2018 Vol. 8, No. 2

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2018, 8(2): .
Abstract:
Present situation and countermeasures of indoor PM2.5 pollution in China
LI Ming, ZHANG Yongyong, HOU Li’an
2018, 8(2): 117-128. doi: 10.3969/j.issn.1674-991X.2018.02.016
Abstract:
Current situation of indoor PM2.5 pollution in China was investigated in terms of concentration level, chemical composition, changing rule and health hazard. It was found that both urban and rural areas in China had different degrees of indoor PM2.5 pollution, and the mean concentration of indoor PM2.5 in some cities reached (764±71)μg/m 3, with cadmium, arsenic and benzo (a) pyrene (BaP) exceeding the standard levels seriously. The challenges to the prevention and control of indoor PM2.5 in China were analyzed, including serious atmosphere pollution, the majority of rural areas using solid fuel, the traditional way of life not easy to change and the low level of awareness about indoor PM2.5. Finally, combining with China’s reality, the countermeasures and suggestions to solve indoor PM2.5 pollution problem were given, respectively from the aspects of city houses, offices, classrooms, hospitals, restaurants as well as rural houses.
Methodologies on choosing appropriate technical roadmap for ultra-low PM emission from coal-fired power plants
SUN Xueli, ZHU Fahua, WANG Sheng, LI Hui
2018, 8(2): 129-136. doi: 10.3969/j.issn.1674-991X.2018.02.017
Abstract(1037) PDF(908KB)(414)
Abstract:
Different from SO2 and NOx ultra-low emission technologies, PM ultra-low emission is the result of the interaction of multiple treatment processes which is a system engineering, so it is necessary to consider the applicability and effectiveness of the primary dust removal and secondary dust removal technology together. At present, PM ultra-low emissions technical route of the coal-fired power plants has been diversified with the development and application of new technology of dust removal and new technology of desulfurization which has synergistic effects for the dust removal. In the past, wet electrostatic precipitator(WESP) dust removal technology as secondary dust removal was the main technology to achieve the ultra-low PM emission, but now the wet desulfurization technology having synergistic effect for the dust removal as secondary dust removal and the electric bag composite dust removal technology able to achieve the ultra-low PM emission by primary dust removal have been applied in the coal fired power plants. The development and application status, effect and applicability of primary and secondary dust removal technology were analyzed, and the principles and methods to choose the ultra-low PM emission technology for coal-fired power plant put forward.
Study on denitration by dielectric barrier discharge technology
HUANG Chao, SUN Zhaowei, ZHANG Ning, CHEN Lili, WU Zhe
2018, 8(2): 137-141. doi: 10.3969/j.issn.1674-991X.2018.02.018
Abstract:
Dielectric barrier discharge (DBD) technology is a kind of low-temperature plasma technology which is often used in the removal of pollutants in flue gas. The effect of nitric oxide removal by DBD was studied, and the influences of oxygen content, ethylene content and the addition of activated carbon in the discharge interval on the removal efficiency of nitric oxide were analyzed. The results show that when the oxygen content is less than 3%, the increase of oxygen promotes the removal of nitric oxide, while under the oxygen content of more than 3%, the increase of oxygen will produce excessive oxygen free radical (·O), which inhibits the removal of nitric oxide. The removal efficiency of nitric oxide can be improved by adding activated carbon and ethylene. Through the combination of DBD, activated carbon and ethylene, the removal efficiency of nitric oxide can go up to 90%, and especially the addition of ethylene can promote the removal of nitric oxide.
Preparation of different morphologies of Au/α-MnO2 catalyst for oxidation of carbon monoxide and toluene
TAN Wei, YUAN Zhen, JIANG Jinyuan, CHENG Yongqian, DAI Hongxing
2018, 8(2): 142-148. doi: 10.3969/j.issn.1674-991X.2018.02.019
Abstract:
1-D nanosized rod-like, wire-like, and tubular α-MnO2 (xAu/α-MnO2,x=2%,4%,8%,10%) were prepared using the hydrothermal and PVA-protected NaBH4 reduction methods at different temperatures with KMnO4 and/or MnSO4 as Mn source, respectively. It is shown that the α-MnO2 in xAu/α-MnO2 was tetragonal in crystal structure, surface area of α-MnO2 nanorods, nanowires, and nanotubes was in the range of 48.4-114.0 m 2/g. The 4%Au/α-MnO2 sample possessed the highest adsorbed oxygen species concentration and the best low-temperature reducibility, thus showing the highest catalytic activity: the T50% and T90% (temperatures required for achieving reactant conversions of 50% and 90%) were 11.4 and 16.3 ℃ for CO oxidation, and 210 and 225 ℃ for toluene oxidation at a space velocity of 20 000 mL/(g ·h), respectively. Based on the characterization results and activity data, it is concluded that the better low-temperature reducibility, higher oxygen adspecies concentration, highly dispersed Au NPs, and stronger interaction between Au NPs and MnO2 nanorods were the main factors influencing the catalytic performance of 4%Au/α-MnO2.
