Application of Static Critical Load Models for Acidity to High Mountain Lakes in Europe

Critical load models for acidityprovide a measure of the sensitivity of surfacewaters to acid deposition, and can be used todetermine critical load exceedance and potentiallong-term harmful effects. Three static models,the Steady-State Water Chemistry model, diatommodel and First-order Acidity Balance model, arehere applied to 11 high mountain lakes in Norway,Scotland, the Alps, the Pyrenees and the Tatras.Between five and seven of the lakes show criticalload exceedance, depending on the model used.Nitrogen as well as sulphur deposition isimportant in causing exceedance. Since soil andvegetation cover are generally sparse, geologyand lake retention time appear to be key factorsin the determination of critical load. Retentionof nitrogen is observed, but it is unclearwhether this occurs within the lake or theterrestrial part of the catchment.     

Biofiltration treatment of odors from municipal solid waste treatment plants

An in situ compost biofilter was established for the treatment of odors from biostabilization processing of municipal solid waste. The concentrations of total volatile organic compounds (VOCs) in odors and their components were measured. Biofilter media was characterized in terms of total carbon (TC), total nitrogen (TN), total phosphorus (TP), organic matter (OM), pH value and determination of bacterial colony structure. Gas chromatography–mass spectrometry (GC–MS) analysis showed that the main components of the produced gas were benzene, toluene, ethylbenzene and xylene (BTEX) along with other alkanes, alkenes, terpenes, and sulphur compounds. The compost biofilter had remarkable removal ability for alkylated benzenes (>80%), but poor removal for terpenes (～30%). Total VOC concentrations in odors during the biostabilization process period ranged from 0.7 to 87 ppmv, and the VOC removal efficiency of the biofilter varied from 20% to 95%. After about 140 days operation, TN, TC, TP and OM in compost were kept almost stable, but the dissolved N, NH₄–N and NO₃–N experienced an increase of 44.5%, 56.2% and 76.3%, respectively. Dissolved P decreased by 27.3%. The pH value experienced an increase in the early period and finally varied from 7.38 to 8.08. Results of bacterial colony in packing material indicated that bacteria and mold colony counts increased, but yeasts and actinomyces decreased along with biofilter operation, which were respectively, 3.7, 3.4, 0.04 and 0.07 times of their initial values.     

Trends in the Water Chemistry of High Altitude Lakes in Europe

Here we present the chemical trends of seven high altitude lakes, analysed within the AL:PE and MOLAR Projects of the EU (1999) and selected on the basis of the availability of complete and reliable data for the period 1984–1999. The lakes are representative of the Scandinavian Alps, the Cairngorm Mountains in Scotland, the Alps and the Pyrenees. Significant trends were identified for some indicators of acidification, for instance pH and alkalinity, but not all lakes reacted similarly to decreasing depositions of sulphate and base cations. Differences in lake response are discussed in relation to recent variations of atmospheric deposition chemistry and associated changes in climatic conditions. Beside individual variations of the studied lakes, depending, among other things, on altitude and morphology, catchment characteristics and climate trends play a major role for the reaction of high altitude lakes on changes in atmospheric depositions.     

某化工园区废水处理工程设计实例

采用“分质调节—混凝沉淀—厌氧水解—缺氧生物处理—好氧生物处理”工艺处理某化工园区以氟化工和精细化工废水为主的工业废水。工程运行结果表明：废水经处理后,COD=35 mg/L,TN=5.2 mg/L,ρ（NH₃-N）=3.1 mg/L,TP=0.15 mg/L;COD,TN,NH₃-N,TP的去除率分别为91.1％,67.1％,70.5％,89.3％;出水达到DB 32/T1072—2007《太湖地区城镇污水处理厂及重点工业行业主要水污染物排放限值》中的排放标准。工程设计规模1.0×10⁴ m³/d,工程总投资约5 000 万元,直接运行费用1.50 元/m³。每年减少COD,TN,NH₃-N,TP的排放量分别约为1 324.6,38.69,11.05,4.56 t。该工程的实施明显改善了区域水环境,为太湖流域污染的治理提供了技术支撑。     

Long-term Changes in Environmental Variables of Traunsee,an Oligotrophic Austrian Lake Impacted by the Salt Industry,and Two Reference Sites Hallstättersee and Attersee

