The impact of a chlor-alkali plant on Onondaga Lake and adjoining systems

The pervasive effects an adjoining chlor-alkali plant has had on Onondaga Lake, and the river system that receives the lake discharge, are documented. Effects of the ionic waste discharge of the facility include: (1) ionic enrichment, (2) altered stratification regimes, (3) altered exchange between the lake and river, (4) altered hydrodynamics in the river downstream of the lake, (5) precipitation and deposition of large quantities of calcium carbonate, and (6) altered chemistry of lake sediments regulating P availability. Mercury, benzene, chlorobenzene wastes from the plant have contaminated the sediments and fish of the lake. Deleterious effects of the facility have included: the elimination of fish habitat, exacerbation of the problem of limited Oz resources of the hypolimnion, contamination offish flesh, exacerbation of the problem of low transparency of the lake, and severe O₂ depletion in the lower waters of the river system.     

The oxygen resources of the hypolimnion of ionically enriched onondaga lake,NY, U.S.A.

The depletion of hypolimnetic DO and the upper depth boundary of anoxia for four different years (1978, 1979, 1980 and 1981), and the accumulation of sulfide for a single year (1981), are documented for ionically enriched hypereutrophic Onondaga Lake, NY, USA. The depletion rate, represented as the areal hypolimnetic oxygen deficit (AHOD, g m^?2 day^?1), was extremely high (1.2–2.7 g m^?2 day^?1), The large differences in the rate within individual years and from year to year were largely a result of differences in attendant vertical mixing (parameterized as the hypolimnetic heating rate). The entire hypolimnion (depth interval from 11 to 20 m) was without O₂ by late June of all 4 yr; anoxia was observed above the hypolimnion on some occasions when secondary stratification occurred. Sulfide accumulated progressively in the hypolimnion in 1981 following the onset of anoxia to a volume weighted concentration of I1 mg L^?1. The ionic discharge from an adjoining alkali manufacturer exacerbated the problem of limited O₂ resources of the hypolimnion by: (1) decreasing vertical mixing, (2) prolonging the duration of stratification, (3) causing abbreviated turnovers, and (4) encouraging increased rates of phytoplankton settling.     

The density of inflows to Onondaga Lake,U.S.A., 1980 and 1981

The temporal distributions of the densities of inflows to Onondaga Lake were calculated for the spring to fall period of 1980 and 1981, and compared to the attendant density stratification in ion enriched Onondaga Lake. The industrial utilization of the lake resulted in substantial density differences between the inflows and the lake. Inflows carrying substantial fractions of industrial ionic waste were more dense than the lake, and at times plunged to stratified layers. Water withdrawn from the lower layers of the lake for industrial cooling was displaced to the upper layers as a result of heating. Dilute fluvial inflows were substantially less dense than the lake. The density differences between the inflows and the lake were largely responsible for the rather unique features of density stratification documented for the lake in 1980, and are probably of further importance in nutrient loading to, and cycling in, Onondaga Lake.     

Salinity,chloride, and density relationships in ion enriched Onondaga Lake,NY

The relationship between salinity (S), chlorinity (Cl) and density (d) for the ion polluted (S = 3 to 4.5‰) and stratified Onondaga Lake are presented. The data base includes 220 determinations of the major ionic components collected from ten equally spaced depths. The salinity (S) and ionic strength (I) in the lake can be estimated from S = 1.85 Cl ? 0.28, where Cl is in g kg^?1 and I = 1.456 [Cl^?] ? 0.039, where [Cl] is in mmol L^?1. Due to the high concentration of Ca²⁺ in the lake, the seawater equation of state (Chen and Millero, 1977a) could not be used to estimate reliable densities for the lake (Δd ～ 100 × 10^?6 g cm^?3). A reliable equation of state for Onondaga Lake was derived from the composition data $$d = d_0 + A_v {\text{ }}CL + B_v {\text{ }}Cl^{3/2} $$ where d ₀ is the density of water (g cm^?3), A _v is a temperature dependent parameter related to the infinite dilution apparent molal volumes and B _v is related to the ion-ion interactions of the lake salts. The high ionic content of the lake depresses the temperature of maximum density to 3.18°C and alters the stratification of the lake. The salinity component of the stratification represents 40% of the total density stratification.     

