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1.
Water, Air, &; Soil Pollution - The solubility of the gypsum is generally very high in comparison to many other minerals. The surface and groundwater contacting gypsum formations can easily...  相似文献   

2.
This paper reports on the effect of activating agents such as the impregnation ratio of phosphoric acid (1:1–1:5) at constant activation temperature on the performance of porous activated carbon from waste residues (maize tassel). The variation in the impregnation ratio of the produced activated carbon (AC) from 1:1 to 1:5 enabled the preparation of a high surface area (1,263 m2/g) and a large pore volume (1.592 cm3/g) of AC produced from maize tassel (MT) using a convectional chemical activating agent (phosphoric acid). Impregnation ratios (IR) of the precursors were varied between 1:1 and 1:5 in which it was found that the ratio of 1:4 was optimal based on the high surface area, while 1:5 has the optimal pore volume value for the produced activated carbon.  相似文献   

3.
Spatiotemporal analysis of landscape dynamics is crucial in formulating an appropriate set of actions in landscape management. This paper presents a large scale analysis of the spatiotemporal structure of Istanbul, a highly urbanized city in Turkey, from 1971 to 2002 using forest cover type maps analysed with geographical information systems (GIS) and a spatial statistics programme. The quantitative evidence indicated that increasing population and expanding urbanization caused drastic changes to the temporal and spatial dynamics of land use/land cover pattern in Istanbul. There was a net increase of 5387·3 ha in total forested areas (1·0 per cent) due to mainly reforestation activities even though the population increased three times over a 31‐year period. Increase in number of patches and decrease in mean patch size together demonstrated that the landscape developed into a more fragmented structure that would negatively affect biodiversity and the resilience of the ecosystems. In conclusion, plain increase in forest areas may not always be a favourable situation. The quality, composition and the configuration of forest landscape should also be analysed to present the dynamics of ecosystem in terms of ecological and economical sustainability over a longer time and larger area. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

4.
Treated wastewater (TWW) is an imperative nonconventional water resource for reuse in irrigation to cope with the water shortage and agricultural expansion in Egypt. The Bahr El-Baqar drain in Sharqia, Egypt, is one of the main drains in the Nile Delta that receives various types of wastewater. Monitoring and assessing the drain’s water quality were achieved by collecting georeferenced water samples along the drain during the 2015 summer and winter cropping seasons. Chemical, microbial, and parasitic analyses were performed. Additionally, surface soil samples irrigated with the drain water were gathered from the adjacent area to quantify the main physicochemical properties. Water analysis results revealed that the concentrations of most trace elements were within international standards and the Egyptian allowable levels for TWW reuse in agriculture. Oxygen depletion was observed for all samples collected. The microbial analysis indicated that there was fecal coliform contamination (>1000 per 100 mL) in the summer and winter samples. Concentrations of PO4 and SO4 were within the permissible level for irrigation use, whereas NH4, NO3, and MoO4 concentrations were higher than the recommended values for reusing Bahr El-Baqar water in irrigation. Based on the soil analysis results, Cd contamination was observed, whereas the Pb concentration in soils was slightly higher than its normal range. Mixing Bahr El-Baqar water with freshwater and implementing appropriate on-farm treatment before the reuse are recommended as a prerequisite for reusing Bahr El-Baqar water for irrigation. Bio-diesel fuel and energy oil crops are recommended for the studied region.  相似文献   