Morphometric, hydrological and basic physico-chemicalcharacteristics of three deep Alpine lakes, Traunsee,Hallstättersee and Attersee as well as their long-termbahaviour are presented. The deep Alpine lakesHallstättersee and Traunsee have been influenced by saltmining and the traditional salt industry for over 100 years. Waste products from these activities, entering the lakes, have mainlyaffected the chemistry of these water bodies, especially bysubstantially increasing the chloride concentrations up to 170 mg L^-1. As a consequence of the increased density, mixing conditions of the lakes were altered. The resulting incomplete mixing led to oxygen depletionin deeper layers. In addition, increased nutrientload from the catchment rised the trophic level in the 70s and 80sof the last century in turn, affecting the oxygen content in thehypolimnion. Finally a situation developed where the risk becamehigh for these lakes to become meromictic induced by humanactivity. In fact, Hallstättersee became facultativelymeromictic. This process was interrupted by increased chlorideinput of more than 30 mg L^-1 due to accidental wash outfrom an upstream salt mine rendering Hallstätterseehomogenous in 1978 to 1980 resulting in complete over-turn. Conditions substantially improved in both lakes after miningpractices were altered and restoration measures againsteutrophication were initiated. Chloride and phosphorusconcentrations declined, while oxygen conditions substantiallyimproved in the following years. Conditions in Traunseesubstantially improved and chloride levels near the sedimentdecreased to less than 140 mg L^-1. The third lakeconsidered here, Attersee, always remained in a near-naturalstate although some signs of increased nutrient levels becamevisible in the late 1970s. Chloride concentrations of around 3 mgL^-1 in this lake can be considered as background levels.Attersee can now serve as a reference site for deep Alpine lakesbecause of its ultra-oligotrophic and pristine nature.     

Predicting Freshwater Critical Loads from Catchment Characteristics using National Datasets

Maps of freshwater critical loads are used toguide emission strategies for sulphur and nitrogen bothnationally and internationally. Water chemistry data arerequired to calculate critical loads and the production ofnational maps therefore relies on the existence of extensivechemistry datasets. However, the data required to calculatecritical loads are not readily available for all sites. Thisarticle explores how empirical statistical models mightpotentially be used to predict critical loads using nationallyavailable datasets representing a range of catchmentcharacteristics. Initially a global regression model forexplaining freshwater critical load variation across a broadspectrum of catchment types (from lowland agricultural tomountain lakes) throughout mainland Britain is described. Whenattention is focused on more specific catchment types (i.e.upland and non-arable) it is shown that the global model hasless explanatory power. A regionalisation of Great Britain(based on 100 km grid squares) shows that the global modelcannot necessarily be applied successfully within a narrowerregional context. Separate analyses were undertaken on each ofthe regional subsets using backward selection regression. Thevariables emerging as significant predictors variedsubstantially across the regions, as did the explanatory powerof the models. This was also the case when the analysis wasconfined to upland and non-arable catchments. This approachcould be developed so that critical loads assessments can bemade for populations of standing waters rather than simplythose for which water chemistry is available.     

The Input and Transmission of Fallout Radionuclides Through Redó, a High Mountain Lake in the Spanish Pyrenees

Fallout radionuclides have increasing value as tracers of pathways for pollutant transport through catchment/lake systems, in addition to their more traditional role in dating sediment records. The objectivesof this study, carried out within the EU MOLAR project, were tomeasure atmospheric fluxes of fallout ²¹⁰Pb, ¹³⁷Cs and ⁷Be at Redó, to establish mass balances for theseradionuclides, and test and validate models of pollutant transport through the lake and its catchment. This was achieved by comparing measured fluxes and concentrations in the water column with theoretical estimates using simple compartment models. Several interesting points emerged. Differences betweensoil core and rainwater measurements suggest that Saharan dust may be an important source of fallout ²¹⁰Pb. Fluxes throughthe water column had a clear seasonal trend reflecting winter icecover. Significant concentrations of ¹³⁷Cs are still presentin the water column, due to continued inputs from the catchment and/or remobilisation from the bottom sediments.     

Temporal Trends in Mercury Accumulation in Lake Sediments in Sweden

Lake sediment cores were analyzedto study the history of mercury (Hg) pollution andparticularly to determine whether recent sedimentconcentrations have declined in response todeclining atmospheric deposition of Hg. Sedimentcores from 6 forest lakes distributed fromsouthern to northern Sweden and 3 northernmountain lakes were analyzed for Hg using CVAAS. A400 cm sediment profile from Måkevatten insouthwest Sweden indicates that the onset of Hgpollution occurred in the 18th century. Anindisputable increase in Hg concentrationsoccurred concurrent with the appearance ofspheroidal carbonaceous flyash particles (SCP)derived from fossil-fuel combustion, in themid-19th century. There is a strong correlationbetween Hg and SCP concentrations in the sedimentcores (r=0.67 to 0.91), which suggests a strongrelationship between historical Hg pollution andfossil fuel burning. In contrast to sediment corestaken in 1979, maximum Hg concentrations are nowobserved below the sediment surface and declinetowards the sediment surface. This study confirmsthat reductions in atmospheric deposition of Hgover Sweden have resulted in a decreased transferof total Hg to aquatic environments as reflectedby lake sediments, and that lake sediment profilesof Hg concentrations reflect relative trends inthe atmospheric deposition of Hg rather thanpost-depositional diagenetic processes.     

