2018 Vol. 8, No. 6

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2018, 8(6): .
Abstract:
Application of data assimilation method in updating emission inventory
WANG Jikang, ZHANG Hengde, ZHANG Bihui, YANG Xiaolu
2018, 8(6): 577-585. doi: 10.3969/j.issn.1674-991X.2018.06.077
Abstract:
Data assimilation is to use the observed data to update the pollution sources from top to bottom, which could provide a fast way to update and verify the emission inventories, and also add further information about the temporal variation and some sources that could not easily be quantified by traditional bottom-up methods. The basic principles of several assimilation inversion methods, including the mass balance ,ensemble Calman filter and four-dimensional variation methods were reviewed, and their application methods in emission inventory inversion and optimization introduced. The acquisition method of observation data and the primary emission inventory, the calculation method of uncertainty, and the acquisition method of the relationship between pollution sources and observation data were also introduced. The application of pollution source assimilation inversion methods at different scales of pollution source inventory inversion, both at home and abroad, were summarized. The ensemble Kalman filter or the 4D variation method combined with adjoint model or decoupling direct method was used to determine the relationship between pollution sources and observation data, able to avoid the nonlinearities in the model to a certain extent. The more accurate observations and more precise air quality model were needed in the future to improve the effect of pollution sources inversion.
Optimization and application of accurate control of ultra-supercritical boiler and SCR parameters for NOx real time value up to the standard
ZHANG Guangcai, LI Ruipan, ZHU Xuezhi, TAO Ran
2018, 8(6): 586-592. doi: 10.3969/j.issn.1674-991X.2018.06.078
Abstract:
The current environmental policy requires that the NOx emission of power station boilers is qualified by the control hourly average, while the real time value of emissions is not required. In order to further reduce NOx emissions from power station boilers, improve operation stability and maximize the potential of SCR system, the study and optimization of the influence factors on NOx generation and removal of power station boilers was carried out. Thereby the real time values of NOx emission were all up to standard, and the boiler efficiency improved. The phenomenon of short-term over standard was avoided in the changing condition of the boiler load adjustment. It achieved good results in the safety, stability and economy of the system, and greatly reduced the workload of daily operation adjustment.
2018, 8(6): 593-594.
Abstract:
Study of multi-dimensional water quality safety evaluation method: taking Taihu Lake as an example
ZHAO Yanmin, CAO Wei, ZHANG Lei, MA Yingqun, QIN Yanwen, LIU Zhichao, YANG Chenchen
2018, 8(6): 595-601. doi: 10.3969/j.issn.1674-991X.2018.06.079
Abstract:
Based on the characteristics of water pollution of Taihu Lake, the indicators including water quality, eutrophication, water bloom occurrence and health risk were screened, and a multi-dimensional water quality safety evaluation index system consisting of 4 secondary indicators and 21 tertiary indicators was constructed. Analytic Hierarchy Process (AHP) method was applied to determine the weight of the indicators. The survey data of Taihu Lake in 2012 was used to evaluate the water quality safety grade with the water quality safety index. The results showed that the overall water quality safety of Taihu Lake was only qualified in 2012. The water quality safety grade in the eastern district of lake was medium, while the water quality safety grades in other districts of the lake were qualified. The water quality safety status of Zhushan Lake and Northwest District was the worst, and the water quality safety index was 50.78 and 52.45, respectively. Based on the analysis of the assessment results, eutrophication level and water bloom condition were found to be the main factors affecting the water quality safety of Taihu Lake.
