Table of Content

    20 March 2019, Volume 9 Issue 2 Previous Issue    Next Issue
    Research advances in Low-Level Jets theory and their impact on air pollutant transmission
    XIAO Zhisheng,MENG Fan,XU Jun,HE Youjiang,ZHAO Yuxi,YU Yang,ZHANG Boya
    2019, 9 (2):  111-118.  doi: 10.12153/j.issn.1674-991X.2018.11.200
    Abstract ( 210 )   HTML ( 30 )   PDF (1165KB) ( 98 )   Save

    Low-Level Jet (LLJ) is a weather phenomenon closely related to air pollution and other phenomena. The definitions of low-altitude jets, daily variation characteristics, seasonal variation characteristics, and the formation and development mechanisms of low-altitude jets including inertial oscillation theory, thermal and dynamic effects of terrain, and forcing of weather systems were summarized. The research results of numerical simulation of low-level jets developed at home and abroad and their influence on the transport and diffusion of pollutants discharged from atmospheric pollution sources were summarized. It was suggested that the next step should be to develop the low-altitude jet selection criteria and perform the cross-disciplinary study with air pollution discipline, and to carry out researches on the parameterization scheme and small-scale studies suitable for the numerical simulation of low-level jet in the region.

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    Motor vehicles emission inventory at county level based on vehicle kilometers travel: a case study of Yanqing District of Beijing
    WANG Kai,FAN Shoubin,SUN Gaihong,QI Haoyun
    2019, 9 (2):  119-125.  doi: 10.12153/j.issn.1674-991X.2018.09.140
    Abstract ( 102 )   HTML ( 10 )   PDF (3893KB) ( 35 )   Save

    Vehicle type, environmental condition, vehicle mileage and fuel type of motor vehicles in Yanqing District were surveyed and calculated. The COPERT model was used to compute the emission factors of CO, HC, NOx and PM for passenger cars, buses, small trucks, medium trucks and oversized trucks, respectively. Geographic information system was applied to establish high-resolution exhaust emissions inventory, based on vehicle driving range (VKT) database in Yanqing District obtained by field investigation and Google Earth satellite image. Then the vehicle kilometers travel data and the corresponding pollutants emission were calculated by actual traffic information. The results showed that the annual emission of CO, HC, NOx and PM was respectively 1 995.49, 478.84, 2 466.06 and 156.65 t/a. Specifically, passenger cars had a higher contribution to CO and HC, which accounted for 36% and 72%, while the oversized trucks had a higher contribution to NOx and PM, which accounted for 54% and 49%, respectively. High emissions were mainly distributed in the downtown area due to dense road network and larger traffic volume flow.

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    Structure characteristics and performance analysis of a novel cyclone-jet bubbling tower
    XIAO Yujun,LI Caiting,LI Shanhong,ZOU Yihui
    2019, 9 (2):  126-132.  doi: 10.12153/j.issn.1674-991X.2018.12.200
    Abstract ( 107 )   HTML ( 4 )   PDF (4189KB) ( 18 )   Save

    Based on the principles and advantages of jet bubbling reactor and cyclone separator, a novel type of bubbling tower, cyclone-jet bubbling tower, was designed aiming at the disadvantages of traditional bubbling tower which could not be applied to the flue gas contained large dust content. The distribution of gas phase, the separation property of gas-solid and the efficiency of demisting were analyzed by computational fluid dynamics (CFD) technology. The design integral equation of demisting ring was obtained according to the principle of force balance. The results showed that the uniform distribution of flue gas in the entrance cabin area and the separation of gas-solid at the external tower were achieved by the structure of volute cut-in entrance. The removal efficiency of 5-100 μm and 1-10 μm size dust were 99.43% and 53.70%, respectively. The demisting efficiency was improved from 98.39% to 99.08% by the structure of demisting ring. And the critical particle size of droplet was decreased from 0.047 mm to 0.021 mm. Under the condition of the critical droplet diameter, the demisting efficiency of the swirl plate demister with the demisting ring was 96.20%.