Mercury cycling in the water column of a seasonally anoxic urban lake (Onondaga Lake,NY)

Onondaga Lake, New York, is a hypereutrophic, urban lake that was subjected to industrial discharges of mercury (Hg) between 1947 and 1988. Water samples were collected from April through November 1992 and analyzed for filtered and unfiltered total Hg, methylmercury (CH₃Hg), dimethylmercury, ionic Hg, and elemental Hg to characterize the biogeochemical cycling of Hg during water column stratification and hypolimnetic anoxia. In the spring and late fall when the water column was isothermal, total Hg and CH₃Hg concentrations were relatively constant throughout the water column, at approximately 3–7 ng/L and 0.3–1 ng/L, respectively. Through the summer and early fall, CH₃Hg concentrations systematically increased in the deeper waters, reaching peak concentration in August and September. In September 1992, CH₃Hg concentrations increased from 0.3 ng/L in the epilimnion to 10.6 ng/L in the hypolimnion, an increase of nearly 2 orders of magnitude. At the same time, total Hg increased from 6.6 ng/L in surface water to 21.7 ng/L at depth, a 3-fold increase. The spatial and temporal patterns observed for CH₃Hg agree well with manganese, suggesting that CH₃Hg and manganese are controlled by processes of the same or parallel cycles.     

Mercury cycling in a northern wisconsin seepage lake: The role of particulate matter in vertical transport

During summer stratification, total mercury (Hg_τ) reached maximum concentrations in the O₂ :depleted, hypolimnion of Little Rock Lake, Wl. Initially, the hypolimnetic increase was attributed solely to redox-controlled release of Hg from bottom sediments. However, subsequent depth profiles of Hg indicated that hypolimnetic Hg enrichment could also result from the downward transport and recycling of particulate Hg prior to incorporation in the sediments. Contrasts between Fe and Hg cycles in this lake reinforce this notion. Increases in hypolimnetic Fe were observed during both summer and winter O₂ decreases. In contrast, hypolimnetic Hg concentrations declined during winter. In the ice-free season, the distribution of particulate mercury (Hg_p) correlated with the distribution of chlorophyllous particulates in this lake, re-emphasizing the importance of biotic processes in controlling Hg cycling in the hypolimnion.     

Mercury in Small Freshwater Lakes: A Case Study: Lake Velenje, Slovenia

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.     

Effect of pollution on the blood characteristics ofTilapia zillii G.

Lake Mariut, a shallow brackish water basin near Alexandria, was a highly productive lake; however, it now receives large quantities of pollutants. The amount of DO has been greatly reduced.Tilapia zillii G. have been studied to determine the modification of blood characteristics. In O₂ deficient areas of Lake Mariut the fish undergo asphyxiation.     

Seasonal variability in the Mercury speciation of Onondaga Lake (New York)

Dissolved and particulate Hg speciation was determined on four occasions in the Spring to Fall interval of 1989, at three depths of the water column of Onondaga Lake, New York; an urban system in which the sediments and fish flesh are contaminated with H_g. Species determined included total Hg (Hg_t), reactive (‘ionic’) Hg (Hg_i), monomethylmercury (CH₃HgX), elemental Hg (Hg°) and dimethylmercury (CH₃)₂Hg). Onondaga Lake was found to contain very high levels of Hg_t (2 to 25 ng L^?1 Hg), Hg_j (0.5 to 10 ng L^?1 Hg), and CH₃HgX (0.3 to 7 ng L^?1 Hg), which generally increased with depth in the lake. These concentrations represent a significant level of contamination, based upon comparisons with other polluted and pristine sites. Elemental Hg levels were typically about 0.05 ng L^?1 and (CH₃)₂Hg was near the limits of detection (?0.001 ng) L^?1 in most samples. The greatest CH₃HgX concentrations in the hypolimnion, as well as the largest gradients of both CH₃HgX and (Hg_t), were observed upon the first onset of stratification, in early summer. These concentrations did not become more pronounced, however, as stratification and H₂S levels in the hypolimnion increased throughout the summer. The very low concentrations of (CH₃)₂Hg in these MeHg and sulfide-rich waters calls into question the belief that CH₃HgX and H₂S will react to yield volatile dimethyl-mercury, which can then escape to the atmosphere by diffusion. Mercury speciation was highly dynamic, indicating active cycling within the lake, and an apparent sensitivity to changes in attendant Iimnological conditions that track the stratification cycle.     