5.
In this research, geological and hydrogeological studies were conducted to determine the source of high arsenic levels in the surficial aquifer of Simav Plain, Kutahya, Turkey. One of the two aquifer systems isolated in the study area was a deep confined aquifer composed of fractured metamorphic rocks that supply hot geothermal fluid. The other one was an unconfined alluvial aquifer, which developed within the graben area as a result of sediment deposition from the highlands. This aquifer serves as the primary water resource within the plain. A water quality sampling campaign conducted in 27 wells drilled in the surficial aquifer has yielded an average arsenic concentration of 99.1 µg/L with a maximum of 561.5 µg/L. Rock and sediment samples supported the fact that local metamorphic rocks contained significant amounts of sulfur minerals where arsenic-containing lenses are present inside. It was also determined that a Cu–Pb–Zn mine was operated in the past in the same formation. Arsenic-containing wastes of this mine were deposited near the Simav district center in an uncontrolled manner. This mined formation had arsenic levels reaching to levels as high as 660 mg/kg, which was found out to be the highest arsenic level in the area. Another potential arsenic source in the study area was the geothermal fluid that was used extensively in three geothermal fields with levels reaching to levels as high as 594 µg/L. Uncontrolled discharges of waste geothermal fluid and overexploitation of groundwater were also found to contribute to arsenic pollution in surface/subsurface waters of the plain. Thus, natural sources and anthropogenic influences of arsenic were found to create high concentrations in local water reserves of the area and influence human health. Consequently, death statistics from the 1995 to 2005 period collected from the area has revealed increased rates of gastrointestinal cancers above Turkish average.  相似文献   

6.
Voutsa  D.  Manoli  E.  Samara  C.  Sofoniou  M.  Stratis  I. 《Water, air, and soil pollution》2001,129(1-4):13-32
A 2-yr (1997–1998) survey aiming at the establishment of national data bases concerning the quality of surface waters has been conducted in the major river systems of Macedonia, N. Greece. This paper presents the physicochemical parameters(pH, conductivity, total suspended solids, temperature and DO),the organic pollution parameters (BOD5, COD) and the major N and P species (NO3 -, NO2 -,NH4 +,organic N, orthophosphates and total P) determined at 25 sampling sites located on main rivers, tributaries, streams andditches that drain the major rural, agricultural, urban and industrial areas of N. Greece. Use of multivariate statistics is also made to identify the principal factors which influencethe chemistry of the water in individual river systems.The eutrophication status of the examined systems was evaluatedby means of N/P ratios. Mean N/P ratios showed large variationsamong sampling sites ranging from potential N- to P-limitationconditions. N/P ratios at particular sampling sites showed also great temporal variability thus suggesting temporary states of N- or P- limitation. Most frequently, highest ratio values wereobserved during winter and early spring. Comparisons are made between data from this study region and literature on rivers elsewhere.  相似文献   

7.
ABSTRACT

This study is an economic analysis of the use of different organic fertilizers for organic greenhouse lettuce production as an on-farm trial during the autumn season of 2001–2002. The selected site is located in the preservation area of the Tahtali Dam, which is the most important water source providing drinking water to Izmir, the third largest city in Turkey. The tested fertilizer applications were composed of: (a) farmyard manure, 15 tons/ha?1 + E 2001 + All grow Bioplasma; (b) farmyard manure, 30 tons/ha?1; (c) chicken manure, 15 tons/ha?1 + E 2001 + All grow Bioplasma; (d) chicken manure, 30 tons/ha?1; and (e) control (no fertilizer). The total net profit ranged between $0.38 and $0.90/m2, depending on organic fertilizer applications. The results showed that organic lettuce production with different organic fertilizers can be achieved in greenhouses, but there is still a need to solve some problems related to greenhouse climate control, pest and disease control, biological control, crop rotation, marketing and training of growers.  相似文献   

8.
The ultimate goal of this study is to develop a simple dynamic river water quality model that can be applicable in a data limited situation and is compatible with typical activated sludge models, so that the model can be used in integrated modelling of wastewater and river water quality in the future. A simplified river water quality model was formulated based on a conceptual hydraulic sub-model and simplification of an existing river water quality model. The simplified water quality was derived from the River Water Quality Model No. 1, which is one of the most comprehensive basic river water quality models available in literature. The applicability of the simplified model in data limited situations was investigated using a case study of inorganic nitrogen (nitrate and ammonia) in the Crocodile River (South Africa). The model was calibrated and validated on the basis of independent data collected for four years (1987–1990). The results show that the model can adequately describe the seasonal dynamics of inorganic nitrogen in the Crocodile River. The sensitivity of the model output to the model inputs was also analysed, and the results indicate that the model is most sensitive to the microbial biomass (nitrifier) followed by hydraulic parameters. The relation of river flow versus concentration of inorganic nitrogen in the downstream section of the river was also examined in order to identify the main source and critical time for nitrate pollution.  相似文献   

