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1.
Automated stream dosers that deliver a wet slurry of calcite were installed in 1987 on two Maryland Coastal Plain streams subject to acidic pulses during rainstorms to evaluate the use of stream liming technology to maintain suitable water quality for early life stages of anadromous fish. Results of water quality sampling during baseflow conditions and hydrologic events indicated that significant changes in water chemistry occurred at the upstream (untreated) site during elevated flows on each stream. Observed responses in stream chemistry during the events included declines in pH, acid neutralizing capacity (ANC), and Ca, and increases in monomeric Al concentrations. With the addition of calcite, stream chemistry conditions at the downstream (treated) sites during each event were similar to those observed during baseflow. In situ bioassay experiments indicated that survival of yellow perch eggs and newly-hatched larvae may be enhanced by stream liming.  相似文献   

2.
The short-term results of a 5-yr experimental lake neutralization program involving whole-lake liming of Trout and Bowland Lakes are reviewed. Whole-lake liming did not prevent spring melt pulses of acid and Al in a zone situated under the ice nearshore. Liming did improve whole-lake water quality in a previously acidified lake (Bowland Lake) so that lake trout (Salvelinus namaycush) could be restocked successfully. In situ bioassays showed a statistically significant improvement in survival of overwintering lake trout eggs after liming. Lake trout fry exposed during spring melt also showed increased survival rates after liming except at one site in Trout Lake where liming did not prevent the occurrence of 100% mortality. The resident yellow perch (Perca flavescens) population in Bowland Lake exhibited short-term increases in survival and in recruitment the first year following neutralization. Growth rate responses differed among age cohorts. A preliminary shoal liming experiment in Laundrie Lake suggested that nearshore spawning shoals which are not necessarily protected by whole-lake liming may be protected by treatment with fine calcite gravel.  相似文献   

3.
Comparisons of stream water chemistry over a 2 yr period in East Fork, which drains an entirely forested watershed, and Big Run, which drains a forested watershed 8 % of which is occupied by Big Run Bog, indicated that Big Run Bog had no effect on stream water H+ or Cl? concentrations, but with increasing stream discharge the wetland was a source of Ca++ Mg++, K+, Na+, NO3 ?, and SO4 ?, and a sink for Fe+ +. Further comparisons with Tub Run, which drains a forested watershed, 13 and 12% of which is occupied by Tub Run Bog and an abandoned, unreclaimed coal surface mine, respectively, suggested that Tub Run Bog removes H+, Ca ++, Mg++, Fe++, and 504 ? from inputs of acid mine drainage. Wetland areas on the landscape contribute to the regulation of stream water chemistry in ways that are different from upland areas, and wetlands may have considerable applied potential for minimizing the impact of the mine drainage on stream water quality.  相似文献   

4.
Yearling yellow perch were collected from sixteen Muskoka-Haliburton lakes to determine interrelationships between water quality, Hg residues in fish and fish condition. The lakes studied were Precambrian shield lakes with a pH range of 5.6 to 7.3 and total inflection point alkalinities of 0.4 to 16.0 mg L?1. Mercury residues in yellow perch ranged from 31 to 233 ng g?1 and were inversely correlated (p < 0.001; r = 0.84) with lakewater pH. Stepwise linear regression analyses selected lakewater pH as the only significant parameter associated with Hg accumulations. Alkalinities, sulphate, Ca and dissolved organic carbon (DOC) were not selected as significant. Likewise, lakewater pH and Hg residues in yellow perch were inversely (p < 0.001) correlated with fish condition. Lakewater pH, accounted for 74% and Hg in fish a further 11% of the variability in fish condition. Terrestrial drainage size/lake volume ratios were also correlated (p < 0.05; r = 0.78) with Hg accumulations in perch from a subset of nine headwater lakes. No temporal trends in Hg residues were evident in yellow perch over a 9 yr interval (1978–1987).  相似文献   

