共查询到20条相似文献,搜索用时 15 毫秒
1.
Singh SK Juwarkar AA Pandey RA Chakrabarti T 《Environmental monitoring and assessment》2008,141(1-3):201-212
The biologically treated distillery effluent (BTDE) contains intense colour, high total dissolved solids (TDS), chemical oxygen
demand (COD) and biochemical oxygen demand (BOD). These properties even after primary, secondary and tertiary treatments contain
high concentrations of TDS, COD and BOD. The paper highlights the safe disposal and treatment of BTDE on land through High
Rate Transpiration System (HRTS). HRTS is a zero discharge, low cost, high-tech method for improving the quality of BTDE for
potential reuse. The experiments conducted at bench and pilot scale showed that HRTS having coconut husk as a bedding material
could successfully treat the BTDE with a hydraulic load of 200 m3 ha−1 day−1 having BOD of 100 mg l−1 and 500 m3 ha−1 day−1 having BOD of 500 mg l−1 with average COD load of 0.686 and 2.88 ton ha−1 day−1 during the post and pre monsoon periods respectively. There was no significant increase in the organic carbon of the soil
irrigated with BTDE. The concentrations of various pollutants analyzed in the leachate were within the prescribed limit for
the drinking water sources. The colour removal was 99 to 100% and BOD and COD were possible to treat with optimum hydraulic
loading of BTDE through HRTS planted with Dendrocalamus strictus. 相似文献
2.
Tadesse Getahun Mulat Gebrehiwot Argaw Ambelu Tom Van Gerven Bart Van der Bruggen 《Environmental monitoring and assessment》2014,186(7):4637-4646
The objective of this study was to estimate the potential of organic municipal solid waste generated in an urban setting in a tropical climate to produce biogas. Five different categories of wastes were considered: fruit waste, food waste, yard waste, paper waste, and mixed waste. These fractions were assessed for their efficiency for biogas production in a laboratory-scale batch digester for a total period of 8 weeks at a temperature of 15–30 °C. During this period, fruit waste, food waste, yard waste, paper waste, and mixed waste were observed to produce 0.15, 0.17, 0.10, 0.08, and 0.15 m3 of biogas per kilogram of volatile solids, respectively. The biogas produced and caloric value of each feedstock was in the range of 1.25?×?10?3 m3 (17 kWh)/cap/day (paper waste) to 15?×?10?3 m3 (170 kWh)/cap/day (mixed waste). Paper waste produced the least (<1×10?3(<17.8 kWh)/cap/day), and mixed waste produced the highest methane yield (10?×?10?3 m3 (178 kWh)/cap/day). Thus, mixed waste was found to be more efficient than other feedstocks for biogas and methane production; this was mainly related to the better C/N ratio in mixed waste. Taking the total waste production in Jimma into account, the total mixed organic solid waste could produce 865?×?103 m3 (5.4 m3/capita) of biogas or 537?×?103 m3 (3.4 m3/capita) of methane per year. The total caloric value of methane production potential from mixed organic municipal solid waste was many times higher than the total energy requirement of the area. 相似文献
3.
Yayintas OT Yilmaz S Turkoglu M Dilgin Y 《Environmental monitoring and assessment》2007,127(1-3):389-397
Waste water pollution of industrial areas can answer for the serious consequences of one of the most important environmental
threats to the future. In this study, inductively coupled plasma-atomic emission spectrometry method (ICP-AES) is proposed
to determine heavy metals (Pb, Cu, Cd, Cr, Zn, Al, Fe, Ni, Co, Mn) and major elements (Ca, Mg) in waste water of Kocabas Stream.