9.
The main goal of this study was to investigate spatial patterns in water quality in Lake Beysehir, which is the largest freshwater reservoir in Turkey, by using Landsat-5TM (Thematic Mapper) data and ground surveys. Suspended sediment (SS), turbidity, Secchi disk depth (SDD), and chlorophyll-a (chl-a) data were collected from 40 sampling stations in August, 2006. Spatial patterns in these parameters were estimated using bivariate and multiple regression (MR) techniques based on Landsat-5TM multispectral data and water quality sampling data. Single TM bands, band ratios, and combinations of TM bands were estimated and correlated with the measured water quality parameters. The best regression models showed that the measured and estimated values of water quality parameters were in good agreement (0.60 < R 2 < 0.71). TM3 provided a significant relationship (R 2?=?0.67, p?<?0.0001) with SS concentration. MR between chl-a and various combinations of TM bands showed that TM1, TM2, and TM4 are strongly correlated with measured chl-a concentrations (R 2?=?0.60, p?<?0.0001). MR of turbidity showed that TM1, TM2, and TM3 explain 60% (p?<?0.0001) of the variance in turbidity. MR of SDD showed a strong relationship with measured SDD, with R 2?=?0.71 (p?<?0.0001) for the ratio TM1/TM3 and TM1 band combinations. The spatial distribution maps present apparent spatial variations of selected parameters for the study area covering the largest freshwater lake and drinking water reservoir in Turkey. Interpretation of thematic water quality maps indicated similar spatial distributions for SS, turbidity, and SDD. A large area in the middle portion of the lake showed very low chl-a concentrations as it is far from point and nonpoint sources of incoming nutrients. The trophic state index values were calculated from chl-a and SDD measurements. Lake Beysehir was classified as a mesotrophic or eutrophic lake according to chl-a or SDD parameters, respectively.  相似文献   

10.
The Influence of acid deposition on stream and lake water chemistry was studied in a forested watershed of Hyogo prefecture, Japan. Monthly sampling of four streams, one artificial lake, and precipitation was carried out from 1995 to 2000. The pH of the monthly bulk precipitation and rainwater were ranged from 4.06 to 7.10. No trends were evident during the monitoring periods. The pH and alkalinity in the four streams, which flow into the artificial lake, ranged from 6.37 to 8.72 and 0.077 meqL?1 to 0.485 meqL?1, respectively. The differences in the water quality of the four streams were related to the geology of each watershed. Lower pH and alkalinity were observed during high- discharge periods. On the other hand, the pH and alkalinity of the outflow from the lake ranged from 6.47 to 7.36 and 0.195 meqL?1 to 0.339 meqL?1, respectively. No acidification of the aquatic environment was observed during the investigated periods. The results suggest that this forested ecosystem has the capacity to neutralize incoming acid deposition.  相似文献   

11.
ABSTRACT

This study was carried out to determine the producers' conditions and some technical and economic characteristics of peach growing in Kemalpasa, Izmir. Main data was collected by interviewing peach growers selected by using the random sampling method. In this study, average yield per hectare and average yield per tree were determined to be 16,848 kg and 37.7 kg. Average size of the peach orchard was found to be 1.09 hectares. It was observed that the growers preferred square planting with 4.5 m × 4.5 m spacing, rather than triangle planting. Input use and number of replications of cultural practices during production season were also determined in the study. It was observed that more than 82% of peach growers harvested their crop themselves. Net return obtained per hectare and per tree from peaches was determined to be $839 and $1.88, respectively.  相似文献   

