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Table of Content

Volume 31 Issue 2
25 March 2015
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Spatio-Temporal Distribution of Nitrogen and Phosphorus and Spatial and Multi-Variable Statistical Analysis of Its Impacting Factors in Xiaoqinghe Watershed
WANG Qiong, JIANG De-Juan, YU Jing, ZHANG Hua
2015, 31(2):  137-145.  doi:10.11934/j.issn.1673-4831.2015.02.001
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Water quality of the Xiaoqinghe Watershed in Shandong Province during rainy and dry seasons in the year of 2012-2013 were investigated. Based on the water quality monitoring data of the period, principal component analysis and cluster analysis were conducted to determine spatio-temporal distribution of various forms of nitrogen (N) and phosphorus (P) in the watershed. Meanwhile, spatial analysis and correlation analysis were carried out to analyze effects of types of land use on N and P export. Results show that nitrogen pollution of the watershed was very serious, with the over standard rate of total nitrogen (TN) reaching 100%. Ammonia nitrogen (NH4+-N) and orthophosphate-phosphorus concentrations (PO43--P) were significantly higher in the rainy season than in the dry season, whereas nitrate nitrogen concentration was in a reverse trend. Principal components (Z1) represented mainly by total phosphate (TP) and total dissolved phosphorus (TDP), explained about 50% of the total variability of water quality, while principal components (Z2), consisting mainly of TN, NH4+-N and NO3--N, explained about 20% of the total variability. TN, TP, NH4+-N, PO43--P and TDP concentrations were significantly and positively related to proportion of the residential and industrial zones in the area of the watershed and NO3--N concentration was positively related to proportion of the cropland, but negatively to that of the forestland and grassland. In terms of spatial distribution of nitrogen and phosphorus, the watershed could be divided into three groups of sub-watersheds: Group One and Group Two were distributed mainly along the main stream and in the northern plain, and being receptors of point source pollution wherethe concentrationof N and P were generally quite high and varied sharply, and Group Three was mainly in the southern mountain area, where construction area was quite low in proportion and pollution was low, too, in degree.
Characteristics of Changes in Climate in Typical Grassland Culture Relics Regions in Inner Mongolia
ZUO Hui-Ting, SHEN Wei-Shou, LI Zhong-Liang, YANG Shan-Shan
2015, 31(2):  146-150.  doi:10.11934/j.issn.1673-4831.2015.02.002
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Based on the daily meteorological observation data of the years from 1960 to 2010 at 32 meteorological observation stations in the relics regions of Genghis Khan Mausoleum, Yuan Dynasty Capital and Ganggyur Temple, typical of Inner Mongolia, comparative analysis was done of variations of the four meteorological factors, i.e. annual mean temperature, annual precipitation, aridity, and annual≥10 ℃ accumulated temperature, in the regions, using the linear trend estimation method and M-K nonparametric statistical validation method. Results show that generally, the climates in the three regions tended to be warmer and more arid, and during the 51 years, annual mean temperature and annual accumulated temperature displayed a rising trend, while annual precipitation a declining one. However, the changes varied between years and between regions. In terms of significance of the change for years in aridity, the three regions followed an order of the Genghis Khan Mausoleum >Yuan Dynasty Capital > the Ganggyur Temple , while in terms of mutation in annual mean temperature and annual precipitation, all the three regions experienced mutations in annual mean temperature, indicating that annual mean temperature fluctuated drastically, while phenomena of mutation in annual precipitation were found in the Yuan Dynasty Capital region and the Ganggyur Temple region, but not in the Genghis Khan Mausoleum region, indicating that the changes in annual precipitation were more obvious in the former two regions than in the latter. In terms of chronic sequence, the mutation in annual precipitation came later than that in annual mean temperature did.
