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Table of Content

Volume 31 Issue 3
25 May 2015
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Scales of Hydrological Regulation Service of Dayekou Watershed Eco-system in the Qilian Mountains
SUN Fei-Xiang, Lü Yi-He , HU Jian
2015, 31(3):  273-279.  doi:10.11934/j.issn.1673-4831.2015.03.001
Abstract ( 619 )   HTML ( 2)   PDF (2287KB) ( 1920 )  
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Eco-hydrological service is a main component of ecosystem services. In the upper reaches, mountain eco-system hydrological regulation service is realized through vegetation-soil complex. It was found through monitoring and statistic/correlation analysis of precipitations/runoffs during 2002-2010 in the Dayekou watershed in the northern slope of the mid-section of the Qilian Mountains that the mountain eco-system could turn intermittent precipitations into continuous and relatively stable runoffs through hydrological regulation, thus significantly regulating spatio-temporal distribution of the runoffs. On the time scale of a single rainfall event and continuous raining period, the regulation mainly affects the response relationship of precipitation-vegetation-soil water in the sample site, while on the catchment scale it does the relationship between precipitation and runoff. The statistic and correlation analysis of precipitation/runoff ratio on monthly and yearly scales reveals that vegetation during its growing period has some impacts on runoff of the watershed, but has little on the annual general trend of precipitation - runoff generation in the watershed. The impact of growing vegetationon runoff is reflected in variation of runoff between years. Linear regression statistics and correlation analysis of vegetation indices (leaf area, net primary productivity and vegetation coverage) of 2002-2010 with “blue water""green water” ratio indicates that the increase in vegetation indices is somewhat related to the decrease in “blue water” and the increase in “green water”. According to the conclusion of this study, evaluation of eco-system hydrological services in the Qilian Mountains should take into overall account harmonious development of ecological maintenance in the upper reaches streams and agriculture/animal husbandry in the middle and lower reaches, and the economic and social development of the whole Qilian mountain region as well, and it is essential to recognize objectively the contradiction between the storage of "green water"in the upper reach mountainous eco-system and the demand for "blue water" in the middle and lower reaches.
Distribution of Aquatic Macrophytes in the Huaihe River Basin and Causes
JIANG Li, LI Feng, WANG Zhi-Qiang, CHEN Xin-Sheng, REN Bo, XIE Yong-Hong
2015, 31(3):  280-285.  doi:10.11934/j.issn.1673-4831.2015.03.002
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In order to explore community characteristics and distribution of aquatic macrophytes in the Henan section of Huaihe River Basin and causes, field survey in addition to in-laboratory analysis was carried out of composition of aquatic macrophytes, and characteristics of the water and the soil environment and their relationship in the basin. Results show that a total of 51 species of aquatic macrophytes were detected, including 28 species of emergent plants, 12 species of submerged plants and 10 species of floating-leaved plants, 1 species of floating plant, which accounts for 54.9%, 23.5%, 19.6% and 2.0% of the total, respectively. They formed 14 types of communities, of which 5 were dominated with submerged plants, 6 with emergent plants and 3 with floating leaf plants. The communities varied sharply in environment, especially factors, like NH4+-N, NO3--N,TN,TP and PO43- in the water.CCA reveals that water envionment factors,such as TP, PO43-,NH4+-N and DO concentrations, were the key factors determining distribution of the aquatic macrophytes in the Huaihe River Basin.
Spatio-Temporal Characteristics of Aerosol Optical Depth in North Xinjiang
HUANG Guan, LIU Zhi-Hong, LIU Wei, ZHANG Yang, ZHAN Peng
2015, 31(3):  286-292.  doi:10.11934/j.issn.1673-4831.2015.03.003
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Spatio-temporal distribution and variation of the aerosol optical depth (AOD) in North Xinjiang in 2000 - 2013 was analyzed using MODIS aerosol products various in resolution, and compared with the corresponding visibility data available for correlation analysis. Results show that spatially the mean AOD of the area in the past 14 years was high in the centre and low along the rim; The annual mean AOD of prefecture-level cities in the high-value region was 0.335, about 1.33 times as high as that of North Xinjiang, and was the highest in Kuitun; the annual mean AOD of prefecture-level cities in the sub-high value region was 0.202, about 0.8 times as high as that of North Xinjiang and was the lowest in Tacheng; and there was no prefecture-level city in the low value region. Temporally, the annual mean AOD of North Xinjiang varied between 0.221 and 0.283 in the past 14 years, peaking in 2003 and bottoming in 2005; Within a year, AOD was the highest in Spring and the lowest in Autumn. For years, AODs in all the four seasons displayed a declining trend, and the drop in winter was the most significant; the monthly mean AOD of North Xinjiang varied between 0.186 and 0.395 in the past 14 years, peaking in February and bottoming in October. A significantly negative relationship was observed between monthly mean AOD and monthly mean visibility in Tacheng and Altay (P<0.05), while a reverse one was between the two in Urumqi and Shihezi (P<0.05).
