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1.
Leachate was a major cause of high risk classification. This landfill was set as one with highest possible risk classification due to high vulnerability of private water wells to contamination from leachate flows. The aim of this study is to determine the present and possible environmental risks of the leachate spreading from solid waste dumping site in Tunceli and offer solutions for those determined environmental risks. For this purpose, the characteristics of the leachate were monitored at two station points detected in the solid waste dumping site for 7 months. The characteristics of the leachate were found for pH between 7.9 and 8.7. Oxidation reduction potential (ORP) occurred between ??143 and ??48 mV while conductivity was between 2.8 and 2.6 mS. Total solid matter (TSM) and suspended solid matter (SSM) were between 1000 and 7000 mg/l, 0.2–22.5 mg/l, respectively, while total volatile solids (TVS) occurred between 300 and 1800 mg/l for the two stations. Alkalinity was approximately between 290 and 5210 mg/l, while biological oxygen demand (BOD5) and chemical oxygen demand (COD) results were 15–606 mg/l and 60–1160 mg/l, respectively, for two stations in all sampling time. In both stations, orthophosphate, ammonium nitrogen, nitrate, sulfate, and chloride analyses stayed between 3.04 and 921.1 mg/l; 0.29–619.36 mg/l; 8.94–135.04 mg/l; 125.9–1360.9 mg/l and 99.9–1249.9 mg/l, respectively, in 6 months. As a result of the characterization studies obtained from the leachate, it was found that the amounts of water entering into the waste mass and the retention period of the water in the mass were very effective in the temporal character change of the leachate. According to the Discharge Standards for Solid Waste Assessment and Disposal Facilities and Discharge to Waste Water Infrastructure Facilities of waste management regulation, the results were found to be risky. Consequently, the site in question needs to be urgently rehabilitated when considering the environmental risks of the leachate spreading from the site.  相似文献   

2.
Magnetic properties and heavy metal content of landfill leachate sludge samples from two municipal solid waste disposal sites near Bandung, West Java, Indonesia, and their correlation with heavy metals are studied in the present work. Leachate was found to be sufficiently magnetic with mass-specific magnetic susceptibility that varies from 64.8 to 349.0 × 10−8 m3 kg−1. It is, however, less magnetic than the soils around the landfill sites. The magnetic minerals are predominantly pseudo-single domain and multidomain magnetite. Leachate samples from the older but inactive disposal site, Jelekong, are found to be more magnetic than that from Sarimukti, the younger and active site. The enhancement of leachate due to the soil-derived ferrimagnetic particles is possibly the same for both Sarimukti and Jelekong. The fact that strong correlation between magnetic parameters and heavy metals is observed in Jelekong but is absent in Sarimukti suggests that the use of magnetic measurement as a proxy measurement for heavy metal content in leachate is plausible provided that the magnetic susceptibility exceeds certain threshold value. Moreover, the accumulation of magnetic minerals and heavy metals in leachate might depend on the activity and the age of landfill site.  相似文献   

3.
In this study, the characteristics of sewage of small community were determined for 6 months to ascertain the type of treatment required in subtropical conditions. The results demarcated sewage of this community as a medium-strength wastewater (chemical oxygen demand: 475 mg/L, biochemical oxygen demand: 240 mg/L and total suspended solids: 434 mg/L). Chemical oxygen demand to sulphate ratio of the sewage (11.6) established that it was amenable to anaerobic digestion. The temperature, strength, biodegradability and components of sewage were suitable for anaerobic digestion, and thus, upflow anaerobic sludge blanket reactor (UASB) was selected for its treatment. These reactors are often shutdown in small communities due to environmental and/or socio-economic factors. The ability of two UASB reactors, seeded with cow dung (UASBCD) and activated sludge of a dairy treatment plant (UASBASDIT) to restart after a long idle period of 12 months, was investigated along with sludge analysis by scanning electron microscope. Biomass in both reactors reactivated rapidly after shutdown period and within 30 days after substrate feeding achieved uniform removal efficiencies for chemical oxygen demand, total suspended solids, total dissolved solids, chloride and oil and grease. Chemical oxygen demand removal efficiency of both reactors became uniform and remained close to 80% after 30 days through reactivation of microbes in sludge bed due to adequate food and temperature conditions. During restart-up, at an average organic loading rate of 0.902 kg COD/m3 per day, methane yields of 0.091 and 0.084 m3/kg COD removed were achieved for UASBCD and UASBASDIT reactors, respectively.  相似文献   