Sulfur vs. silica retention in oligotrophic lake sediments: Test of a simple residence time model

Limnologists have modeled solute retention (% of input) in lake sediments using the parameter: 100 k _s {(z:t _w +k _s}^?1, wherek _s is an empirical mass transfer coefficient or ‘sedimentation velocity’ (m yr^?1), z is lake mean depth (m), andt _w is lake hydraulic residence time (yr). This flushing or residence time model was tested against sulfate and silica concentrations in lakes of the northeastern and northcentral U.S.A., using data collected during the U.S. EPA's Eastern Lake Survey. This parameter failed to predict intra-regional variations in lake sulfate at fall turnover, but was consistently negatively correlated with silica in each of the regional lake populations. However, except in the western section of the Upper Peninsula of Michigan, lake sulfate was everywhere inversely dependent on DOC [mean slope=?0.020(SE=0.03) meq mM^?1]. Sulfur retention in aquatic environments appears more closely coupled to organic carbon and trophic state, than to variations in hydraulic residence time.     

The distribution of nitrogen species in polluted Onondaga Lake,N.Y., U.S.A.

The temporal and vertical distributions of four N species, N0₃ ^?, NO₂ ^?, total ammonia (T-NH₃), and free ammonia (NH₃), are documented for Onondaga Lake, an urban, polluted, hypereutrophic, dimictic, lake that receives a very high load of T-NH₃. Nitrate and NO₂ ^? were lost rapidly from the hypolimnion, and T-NH₃ accumulated to high concentrations (maximum > 10 mgN L^?1), after the onset of anoxia, consistent with the lake's high level of productivity. The concentrations of T-NH₃, NH₃ and N0₃ ^? that were maintained in the epilimnion (average concentrations at a depth of 1 m of 2.81, 0.16 and 0.91 mgN L^?1, respectively), and concentrations of N0₂ ^? that developed in the epilimnion (maximum of 0.48 mgN L^?1), were high in comparison to levels reported in the literature. These elevated concentrations are largely a result of the extremely high loads of T-NH₃, and its precursors, received by the lake. Water quality problems in the lake related to the prevailing high concentrations of N species include potential toxicity effects and severe lake-wide oxygen depletion during fall turnover.     

Extreme acidification of a lake in southern Norway caused by weathering of sulphide-containing bedrock

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.     

A chloride budget for Onondaga Lake,New York,U.S.A.

A Cl budget is presented for a 12 yr period (1970–1981) for Cl enriched (approximate volume-weighted average concentration of 1500 mg Cl L^?1) Onondaga Lake, New York. The budget utilizes continuous discharge and lake and stream water chemistry data, collected at an interval of approximately 2 weeks, over the 12 yr study period. Budget calculations are supplemented by high frequency water chemistry data from the lake and the tributary carrying the major portion of the loading. More than 85% of the external load of Cl (approximately 9 × 10⁸ kg yr^?1) to the lake originates from an alkali manufacturer. Export of Cl from the lake was highly correlated to outflow from the lake (R = 0.915, for a resolution of 1 mo). A good balance between estimated external loads and lake export was obtained (within 7%) for the 12 yr period, indicating that lake concentrations are consistent with external loading of this conservative substance. The results of this analysis contradict previous calculations that indicated 40 to 50% of the Cl in the lake originated from natural internal sources.     

Changes in water quality in the Laflamme Lake Watershed Area,Canada

The Laflamme Lake Watershed Area is located in a sensitive region on the Canadian Shield and is subjected to wet atmospheric loading between 17 and 25 kg ha^?1 yr^?1. From 1981 to 1988, the level and fluctuations of the atmospheric deposition of acidifying substances has led to various responses in the water chemistry of headwater lakes in the area. The general trend in atmospheric inputs is a gradual increase of acidifying substances from 1981 to 1985 followed by a 2 yr decrease then a return to previous values. In the two lakes with almost no alkalinity acidification has occured throughout the 1983 to 1988 period. In the four lakes with slightly higher alkalinity values, a reversal in acidification is seen when atmospheric loading decreased in 1986. Along with the interannual trends, seasonal variability to acidification occurs with sensitivity of surface waters being highest during spring melt. Sensitivity to acidification can also be altered by watershed processes and in the Laflamme Lake Watershed, soil processes are effective in altering the acidity of precipitation before it reached the lake. In this watershed, wet atmospheric inputs of H⁺ and NO₃ ^? are larger than surface water outputs while the reverse occurs for Ca²⁺, Mg²⁺, Na⁺, K⁺, Cl^? and SO₄ ^2?.     