Spatial distribution and pollution assessment of heavy metals in Minjiang River mainstream
QIAO Fei, SHI Yao, QIN Yanwen, MA Yingqun, LIU Zhichao, YANG Chenchen
2018, 8(6): 602-609. doi: 10.3969/j.issn.1674-991X.2018.06.080
Abstract:
In order to explore the pollution level of heavy metals in Minjiang River mainstream, the contents and spatial distribution of As, Cd, Cr, Cu, Pb and Zn in surface water, suspended solids and surface sediments were analyzed. The integrated pollution index and geoaccumulation index were used to evaluate the contamination degree of heavy metals in surface water and surface sediments respectively. The results indicated that the contents of the heavy metals in surface water were below Grade I standard of Environmental Quality Standards for Surface Water (GB 3838-2002). The contents of the 6 heavy metals in suspended solids exceeded the average contents of the stream sediments in China. Similar patterns of spatial distribution in suspended solids were observed for As, Cr and Pb, with the highest contents both at the middle and lower reaches. The contents of Cd and Pb in surface sediments exceeded the average contents of the stream sediments in China. Similar patterns of spatial distribution in surface sediments were observed for Cr and Cu, with the highest contents at the downstream in Yibin section. The contents of Cd in suspended solids and surface sediments were the highest, being 2.99 mg/kg and 39.94 mg/kg respectively, which were 23.00 and 307.23 times the average contents of the stream sediments in China. The integrated pollution index assessment showed that the water quality of surface water was good in Minjiang River mainstream, and the geoaccumulation index assessment showed that Cd was the major pollution element in surface sediments.
Phosphorus forms and potential release characteristics of phosphogypsum in Tuojiang River basin
YANG Geng, QIN Yanwen, MA Yingqun, HAN Chaonan, LIU Zhichao, YANG Chenchen
2018, 8(6): 610-616. doi: 10.3969/j.issn.1674-991X.2018.06.081
Abstract:
The phosphorus form and content, release kinetics characteristics of phosphorus and the influence of environmental factors on phosphorus release were investigated from phosphogypsum samples collected in Tuojiang River basin. The results showed that the TP content of phosphogypsum was 3.70 mg/g, and the release of phosphorus was mainly carried out by Ex-P, Org-P and Fe-P. Among them, Ex-P and Fe-P accounted for a large proportion. When the ratio of water to phosphogypsum was 500 ∶1, the phosphorus release reached the maximum value, and the phosphorus release mainly occurred in the first 8 hours. The maximum release rate of phosphorus from phosphogypsum was 3.52 mg/(g ·h). The first order kinetic equation can fit the phosphorus release kinetic process well with the maximum release Qmax of 2.30 mg/g under the experimental condition. The pH had significant effect on phosphorus release from phosphogypsum, and either acidic or alkaline water environment was conducive to release of phosphate. Higher salinity and temperature were favorable to the release of phosphorus, and total phosphorus release increased the most as temperature increasing from 10 to 25 ℃ with the maximum at 25 ℃.
Characteristics of nitrogen and phosphorus discharge of main industrial parks in Chongqing in Three Gorges Reservoir Area
CAO Wei, QIN Yanwen, MA Yingqun, YANG Chenchen, LIU Zhichao
2018, 8(6): 617-626. doi: 10.3969/j.issn.1674-991X.2018.06.082
Abstract:
In order to clarify the sewage discharge status of key industrial parks in the Three Gorges Reservoir Area, with Changshou chemical park, Fuling industrial Park and Wanzhou industrial park as the key research objects, a total of 48 water samples were collected and analyzed from the drainage channels of sewage treatment plants, the main sewage outlets, the streams into the reservoir and the mainstream of the Yangtze River. The results showed that the concentrations of $NH^{+}_{4}$-N, TN and TP in the water of the drainage channels of sewage treatment plants were 2.58, 13.91 and 0.43 mg/L, the concentrations of $NH^{+}_{4}$-N, TN and TP in the water of main sewage outlets were 18.88, 29.38 and 4.42 mg/L, the concentrations of $NH^{+}_{4}$-N, TN and TP in the water of the stream into the reservoir were 5.48, 12.89 and 0.78 mg/L, the concentrations of $NH^{+}_{4}$-N, TN and TP in the water of the main stream were 0.32, 5.12 and 0.22 mg/L, respectively. The nitrogen and phosphorus concentrations of the main sewage outlets and the stream into the reservoir were 1.93-59.59 times higher than that of Yangtze River main stream water body, which showed that the nutrient salt input characteristics were remarkable to the water quality of the reservoir area. It was suggested that Chongqing City should plan the construction of industrial parks reasonably, control the discharge of industrial wastewater of different industries strictly, reduce the total amount of pollutants entering the river, and reduce the water environment risk in the reservoir area.