4.
Riverbank filtration (RBF) is an efficient and low-cost natural alternative technology for water supply application in which surface water contaminants are removed or degraded as the infiltrating water moves from the river to the pumping wells. In this study, a full-scale RBF site consisting of three vertical wells installed 50 m from Nile bank was investigated. The RBF systems are particularly well suited for providing better water quality than withdrawal directly from the Nile River to produce drinking water for New Aswan city. The study is carried out by taking samples over 1 year from riverbank filtrates wells, Nile River (as induced surface water), and some production wells were collected and analyzed. Physicochemical and microbiological measurements such as turbidity, dissolved oxygen, total suspended solids, total organic carbon, total dissolved solids, electrical conductivity, pH, Fe, Mn, NH3, NO2, NO3, PO4, Ca, Mg, Na, K, HCO3, SO4, Cl, total bacteria, and total coliform were carried out. The results of bank filtrate were compared with those of the natural groundwater and previous reported Nile water. Chemical and bacterial quality parameters of RBF are under the allowable limits for drinking water. Moreover, bank filtration is simultaneously improved the ambient groundwater and cleaned Nile water in the studied area. Result of this full-scale RBF plant showed the effectiveness of riverbank filtration as a proven treatment technique in Nile Valley with a fraction of cost comparing to conventional surface treatment plants.  相似文献   

5.
《Applied Geochemistry》2001,16(7-8):659-718
The literature has been critically reviewed in order to assess the attenuation processes governing contaminants in leachate affected aquifers. Attenuation here refers to dilution, sorption, ion exchange, precipitation, redox reactions and degradation processes. With respect to contaminants, focus is on dissolved organic matter, xenobiotic organic compounds, inorganic macrocomponents as anions and cations, and heavy metals. Laboratory as well as field investigations are included. This review is an up-date of an earlier comprehensive review. The review shows that most leachate contamination plumes are relatively narrow and do not in terms of width exceed the width of the landfill. The concept of redox zones being present in the plume has been confirmed by the reported composition of the leachate contaminated groundwater at several landfills and constitutes an important framework for understanding the behavior of the contaminants in the plume as the leachate migrates away from the landfill. Diverse microbial communities have been identified in leachate plumes and are believed to be responsible for the redox processes. Dissolved organic C in the leachate, although it appears to be only slowly degradable when the volatile organic acids are gone, apparently acts as substrate for the microbial redox processes. Several xenobiotic organic compounds have been found to be degradable in leachate contaminated groundwater, but degradation rates under anaerobic redox conditions have only been determined in a few cases. Apparently, observations in actual plumes indicate more extensive degradation than has been documented in the laboratory. The behavior of cations in leachate plumes is strongly influenced by exchange with the sediment, although the sediment often is very coarse and sandy. Ammonium seems to be subject to anaerobic oxidation, but the mechanisms are not yet understood. Heavy metals do not seem to constitute a significant pollution problem at landfills, partly because the heavy metal concentrations in the leachate often are low, and partly because of strong attenuation by sorption and precipitation. Although complexation of heavy metals with dissolved organic matter is significant, the heavy metals are in most cases still strongly attenuated in leachate-polluted aquifers. The information available on attenuation processes has increased dramatically during the last 15 a, but the number of well-documented full scale leachate plumes are still few and primarily from sandy aquifers. Thus, the diversity of attenuation processes in leachate plumes is probably not yet fully understood. Apparently, the attenuation processes in leachate plumes may for many contaminants provide significant natural remediation, limiting the effects of the leachate on the groundwater to an area usually not exceeding 1000 m from the landfill.  相似文献   