EFFECT OF REDUCED SALINITY INPUT ON RIVER STRATIFICATION AND DISSOLVED OXYGEN

Changes in the occurrence, character, and longitudinal extent of salinity (S) stratification, and related impacts on dissolved oxygen (DO), in the Seneca and Oswego Rivers, NY, in response to the abatement of ionic pollution of inflowing Onondaga Lake, is documented. The analysis is based on vertical profiles of specific conductance and DO collected over a 20 km reach of the river system for several years before and after the closure of the source of the ionic pollution, a soda ash manufacturing facility. TheS difference between the lake and the Seneca River decreased from about 2.6 to 0.7 parts per thousand (%.) following the closure; more than 50% of the continuing difference is associated with lingering ionic waste loading from soda ash production. The occurrence and longitudinal range of theS stratification phenomenon was, and continues to be, highly dependent on river flow. It is most strongly manifested when river flow is low. The occurrence, magnitude, and longtitudinal extent ofS stratification have decreased, and vertical exchange between the stratified layers has increased, since the closure, thereby ameliorating the coupled negative impact on the river's oxygen resources. However, under low flow conditions (e.g., probability of occurrence equal to 15%)S stratification continues to extent > 2 km upstream and > 8 km downstream of the point of entry of Onondaga Lake into the Seneca River. Severe DO depletion in the lowel river layer, representing violations of New York water quality standards, continues to occur where S stratification prevails. Elimination of the continuing ionic waste inputs from soda ash production would further limit the stratification phenomenon and improve the river's DO problem.     

Characterization of recently 14C pulse-labelled carbon from roots by fractionation of soil organic matter

The inability of physical and chemical techniques to separate soil organic matter into fractions that have distinct turnover rates has hampered our understanding of carbon (C) and nutrient dynamics in soil. A series of soil organic matter fractionation techniques (chemical and physical) were evaluated for their ability to distinguish a potentially labile C pool, that is ‘recent’ root and root‐derived soil C. ‘Recent’ root and root‐derived C was operationally defined as root and soil C labelled by ¹⁴CO₂ pulse labelling of rye grass–clover pasture growing on undisturbed cores of soil. Most (50–94%) of total soil + root ¹⁴C activity was recovered in roots. Sequential extraction of the soil + roots with resin, 0.1 m NaOH and 1 m NaOH allocated ‘recent’ soil + root ¹⁴C to all fractions including the alkali‐insoluble residual fraction. Approximately 50% was measured in the alkali‐insoluble residue but specific activity was greater in the resin and 1 m NaOH fractions. Hot 0.5 m H₂SO₄ hydrolysed 80% of the ¹⁴C in the alkali‐insoluble residue of soil + roots but this diminished specific activity by recovering much non‐¹⁴C organic matter. Pre‐alkali extraction treatment with 30% H₂O₂ and post‐alkali treatment extractions with hot 1 m HNO₃ removed organic matter with a large ¹⁴C specific activity from the alkali‐insoluble residue. Density separation failed to isolate a significant pool of ‘recent’ root‐derived ¹⁴C. The density separation of ¹⁴C‐labelled roots, and roots remixed with non‐radioactive soil, showed that the adhesion of soil particles to young ¹⁴C‐labelled roots was the likely cause of the greater proportion of ¹⁴C in the heavy fraction. Simple chemical or density fractionations of C appear unsuitable for characterizing ‘recent’ root‐derived C into fractions that can be designated labile C (short turnover time).     