Boosting Effect and Spatial Differentiation of Carbon Emissions Within Industrial Sector in Xi’an
ZHANG Yan-Fang, WEI He-Jie
2015, 31(3):  293-300.  doi:10.11934/j.issn.1673-4831.2015.03.004
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To better understand boosting effects and spatial differentiation of carbon emission from various industrial plants in Xi’an, an input-output analysis model was used to calculate direct and indirect carbon emissions from the plants. In line with relevant targets with county or district as basic unit, carbon emissions from various plants were distributed spatially among counties or districts as unit. It was found that about 90% of the industrial plants had more indirect carbon emission than direct carbon emission and the carbon emission within the sector displayed strong boosting effects and context effects. Carbon emissions from manufacturing industries like general equipment, special purpose equipment and electric equipment and machinery, etc.were higher in boosting effect, leading to increased carbon emissions from the industries, like thermo-power production thermo-power supplying, metal smelting, rolling processing, petroleum refining and  coke making, etc.. In Xi’an, the spatial distribution of carbon emissions from 6 major representative industries showed that Weiyang, Huxian and Yanta were priority districts for carbon emission reduction. In Xi’an City, the pulling effect of industrial carbon emission displayed a decreasing trend in geometrical progression from the innermost of the city to circumference of the city. The findings could serve as reference for policy-makers to determine responsibility each industrial sector should undertake for reduction of carbon emission. It is also helpful to the construction of a low-carbon city and realization of industrial upgrading in Xi’an City.
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Agent-Based Modeling and Simulation of Agro-industrial Compound Eco-industrial Park
HUANG Yi-Qiao, LIU Jing-Ru, WANG Xiao-Hua
2015, 31(3):  301-307.  doi:10.11934/j.issn.1673-4831.2015.03.005
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An Agro-industrial compound eco-industrial park is a society-economy-nature symbiotic system integrating agriculture and industry. A small-scale "enterprise and peasant household" agro-industrial compound eco-industrial park with a product-waste exchanging framework model is built up, using the Agent modeling method. Its economic, environmental and social benefits are analyzed through systematic simulation, and impacts and effects of the agro-industrial symbiosis on development and evolution of the agro-industrial compound ecosystem discussed in depth from the viewpoint of system simulation. Results of the simulation show that total output, total profit and symbiotic turnover of the park all display a stably rising trend along with cyclic changes and the increase is getting more obvious when symbiotic enterprises join in. The waste recycling rate in the park grows rapidly, the pesticide and chemical fertilizer application rates reduce gradually, and the organic manure application rate increases. Development of the park brings about a high proportion of eco-farming households, indicating that more and more farmers choose the path of eco-farming.
Analysis of Municipal Solid Waste Transfer Efficiency and Its Affecting Factors in Pudong New District Based on the DEA-Tobit Two-phase Method
ZHENG Ying-Ying, ZHOU Rui, WANG Xin-Jun
2015, 31(3):  308-313.  doi:10.11934/j.issn.1673-4831.2015.03.006
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By taking into account ecomic and environmental efficiencies comprehensively,the DEA-Tobit two-phase method was used to investigate transfer efficiency of municipal solid waste(MSW)and its affecting factors in the Pudong New District.In Phase One, the SBM-Model of the DEA method was used to analyze overall efficiency of the 13 MSW transferring units in the Pudong New District, and it was found that the mean MSW transfer efficiency was 0.668. Problems, like input redundancy, excessive undesirable outputs, etc. existed quite extensively in the district, and the spatial distribution of MSW transfer efficiency was characterized by being higher in the north and lower in the south. In Phase Two, the Tobit Model was applied to exploring external influencing factors. It was found that the collection density and sorting of MSW and equipment of the staging stations were the main factors affecting MSW transfer efficiency.
Features of Domestic Wastes and Environmental Awareness of People in the Rural Area of Southwest China
HAN Zhi-Yong, MEI Zi-Li, KONG Chui-Xue, CHEN Xi-Hui, FAN Jian-Qiang, XIE Yan-Hua
2015, 31(3):  314-319.  doi:10.11934/j.issn.1673-4831.2015.03.007
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Southwest China plays an important role in sustaining development of the country and has become one of the most important ecological shelters in China. Regarding the increasingly serious pollution of domestic wastes, 22 villages were selected randomly in the rural area of Southwest China for investigation of status quo of domestic waste pollution, disposal of domestic waste, people’s knowledge of domestic waste and their willingness to pay for domestic waste management by means of questionnaires;features of the domestic waste were investigated by field sampling and laboratory test. Results show that in that region, the domestic waste in the region, generated at was 178 g•d-1 per capita and composed mainly of kitchen waste, dust, rubber and paper, was 107 kg•m-3, 37.04 %, 25.73 %, 37.23 % and 8008 kJ•kg-1 , respectively. These domestic wastes were featured by low content of inert waste, high content of recyclable, low bulk density and high calorie. People in this area primarily learn about contamination of domestic waste from their intuitiveness, and their knowledge of recyclable wastes was greatly influenced by waste recyclers. Moreover, they lacked  recognition of toxic waste. Age, education and annual income of the people significantly influenced their knowledge of domestic waste, but not their willingness to pay for waste management. However, people’s willingness to pay for waste management decreased exponentially with the charge for waste disposal. If the charge for waste disposal is kept less than RMB¥5.00 per month per household, it is possible to implement the waste disposal charging system for management of domestic waste in the rural area of Southwest China.