The concentration of metals in the waste water samples taken from 9 different stations (St.) in Biga-Kocabas Stream in November
2004 (autumn period) were determined after simple pretreatment of samples by the proposed ICP-AES method. An analysis of a
given sample is completed in about 15 min for ICP-AES the method. The results of heavy metals concentrations in waste water
were found between 0.00001–77.69610 mg l−1 by the ICP-AES technique. The concentrations of Pb, Cd, Cu, Zn, Cr, Al, Fe, Mn, Ni, Co, Mg and Ca 0.00001 (St.3,6,7) – 0.0087
mg l−1 (St.9), 0.00001 (St.4-7) – 0.0020 mg l−1 (St.8), 0.00001 (St.1,3-7,9) – 0.0041 mg l−1 (St.2), 0.0620 (St.2) – 0.2080 mg l−1 (St.3), 0.0082 (St.6) – 0.2290 mg l−1 (St.8), 0.3580 (St.2) – 1.7400 mg l−1 (St.3), 0.2240 (St.1) – 0.6790 mg l−1 (St.3), 0.0080 (St.1) – 1.5840 mg l−1 (St.3), 0.0170 (St.3) – 0.0640 mg l−1 (St.2), 0.0010 (St.1,4,5,8) – 0.0080 mg l−1 (St.3), 5.0640 (St.9) – 5.2140 mg l−1 (St.1) and 43.3600 (St.2) – 77.6961 mg l−1 (St.9), respectively. Also we measured environmental physicochemical parameters such as temperature, salinity, specific conductivity,
total dissolved solid (TDS), pH, oxidation and reduction potential (ORP), and dissolved oxygen (DO) in the waste water at
sampling stations. 相似文献
4.
Lacerda LD Molisani MM Sena D Maia LP 《Environmental monitoring and assessment》2008,141(1-3):149-164
The Northeastern semi-arid Brazilian region is experiencing rapid social and economic development based on improving water
management and even in areas of low human occupation, anthropogenic emissions of N and P surpass natural emissions in at least
one order of magnitude and these additional loads can alter the water quality of the receiving estuaries. This study estimates,
using an emission factor approach, the annual emissions of N and P from natural processes and anthropogenic sources for estuaries
along the Ceará State, NE Brazil. Emission factors from natural sources are one to two orders of magnitude lower than those
for anthropogenic sources. Among the anthropogenic activities, the aquaculture is responsible for most N emission (0.52 t
km−2 year−1) followed by waste water and husbandry. For P, the largest average emission factors are from husbandry (0.30 t km−2 year−1), waste water and agriculture. 相似文献
5.
The toxicity characteristic leaching procedure (TCLP) is the current US-EPA standard protocol to evaluate metal leachability
in wastes and contaminated soils. However, application of TCLP to assess lead (Pb) leachability from contaminated shooting
range soils may be questionable. This study determined Pb leachability in the range soils using TCLP and another US-EPA regulatory
leaching method, synthetic precipitation leaching procedure (SPLP). Possible mechanisms that are responsible for Pb leaching
in each leaching protocol were elucidated via X-ray diffraction (XRD). Soil samples were collected from the backstop berms
at four shooting ranges, with Pb concentrations ranging from 5,000 to 60,600 mg kg−1 soil. Lead concentrations in the TCLP leachates were from 3 to 350 mg l−1, with all but one soil exceeding the USEPA non-hazardous waste disposal limit of 5 mg l−1. However, continued dissolution of metallic Pb particles from spent Pb bullets and its re-precipitation as cerussite (PbCO3) prevented the TCLP extraction from reaching equilibrium at the end of the standard leaching period (18 h). Thus, the standard
one-point TCLP test would either over- or under-estimate Pb leachability in shooting range soils. Lead concentration in the
SPLP leachates ranged from 0.021 to 2.6 mg l−1, with all soils above the USEPA regulatory limit of 0.015 mg l−1. In contrast to TCLP, SPLP leaching had reached equilibrium, with regard to both pH and Pb concentrations, within the standard
18 h leaching period, and the analytical SPLP results were in good agreement with those derived from modeling. Thus, we concluded
that SPLP is a more appropriate alternative than TCLP for assessing lead leachability in range soils. 相似文献
6.
Jun Yao WenBing Li FangFang Xia YuanGe Zheng ChengRan Fang DongSheng Shen 《Environmental monitoring and assessment》2012,184(6):3711-3720
Fly ash samples were taken from solid waste incinerators with different feeding waste, furnace type, and air pollution control
device in six cities of Zhejiang province. The solid waste incinerators there constitute one fifth of incinerators in China.