Application of sludge micro bulking technology in low-load domestic sewage treatment
CHEN Jian, ZHOU Xie, LI Ping, HUANG Wei, GONG Ling, DIAO Xiangwei
2018, 8(2): 149-154. doi: 10.3969/j.issn.1674-991X.2018.02.020
Abstract:
A town sewage treatment plant in Chongqing was studied, and it was found that the sewage treatment plant sludge index (SVI) was between 262-380 mL/g and at the sludge bulking state. Low dissolved oxygen and low sludge load were the main reasons of sludge bulking in the sewage treatment plant. Micro bulking of activated sludge in a certain extent could not only guarantee the stable discharge of CODCr, ammonia nitrogen, SS, TP and other indicators in the effluent, but also be conducive to the energy saving of the sewage treatment plant.
The performance of combined process of biological pond and constructed wetland for cadmium removal from irrigation water
YANG Deng, YIN Xiaohui, ZOU Huiling, FANG Yayu, CEHN Nan, ZHANG Hao, WEI Xiangdong
2018, 8(2): 155-160. doi: 10.3969/j.issn.1674-991X.2018.02.021
Abstract:
The cadmium removal effect in irrigation water by the combined process of biological pond and constructed wetland was investigated through a field experiment. The influence of hydraulic retention time (HRT) on the cadmium removal effect and the daily variation rules of purification effect were further analyzed. Results show that the average concentration of total cadmium in irrigation water of the experiment area is 13.92 μg/L, which is 1.39 times of the cadmium limit in Standards for Irrigation Water Quality (GB 5084-2005). Most of them are dissolved cadmium, accounting for 77.8%. After the treatment by the combined process, the average removal rate of total cadmium reaches 42.0%, and the effluent in 85.2% of days during experiment can reach the standard. With the extension of the HRT, the cadmium removal rate of the combined process increases at first and then decreases, and the optimal HRT found to be 19 hours. In addition, the daily variation rules of cadmium removal rate by biological pond and constructed wetland both present as a single peak curve which shows lower value in the morning and evening but higher value at noon, and meanwhile the highest efficiency appears at 13:00.
Analysis of surface species diversity of sponge iron filler with different height in BAF
WAN Qiong, WU Yi, WANG Xin, WU Yinghai, WEI Dongyang, HE Tao, JIANG Qi
2018, 8(2): 161-168. doi: 10.3969/j.issn.1674-991X.2018.02.022
Abstract:
The microbial abundance and diversity of sponge iron filler in different height of BAF reactor were analyzed and studied by polymeraes chain reaction(PCR) amplification of the target fragment, Illumina high-throughput sequencing and biological information analysis. The results show that the dominant species in the raw Ctrl (raw water) and the reactor were mainly Proteobacteria, followed by Bacteroidetes. In Rank-Abundance distribution curve, the number of Ctrl species is 1 193, while that of DO1 (BAF upper), DO2 (BAF middle) and DO3 (BAF lower) is 2 389, 2 211 and 1 890, respectively, and DO1 has the highest abundance and species diversity. In the reactor, with the decrease of DO (or the decrease of filler spatial position), the richness and diversity of microbial community decreased gradually. It is found that the Chao1 index is more sensitive to the species richness than the observed species index, and the measured number of operational taxonomic units (OTUs) is about 400 higher. DO1 and DO2 samples had higher homogeneity, and the proportion of dominant bacteria in DO3 and Ctrl samples was high and the homogeneity was low. The species composition of DO1 and DO2 was observed to be most similar by PCoA.
Experimental study on adsorption of copper containing wastewater by modified attapulgite
SHI Wanli, ZHAO Zehua, YE Fei, XU Yuanshun
2018, 8(2): 169-175. doi: 10.3969/j.issn.1674-991X.2018.02.023
Abstract:
The experiment of adsorption of copper containing wastewater by modified attapulgite was performed to study the adsorption performance, process, thermodynamics, kinetics and its influence factors of modified attapulgite on copper containing wastewater. The results showed that the adsorption efficiency of acid modified attapulgite increased by 38.61% under the condition of 1 mol/L HCl, which indicated that the acid modification could activate the pore structure in attapulgite so as to significantly improve the adsorption performance. The maximum removal rate of copper ions by attapulgite could be up to 87.57% at the optimum reaction conditions as follows: the initial copper ion concentration of 100 mg/L, at temperature of 20 ℃ and the dosage of acid-modified attapulgite of 6 g/L. The adsorption of attapulgite on the copper containing wastewater was in accordance with the first-order kinetic equation and the Redlich-Peterson isotherm equation, and the fitting correlation coefficients R 2 were 0.929 and 0.984 respectively, indicating that the adsorption process of attapulgite could be classified as physical adsorption. With the initial concentration of copper ions increasing, the modified attapulgite has a good adsorption effect on copper containing wastewater.