Distribution of Fine Roots in Poplar-Winter Wheat Intercropping System and Its Response to Nitrogen Fertilization
WU Yong-Bo, WU Dian-Ming, XUE Jian-Hui, CHU Jun
2015, 31(3):  320-325.  doi:10.11934/j.issn.1673-4831.2015.03.008
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The method of stratified digging was adopted to study temporal and spatial distribution of fine roots in a four-year old poplar-winter wheat intercropping system relative to nitrogen fertilization and its difference from that in the winter wheat mono-cropping system, and to explore effect of the intercropping system reducing nutrient loss with runoff. Results show that (1) the winter wheat in the mono-cropping system was higher than that in the intercropping system in fine root length density and root dry weight per unit of soil; (2) the peaks of root length density and root dry weight per unit of soil appeared during the wheat milking stage in both systems; (3) with increasing nitrogen application rate, both the wheat and the poplar increased in fine root length density and root dry weight per unit of soil and for poplar the increase mainly occurred in the >40-80 cm soil layers; and (4) intercropping reduced nitrogen loss with leaching by 49.08%-55.49%.
Diversity of Birds in Five Lakes of Nanchang During Migration and Wintering Periods
SHAO Ming-Qin, SHI Wen-Juan, JIANG Jian-Hong, GUO Hong
2015, 31(3):  326-333.  doi:10.11934/j.issn.1673-4831.2015.03.009
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Diversity of birds in the five lakes of Nanchang during the period from October 2013 to April 2014 was investigated using the line transect and point count methods. A total of 114 species of birds belonging to 40 families 12 orders were recorded. Of the 114 species, 52 were water fowls, 3 [Oriental white stork (Ciconia boyciana), Black stork (Ciconia nigra),Siberian crane (Grus leucogeranus)] in the first category of national protected bird species and 6 in the second category of national protected bird species. In terms of type of settlement, residents and winter migrants dominated the species observed, accounting for 49.12% and 36.84%, respectively. Composition of the birds in type of settlement varied slightly with the season. Among the five lakes, the Aixi Lake was the highest (75 species) in number of bird species (F4,30=5.474,P=0.002), but the lowest (33.33%) in proportion of water fowl species to the total bird species. The Junshan Lake was the lowest in number of bird species and of forest bird species. The Jinxi Lake, Qinglan Lake, Junshan Lake were higher than the Aixi Lake and Yao Lake in number of water fowl species. The Yao Lake was the highest in diversity and evenness indices of the bird species, while the Junshan Lake was the lowest, but the highest in dominance. Among the five lakes, the Aixi Lake and Yao Lake were the highest in similarity coefficient of bird species. Evenness of bird species in the five lakes was much higher during the two migratory periods than during the wintering period (F2,4 =8.352, P=0.037). The number and percentage of water fowl species during the autumn migration period was quite similar to that, respectively, during the wintering period (F2,4=10.111, P=0.027) and extremely and significantly (F2,4=19.867, P=0.008) higher than that during the spring migration period. Urban lakes with reasonable exploitation can still provide a good living habitat for birds. Aquaculture may decrease diversity of bird species and simplify community structure of the birds.
Effects of Withering of Cyanobacteria Bloom on Abundance and Community Composition of Ammonia-Oxidizing Bacteria in Surface Lake Sediments
HUANG Rui, SHEN Feng, LUO Juan, WANG Si-Chen, TANG Qi-Tong, XU Hui-Min, WU Yan, ZHAO Da-Yong
2015, 31(3):  334-339.  doi:10.11934/j.issn.1673-4831.2015.03.010
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A simulation system was constructed to investigate effect of withering of Cyanobacteria bloom on abundance and community compostition of ammonia-oxidizing bacteria (AOB) in surface sediments.The system consisted of three treatments, [i.e. (1) CK, (2) addition of lab-cultured Cyanobacteria and (3) addition of wild Cyanobacteria collected from a lake]. Abundance, community composition and diversity of AOB were analyzed with the real-time qPCR and molecular biological methods, like clone library, etc.. Results show that (1) Treatments 2 and 3 were much higher than Treatment 1 in abundance and community diversity of AOB; (2) N. oligotropha group of Nitrosomonas was the dominant AOB group, accounting for approximately 75% of the total AOB community in the surface sediments; and (3) Compared to Treatment 1, Treatments 2 and 3 were found to have some new AOB groups, such as N. communis and Nitrosospira. The findings indicate that N.oligotropha is absolutely the dominant group in all the treatments, and withering of Cyanobacteria bloom may improve AOB in the surface lake sediments in both abundance and diversity.
Effect of Application of Mushroom Residue on Composition of Soil Aggregates in Paddy Field and Its Evaluation
LI Fang-Liang, WANG Huang-Ping, ZHANG Qing, WANG Qiu-Ying, LUO Tao
2015, 31(3):  340-345.  doi:10.11934/j.issn.1673-4831.2015.03.011
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Soil sample were collected from paddy fields different in mushroom residue application rate for analysis in laboratory of compostiton and stability of soil aggregates.Results show that application of mushroom residue change the distribution of soil aggreates to a certain extent.All in all, soil aggregates > 2.0, 0.5-1.0 and 0.25-0.5mm were dominant fractions, regardless of treatment (mushroom residue application rate). Application of mushroom residue increased the content of >2.0 mm soil aggregates, and the higher the mushroom residue application rate, the higher, the content of > 2.0mm soil aggregates. Mean weight diameter (MWD) and geometric mean diameter (GMD) increased with rising mushroom residue application rate (except for MR3), while fractal dimension (D) decreased with the rising rate. Correlation analysis shows that MWD is significant and positively related to GMD, and the contents of > 2.0  and 1.0~2.0 mm soil aggregates are significantly and positively related to MWD and GMD, but negatively related to D, though not significantly. MWD and GMD could be used as indices in evaluating stability of > 2.0  and 1.0-2.0 mm soil aggregates in soils applied with mushroom residue.