Heavy metals and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed in the fly ash. Moreover, the fly ash samples were extracted by toxicity
characteristic leaching procedure (TCLP). The biotoxicity of the leachate was evaluated by Chlorella pyrenoidosa. High variation and contents were found for both the heavy metals and PCDD/Fs. The contents of Zn, Cu, As, Pb, Cd, Cr, Ni,
and Hg in the fly ash samples varied from 300 to 32,100, 62.1–1175, 1.1–57, 61.6–620, 0.4–223, 16.6–4380, 1.2–94.7, and 0.03–1.4 μg g−1 dw, respectively. The total contents of 17 PCDD/Fs varied from 0.1128 to 127.7939 μg g−1 dw, and the 2,3,7,8-TeCDD toxic equivalents (TEQ) of PCDD/Fs ranged from 0.009 to 6.177 μg g−1 dw. PCDF congeners were the main contributor to the TEQ. The leachate of the fly ash showed biotoxicity to C. pyrenoidosa. A significant correlation was found between the Cd and EC50 values. Further research is required to investigate the environmental impact of the various pollutants in the fly ash. 相似文献
7.
Modeling Phosphate Influence on Arsenate Reduction Kinetics by a Freshwater Cyanobacterium 总被引:1,自引:0,他引:1
Arsenic speciation in natural surface-water systems can be highly impacted through biological processes that result in non-thermodynamically
predicted species to dominate the system. In laboratory experiments, arsenate reduction by a freshwater cyanobacterium exhibited
saturation kinetics increasingly inhibited by elevating solution phosphate concentrations. Approximately 100% arsenate reduction
occurred by days 4, 7, and 10 in the low (0.35 μm), middle (3.5 μm), and high (35 μm) phosphate treatments, respectively,
with maximum arsenate reduction rates ranged from 0.013 μmol As g C−1 day−1 in the high-phosphate treatment to 0.398 μmol As g C−1 day−1 in the low-phosphate treatment. Saturation kinetic models were utilized to evaluate the impact of cell growth and arsenate-phosphate
uptake competition on arsenate reduction rates by the cyanobacterium. Results showed reduced arsenicals dominate arsenic speciation
once growth reached steady state, indicating reduced arsenicals may dominate natural systems, even when considering conservatively
high, abiotic arsenic reoxidation. 相似文献
8.
Characterization of the Leachate in an Urban Landfill by Physicochemical Analysis and Solid Phase Microextraction-GC/MS 总被引:1,自引:0,他引:1
The aim of this study is to evaluate extensively the characterization and identification of major pollutant parameters by paying attention to the organic chemical pollution for unregulated dumping site leachate in Eskişehir/Turkey. The study that is first and only one research has been very important data related with before new sanitary landfill site in Eskişehir city. For this purpose, in this study leachate samples were collected in-situ at monthly interval for a period of 8 months. Firstly, thirty three physicochemical parameters were monitored. Secondly, SPME technique was used for identification of organic pollutants. Meteorological data were also recorded for the same sampling period to correlate meteorological data and physicochemical parameters. Mean values are used in the correlation analysis. Correlation is shown only for the relationship between air temperature and NO3
−. No correlation has been found between rain and leachate quality parameters since the amount of rain was very low during the sampling period. However, analysis results were generally decreased in winter season when each parameter and each sampling point are examined separately. According to correlation between every parameter, especially solid content and dissolved oxygen concentration of leachate is affecting to other parameters. Also, sodium and potassium are changing proportionally with same parameters (suspended solids, fixed solids, dissolved oxygen) and high correlation between chloride and heavy metal concentration is showing. The results were statistically evaluated by use of SPSS 10.0 program. Second part of the study, the leachate was extracted by Solid Phase Microextraction (SPME) technique and then analyzed. Of the methodologies tested in this study, the best one selected was based on 100 μ m polydimethylsiloxane coated fiber (PDMS), headspace with heating (Δ HS) sampling mode and an extraction time of 15 min. at a temperature of 50
o
C. Thirty three organic compounds in leachate were identified by GC/MS. 相似文献
9.