Atmospheric VOCs Pollution Level and Its Diurnal Variation in Typical Urban Traffic Area and Background Area of Nanjing of China in Spring
SUN Yun-Jie, LU Jian-Gang, ZHAO Xin, ZHOU Xiao-Jing, DAN Yan-Hong, YING Rong-Rong, FENG Yan-Hong, LIN Yu-Suo
2015, 31(2):  151-157.  doi:10.11934/j.issn.1673-4831.2015.02.003
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In the spring of 2014, air samples were collected from a typical traffic area and a background area of Nanjing using Tedlar bags. In line with the methods of USEPA TO-15, a total of 30 kinds of volatile organic chemicals were detected. VOCs pollution of the air in the typical area and its diurnal variation were alsocharacterized. Results show that the concentration of VOCs in the air of the traffic area ranged from 122.58 to 236.97 μg·m-3, with the average value being (149.31±36.70)μg·m-3; while that in the background area was between 27.24 and 54.68 μg·m-3, with the average value reaching (43.29±10.53)μg·m-3.With respect to types of pollutants, olefins, aromatics, halogenated hydrocarbons and esters are the most prevalent contaminants in the atmosphere. In the traffic area, BTEX was the dominant volatile contaminant, ranging from 18.72 to 41.28 μg·m-3 in concentration and averaging (25.39±7.63) μg·m-3. As for diurnal variation of BTEX, its peaks appear at 9:00, 12:00 and 18:00, which is closely related to traffic volume. By contrast, the concentration of BTEX was relatively low without apparent variation in the air of the background area. The principal component analysis of BTEX in the traffic area reveals that benzene, ethylbenzene, p-m-xylene, o-xylene, 4-ethyl, 1, 3, 5-trimethylbenzene, 1, 2, 4 – trimethylbenzene were the major contributors to the pollution. Automobile exhaust was the principal source of BTEX contaminants in the traffic area.

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Spatial Variation of Domestic Water Consumption and Fate of Domestic Sewage in Rural Areas of Taihu Region, Jiangsu
LI Xin-Yan, LI Heng-Peng, YANG Gui-Shan, ZHANG Huan, CHEN Bei-Ye
2015, 31(2):  158-165.  doi:10.11934/j.issn.1673-4831.2015.02.004
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A survey was carried out by means of questionnaires of domestic water consumption and fate of domestic sewage in the rural areas of the Taihu Region, Jiangsu Province, China. Results show that rural domestic water consumption per capita varies sharply from area to area. The plain areas followed an order of Changzhou [99.2 L·(person·d)-1] > Suzhou [76.9 L·(person·d)-1] > Wuxi [64.1 L·(person·d)-1] and the hilly areas an order of Wuxi [118.6 L·(person·d)-1] > Zhenjiang [109.1 L·(person·d)-1] > Changzhou [93.6 L·(person·d)-1]. Income of the farmers and the population in the area are the two most important factors affecting domestic water consumption in the rural areas. Septic tanks are the most common way to treat domestic sewage in this region, and their domestic sewage treatment rate reached 96.6%, 92.8%, 91.0% and 84.9% in Wuxi, Suzhou, Changzhou and Zhenjiang, respectively. But the existing sewage treatment facilities are still far from enough to effectively reduce the pressure of sewage discharge on surface water environment. In terms of domestic sewage treatment efficiency, an order of Wuxi >Changzhou > Suzhou is found in the plain areas, being 60.9%, 22.8% and5.2%, respectively, and an order of Wuxi > Zhenjiang > Changzhou is in the hilly areas, being 55.7%, 9.1% and2.2%,respectively.
Accumulation Characteristics of Heavy Metals in Soils as Affected by Land Use in Southeast Tianjin
CHEN Zong-Juan, ZHANG Qian, ZHANG Qiang, SUN Wen-Bin, JU Mei-Ting, SHAO Chao-Feng, LI Fa-Sheng, GU Qing-Bao
2015, 31(2):  166-173.  doi:10.11934/j.issn.1673-4831.2015.02.005
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In order to investigate accumulation of heavy metals (As, Cd, Cr, Co, Cu, Pb, Ni, V, Zn, Hg) in topsoils different in land use in Southeast Tianjin, soil samples were collected from places different in land use, i.e. industrial land, residential land and agricultural land, for analysis of contents of the heavy metals in the topsoils. Accumulations of the heavy metals were characterized with the single factor index method and the Nemerow comprehensive index method. Results show that industrial lands were quite high in accumulation of Cd, As, Co, Ni and Zn; residential lands were inaccumulation of Cd, As, Co, Zn and Pb; and agricultural lands were in accumulation of Cd, As, Co and Zn. In the studied area as a whole, Cd was heavily accumulated, As moderately accumulated, and Co, Cu, Pb, Ni, V and Zn slightly accumulated; and Cr and Hg was quite close to their respective background value. The evaluation using the Nemerow comprehensive index method indicated that the heavy metals in the soils of most parts of the studied area accumulated to a moderate or severe degree, and by means of the evaluation using the Nemerow comprehensive index method, the three types of land use displayed an order of agricultural land > industrial land > residential land. Comparing with other regions of China, the studied area is obviously higher in accumulation of Cd, As and Co in surface soil.