Decomposition of Soil Organic Carbon in Loess Tableland Relative to Type of Land Use
LI Yuan-Yuan, QI Lu, LIU Meng-Yun, LIU Li-Wen, ZHANG Yu-Ying 
2015, 31(3):  346-352.  doi:10.11934/j.issn.1673-4831.2015.03.012
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In order to explore effects of land use on decomposition of soil organic carbon in the Loess Plateau, soil samples were collected from lands different in land use, woodlot, shrubland, natural grassland and farmland for analysis of soil organic carbon and its mineralization characteristics. Results show that no matter whether in soil organic carbon content, organic carbon density, mineralizable carbon content and organic carbon mineralization rate, natural grassland, shrubland and forestland are all higher than farmland; while in soil organic carbon mineralization rate and soil respiration rate, farmland and arbor-shrub land are higher than natural grassland and shrubland. During the 1575 h of soil incubation, soil mineralization, regardless of land use,can be divided into four phases: 0.5─5 h (first phase), 5─111 h (second phase), 111─399 h (third phase), 399─1 575 (fourth phase). The first 399 h is the main period when minerlizable carbon is emitted; during the first 111 h, soil mineralization carbon emission rate peaks and drops the fastest too; as a whole, cumulative soil mineralizable carbon emission increased and cumulative emissions rate gradually decreased with the incubation going on. Soil organic carbon mineralization rate is closely related to the content of total organic carbon, and soil respiration is not so related to the content of total organic carbon or total mineralized carbon.
Impact of Water Turbidity on Growth of Submerged Plant Potamogeton Cripus
WANG Jin, LIN Chao, ZHANG Yi-Min, YANG Fei
2015, 31(3):  353-358.  doi:10.11934/j.issn.1673-4831.2015.03.013
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Impacts of turbidity (30±3, 60±3 and 90±3 NTU) of a waterbody on light intensity and hence on growth, photosynthesis and antioxidant activity of Potamogeton cripus growing therein were studied . Changes in plant height, leaf number, and photosynthesis and activities of superoxide dismutase(SOD) and peroxidase (POD) in the shoot of Potamogeton cripus caused by light stress were investigated. Results show that the effects of turbidity on growth rate of the Potamogeton cripus varied with the degree of turbidity, but insignificantly. At the end of the experiment, no significant differences (P>0.05) were observed between CK and groups different in turbidity in effect on plant height; the effect of lower turbidity (<30 NTU) on leaf number was not significant on D20 and D27 and became apparent near the end of the experiment, while the effects of turbidity (60 and 90 NTU) inhibiting leaf number were extremely significant (P<0.01). Before D10, turbidity did not show much influence  (P>0.05) on maximum quantum yield () or photochemical quenching (qp), but afterwards Fv/Fm in all the turbidity groups gradually declined with the test going on. The effect of turbidity on electron transport rate(e,t) of the plant was always extremely significant (P<0.01) in all the groups. However, the activity of superoxide dismutase (SOD) in the plant increased with rising turbidity in degree, but that of peroxidase (POD) increased first and then decreased.  
Forms and Bioavailability of Phosphorus in Waterand Sediments of Lake Caohu
GONG Ying, WANG Ning, LI Yu-Cheng, ZONG Ning, LUO Jun, XIE Hao
2015, 31(3):  359-365.  doi:10.11934/j.issn.1673-4831.2015.03.014
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To explore endogenouspollution and bio-availabilityof different forms of phosphorus (P) in the water and sediments of Lake Chaohu, conventional chemical approaches and diffusive gradients in thin-films (DGT) technology were used in this study to analyze spatial distribution of different forms of P in the water and sediments and P adsorption by sediments in different zones. Results show that the water in the western part of the lake washigher than the waters in the central and eastern parts of the lake in content of total P (TP) and dissolved inorganic P (DIP) and could be sorted into the level of eutrophication. Among the five chemically extractable forms of Pin the sediments, TP, Fe/Al-P (iron/aluminum bound P) and AAP (algal-available P) in the three parts of the lake followed an order of western part > eastern part >centralpart in content; OP (organic P) in an order of eastern part > western part > central part; Ca-P (Calcium bound P) did not vary much between the parts; and DGT-P (P determined with the DGT method) did not either within the lake, but did in the areas of river mouths, indicating that the areas of river mouths were greatly influenced by the pollutants carried by river flows. DGT-P in the sediments was positively related to highly active AAP, Fe/Al-P,OP and DIP, with coefficient R being 0.541, 0.547,0.731(P<0.01) and 0.438(P<0.05), respectively, which indicates that the DGT device was effective in monitoring bio-available Pin the sediments. Isothermal adsorption study indicates that the sediments in the western and eastern parts of the lake were both high in P adsorption potentiality, while those in the central part was quite low. However, DGT-P in equilibrium solutions varied sharply, with the highest equilibrium concentrationof the sample from Sampling Site No. 9(0.62mg•L-1) in the western part of the lake being 9 times as high as that of the sample from Sampling Stie No. 3(0.07mg•L-1) in the eastern part of the lake, suggesting that sediments may influence, to a quite extent, bio-availability of P in the overlaying water.