Eutrophication and Sedimentation Patterns in Complete Exploitation of Water Resources Scenarios: An Example from Northwestern Semi-arid Mexico 总被引:1,自引:0,他引:1
Sánchez-Carrillo S Alatorre LC Sánchez-Andrés R Garatuza-Payán J 《Environmental monitoring and assessment》2007,132(1-3):377-393
Water requirements to supply human needs lead water stakeholders to store more water during surplus periods to fulfil the
demand during – not only – scarcity periods. At the reservoirs, mostly those in semi-arid regions, water level then fluctuates
extremely between rises and downward during one single year. Besides of water management implications, changes on physical,
chemical and biological dynamics of these drawdown and refilling are little known yet. This paper shows the results, throughout
a year, on solids, nutrients (N and P), chlorophyll-a, and sedimentation changes on the dynamics, when the former policy was applied in a reservoir from the semi-arid Northwestern
Mexico. Water level sinusoidal trend impinged changes on thermal stratification and mixing, modifying nutrient cycling and
primary producer responses. According to nitrogen and phosphorus concentration as well as chlorophyll-a, reservoir was mesotrophic, becoming hypertrophic during drawdown. Nutrient concentrations were high (1.22 ± 0.70 and 0.14 ± 0.12 mg
P l−1), increasing phosphorus and lowering N:P significantly throughout the study period, although no intensive agricultural, no
urban development, neither industrial activities take place in the watershed. This suggests nutrient recycling complex mechanisms,
including nutrient release from the sediment–water interface as the main nutrient pathway when shallowness, at the same time
as mineralization, increases. Outflows controlled nitrogen and phosphorus availability on the ecosystem while organic matter
depended on river inflows. As on other subtropical aquatic ecosystems, nitrogen limited primary productivity (Spearman correlation
R = 0.75) but chlorophyll-a seasonal pattern showed an irregular trend, prompting other no-nutrient related limitants. Shallowness induced a homogeneous
temporal pattern on water quality. This observed temporal variability was mainly explained statistically by changes on solids
(mineral and organic), chlorophyll-a and flows (62.3%). Annual sedimentation rates of total solids ranged from 11.73 to 16.29 kg m−2 year−1 with organic matter comprising around 30%. N:P ratio on sedimentation rates were as high as could be expected in a resuspension
dominated ecosystem, and spatially inverse related with N:P ratio on bottom sediments. Distance from river inlet into the
reservoir reveals a marked spatial heterogeneity on solid and nitrogen sedimentation, showing the system dependence on river
inflows and supporting resuspension as the main phosphorus pathway. Accretion rates (2.19 ± 0.40 cm year−1) were not related to hydrological variability but decreased with the distance to the river input. Total sediment accumulation
(9,895 tons km−2 year−1) denotes siltation as other serious environmental problem in reservoirs but possibly not related with operational procedures. 相似文献
10.
Evrendilek F Berberoglu S Taskinsu-Meydan S Yilmaz E 《Environmental monitoring and assessment》2006,119(1-3):527-543
Abstact Aboveground biomass, aboveground litterfall, and leaf litter decomposition of five indigenous tree stands (pure stands ofPinus brutia,Pinus nigra,Cedrus libani,Juniperus excelsa, and a mixed stand ofAbies cilicica,P. nigra, andC. libani) were measured in an eastern Mediterranean evergreen needleleaf forest of Turkey. Measurements were converted to regional scale estimates of carbon (C) stocks and fluxes of forest ecosystems, based on general non-site-specific allometric relationships. Mean C stock of the conifer forests was estimated as 97.8± 79 Mg C ha−1consisting of 83.0 ± 67 Mg C ha−1in the aboveground and 14.8 ± 12 Mg C ha−1in the belowground biomass. The forest stands had mean soil organic carbon (SOC) and nitrogen (SON) stocks of 172.0 ± 25.7 Mg C ha−1and 9.2 ± 1.2 Mg N ha−1, respectively. Mean total monthly litterfall was 376.2± 191.3 kg C ha−1, ranging from 641 ± 385 kg C ha−1forPinus brutiato 286 ± 82 kg C ha−1forCedrus libani. Decomposition rate constants (k) for pine needles were 0.0016 forCedrus libani, 0.0009 forPinus nigra, 0.0006 for the mixed stand, and 0.0005 day−1forPinus brutiaand
Juniperus excelsa. Estimation of components of the C budgets revealed that the forest ecosystems were net C sinks, with a mean sequestration rate of 2.0 ± 1.1 Mg C ha−1 yr−1ranging from 3.2 ± 2 Mg C ha−1forPinus brutiato 1.6 ± 0.6 Mg C ha−1forCedrus libani. Mean net ecosystem productivity (NEP) resulted in sequestration of 98.4 ± 54.1 Gg CO2 yr−1from the atmosphere when extrapolated for the entire study area of 134.2 km2(Gg = 109 g). The quantitative C data from the study revealed the significance of the conifer Mediterranean forests as C sinks 相似文献
11.