Endangerment Grade and Protection Priority of Rare Plant Species in Baohuashan National Forest Park, Jiangsu Province
CHEN Rui-Bing, ZHANG Guang-Fu, LIU Juan, LI Shuo
2015, 31(2):  174-179.  doi:10.11934/j.issn.1673-4831.2015.02.006
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Grading of rare plant species in endangerment is crucial to determination of priorities of their conservation at a regional level. Based on field surveys, 24 selected rare and wild plant species in the Baohuashan National Forest Park, Jiangsu Province in subtropical East China, were evaluated quantitatively in the light of the Categories and Criteria of the IUCN Red List. For each species, endangerment coefficient and protection priority value was calculated, and grade in endangerment and sequence in protection priority determined. Results show that (1) the protection priority values of those species ranged from 0.327 8 to 0.802 2; (2) the 24 species could be classified into 5 categories in endangerment, that is, 1 in Category EW (extinct in wild species), 2 in Category CR (critically endangered species), 11 in Category EN (endangered species), 7 in Category VU (vulnerable species), and 3 in Category NE (nearly endangered species); and (3) habitat fragmentation and human disturbance resulting from tourist activities are the two major threats to the protection of rare plants in this area. Therefore, it is essential and urgent to intensify the management of tourism and hence to reduce human disturbance, and keep regular monitoring of dynamics of the threatened plants. The measures will help exert effective protection of those plant species.
Effects of Soil Moisture Regime on Rhizomatic Germination and Young Shoot Growth of Carex cinerascens
YANG Yang, CAO Yun, ZHANG Su-Juan
2015, 31(2):  180-187.  doi: 10.11934/j.issn.1673-4831.2015.02.007
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An indoor pot experiment cultivating Carex cinerascens using rhizomes to explore effects of soil moisture regime on rhizomatic germination, growth of young shoots and physiological features of the plants. The experiment, lasting 60 days, was designed to have 8 water treatments, i.e. C1(severe drought 2%), C2(10%), C3(15%), C4(20%), C5(25%), C6(30%), C7(40%, water saturation) and C8(50%, flooded with 2-cm-rhick overlying water). Result show: (1) Rhizomatic germination rate of the plant was low in Treatments C1 and C8 and reached 100% though in Treatment C2, where the young shoots were only 2/3 of those in Treatment C6, the maximum in mean plant height. Average height and aboveground biomass of the young shoots increased first and then decreased as the soil water content increased, and an exponential relationship was observed between height and biomass of the shoots; (2) Length, width, area and number of the leaves displayed a similar trend, increasing first and then decreasing as the soil water content increased except for Treatment C4. The plants adapted themselves to variation of soil water content by regulating their plant size, leaf area, number of leaves and growth rate for survival; (3) Contents of Chl a, Chl b, SPAD and Chl in young shoots also followed the same trend in variation, increasing first and then decreasing as soil water content increased, but chl a/b ratio did a reverse trend, decreasing first and then increasing as soil water content increased; The 8 treatments did not differ much in leaf water content and Car/Chl; Under water stress (too much or too little), the plants raised Chl a/b, maintained Car/Chl and rationalized distribution of Chla and Chlb, to guarantee normal photosynthesis process; (4) Quantitative analysis using the Gaussian Model shows that the ecological amplitude of water content for rhizomatic germination and growth of young shoots of Carex cinerascens was in the range of 4.15% -51.35%, and the optimum water content in the range of 16.22% -39.55%.