5.
Depth profiles of total S, organic S, soluble SO 4 2? -S, FeS, and FeS2 were characterized for Sphagnum-derived peat cores collected from 9 sites. Marcell S-2 Bog (MN), Tamarack Swamp (PA), Cranesville Swamp (MD/WV), and Big Run Bog (WV) receive water from precipitation and upland runoff; atmospheric S deposition is 13, 47, 54, and 114 mmol m?2, yr?1, respectively. McDonald's Branch Swamp (NJ) is predominantly groundwater fed. Tub Run Bog (WV) and Allegheny Mining Bog (MD) receive augmented SO 4 2? inputs through acid coal mine drainage. Jezerní slat' and Bo?í Dar Bog in Czechoslovakia receive atmospheric S inputs of 33 and 243 mmol m?2 yr?1, respectively. In the peat from all sites except Allegheny Mining Bog, where the substantially augmented SO 4 2? input was reflected in an unusually high dissolved SO 4 2? pool in the surface peat, organic S (probably mostly carbon bonded S) was the dominant S fraction; FeS2 was generally the dominant inorganic S fraction. Subsurface peaks in total S, organic S and FeS2-S in peat from the runoff water fed sites were interpreted as indicative of depth-dependent patterns in S reduction/oxidation and in S immobilization/mineralization. Unless SO 4 2? inputs to a site are tremendously augmented (e.g., Allegheny Mining Bog), the rapid turnover of the dissolved SO 4 2? pool combined with the relative stability of the other inorganic and organic S pools, apparently functions as an effective buffer against site differences in S inputs, leading to a general similarity in vertical S profiles in the peat deposits.  相似文献   

6.
We examined the influence of a forested landscape on the quality of water in a stream originating on an urban landscape and flowing through National Forest lands. Sample sites included an urban stream (URB), a site on the same stream but within a National Forest (FOR) and 2 km downstream from the URB site, and a small, undisturbed, forested reference tributary of the main stream (REF). We monitored stream water quality from March 2002 through June 2003. Average base flows for the three stream sites were URB = 184 L s?1, FOR = 420 L s?1, and REF = 17 L s?1. We analyzed weekly stream water samples for NO3 ?, NH4 +, PO4 +, Cl?, K, Ca, Mg, SO4, SiO2, pH, conductivity, total suspended solids (TSS), and bacteria on a monthly basis. Most solutes were higher in concentration at the URB site, as were conductivity, TSS, and bacteria counts. Reductions in NO3 ?, NH4 +, and PO4 + concentrations between the URB and FOR sites were inferred from changes in nutrient:chloride ratios. Bacteria populations were greater and more responsive to stream temperature at the URB site. Water quality responses to changes in stream discharge varied among sites but were greater at the URB site. By all measures, water quality was consistently higher at the FOR site than at the URB site.  相似文献   

7.
Two species of fish, omnivorous Catostomus commersoni (white suckers) and carnivorous Perca flavescens (yellow perch) were collected from three natural lakes with different pH ranges (circumneutral, pH 6.5 to 6.8; variable, pH 5.8 to 6.7; and acidic, pH 4.9 to 5.4). The lakes are located in the North Branch of the Big Moose River drainage system in the New York State Adirondack Park Preserve. Concentrations of potentially toxic elements (Al, Cd, Cu, Ph, and Se) were measured by electrothermal atomic absorption spectrophotometry in water, sediment and fish (bone, gill, kidney, liver and muscle) from each lake. The results showed that concentrations of Pb and Cd were significantly higher (P < 0.05) in some of the tissues of the fish collected from the acidic lake. Also, the yellow perch from the acidic take had significantly higher (P<0.05) Se concentrations in their muscle and livers than fish from the other lakes. The concentrations of Al were elevated in the gill tissues of both fish species from the acidic lake relative to fish from the other lakes. Possible mechanisms contributing to these differences in tissue concentration are discussed.  相似文献   

8.
Acid mine drainage (AMD), a legacy of coal and mineral extraction, contaminates streams with complex mixtures of acid and heavy metals that are usually partitioned between the water column and substrate. Understanding the conditions under which sediments retain toxicity after the water column is cleared is important for predicting the long term success of remediation efforts. We conducted laboratory and field experiments to evaluate the relative contribution of acidity versus metals to the toxicity of AMD contaminated sediment towards aquatic macroinvertebrates. Laboratory bioassays showed that precipitate-coated substrate from AMD-impacted sites were toxic to Ctenodaphnia magna and reduced growth of mayflies (Ephemeroptera: Heptageniidae). Toxicity correlated more with acidity released from the sediment than with metals. After transplantation to a clean stream, the same Al- and Fe-contaminated substrate were not toxic to daphnia and was readily colonized by benthic macroinvertebrates within 5 weeks.  相似文献   