6.
Unscientific disposal of municipal solid waste causes groundwater contamination. The migration of leachate from the solid waste dumpsite to the aquifer varies according to the geohydrological profile of the dumpsite. A detailed study of the mechanism of leachate percolation to the groundwater helps to design a proper groundwater remediation technique. Multilevel boreholes were drilled in the periphery of the Perungudi dumpsite, Chennai, India. The major lithological layers and the geochemical analysis of the contaminant migrated from the dumpsite to the underlying aquifer has been studied. The distribution of heavy metals such as Pb, Fe, Zn, Cr, and Cd follows a similar trend in the pollutant source, groundwater samples around the dumpsite, and at various litho units beneath the dumpsite. The analysis thus helps to find an appropriate groundwater remediation technique to remove the specific contaminant and thereby provide a safe drinking water for the surrounding community.  相似文献   

7.
Unsafe lead (Pb) concentrations in leafy vegetables raised in urban and peri-urban agricultural production systems have been reported across cities in Northern Nigeria, even though Pb concentrations in soils are within regulatory safe levels. This study examined the soil enrichment, adsorption and chemical species of Pb in urban garden fields irrigated with untreated wastewater at three industrial locations in Kano, northern Nigeria. Total Pb in the soil profiles ranged from 9 to 91 mg kg?1 and decreased rapidly from the surface to the subsurface layer, but attaining nearly constant concentration at depth ≥1.2 m in the profiles. The potentially labile Pb maintained fairly constant concentration with depth up to 0.9 m, but decreased fairly rapidly with depth thereafter. There was a significant Pb enrichment of the soils, extending up to 30–60 cm depth in the soil profiles. The adsorption of Pb by the soils increased drastically with pH, and attained maximum adsorption at pH ≥ 7.0 in the surface layer, and at pH ≥ 6 in the subsurface layer. The surface soils adsorbed between 85 and 97 % of added Pb at pH ≤ 5. Free Pb2+ activities in soil solution accounted for between 46 and 87 % at pH 5–7 of total dissolved Pb (PbT). The quantifiable chemical species of Pb in solution consisted mainly of PbOH+, PbSO 4 · , PbCl+ and PbOH 2 · which accounted for between 0.9 and 26 % of PbT in soil solution at pH ≥ 5.0, but declining to between 0.1 and 2.1 % at pH ≥ 7.5. There was no apparent equilibrium between Pb2+ activities and known Pb-compounds in the soils. It was concluded from the data that reports of excess Pb concentrations in leafy vegetables raised in these soils are consistent with high free Pb2+ activities maintained in soil solution by these predominantly sandy-textured soils.  相似文献   

8.
Landfilled wastes manifest slow decomposition, producing emanation of gases, and outflow of leachate. Waste mass shows various chemical reactions and complex evolutions that occur under the influence of natural agents, as rain and microorganisms. These reactions lead to biological, physical, and chemical transformations of wastes. The intensity of the phenomenon is related to the air and the humidity. These factors originate from the initial composition of the solid waste, the operating mode of the landfill, and the geological and hydrogeological conditions. Leachate is considered a major source of groundwater pollution. It has a complex nature; it typically contains high concentrations of chemical hazardous including heavy metals, chemical compounds that may severely pollute the environment. These challenges are faced all over the world by environment protection agencies and waste management bodies. The challenge differs according to the specific situation of the site, the climatic, environmental, and geological factors. The international literature is rich with studies in this concern. Each country or region of the world has its own legislation and laws governing waste management, e.g., the European Commission Legislation, the US Environmental Agency, and so forth. The main objective of this study is to shed light on the environmental consequences of a landfill site located in the southeast of Riyadh City, Saudi Arabia. It constitutes a peculiar case because of its situation, its exploitation mode, and nature of buried wastes. The study made use of satellite MSS, TM, ETM and SPOT image 2007, and Digital Elevation Model (DEM), respectively. Geological, morphological, hydrological, hydrochemical, and detailed drainage analyses were performed. Records of meteorological stations were also used in this study. The satellite images illustrate the evolution of the site through time since its start in the 1990s of the twentieth century. The main geological units outcropping in the area are the Sulaiy Formation, the Yamama Formation, Khabra deposits, floodplain deposits, alluvium, and sheet gravel. Drainage analyses shows a dendritic nature for the network, a total area of 2,113 km2, basin slope of 0.016, perimeter of 430?×?103, and a mean elevation of 635 m. Annual rainfall is around 100 mm, evapotranspiration is about 2,900 mm, wind speed averages at 5.1 km/h, and runoff peak is within 2.7–4.7 m3/s. A plume of total dissolved solids and nitrates was observed to initiate from the landfill site. Heavy metal concentration confirms the same result. Planners, environmentalists, decision makers, and other interest groups can use the findings of this study for environmental management of the landfill and protection of the downstream part of the Sulaiy tributary from leachate contamination. The results indicate the importance of monitoring landfills through the combined use of ground and satellite monitoring.  相似文献   