Landscape Prediction of Yangtze Estuarine Wetlands in 2020 Under Different Scenarios
LI Xi-Zhi, LI Xiu-Zhen, REN Lin-Jing, SHEN Fang, YAN Zhong-Zheng, HUANG Xing
2015, 31(2):  188-196.  doi:10.11934/j.issn.1673-4831.2015.02.008
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Based on the analysis of classified remote sensing images of the Yangtze Estuarine wetlands of 1980-2010, landscapes of the wetlands (Chongming Dongtan, Nanhui Biantan and Jiuduansha) in 2020 under three different scenarios (ecological protection, current trend and intensified reclamation) were predicted using the Dyna-CLUE and CA models. Results show that by 2020, the total area of the wetlands outside the dike will have increased by 56 and 44 km2, and decreased by 7 km2, respectively, under the three different scenarios. The area ratios of Phragmites/Spartina/Scirpus will have changed from 36:38:26 to 46:34:20, 38:38:24 and 38:37:25 respectively by 2020. Under the scenario of ecological protection, the area of the estuarine wetlands in Chongming Dongtan, Nanhui Biantan and Jiuduansha will have increased by 7 , 43 and 6 km2, respectively. Conversely, under the scenario of current trend or intensified reclamation, the area of estuarine wetlands will have been on a declining trend. The results of thestudy can provide some reference for the proper utilization and protection of the Yangtze Estuarine wetlands.
Coupling Relationships of Terrain Factors With Landscape Pattern and Ecological Restoration Measures in Small Watershed in Loess Hilly-Gully Region
GENG Sha, SHI Yun
2015, 31(2):  197-203.  doi:10.11934/j.issn.1673-4831.2015.02.009
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Gaojianpu Watershed in Pengyang County, a typical loess hilly region, was selected as subject of study. The watershed was divided into 8 types of landscape in the light of the ecological restoration measures adopted therein. With the aid of ArcGIS10.0 software, data of the status quo of landscape were processed and spatial distribution of landscape types in the watershed analyzed with spatial analysis methods, like spatial overlay, terrain analysis etc., by taking into account landform features of the watershed, delineation of elevational gradient zones by “ridge”、 “hill”、 “slope”  and  “gully”, based on DEM topographic maps and remote sensing images of the watershed and topographical factors, like slope, aspect, etc.. Results show that topographical elements are important factors affecting watershed ecological restoration, and spatial distribution of restored ecological landscapes in the watershed is closely related to topographical factors of the watershed and characterized by obvious vertical distribution. With rising elevation, landscape type changes, following an order of gully forest, economic fruit forest, grain-for-green grassland, enclosure for natural restoration, contour terrace fields, piezoglypts, and barren slope for afforestation; spatial distribution of landscape components is much affected by slope, with distribution ratio gradually increasing first and then decreasing; with aspect turning from shady aspect to sunny slope, grain-for-green grassland, contour terrace fields and barren slope for afforestation decreases in distribution ratio, while enclosure of barren hills for natural restoration, and economic fruit forest increases, and piezoglypts and gully forest landscape were not affected.
Effects of Landuse in Lake/Reservoir Shore Area on Reduction Rate of Nitrogen and Phosphorus in Groundwater
WANG Shou-Quan, YUAN Xu-Yin, HAN Lei, LIU Bin-Wu, LUO Xiao-Yong
2015, 31(2):  204-210.  doi:10.11934/j.issn.1673-4831.2015.02.0010
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Spatial variation of nitrogen and phosphorus concentrations in shallow groundwater in shore areas different in land use (cropland, grassland, woodland and barren bottomland) around Lake Tianmu and the Daxi Reservoir, to the west of Lake Taihu was studied, and effect of landuse reducing N and P in shallow groundwater and its affecting factors analyzed. Results show that nitrate-N was the major form of inorganic nitrogen in the shallow groundwater, varying in the range of 0.48 -6.83mg·L-1, and comparatively, ammonia-N was quite low in concentration. Woodland and grassland showed good effects of reducing nitrate-N in groundwater, with nitrate-N reducing rate reaching to 68.3% and 63.4%, respectively, while cropland did a reverse trend, increasing the concentration of nitrate-N somewhat. The phosphorus in the groundwater was mainly in the form of dissolved phosphorus. Barren land was the highest in P reduction rate, reaching up to 32.0% and followed by grassland and woodland. On the whole, the effect of land use in the shore area was far more obvious on the reduction of N than on P. Correlation analysis indicates that soil structure, vegetation type and hydrological regime were the major factors affecting N and P reduction rates in the studied shore area.