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    Pollution whole-process control analysis of typical dry pulverized coal bed gasification
    WANG Hejing,MU Binzi,LI Jun,CUI Jishan
    2019, 9 (2):  133-138.  doi: 10.12153/j.issn.1674-991X.2018.11.080
    Abstract ( 71 )   HTML ( 7 )   PDF (818KB) ( 37 )   Save

    Modern coal chemical industry is a new industry based on traditional coal chemical industry, which is oriented by clean utilization and efficient transformation of coal. During the 13th Five-year Plan period, China's modern coal chemical industry is still at the demonstration stage. Typical dry pulverized coal bed gasification technology is an important technology in modern coal chemical industry. Through the analysis of the pollutant discharge characteristics of the whole process and from the perspective of source control, the suggestions for optimizing the selection of raw and auxiliary materials and optimizing the process structure design and equipment selection were put forward. From the perspective of process control, the suggestions of key parameters of process control operation, enhancement of routine inspection and optimization of pollution source discharge were put forward. From the perspective of end-of-pipe treatment, the corresponding treatment technologies of main discharge links of pollutants were listed.

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    The effects of filamentous sludge bulking on performance and bacterial community structure of pilot-scale denitrification reactor
    XU Zicong,LI Haisong,HU Peiji
    2019, 9 (2):  139-144.  doi: 10.12153/j.issn.1674-991X.2018.10.300
    Abstract ( 105 )   HTML ( 10 )   PDF (2049KB) ( 49 )   Save

    The effect of filamentous sludge bulking on the performance of a pilot-scale denitrification reactor with effective volume of 10 m 3 and flow rate of 300 m 3/d was investigated. The changes of bacterial community structure were analyzed by high throughput sequencing.When the reactor operated normally for 66 days, sludge bulking phenomenon was observed and sludge sedimentation performance deteriorated significantly; the SV30 rose from 30% to 85%, and the biomass in the reactor decreased, with the mixed liquid suspended solids (MLSS) decreasing from 3 300 mg/L to 1 400 mg/L. The microscopic examination found that a large number of filamentous micro-organisms extended out of the flocs, and the close bacterial micelles were destroyed, which indicated that the sludge bulking was mainly caused by filamentous bacteria. Furthermore, high-throughput sequencing confirmed the filamentous bacteria such as Thiothrix, Leptothrix and Haliscomenobacter were enriched after sludge bulking, and were changed by filamentous bacteria types and environmental factors, indicating that higher sulfide and lower DO may provided better conditions for sludge bulking. It was noted that the denitrification performance of the reactor was not affected by sludge bulking and sludge loss, which may attribute to the increase in abundance of denitrifiers such as Methyloversatilis, Hydrogenophaga and Thiothrix (29.74%, 1.69% and 3.45%, respectively). Besides, the shift of bacterial community structure might cause changes in the abundance of functional genes.

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    Effect of A/O+ aluminum sludge filled constructed wetland combined process on rural domestic sewage
    ZHANG Ruibin,XI Daoguo,WANG Leyang,HUANG Jinxin,ZHANG Qiang
    2019, 9 (2):  145-150.  doi: 10.12153/j.issn.1674-991X.2018.11.270
    Abstract ( 108 )   HTML ( 8 )   PDF (1850KB) ( 48 )   Save

    The aluminum sludge, a by-product of the water supply plant, was used as the filler of the constructed wetland, and A/O+ aluminum sludge filled artificial wetland combination process was adopted to treat the rural domestic sewage. The results showed that the total average removal rates of chemical oxygen demand, ammonia nitrogen, total nitrogen and total phosphorus were 82.33%, 81.58%, 76.22% and 86.50%, respectively, and the effluent quality could reach Level 1A standards of Pollutant Discharge Standard of Urban Sewage Treatment (GB 18918-2002). The removal rate of TP was 50.43% in aluminum sludge filled constructed wetland, significantly higher than that of traditional wetlands. The adsorption of aluminum sludge filler was the main way to remove phosphorus. The combination process of A/O + aluminum sludge filled constructed wetland could effectively improve the efficiency of nitrogen and phosphorus removal, realize the deep treatment of sewage, alleviate the blocking of wetlands, and extend the service life of constructed wetlands.