Citation of cyanobacterial cultures from the shores of south west coast of Gujarat, India and their relationship with sea water quality, influenced by extensive pollutant runoff is reported in this study. Intensity of pollution was evaluated by physico-chemical analysis of water. Higher load of suspended solids (60–1000 mg l−1) and nutrients (PO4
−P: 1.3–4 μmole l−1 and NO3
−N: 12.5–17.8 μmole l−1) were persistent throughout the analysis. Community structure is seen to be influenced by such persistent pollution. Twenty nine cyanobacterial species were isolated belonging to 9 genera of 4 families, with an elevated occurrence of Oscillatoria and Lyngbya species. No heterocystous cyanobacteria were isolated throughout the study. 相似文献
12.
Assessment of water pollution in different bleaching based paper manufacturing and textile dyeing industries in India 总被引:3,自引:0,他引:3
Paper industries using different raw materials such as hard wood, bamboo, baggase, rice-straw and waste papers and bleaching
chemicals like chlorine, hypochlorite, chlorine dioxide, hydrogen peroxide, sulphite and oxygen were studied to estimate organic
pollution load and Adsorbable Organic Halides (AOX) per ton of production. The hard wood based paper industries generate higher
Chemical Oxygen Demand (COD) loads (105–182 kg t−1) and Biochemical Oxygen Demand (BOD) loads (32.0–72 kg t−1) compared to the agro and waste paper based industrial effluents. The bleaching sequences such as C–EP–H–H, C–E–H–H, C–E–Do–D1
and O–Do–EOP–D1 are adopted in the paper industries and the molecular elemental chlorine free bleaching sequence discharges
low AOX in the effluent. The range of AOX concentration in the final effluent from the paper industries was 0.08–0.99 kg t−1 of production. Water consumption was in the range of 100–130 m3 t−1 of paper production for wood based industries and 30–50 m3 for the waste paper based industries. Paper machine effluents are partially recycled after treatment and pulp mill black
liquor are subject to chemical recovery after evaporation to reduce the water consumption and the total pollution loads. Hypochlorite
bleaching units of textile bleaching processes generate more AOX (17.2–18.3 mg l−1) and are consuming more water (45–80 l kg−1) whereas alkali peroxide bleaching hardly generates the AOX in the effluents and water consumption was also comparatively
less (40 l kg−1 of yarn/cloth). 相似文献
13.
Delucchi F Tombesi NB Freije RH Marcovecchio JE 《Environmental monitoring and assessment》2007,132(1-3):445-451
Systematic measurements of both Tributyltin (TBT) and Dibutyltin (DBT) in sediments along different locations in the inner
zone of Bahía Blanca estuary were done. Two samples were taken near the main dry dock facility, at Puerto Belgrano naval base,
in Argentina. TBT concentrations from non-detected to 170.3 ng Sn g−1 were measured in the inner region of the estuary, and higher one of 3,288 ng Sn g−1 near the dry dock at Puerto Belgrano. DBT values ranging between non-detected and 75.2 ng Sn g−1 were obtained along the principal channel, but extreme concentration of 1,645 ng Sn g−1 was measured at Puerto Belgrano. These values show that this estuary is affected by organotin pollution, mainly in areas
of heavy shipyard activities. 相似文献
14.