Changed weight trophic level index method and its application to Longhe tributary of the Three Gorges reservoir area
HAN Xuemei, FU Guo, LIU Qingqing, ZHANG Shen, ZHAO Jian
2018, 8(6): 627-634. doi: 10.3969/j.issn.1674-991X.2018.06.083
Abstract:
Aiming at the deviation problem existing in the evaluation method of weighted average comprehensive nutritional status index TLI(Σ), when making by averaging the values of five evaluation indexes, including Chla, TP ,TN, SD and CODMn. The expressing efficacy of nutrient levels of different evaluation indicators under different lake conditions (nitrogen limitation, phosphorus limitation, nitrogen-phosphorus synergistic effect) was analyzed. The three indicators of Chla, TP and TN were selected as evaluation indicators, and the changed weight trophic level index (TLICW) evaluation method for comprehensive nutritional status index was obtained by comparing the apparent and potential nutritional status indexes. The method was applied in the Longhe River, a tributary of the Three Gorges Reservoir area. It showed that the TLICW method with variable weights was more prominent in describing the characteristics of nutritional status than the TLI(Σ) method. It was in the status of light eutrophication evaluated by TLICW method while in the status of mesotrophication by TLI(Σ) method. The TLICW mean value determined by the multi-lake response relationship reveals that Longhe River was one trohpic level higher than determined by the Longhe River response relationship. The eutrophication thresholds of the TP and TN determined by the Longhe River response relationship was of 2.75 and 3.00 times respectively of multi-lake response relationship, indicating that there was a clear over-protection problem when the multi-lake response relationship was used in the eutrophication evaluation of Longhe River.
Study on online monitoring and early warning indicator system of pollution sources in chemical industry
CAO Wei, QIN Yanwen, ZHANG Lei, ZHAO Yanmin, MA Yingqun, YANG Chenchen
2018, 8(6): 635-641. doi: 10.3969/j.issn.1674-991X.2018.06.084
Abstract:
The accident warning indicators were optimized by the analytic hierarchy process. By calculating and comparing the weights of each indicator, the heavier indicator was selected to form the water pollution accident warning indicator system. On the basis of this, the framework of the pollution sources online monitoring and early warning indicator system was initially constructed in the light of the general production and pollutant discharge situations of the industrial enterprises. Taking the delayed coking process of one enterprise as an example, the above method was applied to analyze the environmental pollution that may occur in the production process, calculate the weights of each indicator using the analytic hierarchy process, and determine the construction process of the early warning indicator system. The indicators that need to be monitored online were finally determined for the delayed coking devices, including CODCr, petroleum hydrocarbon, ammonia nitrogen, sulfides and phenols.
Economic policies of plastic bag reduction of foreign countries and regions and its enlightenment to China
ZHANG Jiaxu, DENG Yixiang, ZHANG Chenglong
2018, 8(6): 642-650. doi: 10.3969/j.issn.1674-991X.2018.06.085
Abstract:
Based on the analysis of the characteristics of the plastic bag management policies in China mainland, the effectiveness and existing problems were summarized. The environmental economic policies of plastic bags enacted by some countries and regions were classified in terms of price leverage and tax leverage, on the basis of the analysis of development history, policy content and management methods. Two suggestions to improve the plastic bag economic policies were put forward borrowing the successful experience in the above countries and regions. Firstly, the current plastic bag charging system should be improved by expanding management scope and setting low bound of the charging prices, et al. Secondly, the taxation system should be established for the plastic bag management, including implementing taxation for specific use only and setting reasonable tax rates, et al.