Fractions of Phosphorus and Migration in Sediments in Flooded Sinkages Around Panxie Coal Mine in Huainan
XIE Kai, XU Xin, ZHANG Lei
2015, 31(2):  211-217.  doi:10.11934/j.issn.1673-4831.2015.02.0011
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SinkagePJ, GQ and XQ are the three representative subsidences flooded with water in the eastern, central and western parts of the Panxie mining in Huainan, selected as subjects for relevant research. Fractions of phosphorus in the sediments of the studied sinkages were analyzed with the modified Psenner tractional extraction method, and distributions of phosphorus fractions, organic matter (OM), total nitrogen (TN) and iron oxides and translocation and transformation of the phosphorus in the sediments were also explored, taking into account of relevant water quality parameters. It was found that physicochemical properties and phosphorus fractionation varied significantly from layer to layer in the sediment profile. A declining trend down the profile was found with OM, nitrogen, phosphorus, and various forms of iron, Among the P fractions, BD-P tended to turn into other forms of phosphorus, which was closely related to iron oxidation-reduction, and Fe-Al-P accounted for a fairly large proportion (BD-P and NaOH-P amounted to 50% of TP), which is a pool ready to release phosphorus. But at the same time, the high content of iron oxides in Panxie mining area had a strong effect inhibiting phosphorus migration.
Methane Oxidation Potential of Landfill Cover Soil and Its Influencing Factors
ZHANG Hou-Hu, PENG Yu, CAI Bang-Cheng, ZHAO Jun
2015, 31(2):  218-222.  doi:10.11934/j.issn.1673-4831.2015.02.0012
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An indoor batch incubation experiment was carried out to explore methane oxidation potentials of four  kinds of typical landfill cover soils [aged sandy cover soil (ASCS), new sandy cover soil (NSCS), aged clayey cover soil (ACCS) and new clayey cover soil (NCCS) ]and effects of moisture content and temperature on methane oxidation rate (MOR) of ASCS and ACCS. Results show that in terms of MOR, the four types of cover soils followed an order of ACCS >ASCS >NCCS >NSCS; MOR of the aged cover soils was dramatically affected by both moisture content and temperature and ascended and then descended with rising water content and temperature; MOR was the highest when moisture content and temperature was at 25% and in the range of 20-30°C,respectively. Besides, addition of sawdust (SD) and cow dung (CD) mixture with mixing ratio varying between 4:0 and 3:1, increased MOR significantly in NSCS and NCCS; MORs peaked in NSCS and NCCS added with SD and CD mixture 1:3 in ratio, being about 1.63 and 1.41 times as high as that in the control, respectively. It is, therefore, recommended that in designing landfill cover, SD and CD mixture be added to increase CH4 oxidation potential of new cover soils.
Effect of Nitrogen Forms on Aluminum Toxicity to Soybean (Glycine max ) and Aluminum Speciation on Root Surface
LIU Yuan, XU Ren-Kou
2015, 31(2):  223-229.  doi:10.11934/j.issn.1673-4831.2015.02.0013
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Al toxicity, being a major factor limiting plant growth in acid soils, has been investigated extensively, but little has been reported on relationship between Al toxicity and Al speciation on plant root surface. A hydroponic experiment, designed to have two treatments, alternation of N and Al, or both N and Al simultaneously, was carried out to explore effects of forms of nitrogen on Al toxicity to soybean(Glycine max) and joint effect of N and Al on Al speciation on soybean root surface. Results show that regardless of treatment, the amount of Al ions adsorbed on soybean root surface was higher in the nitrate system than in the ammonium system when N and Al were added simultaneously. In the treatment of alternation, Al toxicity to soybean was observed, significantly inhibiting extension of soybean roots and reducing biomass of the plant, and did not differed much in extent between the ammonium system and the nitrate system. However, the growth of soybean was better in the nitrate system than in the ammonium system no matter whether in treatments with or without aluminum. Nitrate also enhanced the absorption of Mg, K, and Mn by soybean roots. Ammonium alleviated Al toxicity to soybean by competing for adsorption sites with Al when both N and Al were present in the solution.