9.
Nelson Lake, a moderately acidic (pH 5.7), metal-contaminated (Cu 22 μg L?1; Zn 18 ug L?1) lake, 28 km from the smelters at Sudbury, had a degraded fish community in the early 1970's, with lake trout (Salvelinus namaycush) scarce, smallmouth bass (Micropterus dolomieui) extinct, and the littoral zone dominated by the acid-tolerant yellow perch (Perca flavescens). Liming of the lake in 1975–76 increased pH to 6.4, and decreased metal concentrations. Chemical conditions have remained relatively stable in the 10 yr following base addition. Initially, it appeared that neutralization produced dramatic changes in the resident fish community. Yellow perch abundance declined rapidly after neutralization, lake trout abundance increased to the extent that 3.26 kg ha?1 were caught in the winter of 1980, and reintroduced smallmouth bass reproduced and established a large population. However, these changes in the fish community can not be directly attributed to liming, as water quality and the sport fisheries of an unlimed nearby lake also improved. Reduced emissions from Sudbury smelters were responsible for improvements in the untreated lake. Recovery of the lake trout population in Nelson Lake appears to have begun prior to liming. Of the lake trout sampled during the 1980 winter fishery, 65.8% were present prior to the chemical treatment. Predation by lake trout was the likely cause of the perch decline. Our results suggest that chemical conditions producing population level responses in fish have abrupt thresholds and that neutralization of lakes above these thresholds may not produce distinguishable effects.  相似文献   

10.
Due to increased whole-tree harvesting in Swedish forestry, concern has been raised that a depletion of nutrients in forest soil will arise. The Swedish Forest Agency recommends compensation fertilization with wood ash to ensure that unwanted effects are avoided in the nutrient balance of the forest soil and in the quality of surface water. In this investigation, the chemistry of two first-order streams, of which one was subjected to a catchment scale treatment with 3 tonnes of self-hardened wood ash/ha in the fall of 2004, was monitored during 2003?C2006. Large seasonal variations in stream water chemistry made changes due to ash application difficult to detect, but evaluating the ash treatment effects through comparison of the stream water of the treated catchment with the reference was possible via statistical tools such as randomized intervention analysis in combination with cumulative sum charts. The wood ash application did not yield any significant effect on the pH in the stream water and hence did not affect the bicarbonate system. However, dissolved organic carbon increased, a previously unreported effect of WAA, bringing about an increase of organic anions in the stream water. The wood ash application also induced significant increases for Ca, Mg, K, Si, Cl and malonate, of which K was most prominent. Although significant, the changes induced by the wood ash application were all small compared to the seasonal variations. As a tool to counteract acidification of surface waters, WAA seems to have limited initial effects.  相似文献   

11.
In 1986 Lake Langedalstjenn in southern Norway was a weakly acidified lake with a pH of 5.2–5.6, and an average concentration of SO4 of 330 μeq L?1. The total Al concentration varied between 10 and 20 μeq L?1 (expressed as Al3+). The lake supported populations of brown trout and perch and had supplied about 100 people with drinking water until the late 1980's. During 1986–1989, a dramatic change in the water chemistry occurred because of blasting of and weathering of sulphidic gneisses in the watershed. The oxidation of sulphide to sulphate (sulphuric acid) caused an increase in the SO4 concentration of the draining stream of up to ≈ 4800 μeq L?1. Weathering and/or cation exchange of Ca and Mg neutralized approximately 52% of the protons from the sulphuric acid production, while about 46% were consumed by mobilization of aluminium and iron. Nevertheless, about 2% of the hydrogen ions from the sulfuric acid were still present, which resulted in a stream pH of 4.0. In the lake, the pH was 4.4, and the concentrations of all major cations and anions were significantly lower than in the heavily affected stream. Mixing of the stream water with lake water, formation of aluminium-sulphate complexes and coprecipitation of Ca may explain the resulting concentrations of major ions in the lake.  相似文献   

12.
Mercury concentrations in basic ecosystem compartments of the Wabigoon-English River system are interrelated. Statistically significant correlations are evident between Hg levels in various biotic-young northern pike (Esox lucius), yearling yellow perch (Perca flavescens) and crayfish (Orconected virihs) and abiotic compartments (water, surface sediments). Highly significant positive correlations are found between methyl-mercury in water and Hg in biota. Highly significant positive correlations also exist between Hg levels in different organisms, despite differences in habitat, diet, uptake routes and proportion of bodyburden that is in the methyl form. A plausible basis for these relationships is the rapid equilibration between methyl and inorganic Hg in and between various abiotic components of the ecosystem and subsequent incorporation into food webs. As sediment-water partitioning for inorganic and methylmercury is also rapid it is likely that in lakes and slow moving river reaches, local environmental variables probably largely govern Hg body burdens in biota.  相似文献   