9.
The present paper undertakes a study of the physico-chemical properties and toxic heavy metals content in the untreated and treated pharmaceutical effluents in order to evaluate the working efficiency of industrial effluent treatment plants. The treatment efficiency achieved for various parameters was conductivity (79.94%), alkalinity (93.91%), hardness (87.70%), chloride (89.24%), cyanide (79.66%), phosphate (99.19%), total dissolved solids (85.89%), total suspended solids (96.87%), salinity (52.41%), dissolved oxygen (27.32%), biochemical oxygen demand (83.39%) and chemical oxygen demand (72.21%). The removal efficiency achieved for different heavy metals was Cu2+ (79.66%), Ni2+ (69.22%), Cr6+ (80.15%), Pb2+ (72.14%), Fe3+ (92.59%) and Zn2+ (90.61%). The level of biochemical oxygen demand (64 mg L?1) in the treated effluents was above the limit of 30.0 mg L?1, chemical oxygen demand level (208 mg L?1) was close to a limit of 250 mg L?1, while average Pb2+ concentration (0.10 mg L?1) was on the borderline of maximum permissible limit of 0.10 mg L?1 set by Central Pollution Control Board for safe discharge of industrial effluent in inland surface water. The average concentration of cyanide (0.01 mg L?1) in the treated industrial effluent of our study is of great concern to the fisheries of freshwater ecosystem in which the effluents finally get discharged. Based on the results of the present study, it is concluded that the pollution level in the discharged pharmaceutical effluent is of the great concern requiring proper treatment and regular scientific monitoring so as to protect the environmental degradation of water resources and facilitate the propagation of the aquatic life.  相似文献   

10.
Characterization of content and source of heavy metals in soils are necessary to establish quality standards on a regional level. In relation to this, two zones, (sampling zone-1) and (sampling zone-2) depending on nature and intensity of wastewater disposal along the peri-urban area of Peshawar, Pakistan were selected. Thirty-six samples of wastewater and topsoil each were collected to determine the content of Pb, Cr, Cd, Cu, Zn, Ni, Fe and Mn, and physico-chemical parameters like pH, electrical conductivity, total solids, total dissolved solids, total suspended solids, and organic matter. Analytical determinations were performed by atomic absorption spectroscopy after microwave sample digestion in acid solution. Chemometric techniques which include hierarchical cluster analysis, principal component analysis, correlation analysis, and tukey test were applied. Concentrations of physico-chemical properties in wastewater and soil were higher in sampling zone-2. Concentrations of six heavy metals in wastewater and two in soil exceeded permissible limits of World Health Organization (Guidelines for drinking water quality, 4th edition, 2011), European Union (Heavy metals in wastes, European commission on environment. http://ec.europa.eu/environment/waste/studies/pdf/heavymetalsreport, 2002). Hierarchical cluster analysis grouped eight heavy metals into two clusters for wastewater and five clusters for soils. Principal component analysis describes four factors possessing Eigenvalues greater than 1.0 and explained the cumulative total variance of 84% with factor 1, having positive loading of anthropogenic metals (Cd, Cu, and Ni). Significant correlation was found between anthropogenic metals like Ni and Cd in water and between Cu and Cr in soil. Further research in other agricultural lands in peri-urban region would improve the basis for proposing such soil quality standards.  相似文献   