IBR Index-Based Assessment of Toxicity of No.0 Diesel Fuel to Sparus macrocephalus
JIANG Mei, LI Lei, SHEN Xin-Qiang, WU Qing-Yuan, NIU Jun-Xiang, XU Gao-Peng
2015, 31(2):  230-237.  doi:10.11934/j.issn.1673-4831.2015.02.0014
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Changes in activities of antioxidant enzyme superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST) ,peroxidase (POD) and lipid oxidation degree (content of malonyldialdehyde, MDA) in livers, gills and muscles of Sparus macrocephalus exposed to water soluble fractions of No.0 diesel fuel (WSF) were studied, to quantitatively assess toxicity of No. 0 diesel fuel to the fish using the integrated biomarker responses(RIB)index method. Results show that once exposed to 0.60, 0.30 and 0.015 mg·L-1 of WSF, the fish were subjected to a regular pattern of change, i.e. induction-inhibition, in activities of SOD, GST and CAT in liver, gill and muscle, and in activity of POD as well. MDA content showed a reverse trend, that is, declining first and then rising. The effects varied somewhat from organ to organ, and the effect of inducing enzymatic activities was observed earlier in liver than in the other organs. In terms of oxidation stress tolerance obtained through RIB analysis, the organs followed an order of liver > gill > muscle. On the whole, RIB varied in a trend, rising first and then falling and RIB in liver was positively related to WSF concentration of No. 0 diesel fuel.
Effects of F- and Cl-on Growth of Chlamydomonas reinhardtii
LI Qian, WU Yan-You, LIANG Yong-Jie, WU Yun-Dong, ZHU Hong-Li
2015, 31(2):  238-243.  doi:10.11934/j.issn.1673-4831.2015.02.0015
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To explore toxic effects of F- and Cl- on growth of Chlamydomonas reinhardtii for comparison, algal biomass, specific growth rate and growth inhibition rate as affected by concentration of F- or Cl- were determined with the Erlenmeyer flask cultivation method and model analysis. Results show that F- in the range of 5-80 mg·L-1 was toxic to C. reinhardtii, inhibiting its growth and the growth inhibition rate increased with increasing exposure time and F- concentration, but its maximum growth inhibition rate dropped below 62% on D 10, which suggests that C. reinhardtii is quite tolerable to F- below 80 mg·L-1 in concentration. By contrast, Cl- could either promote or inhibit growth C. reinhardtii of  depending on Cl- concentration. When Cl- concentration was up to 12800 mg·L-1, its growth inhibition rate reached as high as 96%. F- and Cl- differs in effect on growth of C. reinhardtii, which is reflected mainly in the laws of the functions of the growth effect models varying with F- or Cl- concentration. Besides, in terms of EC50 under the same exposure time  F- (18.0 to 56.4 mg·L-1) was far too lower than Cl- (1 074 to 2 360 mg·L-1). That is to say, F- is more toxic to C. reinhardtii than Cl-,but the ecological risk of Cl- in the environment may not be ignored, either.