Effects of Microcystis aeruginosa Bloomon Dynamics of Phosphorus at Interface of Water and Sediments: a Simulation Study
ZHU Yong-Li, WU Qing, XU Sha, WU Li-Yun, HAN Jian-Gang
2015, 31(3):  366-371.  doi:10.11934/j.issn.1673-4831.2015.03.015
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Water and sediment were sampled from the Meiliang Bay of the Taihu Lake, China, to build up a simulated sediment-water system with Microcystis aeruginosa  added for simulation of the occurrence of Microcystis aeruginosa bloom, with a view to defining how and to what extent alga bloom contributes to variation of Phosphorus in the sediment-water interface. Microcystis aeruginosa in the water column always stayed in a state of alternation of proliferation and suspension during the incubation period (238 day). Proliferation of the algae increased pH in the overlying water by 11%-14%. After the first boom of proliferation of the algae, TP in the water decreased by over 90%, while organic P (Or-P) in the sediment increased substantially. The proportion of water-soluble P (WP) in TP decreased from the initial 93% to 11% during the period of alternation of proliferation and suspension,whilethe content of Or-P alternated decreasing and increasingduring the period. WP contents in both the water and the sediment dropped rapidly to a very low level during the first boom of proliferation of the algae, but afterwards, the content bounced back on average by 2.7 times in the waterand 1.7 times in the sediments. In the sediment, activity of alkaline phosphatase was negatively correlated with Or-P content (P<0.05) and positively correlated with WP content (P<0.01). Hence, it is believed that quite a portion of alga cells rapidly decayed and decomposed during the bloom releasing a considerable amount of WP, which to a certain extent sustained the population of Microcystis aeruginosa in alternation of proliferation and suspension.  
Phosphate Adsorption Characteristics of La-containing Biochar
DAI Min, WANG Jian-Guo, CHAO Jun-Wei, TANG Fang, ZHU Li-Jun
2015, 31(3):  372-379.  doi: 10.11934/j.issn.1673-4831.2015.03.016
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As a kind of high-effect, low-cost, environment-friendly and recyclable PO43- adsorbent intended for use in farmlands, La-containing cornstalk based biochar was prepared for the first time for analysis of phosphate adsorption characteristics with thermodynamic, isothermic and kinetic methods. During the adsorption process, its Gibbs free energy declined below zero, while enthalpy and entropy both rose above zero.Its adsorption isotherm fitted the Langmuir model and its adsorption peaked up to 78.36 mg·g-1 at 25℃.Its kinetics fitted the pseudo-second-order kinetic model with its adsorption rate constant being 23.19×10-2 mg·g-1·min-1 when the  initial phosphate concentration was 50 mg·L-1.The straight line fitted with the intra-particle diffusion model failed to pass the origin of the coordinates, but was displayed in a two-section line; When soil pH lingered in the range of 3–7,its phosphate adsorption capacity was quite high and not affected by any of the coexisting ions, except 200 mg·L-1 of CO32- and 2000 mg·L-1 of CO32-and F-. Its phosphate adsorption was a kind of spontaneous endothermic reaction, and physical adsorption dominated monolayer adsorption. Its adsorption process was governed mainly by surface diffusion and intra-particle diffusion and its adsorption rate by thickness of the boundary layer. The La-containing cornstalk-based biochar is extensively applicable to farmlands with pH in a wide range, quite strong in disturbance resisting ability and quite high in phosphate adsorption and adsorption rate. The La-containing cornstalk-based biochar enjoys a broad application prospect in the future in remedying eutrophied bodies and purifying phosphorus-polluted wastewater.  
Impact of Organic Pollutant Loading on Effect of Artificial Tidal Flow Wetland Purifying Rural Domestic Sewage
DU Xin, SHI Chun-Hong, MA Fang-Shu
2015, 31(3):  380-384.  doi:10.11934/j.issn.1673-4831.2015.03.017
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With increasing discharge of domestic sewage in the rural areas, conventional constructed wetlands gradually fail in reoxygenation capacity, oxygen environments of their beds directly affect pollutants removal efficiency. By simulating the characteristic of intermittent discharge of domestic sewage in the rural areas, a new type of artificial tidal flow wetland (ATFW) was constructed in lab for an experiment to explore impact of COD loading (167.9, 221.9, 610.3 and 760.0 g·m-2·d-1) on oxygen environment of the bed and pollution removal efficiency.Results show that concentration of organic pollutants is the main factor limiting COD removal efficiency of the tidal flow; COD removal efficiency of the system may reach as high as 95.6%; theammonia nitrogen (NH4+-N) removal efficiency increased with rising organic pollutant loading from 85.2% to 98.7%; and higher organic pollutant loading favored assimilation of heterotrophic bacteria and enhanceddenitrification. The removal of total nitrogen (TN) follows a trend similar to that of NH4+-N with the highest TN removal rate reaching up to 80.3%. Although adsorption is regarded as the primary pathway of phosphorus removal, which is determined by influent phosphorus concentration, the proportion of total phosphorus (TP) removal throughadsorption was low due to the poor adsorption capacity of volcanics. Higher OLR stimulated phosphorus accumulating organisms (PAOs) to absorb P, pushing TP removal rate up to 71.0%.  