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    Application progress of microbial agents in water remediation
    TANG Wei,ZHANG Yuan,WANG Shuping,DING Sen,QIAN Chang
    2019, 9 (2):  151-158.  doi: 10.12153/j.issn.1674-991X.2018.11.050
    Abstract ( 234 )   HTML ( 24 )   PDF (998KB) ( 138 )   Save

    The use of microbial agents for bioremediation of polluted water has the characteristics of cost-effectiveness, low energy consumption and no secondary pollution. In recent years, great progress has been made in the research and application of microbial agents in water remediation, which has become one of the research hotspots of water bioremediation technology. Through literature search and patent statistics, the research and application status of microbial agents at home and abroad were analyzed. The principle of microbial agents in water remediation and the removal of nitrogen, phosphorus, heavy metals and refractory organics in water were reviewed. The preparation process of microbial agents was briefly introduced, and the application of microbial agents in the repair of black and odorous water bodies, aquaculture water bodies and micro-polluted water sources was summarized. Finally, the problems of microbial agents in water remediation were analyzed, and their development prospects forecasted.

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    Temporal and spatial variation of main pollutants in Baihexi River,the western inflow river of Erhai Lake
    DAI Dan,GE Jun,HU Xiaozhen,LEI Kun,PANG Yan,KONG Xin,GUAN Heqing
    2019, 9 (2):  159-166.  doi: 10.12153/j.issn.1674-991X.2018.12.210
    Abstract ( 85 )   HTML ( 5 )   PDF (2738KB) ( 64 )   Save

    To explore the impacts of the inflow rivers on the water quality of Erhai Lake, a continuous survey of water quality for the Baihexi River, the inflow river of west Erhai Lake, was carried out from September 2013 to August 2014. The spatial and temporal variations of the pollutant concentrations and sources were studied, the pollutant loads into the lake estimated, and their main sources analyzed. The results indicated that the water quality of the upstream and the midstream of the Baihexi River were relatively good, with an average of Grade Ⅲ (Environmental Quality Standards for Surface Water (GB 3838-2002)); followed by the estuary and downstream regions, which were in Grade Ⅳ. The CODMn ((5.10±1.38)mg/L) and concentration of N H 4 + -N ((0.87±0.76)mg/L) in Baihexi River was relatively low, while the concentration of TN ((2.81±1.24)mg/L) and TP ((0.26±0.12)mg/L) was high, TN and TP are the main indicators of water pollution. The main pollutant loads were the highest during July to October, accounting for about 70% of the total annual pollutant loads, followed by December to February, accounting for 18% or so, and the pollutant loads were relatively low in other months. The CODMn and N O 3 - -N concentrations in the wet season were obviously higher than those in the dry season (P<0.05), while the concentrations of N H 4 + -N, TN and TP in the wet season had no significant difference with those in the dry season. These indicated that CODMn and N O 3 - -N mainly derived from non-point sources, while N H 4 + -N, TN and TP were affected by both point sources and non-point sources.

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    Purification effect and stability of water quality of different functional units in Laoyuhe Wetland Park of Dianchi Lake
    SONG Xueyan,MA Lan,ZHAO Haixi,TU Qi,LU Yifeng,LU Shaoyong
    2019, 9 (2):  167-174.  doi: 10.12153/j.issn.1674-991X.2019.01.030
    Abstract ( 323 )   HTML ( 13 )   PDF (3017KB) ( 38 )   Save

    Taking Laoyuhe Wetland Park (WPlyh) in Dianchi Lake as the research object, sampling points were set up in different functional units of the wetland to analyze the removal effects of CODCr, N H 4 + -N and TP by different functional units in the testing operating period from April 15 th, 2015 to May 14 th, 2015. Sampling points were also set up at the inlet and outlet of wetlands and the long term operation effects in the period from April, 2015 to March, 2017 were monitored and analyzed. It revealed that during the WPlyh test run, the CODCr, N H 4 + -N and TP concentrations in the outlet were significantly lower than those in the inlet, with the removal rates of 40.07%, 48.48% and 40.38%, respectively, while the treatment effect was still unstable. Among the functional units, the surface flow wetland at the entrance of the lake had the best removal effect on CODCr with removal rate of 10.36%, the front part of the inter-forest shallow-water wetland had the best removal effect on N H 4 + -N with the removal rate of 17.59%, and the back part of the inter-forest shallow-water wetland had the best removal effect on TP with the removal rate of 9.44%. It means that the decontamination rate of the inter-forest shallow-water wetland accounted for 53.15% of WPlyh total decontamination rate, which could be regarded as the best purification unit in the wetland parks. WPlyh's monthly reductions and removal rates for CODCr, N H 4 + -N, and TP during long term operation and the removal rates of the three characteristic pollutants showed a downward trend with time. Especially after one year of operation, the downward trend was most obvious.