Effect of Thermal Alkaline Pretreatment on Production and Composition of Volatile Fatty Acid(VFA) in Food Waste Under Anaerobic Fermentation
SONG Zhen-Xia, WEN Fei, XU Jian-Ping, XU Da-Yong, CAI Chang-Feng
2015, 31(2):  244-248.  doi:10.11934/j.issn.1673-4831.2015.02.0016
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An experiment was carried out to explore effects of pretreatment of food waste with alkali at 80℃ for 30 minutes on production, concentration and composition of volatile fatty(VFA) in the food waste under single phase anaerobic fermentation at 35℃as affected by pH in the pretreatment. The experiment was designed to have five pH treatments, i.e. 8.0, 9.0, 10.0, 11.0 and 12.0. Results show that pH in the pretreatment significantly affected concentration and composition of the VFA produced in food waste under anaerobic fermentation. The content of total VFA, propionic acid and butyric acid in Treatments 10.0, 11.0 and 12.0, was higher than their respective ones in Treatments 8.0 and 9.0. During the 120 hours of anaerobic fermentation, contents of acetic acid and butyric acid are evidetly higher than contents of pentanoic acid in terms of proportion in composition for all treatments; and the sum of acetic acid and butyric acid accounted for 62.02%-82.08% of the total VFA, indicating a typical butyric acid-type fermentation. VFA concentration was the highest in Treatment 11.0, reaching up to 60.14 g?L-1 at the end of the 120-hour anaerobic fermentation and being 6.14%-48.45% higher than that in the other 4 treatments. Obviously pH 11.0 is the optimal one for thermo alkaline pretreatment of food waste for VFA production via anaerobic fermentation.
Straw/Grain Ratio of Wheat and Vertical Distribution of Wheat Straw in Jiangsu Province
GU Ke-Jun, XU Bo, GU Dong-Xiang, ZHANG Si-Mei, ZHANG Chuan-Hui, SHI Zu-Liang, YANG Si-Jun
2015, 31(2):  249-255.  doi:10.11934/j.issn.1673-4831.2015.02.0017
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In order to define total and characteristics of spatial distribution of the wheat straw resources in Jiangsu Province, investigations were done of straw resources of 13 varieties of spring wheat and 19 varieties of semi-winter wheat, commonly cultivated in Jiangsu. Samples of wheat straw were cut generally into 5 sections, 5 cm each, beginning from the basal node, 0-5, >5-10, >10-15, 15-20  and >20cm, dried and weighed separately and the spikes were threshed, leaving hull and rachis (Section 6), which were dried and weighed, too. On such a basis, analysis was done of straw/grain ratio and proportion of each section of straw to the whole wheat straw in biomass in relation to wheat variety and yield, Results show that the varieties of spring wheat were much lower than those of semi-winter wheat in straw/grain(S/G)ratio . The former was 1.05- 1.07 and the latter was 1.38 - 1.40 on average. However, both the two ecological types of wheat decreased in S/G ratio with increasing yield. The varieties of spring wheat varied in the range of 0.96 - 1.42, while those of semi-winter wheat did in the range of 1.21 -1.77. The variation differed from year to year. In the 2010 ~ 2011 wheat season, the crops low in yield (4000-6250 kg·hm-2) were significantly higher in S/G than those super-high in yield (> 8500 kg·hm-2), while in the 2012-2013 wheat season, no big difference in S/G between crops high or low in yield. The two varieties of wheat, different in eco-type, differed, too, in spatial distribution of straw. The proportion of the six parts (5 sections of straw and spike) was 8.00%, 7.06%, 6.64%, 6.57%, 48.00% and 23.75%, respectively, of the total of a whole spring wheat plant, and 10.11%, 8.07%, 7.39%, 7.06%, 44.53% and 22.85%, respectively, of the total of a whole semi-winter wheat plant. When the crop varied within the range from 4750 to 8500 kg·hm-2 in yield, the proportions of the six parts of plant did not change much, but when the crop was super high in yield (>8500 kg·hm-2), the proportion of Section 6 was significantly lower than that when the crop was low in yield (4000-4750 kg·hm-2). The S/G and straw distribution of wheat in Jiangsu Province are much affected by eco–type and grain yield level of the wheat.