13.
In an effort to improve the fisheries potential of many West Virginia mountain streams by increasing the alkalinity and pH, the West Virginia Department of Natural Resources (DNR) is conducting research into the feasibility of a point source limestone application technique. This research was to provide data that would assist in the design of future projects and the selection of appropriate methodology. Thirteen metric t and 33.3 t of 0.64 cm crusher run ground limestone aggregate were applied as a single deposition to Crouch and Yokum Runs, respectively. Limestone was applied to Crouch Run a year prior to treatment of Yokum Run. The point source treatment produced discharge dependent changes in the downstream water chemistry. The pH increased from an average of 4.73 above the application point to 5.70 below. At high stream discharges, the pH dropped, but never to the pretreatment background level. Increases in Ca concentrations and ANC were also observed downstream of the limestone application site. Sediment analysis was performed to determine the calcite concentration within the stream bed by both an instrumental technique (x-ray fluorescence (XRF)) and an HC1 leach technique to indicate the extent of downstream movement and distribution of limestone. The analysis showed both a limited downstream transport and a variable spread of limestone across the stream channel. The XRF and wet laboratory methods of quantifying the calcite content of the sediments were compared. Although statistical analysis indicated a difference in precision between the x-ray fluorescence and HC1 leach methods, the acid leach method can be considered an economical alternative to x-ray fluorescence. Recommendations are made on methods to increase the effectiveness of the point source treatment and the design of future research.  相似文献   

14.
The present study is mainly focusing on mortality variations of fish due to changing Alchemistry of mixing zones. An artificial mixing zone was made by pumping water from a limed stream and an acidic tributary into a mixing channel. Atlantic salmon (Salmo salar L.) parr were exposed to the mixed water, limed stream water, and acidic tributary water. Mortality, blood haematocrit and plasma Cl?-concentration were recorded. Neither mortality, nor changes in haematocrit and plasma Cl? were observed when fish were exposed to limed water, while in both acidic and mixed water, mortalities and loss of plasma Cl? were observed. The highest mortality rates were found within the initial part (0 to 20 s) of the mixing zone. Blood haematocrit increased only in fish exposed to acidic tributary water. Our results shows that changes in Al-chemistry and subsequent Al-polymerization occur when acidic tributary water is mixed with limed stream water. We have also demonstrated that the toxicity which can arise in mixing zones are greater than in the original acidic water before mixing. The variations in mortality observed are associated with the quality and quantity of Al-polymerization as well as ageing of the polymers.  相似文献   

15.
A species of commercially obtained freshwater mussel (Elliptio complanata) was shown to actively filter, concentrate, and retain fecal coliform (FC) bacteria from a variety of freshwater stream environments. Fecal coliform densities in mussel viscera were maximum within 48 hr of in situ exposure. Significant FC reproduction did not occur in mussel viscera at temperatures below 30 °C. Variation in replicate FC determinations from mussels exposed in situ for 48 hr was less than that obtained directly from water samples. Numbers of FC concentrated in mussel viscera were retained for several hours after FC densities declined in the surrounding water, suggesting the utility of mussels to record recent episodes of fecal pollution.  相似文献   

16.
Samples of ash from municipal refuse incinerators in six Connecticut towns as well as samples of incinerated sewage sludge were collected during 1988 and 1989. The samples were analyzed for pH, metal content by HNO3 + H2O2 digestion, extractable metals by solvents including NaOAc, DTPA, H2CO3 and H2O. Two samples were examined for metals that could be leached by H2O from laboratory columns. Most ash samples were highly alkaline and their pH changed slowly, decreasing by about two pH units over a 6-week period. The variability in metal content of ash from different incinerators was similar to that observed in samples obtained from the same facility at different times. Only a portion of the metals were extracted by the solvents in the order NaOAc > DTPA > H2CO3 > H2O. The relative amounts of the total metals in the ash that could be extracted with specific solvents varied widely, suggesting different chemical forms in different ashes. After the initial removal of large concentrations of metals in the leachates from laboratory columns over 2 to 3 days, leaching of metals continued at extremely low concentrations that were generally below drinking water standards.  相似文献   

