dual pressure of renovation and construction. This requires that the integrated assessment for the planning and operation of the urban drainage system is obligatory. To evaluate the urban drainage system, an integrated assessment methodology based on the analytic hierarchy process (AHP), integrated simulation, and fuzzy assessment is established. This method is a multi-criteria decision adding app roach to the assessment of the urban drainage system comprehensively. Through the integration of the Storm Water Management Model (SWMM), a simple wastewater treatment plant model, and a surface water quality model, an integrated modelling system for the urban drainage system is developed and applied as a key tool for assessment. Using the established method, a case study in Shenzhen City has been implemented to evaluate and compare two urban drainage system reno vation plans, the distributed plan and the centralized plan. Because of the particularity of this case study, the established method is not applied entirely. Considering the water environ mental impact, ecological impact, technological feasibility, and economic cost, the integrated performance of the distri buted plan is better. As shown in this case study, the proposed method is found to be both effective and practical.
  • HE Weiqi, LIU Xuehua, CHEN Jining, CHEN Shan
    This study focused on the water quality of the Guanting Reservoir, a possible auxiliary drinking water source for Beijing. Through a remote sensing (RS) approach and using Landsat 5 Thematic Mapper (TM) data, water quality retrieval models were established and analyzed for eight common water quality variables, including algae content, turbidity, and concentrations of chemical oxygen demand, total nitrogen, ammonia nitrogen, nitrate nitrogen, total phosphorus, and dissolved phosphorus. The results show that there exists a statistically significant correlation between each water quality variable and remote sensing data in a slightly-polluted inland water body with fairly weak spectral radiation. With an appropriate method of sampling pixel digital numbers and multiple regression algorithms, retrieval of the algae content, turbidity, and nitrate nitrogen concentration was achieved within 10% mean relative error, concentrations of total nitrogen and dissolved phosphorus within 20%, and concentrations of ammonia nitrogen and total phosphorus within 30%. On the other hand, no effective retrieval method for chemical oxygen demand was found. These accuracies were acceptable for the practical application of routine monitoring and early warning on water quality safety with the support of precise traditional monitoring. The results show that performing the most traditional routine monitoring of water quality by RS in relatively clean inland water bodies is possible and effective.
  • CHANG Miao, PENG Lijuan, WANG Shiwen
    The establishment of the environmental management system in the financial sector can be effectively promoted through the introduction of the environmental protection concept and its implementation by the financial sector. The impact of a sustainable development system on the sector is analyzed in this article from three aspects: environmental risk assessment, financing support for environmental protection projects, and financial services to environmentally friendly corporations and individuals. Influential factors on the development of the environmental management system in China’s financial sector are discussed from the perspective of various entities such as financial institutions, financial regulation authorities, environmental protection departments, corporations, and the public. It is pointed out that China’s financial sector is now in the transitional phase from a defensive attitude to a preventive attitude. Strengthening governmental guidance, the supervision of regulators as well as public awareness of environmental protection should be used to enhance the initiative in the development of the environmental management system in the Chinese financial sector.
  • WANG Xiangrong, YONG Yi, ZHANG Hao, WANG Pingjian, WANG Shoubing, CHEN Weizhen, WANG Shixiong, HO Hing Hon
    The background, concept, connotation, principles, and methods of eco-planning for an Eco-Demonstration Park (EDP) and sustainability were examined based on a case study of the Luhua EDP in the Chongming Island of Shanghai, China, which is an important part of Shanghai Eco-city planning and construction in the 21st century. By analyzing natural, social and economic conditions, calculating population using the land capacity eco-model, eco-function zoning, and eco-construction, an innovative eco-industrial structure and technical chain were formulated. A comprehensive eco-planning scheme for the EDP was proposed, including planning and management strategies for subsystems of efficient industry, good quality human settlement, high standard eco-construction and eco-tourism as well as effective environmental protection and attractive landscape. The EDP should be an area with coordinated and sustainable economic, social and environmental subsystems. Eco-planning for the EDP should be a very important part of eco-city planning and sustainability. The paper aims to set up a theoretical framework and practical basis for eco-planning and promoting harmony between human and nature.
  • ZHANG Liquan, GAO Zhanguo, Armitage Richard, Kent Martin
    The spectral reflectance of recently formed salt marshes at the mouth of the Yangtze River, which are undergoing invasion by Spartina alterniflora, were assessed to determine the potential utility of remotely sensed data in assessing future invasion and changes in species composition. Following a review of published research on remote sensing of salt marshes, 53 locations along three transects were sampled for paired data on plant species composition and spectral reflectance using a FieldSpec Pro JR Field Portable Spectroradiometer. Spectral data were processed concerning reflectance, and the averaged reflectance values for each sample were re-analysed to correspond to a 12-waveband bandset of the Compact Airborne Spectral Imager. The spectral data were summarised using principal components analysis (PCA) and the relationships between the vegetation composition, and the PCA axes of spectral data were examined. The first PCA axis of the reflectance data showed a strong correlation with variability in near infrared reflectance and ‘brightness’, while the second axis was correlated with visible reflectance and ‘greenness’. Total vegetation cover, vegetation height, and mudflat cover were all significantly related to the first axis. The implications of this in terms of the ability of remote sensing to distinguish the various salt marsh species and in particular the invasive species S. alterniflora were discussed. Major differences in species with various physiognomies could be recognised but problems occurred in separating early colonising S. alterniflora from other species at that stage. Further work using multi-seasonal hyperspectral data might assist in solving these problems.