Assessment of Potential Non-Point Source Pollution Risks of High-Yield Farmland With Life Cycle Assessment Method
WANG Yi-Chao, ZHAO Gui-Shen
2015, 31(2):  256-261.  doi:10.11934/j.issn.1673-4831.2015.02.0018
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The Life cycle Assessment (LCA) method has been an effective tool to evaluate negative externalities of agro-ecosystems. Here, it is used to comprehensively predict and evaluate potential non-point source pollution risks of grain production in high-input high-output grain production areas, starting with the sources of external input of the agricultural system. Huantai County of Shandong, in North China Plain was selected as a case for study. Results show that under the winter wheat-summer maize rotation system, which is a typical farming system in North China Plain,for of non-point source pollution, eutrophication potential (EP) ranks first and is followed by aquatic ecotoxicity potential (AEP), and acidification potential (AP). Cultivation of summer maize is much higher in all the three indices, and what is more, EP and AEP of the cultivation of summer maize and EP of the cultivation of winter wheat all exceeded the world’s per capita environmental impact potentials of the year of 2000. The complex non-point source pollution potential risk Index(IP) of the cultivation of winter wheat and summer maize, iwas 1.08 and 1.45, respectively, and obviously the latter is 34% higher than the former. Under the winter wheat-summer maize rotation system, the crop of summer maize contributes more than the crop of winter wheat to non-point source pollution. Application of nitrogen fertilizer contributes 99.75% and 88.06%, respectively, to AP and EP, and application rate of pesticides determines size of AEP. Based on the fertilizer application rate recommended in the nutrient management optimization programme for agricultural non-point source pollution comprehensive management techniques demonstration zones, it can be predicted that the IP of the crop of winter wheat and of summer maize may decrease by 2.91% and 18.35%, respectively, nevertheless, the latter is still higher than the former inIP. Therefore, it can be assumed that the practice of reducing input of nitrogen fertilizer and pesticide is the key to control of agricultural non-point source pollution.
Parameters of Exposure Models for Sewage Treatment Plants and Their Impacts on Fate of Chemicals
FENG Jie, ZHOU Lin-Jun, LIU Ji-Ning, SHI Li-Li, WANG Ji-Kui
2015, 31(2):  262-268.  doi:10.11934/j.issn.1673-4831.2015.02.0019
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Models for prediction of exposure of sewage treatment plants (STPs) are an important means of assessing fate of chemicals in the environment. Investigations and measurements were performed of parameters of the treatment technologies, sewage properties and environmental conditions of some typical STPs in China.Results show that the concentrations of BOD5 and suspended solids in inflows of the STPs in China are generally lower than those of the STPs in the EU. Fates for 2,6-di-tert-butylphenol, 2,4-di-tert-amyl phenol and 1-naphthol were compared using the EU SimpleTreat model between scenario parameters of China and the EU. It was found that in China of the three chemicals, a relatively low percentage entered into sludge and a quite high percentage discharged into waterbody, which indicates that pollution risk of the water environment is quite high. Sensitivity analysis of the model shows that the BOD5 and SS in inflow of STPs, organic carbon content in activated sludge and environment temperature are the main factors affecting fate of the chemicals.
A Quantitative Structure-Activity Relationship Model for Prediction of Octyl Alcohol/ Air Partition Coefficient of Organic Chemicals
FAN De-Ling, SONG Bo, LIU Ji-Ning, WANG Lei, ZHOU Lin-Jun, SHI Li-Li
2015, 31(2):  269-272.  doi:10.11934/j.issn.1673-4831.2015.02.0020
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Octyl alcohol/air partition (KOA) is an important parameter to describe distribution of organic chemicals in the air and environment and critical to evaluation of distribution, migration, transformation and ecological effects of chemicals. A total of 309 chemicals were structurally optimized with quantum chemistry methods and screened with the genetic algorithm for optimal descriptors. A quantitative structure-activity relationship (QSAR) model of log KOA was developed using the multiple linear regression (MLR) and neural network algorithm. The developed QSAR model indicates that the three Dragon descriptors (Nsk, Mor12u and HDon) were the main factors affecting Octyl alcohol/air partition coefficient of chemicals. The resultof fitting with the QSAR model shows that the R2 and SE (standard error)of the multiple linear regressions model was 0.911 and 0.880, respectively, while the R2 and RMSE(root mean square error) of the neural network model was 0.839 and 0.830, respectively. Application domain of the QSAR model was evaluated with the leverage method. The evaluation shows that the model is quite high in goodness-of-fit, robustness and predictive ability. Therefore, the QSAR model can be used to make up the missing data of lg KOA, thus lowering the cost of testing and uncertainty of data evaluation.