Nutrient Absorption and Dry Matter Accumulation of Greenhouse Vegetable Under Optimized Coupling of Water and Fertilizer
CAI Shu-Mei, Lü Wei-Guang , TIAN Ji-Lin, LI Jian-Yong, ZHU En, YU Ting-Yuan, ZHU Hai-Tao
2015, 31(3):  385-389.  doi:10.11934/j.issn.1673-4831.2015.03.018
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A field experiment was conducted to study characteristics and regularity of nutrient uptake and accumulation of dry matter of greenhouse vegetable under micro-sprinkling irrigation and their relationship. Results show that N, P and K contents in the plant varied sharply with the plant growing stage. The plant in the prime vegetative growth stage was much higher in nitrogen, phosphorus and potassium content than that in the seedling stage. However, contents of the nutrients declined slightly after the plant entered its maturing stage. As far as nutrient absorption rate was concerned, the prime vegetative growth stage was the highest for all the three nutrients and then the seedling stage and maturing stage, and the three nutrients followed an order of potassium > nitrogen > phosphorus. In terms of nutrient and dry matter accumulation, the three growing stages followed an order of prime vegetative growth stage > seedling stage > maturing stage. In addition, correlation analysis shows that plant dry matter accumulation was significantly and positively related to nutrient uptake. Under optimized coupling of water-fertilizer, positive relationships were found between the three nutrients mutually promoting each other in absorption.
Distribution and Sources of PAHS in Soil at the Site of a Former Typical Pesticide Plant
ZHANG Xiao-Fei, LIN Yu-Suo, DENG Shao-Po, LONG Tao, XU Jian, HUANG Yao
2015, 31(3):  390-397.  doi:10.11934/j.issn.1673-4831.2015.03.019
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A field investigation was carried out of the site of a deserted pesticide plant to explore content, distribution and possible sources of PAHs, a kind of chemicals extremely hazardous to human health. Results show that PAHs were detected in the soil 0-6.0 m in depth. In the soil samples with PAHs detected, benzoapyrene (Bap), a kind of strong carcinogen, averaged 1.63 mg•kg-1 in concentration, with the highest reaching 8.83 mg•kg-1 and 60% fell into the category of “heavily polluted”. With increasing soil depth, concentration and detection rate of polycyclic PAHs gradually decreased. In the 0-1.2 m soil layer, the percentages of ≤3-ring PAHs, 4-ring PAHs and≥5-ring PAHs in total PAHs were almost equal and phenathrene (Phe), Fluoranthene (Fla) and pyrene (Pyr) were the dominant chemicals. In the 1.2-6.0 m soil layer, PAHs with 3 or fewer rings became dominant, and was mainly consisted of naphthalene (Nap) and 2-methylnaphthalene (2-Mnap).  Characteristic compounds molecule ratio analysis reveals that PAHs in the soil of the site came mainly from 2 sources:one is leakage of petroleum products from the plant in the process of their being used in production of pesticides and burning of wastes, and the other is burning of grass, wood, coal and other garbage. Checking with the layout of the former pesticide plant, it was found that the sites of soil samples containing PAHs coincide with those of the workshops of the former pesticide plant, indicating a strong relationship between the presence of PAHs in the soil and the production activities of the former plant.
Application of Species Sensitivity Distribution (SSD) to Derivation of Water Quality Criteria for Pesticides
LIANG Xia, ZHOU Jun-Ying, LI Jian-Hong, WANG Xiang-Lan, SONG Ning-Hui, SHAN Zheng-Jun
2015, 31(3):  398-405.  doi:10.11934/j.issn.1673-4831.2015.03.020
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Deriving methods play an important role in water quality criteria is critical derivation. Species sensitivity distributions (SSD) is a common method used to derive water quality criteria in the world. A number of models are available for use to derive water quality criteria, but not all the models could well fit the toxicity data sets of pesticides. In order to select one that fits with high goodness, 4 typical pesticides were selected in the study to compare the models in goodness of fit. Results show that Sigmoid, Gaussian,Gompertz and Exponential growth were better than the other models in fitting curve tendency, rationality of HC5 and goodness of fit. Therefore it is suggested that when utilizing SSD to derive criteria for pesticides, Sigmoid, Gaussian, Gompertz and Exponential growth should be used to get fitting curves first, and then the most optimal model should be chosen for use to determine benchmark values for the water quality criteria, so as to ensure scientificity of the derivation of the water quality criteria. The findings can serve as scientific references for selection of derivation methods for formulation of water quality criteria for pesticides.