Influence of riverbed in-situ remediation on microbial community in urban rivers
LI Helong, LI Shuangfei, LI Weiqi, LIN Jing
2018, 8(2): 176-184. doi: 10.3969/j.issn.1674-991X.2018.02.024
Abstract:
An overall microbial community analysis was performed with molecular biological testing methods for the riverbed after in-situ remediation. The results showed that the microbial community structure and diversity were changed obviously after in-situ ecological remediation. In the microbial diversity index term, the lower reaches of the river after in-situ remediation were higher than the upstream reaches. In the microbial community structure term, ε-Proteobacteria were the most important bacteria in the upstream, and most of them were pathogenic bacteria, which were related to the surrounding dense population and untreated water. After in-situ remediation, ε-Proteobacteria abundance was reduced in the downstream, furthermore, α-Proteobacteria and β-Proteobacteria became the dominant groups in the lower reaches of the river, and the proportion of other bacteria was also relatively balanced. In addition,NH3-N and other water quality indicators were improved. The research suggested that in-situ remediation technology has obvious effect on city landscape river ecological remediation.
Simulation and optimization of river ecological purification scheme by QUAL2K
ZHANG Ruibin, HUANG Yuying, ZHANG Yu
2018, 8(2): 185-190. doi: 10.3969/j.issn.1674-991X.2018.02.025
Abstract:
Taking the Shizi River in Nanjing City as an example, six kinds of ecological purification scheme were combined by submerged ecological bed, ecological floating bed and biological contact oxidation technology. By inputting different degradation parameters to different units, the six kinds of water treatment technology combination scheme were simulated using the QUAL2K model. The best scheme is selected through the comprehensive evaluation of the simulation effects. The results show that the optimal scenario is comprised of a bio-contact oxidation system in the upstream, followed by an ecological floating bed in the middle stream and a submerged ecological bed in the downstream. Under this scenario, the reduction rates for biochemical oxygen demand (BOD), ammonia nitrogen (NH3-N), total nitrogen (TN) and total phosphorus (TP) were 49.50%, 32.81%, 35.94% and 45.27%, respectively.
An inspiration to pollution permitting system implementation in China from the United States’ stationary source supervisory mechanism
SUN Caiping, LIU Xiaofu, SUN Qihong, LIU Baiyin, WANG Ying, LUO Lei, BAI Yang, CAO Chunling
2018, 8(2): 191-199. doi: 10.3969/j.issn.1674-991X.2018.02.026
Abstract:
Based on an analysis of the development of pollution permitting system in China, the development charaterisitics of the permitting system and the reasons of lacking supervision and inspection were summarized. In America, US EPA issued Clean Air Act Stationary Source Compliance Monitoring Strategy (CAA CMS) in 1991 to ensure that the regulated facilities across the country are evaluated for compliance on a regular basis. The revised history, main contents, organization and guaranteeing systems, and supervision instruments of CAA CMS and the environmental benefits were analysed. Drawing on the experiences of CAA CMS, the compliance-monitoring framework in China for implementing pollution permitting system was put forward. The compliance-monitoring framework consists of central government departments, provinces/locals and enterprises. The central government departments are responsible for developing and issuing a series of rules and regulations. The provinces/locals establish and implement compliance-monitoring plans in accordance with requirements of national policies, and focus resources on those facilities that are most environmentally significant, and they are under supervision and surveillance of the superior departments and the public. The provinces/locals shall conduct inspections and evaluations of enterprises in enhancing implementation of pollution permitting system based on compliance assistance, and increase penalties of polluting enterprises. In addition to the punishment to the enterprises, it is also necessary to pursue managers the enterprises for a criminal violation.