12.
Air quality levels vary over regions due to meteorological factors, proximity to sources, and local conditions (i.e., topography). The Northeast USA is subjected to pollution inputs from both local sources and those from the upwind Midwest USA that are transported by prevailing meteorological patterns. With the passage of the Clean Air Act in 1970 and the establishment of the National Ambient Air Quality Standards (NAAQS), national levels of air pollutants have declined significantly. Our study compared air quality time trends between five of the largest cities within New York State (Albany, Buffalo, New York City, Rochester, and Syracuse) and statewide means to national trends. Data were obtained from the NYS Department of Environmental Conservation (DEC) Bureau of Air Quality Surveillance for six criteria pollutants: carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), particulate matter (PM2.5), and lead (Pb). Regional Kendall tests found significant downward trends for each pollutant statewide from 1980 to 2007, while trends by city varied by decade and pollutant. The evaluation of historical trends of pollution in industrialized nations is useful in showing recent air quality improvements and also in the understanding what can be the result in air pollutant controls in those developing nations currently experiencing high levels of pollution.  相似文献   

13.
《土壤通报》2017,(6):1324-1328
为保障粮食安全和保护耕地质量,本研究重点从标准农田占补动态管理的角度出发,设计并开发了宁波市耕地质量管理信息系统。该系统采用胖客户端(单机)模式,以.Net为开发环境,以Arc GIS Engine组件为主要技术支撑,开发建成以标准农田占补管理为核心应用功能的系统,为农业行政部门提供耕地特别是标准农田质量管理服务。通过系统试运行,能够较好地实现全市标准农田建设占用与补划管理工作的动态管理,保持标准农田数据现势性,为防止多占少补、先占后补和重复占补等现象发生发挥了重要作用。  相似文献   

14.
Atlantic rankers belong to the group of "cryptopodzolic rankers", which are ubiquitous in the mountainous cool/temperate humid regions of Western Europe. The rankers of Galicia (NW Spain) formed by thousands of years of colluviation. The preponderance of Al-stabilised organic matter (OM) masks the horizonation and polycyclic character (i.e., stratification) of these soils. Cryptopodzolic rankers are generally thought to be the outcome of podzolisation. This soil type is part of the recent discussion on how to classify soils developed from nonvolcanic parent material having andic properties.
To better understand the formation processes of these soils, the Al and Fe fractionation of four typical Atlantic rankers were studied by selective dissolution in acid NH4-oxalate, Na-pyrophosphate and the chlorides of K, La and Cu. A high-resolution sampling approach allowed us to investigate the soils in greater detail than simply sampling by horizon. The rankers studied display a distribution of Fe- and AI-OM complexes that is typical of cryptopodzolic soils. However, these organomineral associations were probably immobile due to the high Al saturation. We argue that the soils owe their characteristic chemical status to external factors rather than to translocation of organomineral associations: variations in AI-OM concentrations could be linked to changes in weathering/leaching intensity and colluviation rates caused by anthropogenic disturbances or changes in regional climate regime.  相似文献   

15.
中心小城镇作为上海市都市城镇构造体系的一级,对于区域城市化进程及产业区位调整具有极为重要的意义,同时中心小城镇具有典型的半城市化特征,这是导致中心小城镇成为该区域新的环境污染中心的重要原因。以青浦区为例分析半城市化的具体表现,以枫泾镇镇区内河流水体及沉积物总磷区域及季节特征揭示由半城市化问题所带来的水体污染的严重性。夏季镇区河流所有样点均遭受严重的磷污染,而且区域内差异性大,小城镇河流磷污染严重于其它类型的水体磷污染,这一特征较好地反映了中心小城镇半城市化所带来环境问题的突出性。  相似文献   