Research on Bioavailability of Pyrethroids in Sediments Based on Tenax Desorption Kinetics
LI Juan-Ying, CHEN Mei-Na, LI Zhen-Hua, HU Qian, ZHENG Yi
2015, 31(3):  406-413.  doi:10.11934/j.issn.1673-4831.2015.03.021
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Pyrethroids have been widely used in agriculture, forestry and fisheries as pesticide, and frequently detected in sediment because of their high hydrophobicity and lipotrophy. It is, therefore, of great significance to the assessment of environmental quality and risk to study bioavailability of these compounds in sediments. Tenax desorption kinetics of four pyrethroids (cyhalothrin, bifenthrin, permethrin and fenpropathrin) were analyzed to evaluate bioavailability of the pyrethroids in sediments of the tidal zone in the Yangshan Port, meanwhile results of the Tenax extraction were compared with those of the experiment on bioaccumulation of pyrethroids in Ruditapes philippinarum. Results show that the faction of readily desorbable pyrethroids (Frap) accounted for over 50% in the surface sediments low in organic carbon(OC) content, and the desorption rate of the fractions of readily, slowly and very slowly desorbable pyrethroids varied in magnitude order, being 10-1, 10-2 and 10-5-10-3, respectively. Compared with Frap, single time-point Tenax extraction can be used to evaluate bioavailability of pyrethroid pesticides in sediments, rapidly, economically and effectively. Correlation analysis shows that 24 h Tenax (Cs,24 h) extraction is more suitable to application to the prediction of pyrethroid accumulation concentrations in Ruditape sphilippinarum (Cb) (lg Cb=4.03 lg Cs,24 h-17.02;R2=0.88,P<0.05). The findings of this study may not only provide reliable scientific basis for simple rapid evaluation of bioavailability of pyrethroids in sediments and assessment of environmental quality and risk of marine sediments, but also be used to predict bioaccumulation of permethrin pesticides in bivalve oobenthos, and furthermore, as a simpler and easier method for environmental risk assessment of aquaculture sediments and food risk assessment of relevant aquatic products.  
Effects of Multiwalled Carbon Nanotubes on Ecotoxicity of Cd in Sediment-Zoobenthos System
LIU Shan-Shan, LONG Yi, WANG Meng, MA Tao-Wu
2015, 31(3):  414-419.  doi:10.11934/j.issn.1673-4831.2015.03.022
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The increasingly extensive production and utilization of engineered nanomaterials (ENMs) has led to release of large quantity of the substances into the aquatic environment, where ENMs may interact with other contaminants, and alter their bioavailability and ecotoxicity. Heavy metal cadmium (Cd) and benthic macroinvertebrate Bellamya aeroginosa were selected as model contaminant and test species, respectively, for an experiment to explore changes in Cd bioaccumulation and effects of Cd on two key biomarkers, superoxide dismutase (SOD) and malondialdehyde (MDA), in the hepatopancreas in the presence of multi-walled carbon nanotubes (MWCNTs), different in tube diameter through sediment toxicity test. Results show that MWCNTs, regardless of tube diameter significantly increased Cd bioaccumulation, and MWCNTs, 8-15 nm in tube diameter, displayed a greater effect promoting Cd bioaccumulation than MWCNTs, 20-30 nm in tube diameter. When Cd was low in concentration (5 μg·g-1), the presence of MWCNTs did not affect Cd effect on SOD activity; when Cd was medium in concentration (25 μg·g-1), the presence of MWCNTs significantly induced SOD activity, and the effect was more obvious in the presence of small-diametered MWCNTs than in the presence of big-diametered MWCNTs; and when Cd was high in concentration (100 μg·g-1), the presence of MWCNTs significantly inhibited SOD activity, with the presence of small-diametered MWCNTs in particular. When Cd was medium in concentration, MDA level was much higher in the treatments with MWCNTs than in CK, however, when Cd was high in concentration, MDA level was significantly lower in the treatment with small-diametered MWCNTs than that in the treatment with big-diametered MWCNTs and in CK, indicating that higher Cd bioaccumulation induced by the presence of small-diametered MWCNTs caused severe damage to cells of the zoobenthos, thus lowering drastically MDA level. Therefore, when Cd was medium or high in concentration, the presence of MWCNTs can  significantly enhance the ecotoxicity of Cd on B. aeroginosa, which coincides with the change in Cd bioaccumulation in livers, and the effects of MWCNTs on ecotoxicities of various kinds of contaminants may potentially relate to physicochemical property of MWCNTs, environmental media, and species of the organisms.  
High-Temperature Composting of Mixtures of Chicken Manure and Coconut Husk Different in C/N Ratio
DONG Cun-Ming, ZHANG Man, DENG Xiao-Ken, QIN Hai-Li, ZHAO Yan, LIU Xiao-Yu, RUAN Yun-Ze
2015, 31(3):  420-424.  doi:10.11934/j.issn.1673-4831.2015.03.023
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In high-temperature composting experiments, mixture of chicken manure and coconut husk wasused as basic raw material. The experiments were designed to explore effect of C/N ratio, controlled by regulating proportions of chicken manure and coconut husk in the mixture, on some physical-chemical indices of the material under composting, i.e., temperature, pH, C/N and total nutrients, in an attempt to find the most proper C/N ratio of the raw material for high-temperature composting. Results show that when the mixture was 25 in initial C/N an, reached as high as 57℃during 14 days of composting, the composts in all the treatments showed declining trends in C/N and contents of organic matter and TC; but in pH, they went up in the first 8 days and down toward the end of the composting; TN and IG (seed germination index) increased during the process. At the end of composting, Treatments F1 (20 in initial C/N ratio), Treatment F2 (25 in initial C/N ratio) and Treatment F3 (30 in initial C/N ratio) was 11.13, 11.19 and 10.24, respectively, lower in C/N ratio; 7.94%, 8.63% and 8.29%, respectively, in content of total nutrient and 77.90%, 100.65% and 93.30%, respectively in IG.