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    Modeling of specific growth rate factors of microalgae based on constructional function method and its carbon emission reduction potential
    LIU Jianjian,ZHAO Bingtao,SU Yaxin
    2019, 9 (2):  175-180.  doi: 10.12153/j.issn.1674-991X.2018.11.260
    Abstract ( 68 )   HTML ( 3 )   PDF (1105KB) ( 45 )   Save

    Three key influencing factors of specific growth rate of microalgae, i.e. CO2 concentration, light intensity and nitrogen concentration were chosen, and ten kinds of univariate non-linear models used to construct a multivariate non-linear model between the three factors and the specific growth rate of microalgae by constructional function method. After the correlation parameter test of the significance P value less than 0.05 and the collinear diagnosis of VIF less than 5, the final determination coefficient (R2) of the multivariate nonlinear regression equation was 0.917, which could be used for the effective prediction of the growth rate of microalgae. On this basis, through the analysis of the effect of the equation on the three factors, it was concluded that when CO2 concentration was 5%-15%, the specific growth rate of microalgae was high, and the specific growth rate gradually increased with the increase of light intensity (45-480 μmol/(m2 ·s)) and nitrogen concentration (0-700 mg/L). The biomass yield of microalgae was predicted to be 7.2-100.2 kg/(m3 ·a) by regression model, and the absorption and fixation of CO2 by microalgae was estimated to be 7.92-183.70 kg/(m3·a).

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    Removal characteristics of pollutants by riverine natural wetland in prairie region
    REN Yaozong,LIU Guo,YU Hong,YANG Tianxue,WU Youbing,XU Qiujin,PANG Yan,LI Dongyang,LI Qi
    2019, 9 (2):  181-187.  doi: 10.12153/j.issn.1674-991X.2018.12.290
    Abstract ( 71 )   HTML ( 4 )   PDF (1972KB) ( 28 )   Save

    In order to clarify the removal effects of total phosphorus (TP), total nitrogen (TN) and chemical oxygen demand (COD) in river-type natural wetlands in the grassland, the Hailaer River wetland was studied. The changes of TP, TN and COD in the inlet (Taohai section) and the outlet (Cuogang section) during 2010-2015 were analyzed. The removal effects of TP, TN and COD in wetlands in different months were analyzed, and the mechanism of pollutant removal was discussed. The results showed that the coefficients of variation of TP, TN and COD in the Taohai section were 0.51, 0.73 and 0.39, respectively, and in the Cuogang section were reduced to 0.36, 0.43 and 0.38. The removal rates of TP, TN and COD in Hailaer River wetland were 26.67%, 20.90% and 8.74%, respectively. At present, the load of TP, TN and COD in wetland inflow had not exceeded their purification capacity. During the snowmelt period (May) and summer rain period (August to September), the wetland had lower removal of TP and TN . During the weak surface runoff period (January to March, October to December), the TP, TN and COD were highly removed. The removal of TP by wetland was mainly by bio-assimilation and soil adsorption during ice-thaw period, and by soil adsorption and precipitation during freezing period. The removal of TN by wetland was mainly by nitrification and denitrification and biological assimilation in ice-melting period, followed by sediment adsorption and biological assimilation in freezing period. The removal of COD in wetlands was mainly due to microbial degradation and soil adsorption.