11.
Evaluation of analyses of leachate for inorganic constituents, from selected landfills in Illinois indicates that leachate quality is variable and is strongly affected by waste type and cover material. Twenty parameters were detectable in all samples, but selenium was not detected in any of the samples analyzed. More than 98% of the mean leachate composition was comprised, in descending order, of total alkalinity (bicarbonate plus carbonate), sulfate, sodium plus potassium, calcium plus magnesium, chloride, and iron plus managese. Excluding iron, trace metals contributed less than one percent to the total; of these, copper, zinc and boron were most significant. Based on milliequivalents per liter of major constituents, approximately 73 percent of the cations and 92% of the anions fall within the concentration range of potable waters. Heavy metals, organics, suspended matter, microorganisms, odor and color are among the objectionable qualities of leachate which should not be present in potable waters. In assessing the impact of leachate on ground-water quality, use of indicator parameters in place of comprehensive analyses for routine water samples is frequently desirable in the interest of both time and economics. Availability, mobility, persistence, analyticity and contrast of concentrations in leachate and ground water are important factors to consider in selection of an indicator. Boron, iron, ammonia and total dissolved solids appear to be reliable parameters for indicating ground-water pollution by leachate. Chloride and hardness may also be useful under certain conditions. Sulfate was the least reliable parameter considered. Although many of the trace elements in leachate exceed Illinois Environmental Protection Agency Public Water Supply Standards in more than 50% of the samples, these elements are most useful as indicators when a waste rich in trace elements is deposited in a landfill of unfavorable hydrogeology.  相似文献   

12.
In the present study, the performance of three moving bed biofilm reactors (MBBRs) has been evaluated in series with anaerobic/anoxic/oxic (A2O) units for simultaneous removal of organic matter and nutrients (nitrogen and phosphorous) from a synthetic wastewater with characteristics similar to those of a typical municipal wastewater. Response surface methodology based on central composite design was used to investigate the effects of nitrate recycle ratio, hydraulic retention time (HRT), and influent chemical oxygen demand (COD) on the organic and nutrient removal and optimization process. The optimized values of influent COD, HRT, and R were 462 mg/L, 10 h, and 3.52, respectively. The predicted and observed values at optimized conditions were 92.8% and 93 ± 1.3%, 84.3% and 84 ± 1.3%, 71.7% and 68 ± 1.6% for COD, TN, and TP removals and 100 and 97 ± 1.2 mL/g for sludge volume index, respectively. After that, the influent COD, TN, and TP were increased to 550, 48, and 12 mg/L, respectively, to partly simulate the organics and nutrient variations of real wastewater treatment plants. The COD, TN, and TP removals were 91 ± 1.3, 82 ± 1.1, and 71 ± 0.8%, respectively. The influent COD, TN, and TP were increased again to 650, 56, and 14 mg/L, respectively. After this phase, the COD, TN, and TP removals were 90 ± 0.8, 80 ± 1.2, and 70 ± 1.0%, respectively. Obtained results indicated the good stability of the optimized system and the ability of MBBRs to remain stable at influent organics and nutrient variations. The ratio of attached volatile solids to mixed liquor volatile suspended solids was 1.90 ± 0.10, 2.07 ± 0.09, and 2.25 ± 0.14 in phases 1, 2, and 3, respectively. These high ratios indicate that the microorganisms had favored the attached growth to the suspended growth within the whole operation time.  相似文献   