In this study, the relationship between some physico-chemical properties of soils and lead contamination in soil due to emission
from industrial operations in Samsun province of Turkey was investigated. The extent of timely contamination was studied by
comparing the obtained results with the results of the study conducted in the same region in 1998. An area of 225 km2 (15 km × 15 km), which was divided into 1000 × 1000 m grid squares (16 lines in the east and south directions), was selected
within the industrial area. The total of 256 grid points was obtained and soil samples were collected from three depths (0–5,
5–15, and 15–30 cm) of each grid center in 2004. The total Pb concentrations of soil samples were determined as 65.84–527.04
μg g−1 at 0–5 cm in depth, 58.50 – 399.54 μg g−1 at 5–15 cm in depth, and 44.65–330.07 μg g−1 at 15–30 cm in depth. DTPA-extractable Pb concentrations of soils were found to be in the range of 1.52–9.03 μg g−1, 0.54–7.09 μg g−1, 0.19–6.13 μg g−1 at 0–5, 5–15, and 15–30 cm depths, respectively. There were significant relationships between both total or DTPA-extractable
Pb concentrations and selected physico-chemical properties of soil. According to enrichment factor (EF) values calculated
from the total Pb concentrations, 11.3% of the study area (225 km2) was enriched with Pb in high level, but 77% of the area was in significant enrichment level with Pb. The average total and
DTPA-extractable Pb concentrations increased as 11 and 13%, respectively in comparison with the results of 1998. 相似文献
15.
The feasibility of applying the up-flow anaerobicsludge blanket (UASB) treatment for poultry waste (faeces)water was examined. A continuous-flow UASB pilot scalereactor of 3.50 L capacity using mixed culture was operatedfor 95 days to assess the treatability of poultry waste-water and its methane production. The maximum chemicaloxygen demand (COD) removed was found to be 78% whenorganic loading rate (OLR) was 2.9 kg COD m-3 day-1 athydraulic retention times (HRT) of 13.2 hr. The averagebiogas recovery was 0.26 m3 CH4 kg COD with an averagemethane content of 57% at mean temperature of 30 °C.Data indicate more rapid methanogenesis with higher loadingrates and shorter hydraulic retention times. At feedconcentration of 4.8 kg COD m-3 day-1, anaerobic digestionwas severely retarded at all hydraulic retention timetested. This complication in the reactor operations may belinked to build-up of colloidal solids often associated withpoultry waste water and ammonia toxicity. Isolates fromgranular sludge and effluent were found to be facultativeanaerobes most of which were Pseudomonas genera. 相似文献
16.
In this study, dry season radon flux densities and radon fluxes have been determined at the rehabilitated Nabarlek uranium mine in northern Australia using conventional charcoal canisters. Environmental background levels amounted to 31± 15 milli Becquerel per m2 per second (mBq m−2 s−1). Radon flux densities within the fenced rehabilitated mine area showed large variations with a maximum of 6500 mBq m−2 s−1 at an area south of the former pit characterised by a disequilibrium between 226Ra and 238U. Radon flux densities were also high above the areas of the former pit (mean 971 mBq m−2 s−1) and waste rock dump (mean 335 mBq m−2 s−1). The lower limit for the total pre-mining radon flux from the fenced area (140 ha) was estimated to 214 kBq s−1, post-mining radon flux amounted to 174 kBq s−1.Our study highlights that the results of radon flux studies are vitally dependant on the selection of individual survey points. We suggest the use of a randomised system for both the selection of survey points and the placement of charcoal canisters at each survey point, to avoid over estimation of radon flux densities. It is also important to emphasize the significance of having reliable pre-mining radiological data available to assess the success of rehabilitation of a uranium mine site.2006 Springer. The Australian Government's right to retain a non-exclusive, royalty free licence in and to any copyright is acknowledged. 相似文献
17.
Spatial variability of the shallow groundwater level and its chemistry characteristics in the low plain around the Bohai Sea,North China 总被引:2,自引:0,他引:2
Zaiming Zhou Guanghui Zhang Mingjiang Yan Jinzhe Wang 《Environmental monitoring and assessment》2012,184(6):3697-3710
To characterize the spatial distribution of groundwater level (GWL) and its chemistry characteristics in the low plain around
the Bohai Sea, shallow groundwater depth of 130 wells were determined. Water soluble ions composition, total dissolved solid
(TDS), electric conductivity (EC), total hardness (TH), total alkalinity (TA), and total salt content (TS) of 128 representative
groundwater samples were also measured. Classical statistics, geostatistical method combined with GIS technique were then
used to analyze the spatial variability and distribution of GWL and groundwater chemical properties. Results show that GWL,
TDS, EC, TH, TA, and TS all presented a lognormal distribution and could be fitted by different semivariogram models (spherical,
exponential, and Gaussian). Spatial structure of GWL, TDS, EC, TH, TA, and TS changed obviously. GWL decreased from west inland
plain to the east coastal plain, however, TDS, EC, and TS increased from west to east, TH and TA were higher in the middle
and coastal plain area. Groundwater chemical type in the coastal plain was SO42−·Cl−—Na+ while chemical types in the inland plain were SO42−·Cl−—Ca2+·Mg2+ and HCO3−—Ca2+·Mg2+. 相似文献
18.