  • WANG Xuejiang, XIA Siqing, ZHAO Jianfu
    The biosorption of Direct Black 38 by dried anaerobic granular sludge in a batch system under specific temperatures and initial pH was investigated. The adsorption reaction is pH dependent with higher removal at low pH. The adsorption equilibrium data fit very well with both Langmuir and Freundlich models in the concentration range of Direct Black 38 at all chosen temperatures. The adsorption parameters show that the adsorption of Direct Black 38 is an endothermic and more effective process at high temperatures. The kinetics of adsorption was found to be second order and adsorption rate constants increased with increasing temperature. Activation energy was determined as 26.8 kJ/mol for the process. This suggests that the adsorption of Direct Black 38 by dried anaerobic granular sludge is chemically controlled.
  • ZHANG Ruihua, SUN Hongwen, YIN Jin
    The purpose of this study is to estimate the removal efficiency of As and Cr (VI) by one kind of industrial waste – iron chips, as well as to estimate the effects of typical inorganic anions (sulfate, phosphate, and nitrate
  • ZHANG Fengling, LIU Jingling, YANG Zhifeng, LI Yongli
    The assessment of the ecosystem health of urban rivers and lakes is the scientific basis for their management and ecological restoration. This study developed a three-level indicator system for its assessment. The results indicated that: Zhonghai and Nanhai are in the state of transition from unhealthy to critical state and all the other lakes are in unhealthy states. Water environmental quality, structure and function of the aquatic ecosystem, and the structure of waterfront areas were the constraints. Nanhai was ranked as poor and the others were all ranked as very poor. However, the ecological environment of Zhonghai and Nanhai were better than the others, the sums of the degree of membership to the healthy state and critical state were all close to 0.6. and the restorations of these lakes were moderate. The sums of the degree of membership to the healthy state and critical state of the other lakes were under 0.3, as it was difficult to restore these lakes. Some suggestions on scientific management and ecological restoration of the six lakes were proposed: $`To control non-point pollution and to improve the water quality of six lakes and the water entering into these lakes; $aTo improve the hydrological conditions of six lakes; $bTo rehabilitate the aquatic ecosystem and waterfront areas.
  • SHAN Qihua, YU Yuanchun, ZHANG Jinchi, YU Jian
    To reveal the biological characteristics of urban forest soil and the effects of soil enzyme on soil fertility as well as the correlation between physicochemical properties and enzyme activities, 44 urban forest soil profiles in Nanjing were investigated. Basic soil physicochemical properties and enzyme activities were analyzed in the laboratory. Hydrogen peroxidase, dehydrogenase, alkaline phosphatase, and cellulase were determined by potassium permanganate titration, TTC (C19H15N4·Cl) colorimetry, phenyl phosphate dinatrium colorimetry, and anthrone colorimetry, respectively. The result showed that soil pH, organic carbon (C), and total nitrogen (N) had great effects on hydrogen peroxidase, dehydrogenase, and alkaline phosphatase activities in 0–20 cm thick soil. However, pH only had great effect on hydrogen peroxidase, dehydrogenase, and alkaline phosphatase activities in 20–40 cm thick soil. Hydrogen peroxidase, dehydrogenase, and alkaline phosphatase were important biological indicators for the fertility of urban forest soil. Both in 0–20 cm and 20–40 cm soil, soil enzyme system (hydrogen peroxidase, dehydrogenase, alkaline phosphatase, and cellulase) had a close relationship with a combination of physicochemical indicators (pH, organic C, total N, available K, available P, cation exchange capacity (CEC), and microbial biomass carbon (Cmic)). The more soil enzyme activities there were, the higher the fertility of urban forest soil.
  • GUO Ting, BAI Zhipeng, WU Can, ZHU Tan
    TiO2 supported on active carbon fiber (TiO2/ACF), an absorbable photocatalyst, is a new kind of material applied in air purification. In this paper, the influence of environmental temperature (T) and relative humidity (RH) on the gas-solid adsorption of toluene and the photocatalytic oxidation (PCO) efficiency of adsorbed toluene on TiO2/ACF were studied, and then, the purification capability of TiO2/ACF was estimated. PCO results showed that although the PCO efficiency increased under high RH and T levels, the amount of adsorption of toluene decreased. Moreover, quantitative analysis results of intermediates indicated that more environmental risk emerged when PCO of toluene was carried out at higher environmental T and RH levels because more toxic intermediates would be accumulated on the TiO2/ACF. So, it is significant to control the environmental T and RH conditions in the application of the PCO technique. T = 25°C and RH = 30% is the optimal condition for purifying toluene in our experimental system.