13.
Pollutant association with suspended solids in stormwater in Tijuana,Mexico   总被引：1，自引：1，他引：0  
Stormwater runoff from urban areas is a major source of many pollutants to water bodies. Suspended solids are one of the main pollutants because of their association with other pollutants. The objective of this study was to evaluate the relationship between suspended solids and other pollutants in stormwater runoff in the city of Tijuana. Seven sites were sampled during seven rain events during the 2009–2010 season and the different particle size fractions were separated by sieving and filtration. The results have shown that the samples have high concentration of total suspended solids, the values of which ranged from 725 to 4,411.6 mg/L. The samples were analyzed for chemical oxygen demand, total phosphorus, total nitrogen, and turbidity. The results show that most of the particles in suspended solids are in the particle fraction between 10 and 62 μm. A high association between the concentrations of suspended solids was found for chemical oxygen demand, phosphorus, and turbidity but not for total nitrogen.  相似文献   

14.
Minerals constitute a primary ecosystem control on organic C decomposition in soils, and therefore on greenhouse gas fluxes to the atmosphere. Secondary minerals, in particular, Fe and Al (oxyhydr)oxides—collectively referred to as “oxides” hereafter—are prominent protectors of organic C against microbial decomposition through sorption and complexation reactions. However, the impacts of Mn oxides on organic C retention and lability in soils are poorly understood. Here we show that hydrous Mn oxide (HMO), a poorly crystalline δ-MnO2, has a greater maximum sorption capacity for dissolved organic matter (DOM) derived from a deciduous forest composite Oi, Oe, and Oa horizon leachate (“O horizon leachate” hereafter) than does goethite under acidic (pH 5) conditions. Nonetheless, goethite has a stronger sorption capacity for DOM at low initial C:(Mn or Fe) molar ratios compared to HMO, probably due to ligand exchange with carboxylate groups as revealed by attenuated total reflectance-Fourier transform infrared spectroscopy. X-ray photoelectron spectroscopy and scanning transmission X-ray microscopy–near-edge X-ray absorption fine structure spectroscopy coupled with Mn mass balance calculations reveal that DOM sorption onto HMO induces partial Mn reductive dissolution and Mn reduction of the residual HMO. X-ray photoelectron spectroscopy further shows increasing Mn(II) concentrations are correlated with increasing oxidized C (C=O) content (r = 0.78, P < 0.0006) on the DOM–HMO complexes. We posit that DOM is the more probable reductant of HMO, as Mn(II)-induced HMO dissolution does not alter the Mn speciation of the residual HMO at pH 5. At a lower C loading (2 × 102 μg C m?2), DOM desorption—assessed by 0.1 M NaH2PO4 extraction—is lower for HMO than for goethite, whereas the extent of desorption is the same at a higher C loading (4 × 102 μg C m?2). No significant differences are observed in the impacts of HMO and goethite on the biodegradability of the DOM remaining in solution after DOM sorption reaches steady state. Overall, HMO shows a relatively strong capacity to sorb DOM and resist phosphate-induced desorption, but DOM–HMO complexes may be more vulnerable to reductive dissolution than DOM–goethite complexes.  相似文献   

15.
We examined high frequency fluctuations in water quality parameters in two tropical coastal plain estuaries in response to changing tidal flow conditions. The variability in total suspended sediments (TSS), volatile suspended solids (VSS), total organic carbon (TOC) concentrations, and indicators of water quality, including pH, temperature, salinity, and dissolved oxygen, over one spring tidal cycle during the early wet monsoon season was measured in two estuaries in eastern Sumatra. The relatively high rainfall experienced throughout the year, in combination with the recent extensive vegetation clearing and modification of the landscape, resulted in significant concentrations of TSS, VSS, and TOC being discharged to coastal waters. Maximum values are reached on the ebb tide (TSS > 1,013 mg l−1; VSS > 800 mg l−1; TOC >60 mg l−1). The influence of freshwater discharge and tidal flow on water properties of the lower estuaries is also marked by the variability in salinity, dissolved oxygen, and pH over the tidal cycle, with minimum values for each of these parameters following maximum current velocities and after the completion of the strong ebb tide. Estimation of seaward sediment fluxes, which are of significant interest in a region where rapid environmental change is occurring, would require further examination of sedimentary processes, such as resuspension and advection of sediment, as well as a consideration of neap-spring tidal variations and the effect of seasonality on estuarine circulation.  相似文献   