Reconstruction of MODIS-NDVI Using S-G Filtering Based on Pixel Quality Analysis
LI Ming, SHEN Run-Ping, WANG Di, LI Xin-Hui
2015, 31(3):  425-431.  doi:10.11934/j.issn.1673-4831.2015.03.024
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MODIS NDVI products from maximum value composite (MVC) still contain noise pixels which may affect application of the data for extraction of vegetation information. In order to efficiently remove the noise, it is suggested that high quality pixels representing the same ground object as the noise pixels do be located within a sliding window and means of the high quality pixels be used to replace values of the noise pixels in reconstruction of Savitzky-Golay(S-G) filter, and then the high quality pixels be kept in storage. Both this method and self-adaptive S-G filter can be used effectively to reconstruct 2001 – 2003 MODIS-NDVI chronological data of Jiangxi Province. Compared to the self-adaptive S-G filter reconstruction. the new method improves the correlation of the reconstruction with the high quality portion of the original data, and lowers the correlation of the reconstruction with the noise in the original data; and the reconstructed noise data get much closer to the means of high quality data and standard deviation. Besides, the new method can enhance the fidelity and stability of high quality pixels. Based on pixel quality analysis, S-G filter can reconstruct and yield better MODIS-NDVI dataset and extract more accurate vegetation coverage.  
Study on Lake Water Quality Assessment Based on Simple Modeling and Factor Analysis
TAN Yu-Feng, ZHANG Qi, ZHU Sha, WANG Juan-Juan, JIN Shi-Ke, YOU Wen-Hui
2015, 31(3):  432-439.  doi:10.11934/j.issn.1673-4831.2015.03.025
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With reference to the number of grades and threshold for each grade in a certain standard for water quality evaluation, a water quality evaluation method was established combining multivariate analysis with multi-factor evaluation. Through the regression analysis a corresponding function equation was established, and then by substituting sample data into corresponding relational expressions to build up a table of water quality evaluation indices. At the same time factor analysis was performed to allocate weight to each type of numeric data. Finally, by combining the use of the table of water quality evaluation indices with the weight for each type of numeric data, water quality evaluation indices were worked out for the sampling sites, and then the evaluation was done. With reference to the thresholds in the standard specific to lakes and reservoirs in the “Standard for Surface Water Environment Quality” (GB3838-2002), case studies were done of the Dianshan Lake and the Yuandang Lake. TN,TP, Chl-a and SD were monitored for four seasons consecutively through sampling at 29 sampling points in the studied area. Based on the monitoring data and the analysis with the established model, evaluation was done. Results show that the annual overall evaluation index of the Dianshan Lake is 5.727 and the Yuandang Lake is 5.418, both falling into Category V in water quality. The latter is a little better than the former. Among the four seasons, spring is the best with water quality generally in Category IV, and summer the worst with water quality in Category V minus.  
Quantity and Mass of Particulate Matter Retained on Tree Leaves and Determination Methods
YANG Jia, WANG Hui-Xia, XIE Bin-Ze, WANG Yan-Hui, SHI Hui
2015, 31(3):  440-444.  doi:10.11934/j.issn.1673-4831.2015.03.026
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Since the current washing-membrance-filtering method is not good enough to determine dust-retaining capacity of plant leaves, it is essential to quantitatively define some new potential methods to make up or amend shortages of the current method and to determine intuitively and accurately dust-retaining capacity of plant leaves.  Two sampling sites, the Beijing Botanical Garden and Guomao Bridge, in Beijing were selected. The former is relatively clean and the latter severely polluted. Leaves were collected from Euonymus japonicas, Sophora japonica, Populustomentosa, Ginkgo biloba and Prunus cerasifera in the two sites in Beijing for determination of quantity and particle-size composition of particulate matter (PM) detained on the upper and lower surfaces of the leaves with a scanning electron microscope and then quantity of detained PM per unit leaf area was calculated for comparison with that obtained by the washing-membrance-filtering method. It was found that the PM on leaf surfaces was dominated by the PM<10 (PM with diameter less than 10 μm), which accounted for over 90% of the total quantity of particles. The leaf surfaces of the investigated trees growing at the heavily polluted site (Guomao Bridge) had more PM<2.5 detained than those at the less polluted site (Beijing Botanical Garden) did. A significant linear relationship was observed between the counting method and the washing method in PM mass obtained. However, the difference between the two was very sharp. The PM mass obtained with the washing method was only about 9% as high as that with the counting method. It is, therefore, essential to design and conduct more strictly controlled experiments to determine causes and affecting factors of this big difference, and also to develop techniques for calibrating the current washing methods, or multi-approach combined application techniques.