Study on prediction of total nitrogen removal effect of a surface water purification device based on BP neural network
LI Chunhua, HU Wen, YE Chun, LI Jinze, WEI Weiwei
2018, 8(6): 651-655. doi: 10.3969/j.issn.1674-991X.2018.06.086
Abstract:
A back propagation (BP) artificial neural network model was set up to predict the effect of nitrogen removal using a surface water purification device. The observed data of water quality parameters were used as study sample, and the raw water TN, ammonium nitrogen, nitrate nitrogen, CODMn and operation time of the device selected as projection parameter in this model. Besides, the multivariate linear regression model was introduced to compare with BP neural network. The results showed that the coefficient of determination of BP artificial neural network model was 0.985, which stayed at a high level. And the maximum error was 5.92%. Obviously, BP artificial neural network model was more precise, faster and better than multivariate linear regression model. It could accurately predict the removal effect of TN by purification device.
Characteristics of waste hair biochar and its adsorption to Ni(Ⅱ) and Zn(Ⅱ)
XIE Weixue, LIU Xiaomin, LI Xiaodong, JIAO Yongxia, ZHAO Youcai
2018, 8(6): 656-662. doi: 10.3969/j.issn.1674-991X.2018.06.087
Abstract:
The properties of biochar prepared from waste hair were analyzed by element composition and SEM, and the adsorption ability to heavy metals from domestic wastewater observed.The adsorption kinetics processes of Ni(Ⅱ) and Zn(Ⅱ)were fitted by Lagergren model, and the adsorption isotherm of Ni(Ⅱ) and Zn(Ⅱ) fitted by Langmuir and Freundlich models to investigate the adsorption characteristics of biochar on heavy metals Ni(Ⅱ) and Zn(Ⅱ) in water. The results showed that the carbon content of biochar was high, being alkaline, and the surface structure had porosity with strong adsorption ability. At carbonization temperatures of 300 and 350 °C, the actual maximum equilibrium adsorption for Ni(Ⅱ) was 5.48 and 6.25 mg/g, and the actual maximum equilibrium adsorption for Zn(Ⅱ) was 3.02 and 3.78 mg/g, respectively. The Lagergren model can well describe the adsorption process of Ni(Ⅱ) and Zn(Ⅱ), mainly with chemical adsorption; and the higher the carbonization temperature, the faster the adsorption rate. Langmuir and Freundlich model fitting curves can better describe the isothermal adsorption of Ni(Ⅱ) and Zn(Ⅱ); and the higher the adsorption temperature, the more the adsorption capacity. At the temperature of 20,30 and 40 ℃, the saturated adsorbents of Ni(Ⅱ) were 5.59,7.16 and 7.23 mg/g, and the saturated adsorbents of Zn(Ⅱ) were 1.28,1.29 and 1.32 mg/g, respectively.
The pilot study of harmless disposing equipment of diseased dead animals
LIU Yunpeng, HOU Jiaqi, LI Baoqian, LI Mingxiao, CAO Jinzhong, ZHANG Runkai, WU Gaofeng
2018, 8(6): 662-670. doi: 10.3969/j.issn.1674-991X.2018.06.088
Abstract:
During the harmless disposal of diseased dead animal, the secondary pollution could be generated from the separation of the cutting and mixing processes. Aiming at this problem, in combination with the characteristics of the shredder and the feed mixer, a kind of cutting blade that could simultaneously complete the functions of cutting and mixing was designed. By analyzing the cutting principle, the cutting-line was deviated from the rotation center to achieve the “sliding cut” effect. The blade was designed with circular arc to improve the distribution of stress, and the blade length was increased to make the cutting more stable. The optimal mixing angle between the switch plate and the cutting blade was determined to be 70° by single factor experiment. The equipment adopts the indirect heating heat transfer oil, which has the advantages of high stability and good heat transfer. Through the theoretical calculation, the motor power of the equipment was selected at 3 kW, with the rated speed of 1 440 r/min. The helical gear reducer was selected for reducer with the speed ratio of 1 000. The pilot test showed that the blade could basically complete the function of cutting and mixing. It needed about 20 h to heat up the material and main the temperature at over 90 ℃, while the temperature fluctuation was obvious within 10-20 h. The test result of pestivirus suis, etc. for the disposed products were all negative, showing that harmless disposal had been achieved. The moisture content of the product is 23%, with pH 5.7, seed germination rate 80%, total nitrogen 3.1% and total phosphorus 2.1%, all achieving the requirement of Organic Fertilizer Standard (NY 525-2012).