16.
A vertical two-dimensional, laterally averaged hydrodynamic and water quality model CE-QUAL-W2 was used to simulate water temperature, dissolved oxygen, electrical conductivity, chlorophyll a, total suspended solids, alkalinity, ammonium, phosphate, and total iron in the Sejnane Dam (North Tunisia) in response to external forcings that characterize main features of climate in the southern side of the Mediterranean Sea. The hydrodynamic modelling results show that the model is able to reproduce accurately the measured water surface elevation, spatio-temporal patterns of temperature, dissolved oxygen and other state of variables and to capture most of the seasonal changes in the reservoir. Three scenarios involving the impacts of severe drought season, summer rainfall and total suspended solids load on hydrodynamics and water quality are analyzed. Severe drought reduces the thickness of hypoxic waters from 10 to 2–4 m and shifts the temperature of the entire water column up to 5 °C during summer and about 1.2 °C in winter. The thermocline takes place 1 month before that of the reference and sinks to the bottom faster by 1–2 m per month. Summer rainfall dilutes the first waves of the autumn rains and disrupts the thermal gradient in the water column, which may show complex thermal structures. TSS load has the most negative effects on water quality in that it shifts the phosphorus concentration by 1–3 mg/l and promotes an early warming of surface water in spring and an early cooling since late summer by up to 1 °C. During summer stratification, it contributes to the cooling of the metalimnion by 2 °C on average, which may alter its structure and dynamics as an aquatic biotope.  相似文献   

17.
The present study was carried out in Haraz basin (Iran) that is located in south of the Caspian Sea. The goal of this study was to establish correlations amongst total suspended solids concentration (TSS) and turbidity with total pollutant concentrations to evaluate the dissolved and particle-bound concentrations of major toxic metals. It also aimed to validate TSS and/or turbidity measurements as proxies to monitor pollutant fluxes. Eight metals, namely nickel, lead, cadmium, copper, zinc, cobalt, arsenic and strontium were analyzed for dissolved and total concentrations in water at ten locations within the catchment. TSS and turbidity were also measured. Sampling campaigns were designed to cover both the rainy (December) and the dry (May) season within the basin. The robust relationship between TSS (202–1212 mg/l) and turbidity (63–501 NTUs) in both seasons warranted their interchangeable potential as proxies within the observed ranges. Total element concentrations were plotted in separate attempts versus TSS and turbidity for all locations and both events. Very good linear correlations were attained where the slopes represent the metals concentration on suspended solids and the intercept the dissolved concentration in water. The results achieved by these linear regressions were in very good agreement with independently measured values for dissolved concentration and concentrations on river bed sediments taken at the same locations. This demonstrates that turbidity and/or TSS measurements may be used for monitoring of metal loads if once calibrated against total concentration of metals. The results also revealed that in the lower Haraz catchment metal concentrations on suspended and river bed sediment were homogeneously distributed along the investigated river stretch. This is assumed to be due to intensive gravel and sand mining activities in the upper and middle part of the catchment.  相似文献   