Research on copper-containing etching waste liquid disposal and management countermeasures in Jiangsu Province
GU Mingshi, LI Xingfu, LING Mengdan, JIAO Shaojun, HUANG Wenping, ZHANG Jun, WANG Yuting, ZHANG Houhu, ZHAO Zehua
2018, 8(2): 200-204. doi: 10.3969/j.issn.1674-991X.2018.02.027
Abstract:
Copper etching waste liquid is a kind of hazardous waste which has great harm to the environment, and also has high resource value. A large amount of etching waste is produced in Jiangsu Province every year, and typically the annual production of copper etching waste liquid reached hundreds of thousands of tons, which is one of the hazardous waste types with largest amounts. Based on the investigation of the main technologies and current situations of the disposal of the waste liquid in Jiangsu Province, several aspects of problems in the waste liquid treatment and utilization were analyzed, including the excessive capacity of comprehensive utilization, unstrict system of plant analysis, low level of pollution prevention and control, lack of standard for regeneration products management, and imperfect environmental management system. Besides, the environmental risks in the process of regeneration of copper containing etching waste liquor were discussed, and the control requirements of harmful substances in the regenerated products from the etching waste liquid analyzed. The existing problems in the development of the industry, such as insufficiencies of technical level and management requirements, were preliminary summarized, so as to provide technical support for formulating technical specifications on the treatment and utilization of etching waste liquid in Jiangsu Province.
Relations among undertaking of industrial transfer, economic growth and environmental pollution: a case study in Gansu Province
SHI Yujun, HUANG Juan
2018, 8(2): 205-211. doi: 10.3969/j.issn.1674-991X.2018.02.028
Abstract:
Gansu Province was taken as the sample to investigate the feasibility of realizing economic growth and environmental improvement in the less developed areas with fragile ecological environment. The panel data of Gansu’s 12 cities in 2006-2013 were selected, and fixed effect model used to infer the internal causal relations among the undertaking of industrial transfer, economic growth and environmental pollution. The results show that the undertaking of industrial transfer in Gansu presents a trend of rapid growth, and the growth rate is much higher than the economic growth and pollution emissions. The undertaking of industrial transfer not only promotes the economic growth, but also improves the environment. There exists a positive correlation between economic growth and environmental degradation in Gansu Province in the short term, and it presents the inverted U-shaped curve in the long term. Therefore, it is suggested that the province should develop dual role of the undertaking of industry transfer in the future.
Assessment methods of regional ecosystem service value and a case study of Dongjiang River basin
WANG Xiaoli, GAO Zhenbin, SU Jing, CHEN Zhifan, ZHENG Mingxia, SUN Yuanyuan, JI Danfeng
2018, 8(2): 212-220. doi: 10.3969/j.issn.1674-991X.2018.02.029
Abstract:
To explore the value of regional ecosystem services is an important way to coordinate regional economic development and ecological construction. However, there is no accredited regional ecosystem service value assessment system, and there exist large differences in evaluation results. The common assessment methods of ecosystem services valuation systematically, such as alternative market technology, simulated market technology and equivalent factor method were summarized. Then their advantages and disadvantages were compared from three aspects of evaluation object, scope and process. It is concluded that the equivalent factor method is better suited for assessment of regional ecosystem service value because of its simplicity, comprehensiveness and taking full account of the regional and ecosystem characteristics. Finally, the method was applied to evaluate the ecosystem services value of the Dongjiang River basin. The results show that the total value of the ecosystem services in the Dongjiang River basin is 197.663 billion yuan. Among them, the ecosystem service value of forest, water, wetlands, farmland, grassland, unused land and construction land was 153.674 billion yuan, 15.642 billion yuan, 14.581 billion yuan, 7.574 billion yuan, 4.241 billion yuan, 228.9 thousand yuan and 0 yuan, respectively.
Toxic effects and mechanisms of exposure to single and mixture of mercury, cadmium, lead and arsenic
ZENG Chen, GUO Shaojuan, YANG Lixin
2018, 8(2): 221-230. doi: 10.3969/j.issn.1674-991X.2018.02.030
Abstract(1073) PDF(982KB)(812)
Abstract:
Metals including mercury, cadmium, lead and arsenic in nature are harmful to wildlife and humans. Cadmium and arsenic and/or their related compounds are well-known carcinogens, while mercury and lead may even cause cancer. Human activities are the main sources of mercury, cadmium, lead and arsenic contamination. A group of human diseases are suspected to result from exposure to these metals, and have awakened the public conscious to pay more attention to the risk of these metals in human health. Extensive studies have demonstrated the associations between adverse health effects and exposure to these metals at high dose. However, there is a paucity of information on the adverse effects associated with chronic exposure to the environmentally relevant levels of individual metals and mixtures. The impacts of exposure to mixtures of these metals on human health need to be examined. Depending on exposure route, dose and exposure duration, mercury, cadmium, lead and arsenic differ in metabolic fate, mechanisms of transport and disposition in the body, and have the individual toxicological profiles. The adverse effects and potential molecular evidences associated with the exposure to single and mixture of mercury, cadmium, lead and arsenic were summarized. The applications and future research directions of omics technology, such as genomics, transcriptomics, proteomics, and metabolomics in understanding the mechanisms related to toxicities were also discussed.