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    Application of fibrous biological blanket in control of urban non-point source pollution
    JIANG Dengling,WANG Gongting,HE Liansheng,HU Chunming,ZHANG Danrong,HUO Chuan,DING Tingting,MENG Rui
    2019, 9 (2):  188-193.  doi: 10.12153/j.issn.1674-991X.2018.08.150
    Abstract ( 89 )   HTML ( 2 )   PDF (1184KB) ( 58 )   Save

    The high rate of urban surface hardening can lead to increased non-point source pollution, and thus affect the water quality of surface water. The fibrous biological blanket is a new technology to solve the urban non-point source pollution. It has the characteristics of low cost, fast construction, fast plant growth, high plant survival rate, good landscape effect and convenient management. It can effectively improve the stability of the river slope and intercept and purify the non-point source pollution. The structure and function of fiber biological blanket, purification effect and factors of affecting the purification effect were summarized. The directions and methods to improve the impact resistance of slope surface, the adaptability of soil, the improvement of material and structure and the reduction of maintenance cost were pointed out.

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    Study on spatial distribution of city-industry layout and assessment of residential safety in Beijing-Tianjin-Hebei region
    LI Yangyang,WANG Zishu,LIU Yi,LI Wangfeng,LI Qian
    2019, 9 (2):  194-200.  doi: 10.12153/j.issn.1674-991X.2018.09.070
    Abstract ( 112 )   HTML ( 20 )   PDF (2736KB) ( 50 )   Save

    Beijing-Tianjin-Hebei region is a place with high density of population, which makes residential security an important precondition during new urbanization. However, there are significant spatial differences in the level of regional urbanization development. The problems of city-industry mixing and “dispersed, poorly managed and polluted” enterprises are prominent. Urban human settlement environment security is facing severe challenges, and the spatial layout needs to be further optimized. The spatial relationship of city and industry was analyzed through the geographic information system, and at the same time, the sensitivity of human settlement risk with spatial information was assignment by characteristic index. The analysis found that the Beijing-Tianjin area, Beijing-Shijiazhuang line and Tangshan area were the most residential sensitive and most industrial intensive areas in Beijing-Tianjin-Hebei region. In addition to the obvious suburbanization trend of industrial plants in the Beijing-Tianjin region, the population distribution in Tangshan and middle and south area of Hebei Province was highly overlapped with urban boundaries and industrial plant distribution space, and the relationship between industry and city was complicated. Finally, based on the analysis of the relationship between human settlement security and city-industry relationship, some suggestions for urban spatial pattern optimization and human settlement security were put forward.

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    FTA-based safety evaluation and prevention of dam break and tailings leakage in tailings reservoir
    ZHANG Jiarong,LIU Jianlin
    2019, 9 (2):  201-206.  doi: 10.12153/j.issn.1674-991X.2018.10.190
    Abstract ( 160 )   HTML ( 3 )   PDF (1723KB) ( 72 )   Save

    The hazards, safety evaluation methods and preventive measures of tailings reservoir were systematically studied. The fault tree analysis (FTA) of a tailings reservoir was performed. The results showed that the ways and causes of the tailings reservoir failure and tailings leakage were various, with 17 and 12 ways, respectively. Close attention should be paid to these ways in the actual production process and great efforts made to investigate them and strengthen the pre-control. According to the different conditions that may appear in tailings reservoir, scientific and reasonable countermeasures should be put forward, and pre-control strengthened, which could greatly reduce the losses caused by tailings reservoir dam failure and tailings reservoir leakage.

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    Discussion on environmental risk analysis and management countermeasures of waste power batteries recovery in China
    WANG Yibo,GUO Yuwen,SUN Zhi,RUAN Jiuli,ZHANG Jianqiang
    2019, 9 (2):  207-212.  doi: 10.12153/j.issn.1674-991X.2018.10.090
    Abstract ( 196 )   HTML ( 16 )   PDF (1122KB) ( 69 )   Save

    With the vigorous promotion and use of new energy automobiles, a large number of waste power batteries will be produced. The potential environmental risks in the recycling process are both related to the battery’s own materials, and impacted by the amount of waste, metal regeneration technology, pollution prevention measures and so on. The electrolyte components, the potential environmental risks and potential health risks of batteries during recycling, transportation and storage were analyzed, and the secondary pollution risks of pretreatment and metal regeneration processes also discussed. At the same time, using the market supply A model, it was predicted that China’s waste power battery production will surge in the future. Based on the environmental risks brought by large number of waste power batteries, environmental management suggestions were proposed from several aspects, including accelerating the construction of the recycling system of waste power batteries, strengthening the precise management of key nodes for production and discharge, setting pollution prevention standards, etc.

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