Modelling Acidification and Recovery of Swedish Lakes

The MAGIC model was calibrated to 143 lakes in Sweden, all of which are monitored in Swedish national monitoring programmes conducted by the University of Agricultural Sciences (SLU). Soil characteristics of the lake catchments were obtained from the National Survey of Forest Soils and Vegetation also carried out by SLU. Deposition data were provided by the Swedish Meteorological and Hydrological Institute (SMHI). The model successfully simulated the observed lake and soil chemistry at 133 lakes and their catchments. The fact that 85% of the lakes calibrated successfully without being treated in an individual way suggests that data gathered by the national monitoring programmes are suitable for modelling of soil and surface water recovery from acidification. The lake and soil chemistry data were then projected into the future under the deposition scenario based on emission reductions agreed in the Gothenburg protocol. Deposition of sulphur (sea salt corrected) was estimated to decrease from 1990 to 2010 by 65–73%; deposition of nitrogen was estimated to decrease by 53%. The model simulated relatively rapid improvements in lake water chemistry in response to the decline in deposition from 1990 to 2010, but the improvements levelled off once deposition stabilised at the lower value. There was a major improvement of simulated lake water charge balance acid neutralising capacity (ANC) from 1990 to 2010 in all lakes. The modelled lakes were divided into acidification sensitive and non-sensitive. The modelled sensitive lakes are representative of 20% of the most sensitive lakes in Sweden. By 2010, the ANC in the sensitive lakes was 10 to 50 μeq L^-1 below estimated pre-industrial levels and did not increase much further from 2010 to 2040. Soils at the majority of the modelled catchments continued to lose base cations even after the simulated decline in acid deposition was complete, i.e. after the year 2010. Based on this model prediction, the acidification of the Swedish soils will in general not be reversed by the deposition reduction experienced over the last 10 years and expected to occur by the year 2010.     

Low-Cost Filtration System to Treat First-Flush Stormwater

The aim of this paper is to evaluate the performance of the low-flow filtration system (LFFS) that Kogarah Municipal Council developed for treating and reusing the highly polluted first-flush stormwater (FFSW) while allowing the cleaner subsequent major stormwater flows to be directed to the major street drainage. The LFFS was evaluated through laboratory investigations using columns packed with different filter media to test the removal efficiency of pollutants such as zinc (Zn), total phosphorus (TP), total nitrogen (TN), total organic content, total petroleum hydrocarbons (TPH), and turbidity. The findings from this study demonstrate the effectiveness of the LFFS to largely reduce turbidity, TPH, and trace metals from the FFSW. The LFFS also partially removes dissolved organics, TP and TN. These pollutants are more commonly and effectively removed in subsequent processes of a stormwater treatment train. Further this paper highlights the importance of regular maintenance of the LFFS especially as it is only associated in removing the high pollutant loads during a storm event. Due to this first flush, a thick oily crust-formed layer requires monthly removal, and an entire replacement of the exhausted filter media is required quarterly. However considering the labor required to service the crust formed layer within the LFFS, it is more cost effective to replace the entire depth of filter media monthly.     

Dynamics of Bacterial Abundance,Biomass, Activity,and Community Composition in the Oligotrophic Traunsee and the Traun River (Austria)

The holomictic Traunsee is the deepest and second largest lakein Austria. The special characteristic of this ecosystem isthe fact that local salt and soda industries presumably alterthe lake by the discharge of waste materials. Since thebeginning of the 20th century salt and soda works areannually releasing up to 50,000 tons of solid wastes and up to150,000 tons of chloride into Traunsee. To assess potentialeffects of these anthropogenic impacts on the bacterioplanktonthree sampling sites, influenced as well as not influenced bythe industrial discharge, were chosen for comparison andsampled monthly from November 1997 to October 1998. Bacterialabundance ranged between 0.4 to 3.0 × 10⁶ cells ml^-1 with decreasing numbers along the depth profile. Theproportion of actively respiring bacteria, i.e. INT [2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyltetrazolium chloride]reducing cells, never exceeded 10% of DAPI (4',6'-diamidino-2-phenylindole) stained cells. Fluorescence in situ hybridization (FISH) was used to examine the seasonal and spatial distribution of dominant phylogenetic groups of thebacterioplankton. Up to 84% of bacteria detected with DAPIcould be detected via FISH applying the universal bacterialprobe EUB338. Percentages of alpha- and beta-Proteobacteriaand members of the Cytophaga-Flavobacterium cluster did notexceed 60% of DAPI-stained cells.Beta-Proteobacteriaappeared to be the most abundant group, not only in Traunsee butalso in two reference lakes, Attersee and Hallstättersee. No significant differences in any of the bacterial parameters couldbe detected between the three sampling sites and all measurementswere found in the range reported for oligotrophic lakes. The highdischarge of the Traun River, resulting in a lake water renewaltime of only one year, may diminish possible effects of industrial waste discharge in the pelagic zone.     