  • CHENG Hongguang, HAO Fanghua, REN Xiyan, YANG Shengtian, XIONG Wen, LEI Shaoping
    In this study, calibrations of non-point source (NPS) pollution models are performed based on Black River basin historical real-time runoff data, sedimentation record data, and NPS sources survey information. The concept of NPS loss
  • WU Xuelei, CHEN Lunqiang, PENG Yongzhen, WANG Pu, WANG Yayi
    The effect of dissolved oxygen (DO) concentration on nitrite accumulation was investigated in a pilot-scale pre-denitrification process at room temperature for 100 days. In the first 10 days, due to the instability of the system, the DO concentration fluctuated between 1.0 and 2.0 mg/L. In the next 14 days, the DO concentration was kept at 0.5 mg/L and nitrite accumulation occurred, with the average nitrite accumulation rate at 91%. From the 25th day, the DO concentration was increased to 2.0 mg/L to destroy the nitrite accumulation, but nitrite accumulation rate was still as high as 90%. From the 38th day the nitrite accumulation rate decreased to 15%–30% linearly. From the 50th day, DO concentration was decreased to 0.5 mg/L to resume nitrite accumulation. Until the 83rd day the nitrite accumulation rate began to increase to 80%. Dissolved oxygen was the main cause of nitrite accumulation, taking into account other factors such as pH, free ammonia concentration, temperature, and sludge retention time. Because of the different affinity for oxygen between nitrite oxidizing bacteria and ammonia oxidizing bacteria when DO concentration was kept at 0.5 mg/L, nitrite accumulation occurred.
  • LIN Yishan, HE Yanling, MENG Zhuo, YANG Shucheng
    The direct conversion of methanol into methane is the main process in anaerobic treatment of methanol containing wastewater. However, acetic acid can also be produced from methanol theoretically, which may probably result in an abrupt pH drop and deteriorate the anaerobic process. Therefore, it is interesting to know what would really happen in an anaerobic reactor treating methanol wastewater. In this study, an up-flow anaerobic sludge bed (UASB) reactor treating methanol wastewater was operated. The chemical oxygen demand (COD), acetic acid and pH of the effluent were monitored at different loadings and influent alkalinity. The results showed that the anaerobic reactor could be operated steadily at as low as 119 mg/L of influent alkalinity and high organic loading rate with no obvious pH drops. Volatile fatty acids accumulation was not observed even at strong shock loadings. The microorganisms in the sludge at the end of the test became homogeneous in morphology, which were mainly spherical or spheroidal in shape.
  • YUAN Shoujun, ZHENG Zheng, YU Xin, ZHAO Yongfu, MU Yanyan
    The effects of ?-irradiation pretreatment on anaerobic digestibility of sewage sludge was investigated in this paper. Parameters like solid components, soluble components, and biogas production of anaerobic digestion experiment for sewage sludge were measured. The values of these parameters were compared before and after ?-irradiation pretreatment. Total solid (TS), volatile solid (VS), suspended solid (SS), volatile suspended solid (VSS), and average floc size of samples decreased after ?-irradiation treatment. Besides, floc size distribution of sewage sludge shifted from 80–100 ?m to 0–40 ?m after ?-irradiation treatment at the doses from 0 to 30 kGy, which indicated the disintegration of sewage sludge. Moreover, microbe cells of sewage sludge were ruptured by ?-irradiation treatment, which resulted in the release of cytoplasm and increase of soluble chemical oxygen demand (SCOD). Both sludge disintegration and microbe cells rupture enhanced the subsequent anaerobic digestion process, which was demonstrated by the increase of accumulated biogas production. Compared with digesters fed with none irradiated sludge, the accumulated biogas production increased 44, 98, and 178 mL for digesters fed sludge irradiated at 2.48, 6.51, and 11.24 kGy, respectively. The results indicated that ?-irradiation pretreatment could effectively enhance anaerobic digestibility of sewage sludge, and correspondingly, could accelerate hydrolysis process, shorten sludge retention time of sludge anaerobic digestion process.
  • YANG Yanmei, ZHANG Xiangfeng, YANG Zhifeng, XI Beidou, LIU Hongliang
    Few people have so far explored into the research of the dynamics of various nitrogenous compounds (including water-soluble nitrogen) in composting of food wastes. This study aimed to investigate the solid-phase nitrogen, water-soluble nitrogen, nitrogen loss together with ammonia volatilization in the process of food wastes composting. A laboratory scale static aerobic reactor in the experiment was employed in the composting process of a synthetic food waste, in which sawdust was used as the litter amendment. In the experiment, oxygen was supplied by continuous forced ventilation for 15 days. The results have shown that the concentrations of total nitrogen and organic nitrogen decrease significantly in the composting process, whereas NH4+-N concentration increases together with little fluctuation in NO3--N. After composting, the total content of the water-soluble nitrogen compounds in the compost greatly increased, the total nitrogen loss amounted to 50% of the initial nitrogen, mainly attributed to ammonia volatilization. 56.7% of the total ammonia volatilization occurred in the middle and late composting of the thermophilic stage. This suggested that the control at the middle and late composting of thermophilic stage is the key to nitrogen loss in the food waste compost.