16.
Lake Velenje is located in one of the most polluted regions ofSlovenia, the ?alek Valley. The major source of pollution is the coal-fired thermal power plant in ?o?tanj (?TPP). In the past, dumping of coal ash directly into Lake Velenje and drainage water from the ash disposal site resulted in unique chemical characteristics of the lake water, such as very high pH (10–12) and high concentrations of heavy metals. The introduction of a closed cycle ash transport system in 1995resulted in a very fast recovery of the lake water quality. The aim of our study was to establish the sources, fate and distribution of mercury in Lake Velenje. In order to establishrecent sources of mercury, total mercury and methylmercury concentrations were measured in various environmental samples(lake inflows, outflow, rainwater, sediments, etc.). Total mercury and methylmercury concentrations were measured at thesurface and at different depths to establish mercury cycling, its transport and chemical transformations in the lake. Generalwater quality parameters (such as pH, Eh, O2, temperature,TDS, conductivity) were also determined. The results show that the major sources of mercury in Lake Velenje are lake inflows and wet deposition. Total mercury andmethylmercury concentrations in the water column are very low (total mercury: 0.2–2.7 ng L-1; methylmercury: 20–86 pg L-1) and can be compared to other non-contaminated freshwater lakes. These results suggest that the major form of mercury emitted from thermal power plant stacks is volatile Hg0, whichhas no or very little influence on the nearby surroundings, but rather is subject to long-range atmospheric transport.  相似文献   

17.
岔路河流域水资源合理配置研究   总被引:3,自引:0,他引:3  
水资源合理配置是实现水资源可持续利用的有效调控措施之一。以岔路河流域为研究对象,对该流域的水资源特征进行了分析,采用多目标规划建立流域水资源配置模型,以2007年为规划水平年,以经济效益最大和用水量最小为规划目标,对水资源进行配置。结果表明:在保证生活及生态用水的前提下,节约农业灌溉用水,以发展乡镇工业,从而实现可利用水资源量效益的最大化。  相似文献   

18.
Sadiq  Rehan  Husain  Tahir  Kar  Sudip 《Water, air, and soil pollution》2002,138(1-4):123-140
Chlorine is the most commonly used disinfectant for watertreatment but when in contact with organic precursors it producestoxic compounds known as trihalomethanes (THMs). Chloroform isthe most commonly occurring THM and constitutes approximately90% of the THM concentration. A study was conducted inNewfoundland for estimating the chloroform content in thedrinking water supplies in Clarenville and St. John's. Thesampling program was conducted in two stages, July and October-November. Higher concentrations of chloroform were observed in Clarenville but in St. John's the concentrations werewithin Health Canada guidelines. The chloroform is a probablehuman carcinogen and is categorised as `B2' by U.S. EnvironmentalProtection Agency (U.S. EPA). The human health risk associatedwith consumption of drinking water was estimated by performingprobabilistic analysis. In the first phase bootstrap simulations(B = 250) were performed to calculate the variability in thedata. The normal distribution was found the best-fitted distribution to chloroform concentration data. For eachbootstrapped run 1000 Monte Carlo Simulations (MCS) wereperformed in the second phase. The cancer risk was estimatedusing dose-response relationship of chloroform. Appropriateprobability density functions (PDFs) were defined subjectivelyfor intake rate, body weight, exposure duration, exposurefrequency and averaging time. The excess lifetime human cancerrisk varied from 0.5 × 10-4 to 4.0 × 10-4, and zero to 1.0 × 10-4 for Clarenvilleand St. John's, respectively. The average cancer risks in Clarenville and St. John's communities were 1.2 × 10-4 and 2.5 × 10-5. The estimated probabilitiesof exceedences above 100 ppb (μg L-1), were 100 and 2.5% for Clarenville and St. John's, respectively which emphasised the need for water treatment. Granular Activated Carbon (GAC) was proposed as one of the potential treatment technology for risk reduction in St. John's community. The treatment efficiency of a proposed technology was assumed uniformly distributed and revised risks were calculated. Theaverage risk in St. John's can be reduced to 8.0 ×10-6 after treatment.  相似文献   

19.
The Organic Agriculture Research and Extension Initiative, administered by USDA-NIFA, is the major federal funder of organic agricultural research. Analysis of 733 publications produced during the initiative’s first five years explored the dissemination of this research, and accessibility to and preservation of the publications. Publications associated with conferences (e.g., abstracts) were most numerous (36%). Many publications (69%) were openly accessible online in 2017 but fewer than 10% of these appeared in a stable digital repository. In four of the eight publication categories, access disappeared over time. No program exists to systematically collect and preserve these outputs of organic agricultural research.  相似文献   

20.
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