18.
电镀企业搬迁后场地调查及其环境影响评价   总被引：1，自引：0，他引：1  
刘媛 《岩矿测试》2012,31(4):638-644
对上海新区一家刚搬迁的电镀厂场地进行现场采样,评价土壤、地下水和废水的环境状况。土壤样品检测了pH、CN-及主要重金属离子等11项指标,地下水样品分析主量元素、重金属元素、NH3-N、NO3--N、NO2--N、溶解性总固体、总硬度、CN-、挥发性酚类、高锰酸盐指数等24项指标,废水样品检测化学耗氧量(CODCr)、挥发性酚及土壤的分析指标共13项。结果表明:厂区内土壤呈碱性,综合污染指数为0.67,仅个别采样点Zn、Ni的单项污染指数大于1,土壤总体环境质量尚可;地下水的综合评价指数在4.27～7.58之间,水质判断为很差或极差,不能作为饮用水源,主要污染指标NH3-N、氯化物、溶解性固体、总硬度、重金属元素、氰化物、挥发性酚、高锰酸盐指数等都低于地下水Ⅳ级标准,未见明显的重金属污染;废水除了pH之外,重金属元素、挥发性酚和氰化物等指标都达到城市污水和电镀污染物排放标准。研究成果对污染型企业搬迁后的原厂区环境监测评价具有一定的借鉴意义。  相似文献   

19.
In Mexico, open dumps that are maintained by the municipality but provide no covering of waste are not uncommon. Further, disposal at these sites is often performed by burning. The aim of this study was to determine the leachate plume from an open dump located in a depositional deltaic environment, with arid climate, low rainfall and where the water table is about 2 m below the surface. The methodology comprised analysis of groundwater monitoring wells and geophysical and geochemical prospecting techniques. The 3D geoelectric interpretation shows a typical area of these depositional environments with low resistive values (10–20 Ω-m) associated with the presence of sands and clays interbedded. However, there is a very low resistivity zone associated with the dump’s impact which reaches values below 5 Ω-m, and it is located where the disposal and burning of wastes occurred. Another zone with values above 16 Ω-m appears as a limit for the advance of the saline. This is interpreted as a sandy lenses area. These sandy lenses with higher porosity transport aquifer’s water. Thus the dump is in direct contact by this conduct with clean groundwater. Piper diagrams constructed with the chemical data analysis reveal that the groundwater in the area corresponds to the chlorinated and/or sulfated sodium type, showing the impact caused by the dump. The monitoring well (NP8, on-site) with the highest dissolved solids content behaves anomalously and belongs to the more conductive zone according to the geoelectric profiles. The subsoil geochemical behavior is influenced by the seasonal water table variations provoking the dissolution of burned and unburned wastes, but the effects of slow flows in the direction of the regional flow are not discarded. Although the most impacted area within the dump is characterized to a depth of 10 m, there is a slow flow in the direction of the regional flow that has been moving pollutants out of the dumpsite during its almost 20 years of operation. The results of this study provide valuable information for the authorities to carry out an appropriate restoration project.  相似文献   

20.
Self potential (SP) and electrical resistivity tomography (ERT) methods are used together with the results of groundwater samples hydrogeochemical analysis to assess the impact of the water leak from the landfill garbage site at NamSon located in Northern Hanoi on causing pollution to the surrounding environment and affecting geological structure. Selected survey area covers an area of 180 × 300 m lying in the low land of the NamSon site with a slope ranging about 8 m in direction NW–SE. There are three geophysical measurements lines denoted as T1, T2 and T3. Processing 180 SP data points has allowed to draw maps of equipotential epoch in the two periods in 2015 and 2016. The maps show four zones of SP positive anomalies with maximum amplitudes of about +20 mV where the groundwater flow direction is downward and five zones of SP negative anomalies with minimum values in a range from ?180 to ?260 mV where the groundwater flow direction is upward. Resistivity values of the subsurface layers of soils and rocks have been aquired from 2D inverse model for measuring ERT in March 2015 and March 2016. The results of the ERT allowed to define the low resistivity in the range 15–20 Ωm related to leachate plume from NamSon landfill site. Results of the physico-chemical analysis of groundwater samples from the existing six boreholes show increases in concentration of the measured pollutant parameters indicating contamination of the groundwater as a result of solid waste leachate accumulation. This result is affirmative evidence for the survey results by geophysical technique. The rapid decrease in quality of groundwater over the last year is probably due to the influence of the leachate from the NamSon landfill site.  相似文献   

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