17.
Agronomic use of coal combustion by-products is often associated with boron (B) excess in amended soils and subsequently in plants. A greenhouse study with corn (Zea mays L.) as test plant was conducted to determine safe application rates of five fly ashes and one flue gas desulfurization gypsum (FDG). All by-products increased soil and corn tissue B concentration, in some cases above toxicity levels which are 5 mg hot water soluble B (hwsB) kg?1 soil and 100 mg B kg?1 in corn tissue. Acceptable application rates varied from 4 to 100 Mg ha? for different by-products. Leaching and weathering of a high B fly ash under ponding conditions decreased its B content and that of corn grown in fly ash amended soil, while leaching of the same fly ash under laboratory conditions increased fly ash B availability to corn in comparison to the fresh fly ash. Hot water soluble B in fly ash or FDG amended soil correlated very well with corn tissue B. Hot water soluble B in fly ash amended soil could be predicted based on soil pH and B solubility in ash at different pH values but not so in the case of FDG. Another greenhouse study was conducted to compare the influence of FDG and Ca(OH)2 on B concentration in spinach (Spinacia oleracea L.) leaves grown in soil amended with the high B fly ash. The Ca(OH)2 significantly decreased tissue B content, while FDG did not affect B uptake from fly ash amended soil.  相似文献   

18.
Rencz  A. N.  O'Driscoll  N. J.  Hall  G. E. M.  Peron  T.  Telmer  K.  Burgess  N. M. 《Water, air, and soil pollution》2003,143(1-4):271-288
This study investigates the ranges and spatial variation ofmercury in various media in the wetland ecosystems ofKejimkujik Park, Nova Scotia. Mercury concentrations infive-year-old yellow perch (age based on regression analysesof existing data) ranged from 0.12–0.72 μgg-1(wet weight basis) in 24 lakes. Mercury concentrations inred maple ranged from 5 to 41 ng g-1 and levels inwhite pine ranged from 5 to 58 ng g-1, dry weight.Concentrations of total mercury were found to besignificantly higher in epiphytic lichens (maximum of 660 ngg-1) and in feather mosses (maximum of 395 ng g-1)compared to vascular species. The soil Ah horizon exhibitsthe highest concentrations for both mercury and gold, withmaximum values of 466 and 42.8 ng g-1 respectively;whereas the C-horizon appears to host the most Zn (maximum209.9 μg g-1). Lake water pH and dissolved organic carbon (DOC) were thevariables most highly correlated with mercury in lake watersand yellow perch. No correlations were observed betweenmercury in terrestrial components and mercury in yellowperch; however, mercury in yellow perch was correlated withP in leaf tissues of both red maple and white pine. Theimportance of understanding linkages between terrestrial andaquatic ecosystems is emphasized through this study.  相似文献   

19.
To evaluate the extent to which chemical disequilibrium may exist in stream waters following naturally occurring short-term pH changes, surface water samples were collected from two streams in the Lake Laflamme watershed north of Quebec City, placed in large polyethylene containers and stirred continuously at the in situ temperature; changes in Al speciation were followed with time for up to 24 hr. The original samples were collected during the spring snow-melt period and during summer low flows. In this latter case, a pH depression was induced by artificial acidification (H2SO4; pH 4) and changes in Al speciation with time were followed in both the acidified and the unacidified samples. Aluminum speciation as operationally defined did respond to artificial acidification (pH lowered; non-exchangeable and non-extractable Al decreased), and these pH-induced changes occurred rapidly (< 4 hr). During storage of natural water samples at in situ T for up to 24 hr, little change in Al speciation was noted, even in the case of samples collected during spring snow-melt; no clear cases of chemical disequilibrium existed among the studied samples. The distribution of Al among its various physico-chemical forms thus appears to be established within the stream itself; at a given stream sampling point the speciation of A1 will not necessarily reflect its geochemical origins, but rather the prevailing in situ conditions (e.g. pH, ligand concentrations).  相似文献   

20.
Although composite chemical analyses, such as total petroleumhydrocarbons and total metals, are often used to assess theextent of contamination at an industrial site, it is difficultto relate chemical analyses to the environmental andtoxicological effects of soil contamination. Since toxicity isrelated to contaminant bioavailability and solubility,identification and quantification of leachable contaminantsshould provide an indication of the environmental hazard of the site contaminants. Experiments were performed to determine theleachability and toxicity of contaminants from a flare pit soilwhich was extensively contaminated with hydrocarbons, metals andsalt. Toxicity bioassays included earthworm mortality(Lumbricus terrestris), seed germination and root elongation(Lactuca sativa and Panicum miliaceum L.),algal growth inhibition (Selenastrum capricornutum) andbacterial luminescence inhibition (Pseudomonasfluorescens). Although this soil would require remediationaccording to chemically based soil criteria, neither the contaminated soil nor leachate generated from the contaminated soil were particularly toxic.  相似文献   

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