EKC test and decoupling analysis of carbon emissions in countries along the “One Belt and One Road”
WU Na, FU Zeqiang, WANG Yanhua, HE Chuan, FENG Qiang
2018, 8(6): 671-678. doi: 10.3969/j.issn.1674-991X.2018.06.089
Abstract:
“One Belt and One Road”(OBOR) is a significant initiative proposed by China that shall promote the sustainable development in the countries of the region. One static panel model of Environment Kuznets Curve with cubic term was constructed, and the data of per capita energy consumption, per capita carbon dioxide emissions and real GDP per capita in 2006, 2009, and 2014 in OBOR countries were used to perform EKC test. The results of EKC test showed that the countries were in the phase of the per capita energy consumption decreasing with the increase of per capita GDP and while per capita carbon emissions increasing with the increase of per capita GDP. Meanwhile, the decoupling of per capita carbon dioxide emissions and economic growth in OBOR countries was analyzed. It showed that a transformation from negative dcoupling to decoupling had been experienced in OBOR countries overall. Besides, the current average level of the countries is at the weak decoupling phase. Some solutions such as optimizing structure of energy consumption, strengthening in-depth cooperation on environmental protection and advancing energy-saving and environmental protection industries were presented, to promote the environmental friendly and low-carbon and sustainable development in OBOR countries.
The convention implementation of PFOSF/PFOS production industry based on cleaner production
ZHANG Xin, LI Yanping, QIAO Qi
2018, 8(6): 679-685. doi: 10.3969/j.issn.1674-991X.2018.06.090
Abstract:
Perfluorooctane sulfonate (PFOS) and perfluorooctane sulfonyl fluoride (PFOSF) were listed in Stockholm Convention as the newly-controlled persistent organic pollutants (POPs). As one of the member countries of this convention, China is currently the main country producing PFOS and is actively responding to PFOS reductions. There are many types of PFOS products, which are widely used in industry, lack of substitutes, so it is difficult to control PFOS industry. Therefore, how to implement the control of PFOS production industry is the key to achieve the source reduction of the PFOS performance target. By investigating the current situation of PFOS/PFOSF production industry and identifying the key nodes of PFOS production and emission, the cleaner production management system of PFOS production industry was analyzed. Two aspects of the development of the cleaner production technology were put forward, including the development of related product substitutes in PFOS production industry and the promotion of the cleaner production level in the existing industry. The cleaner production policy means to achieve PFOSF/PFOS performance targets was also proposed.
Performance evaluation of cleaner production audit in electrolytic manganese industry
HAN Guimei, ZHOU Changbo, WANG Fan, LIU Jingjun, ZHAO Zhiyuan, LI Xuhua, GUO Yajing, YUAN Yin
2018, 8(6): 686-694. doi: 10.3969/j.issn.1674-991X.2018.06.091
Abstract:
The development of the electrolytic manganese industry in China and the progress of its cleaner production audit were introduced. Through several rounds of cleaner production audit in the electrolytic manganese industry, the major environmental pollution problems in the electrolytic manganese industry were diagnosed. The standardized management system was established in the industry, the development of cleaner production technologies promoted, and the environmental benefits and economic benefits of typical medium and high fee options analyzed. Combined with the cleaner production evaluation index system of the electrolytic manganese industry, the variation of key cleaner production indexes such as the replacement of toxic and hazardous substances, comprehensive energy consumption and current efficiency in the industry from 2009 to 2017 was analyzed. The results showed that the comprehensive energy consumption had decreased from 8 600 kW ·h/t (in Mn) in 2009 to 6 900 kW ·h/t currently, and the current efficiency had shown an overall upward trend. For a company that had undergone multiple rounds of cleaner production audit, five evaluation indexes such as electrolytic cell, stripping method, DC power consumption, harmless treatment of manganese slag, and synthesis utilization rate and water-soluble manganese content (dry basis) in manganese slag reached the domestic advanced level, and played a leading role in energy conservation and emission reduction of the industry.