Distribution of mercury in the aquatic food web of Onondaga Lake,New York

Historical discharges of mercury (Hg) to Onondaga Lake, New York, have resulted in elevated Hg concentrations in lake fishes. In 1990, a remedial investigation and feasibility study (RI/FS) was initiated to evaluate problems related to Hg and other hazardous substances in the lake. As part of the RI/FS, the distribution of Hg in the aquatic food web was determined to provide input to a site-specific model of Hg cycling and to evaluate potential ecological risks of Hg in the lake. Mercury concentrations were measured in surficial sediments, sediment interstitial water, lake water, phytoplankton, Zooplankton, benthic macroinvertebrates, and fishes (including planktivores, benthivores, and piscivores). The percentage of total Hg accounted for by methyl-Hg (CH₃Hg) generally increased with higher trophic levels, confirming that CH₃Hg is more efficiently transferred to higher trophic levels than is inorganic Hg. Concentrations of total Hg in amphipods and chironomids were closely related to concentrations of total Hg in sediments, suggesting that sediments are a likely source of Hg for benthic macroinvertebrates. Mercury concentrations in edible muscle tissue (fillets) of lake fishes have declined substantially from values found in the early 1970s, reflecting the large reductions in Hg discharges to the lake that have occurred since that time. The CH₃Hg concentrations in fillets and whole bodies of fishes generally were similar, indicating that concentrations in fillets often can provide estimates of concentrations in whole bodies. Methyl-Hg concentrations and bioaccumulation factors increased with higher trophic levels in both the pelagic and benthic components of the lake food web.     

Base neutralizing capacity of sediments from an acidic lake

The base neutralizing capacity (BNC), or alkalinity consumption, of acidic lake sediments may influence the amount of neutralizing agent required to neutralize a lake if the sediment BNC is large relative to the BNC of overlying waters. The extent ofin situ sediment BNC in acidic Bowland Lake (pH 5.0) was inferred by (1) measuring the loss of Ca-45 to acidic sediments from labeled lake water neutralized with CaCO₃, and (2) measuring exchangeable Ca in sediments collected prior to and following neutralization of Bowland Lake with calcite (CaCO₃). The sediment BNC derived from the Ca-45 radiolabeling experiment was 0.01 mg CaCO₃ g^?1 w wt. The mean losses of Ca-45 from the aqueous phase of neutralized and untreated sediment/water mixtures were not significantly different. The mean pH of both neutralized and untreated mixtures decreased to 4.0 during the incubation, possibly because of oxidation of reduced sediments. Sediment BNC estimates derived from literature data for several lakes may be overestimated because of the inclusion of anoxic sediments containing significant amounts of reduced Fe. There was no significant difference in exchangeable Ca between sediments from untreated Bowland Lake and sediments collected 10 m after whole-lake neutralization indicating that little of the supplied alkalinity had been lost to the sediments. Hence,in situ sediment BNC was probably small in Bowland Lake.     

湖南棕红壤的研讨

本文研究了湖南省洞庭湖东西两侧丘岗地区的棕红壤,提出了棕红壤的主要形成特点、特性、类型的一些指标,归纳如下: 1.具有比较弱的脱硅富铝现象,粘粒硅铁铝率为2.7—3.0;淋浴弱(碱金属和碱土金属含量比红壤高0.18—2倍,风化淋溶系数多在0.3以上);粘粒矿物以水云母、高岭石为主;游离铁含量大于2%,游离度50—60%。2.颜色为红黄-暗红棕色;粉/粘比和砂/粘比一般都小于1,粘化值大于1;pH 4.8—5.8;CEC 8—14毫克当量/100克土;ECEC 16.5—23.3毫克当量/100克粘粒;盐基饱和度40-60%。3.参照上述指标,结合母质与地域特点,将其划分若干土属,并提出其利用改良上的相应差异。     

Density stratification in ionically enriched Onondaga lake,U.S.A.

Denstity stratification was characterized in ionically enriched Onondaga Lake for a 7 mo period of 1980, based on paired profiles of temperature and cloride collected at 1 m depth intervals from a single deep water location on 54 different occasions. The lake was both thermally and chemically stratified. The chemical component represented 38.5% of the density stratification for the study period. It was most often the dominant component in establishing the depth of the upper mixed layer, which was unusually shallow in the lake. Further, the presense of the chemical component prolonged the stratification period. The chemical component of stratification decreased progressively through the study. The altered stratification characteristics of the lake may have negative effects on the level of biomass in the upper waters and the oxygen resources of the lower waters.