In this work, water and sediment samples were collected from three different stations located along the Sakarya river between
May and September 2003. Lead, copper, chromium, zinc, nickel and cadmium concentrations were determined by using solvent extraction
and flame atomic absorption spectrometric method. The results show that differences based upon sampling times, regions, sediment
and water samples were observed. The mean levels of copper, nickel, chromium, lead, cadmium, zinc for sediment samples are;
4.630 μg g−1, 13.520 μg g−1, 8.780 μg g−1, 2.550 μg g−1, 9.990 μg g−1 and for water samples are; 0.851 μg g−1, 1.050 μg g−1, 0.027 μg g−1, 1.786 μg g−1, 0.236 μg g−1, 0.173 μg g−1, respectively. 相似文献
19.
In an effort to assess current and future water quality of the only perennial river in southeastern Botswana, this study presents
water quality monitoring and modeling results for the effluent-dependent Notwane River. The water quality along the Notwane
River, pre- and post-implementation of secondary wastewater treatment, was compared and results demonstrated that water quality
improved after the new wastewater treatment plant (WWTP) went online. However, stream standards for chemical oxygen demand,
total dissolved phosphorous, and fecal coliform were exceeded in most locations and the critical dissolved oxygen (DO) reached
concentrations of less than 4 mg L−1. High dissolved P concentrations and intense macrophyte growth at the impounding ponds and at sites within 30 km of the effluent
waste stream confluence suggest that eutrophication was a function of P release from the ponds. Results of DO modeling demonstrated
that an unpolluted inflow at approximately 10 km downstream of the confluence was responsible for raising DO concentrations
by 2.3 mg L−1, while SOD was responsible for a decline in DO concentrations of 1.4 mg L−1 at 6 km downstream of the confluence. Simulations also showed higher DO concentrations during winter months, when water temperatures
were lower. Simulations, in which the distributed biochemical oxygen demand (BOD) loading from cattle excrement was decreased,
produced nominal increases in DO concentrations. An increase in WWTP BOD loadings to projected 2020 values resulted in a 1.3
mg L−1 decrease in the critical DO concentration. Furthermore, a decrease in treatment plant efficiency, from 94% to 70% BOD removal,
produced critical DO concentrations and anoxia along much of the modeled reach. This has significant implications for Gaborone,
especially if decreased WWTP efficiency occurs as a result of the expected future increase in pollutant loadings. 相似文献
20.
Leachate Characterization and Assessment of Groundwater Pollution Near Municipal Solid Waste Landfill Site 总被引:6,自引:0,他引:6
Leachate and groundwater samples were collected from Gazipur landfill-site and its adjacent area to study the possible impact
of leachate percolation on groundwater quality. Concentration of various physico-chemical parameters including heavy metal
(Cd, Cr, Cu, Fe, Ni, Pb and Zn) and microbiological parameters (total coliform (TC) and faecal coliform (FC)) were determined
in groundwater and leachate samples. The moderately high concentrations of Cl−, NO−
3, SO2−
4, NH+
4, Phenol, Fe, Zn and COD in groundwater, likely indicate that groundwater quality is being significantly affected by leachate
percolation. Further they proved to be as tracers for groundwater contamination. The effect of depth and distance of the well
from the pollution source was also investigated. The presence of TC and FC in groundwater warns for the groundwater quality
and thus renders the associated aquifer unreliable for domestic water supply and other uses. Although some remedial measures
are suggested to reduce further groundwater contamination via leachate percolation, the present study demand for the proper
management of waste in Delhi. 相似文献