高盐有机化工废水中COD与TOC的相关性

以COD为指标评价废水的有机物污染程度存在诸多不足,而TOC能更好地反映废水中有机物的含量。以高盐有机化工废水为研究对象,利用多级活性炭吸附工艺对其进行预处理,对原水、吸附出水、再生液中COD与TOC的相关性进行了分析。分析结果表明：在一定范围内,原水COD与TOC满足关系式COD = 56.537 7+ 0.967 04TOC;废水在吸附处理过程中,COD与TOC仍呈线性相关关系,但不同工段需各自建立独立的回归方程;TOC测定结果的精密度较好,且远优于COD直接测定的精密度,回收率范围98.59%~110.69%;利用线性回归方程根据TOC测定结果预测COD,预测结果准确、可靠、精密度好。     

Effects of Liming on the Aquatic Fauna in a Norwegian Watershed: Why Do Crustaceans and Fish Respond Differently?

We studied the effects of liming on fish and crustaceans in a watershed which is in a region known to have one of the highest diversity of aquatic biota in Norway. This watershed, Enningdal, is shared between Norway (1/3) and Sweden (2/3) and includes 61 lakes  >  1.0 ha in Norway. Liming started on a large scale in the 1980s. Currently, a total of 26 of lakes (43%) are limed, covering 93% of the total lake area. The mean value ± S.D. of pH and the concentration of inorganic labile Al in these lakes is 6.62 ± 0.35 and 3 ± 4 μg l⁻¹, respectively. Historical data of fish communities have been obtained from surveys, while test-fishing and sampling of crustaceans were conducted in 24 lakes in recent years (2002–2004). The present study shows that crustaceans to a greater extent than fish has responded to improved water quality after more than 20 years of liming. Of a total of 120 fish populations, 42 (35%) have gone extinct. Only five of the lost fish populations (12%) have been re-established, all due to human re-introductions. Physical barriers are considered to be the main factor preventing fish from invading limed lakes. In contrast, crustaceans have been re-established in most limed lakes. This may be mainly due to their good spreading capacity. However, they might also have survived in refuges within the watershed, or as resting-eggs in the sediment.     

Recovery of Acidified Streams in Forests Treated by Total Catchment Liming

Reduced emissions of acidifying pollutants have changed the acidification process, and as a result, forest soils and surface waters are slowly recovering in Sweden. However, model calculations show that some areas may never recover completely unless further measures, such as liming, are undertaken. Liming of surface waters (lakes, rivers and wetlands) has been successfully practised in Sweden since the 1970s, but repeated treatments are necessary. A full recovery of acidified lakes and streams without frequent liming is however not possible until soil acidification is reversed in the most strongly affected areas. In this study, the recovery of acidified streams was examined using ‘the total catchment approach’ i.e. treatment of both recharge and discharge areas. The aim was to compare the quantitative effect of different treatments on run off chemistry and the recovery of brown trout. Catchments in southwest Sweden were treated with a combination of 2 tons of wood ash and 4, 6 or 12 tons of crushed limestone per hectare in 1998/1999. Treatment of both recharge and discharge areas resulted in fast and significant changes in stream water quality, e.g. increased concentrations of calcium, higher pH and ANC and a decreased concentration of inorganic aluminium. The initial changes were dependent on the distribution of the applied lime between discharge and recharge areas rather than the average dose on the total catchment. Treatment of recharge areas only, resulted in smaller but still significant effects on calcium, pH and ANC in stream water. Furthermore, there was an initial leaching of nitrate but it was only minor compared with the elevated leaching that occurs after a clear-cut. As a result of the treatments, brown trout is now successfully reproducing. Olle Westling (deceased).     

Spatial and Temporal Comparison of Polycyclic Aromatic Hydrocarbons and Spheroidal Carbonaceous Particles in Remote European Lakes

Spheroidal carbonaceous particles (SCP) and polycyclicaromatic hydrocarbons (PAH) have been measured in the dated sediment cores of 10 remote lakes distributed across Europe. The geographic trends were evaluated by examination of the superficial sediment fluxes and total sediment inventories. The highest levels of both markers were observed in the Eastern European lakes whereas the minimal values corresponded to the lake located in the Arctic. However, this SCP-PAH correlation was not observed after exclusion of the end member lakes from the series. The temporal trends of both pollutant markers are consistent with the history of pyrolytic emissions over Europe. However, the downcore SCP distributions are shorter than the PAH profiles in nearly all lakes. The differences are probably related to the different size particle fractions involved in the measurement of each marker, >5 and >1 m for SCP and PAH, respectively. Thus, the two proxies probably reflect pollution inputs from closer (SCP) and more distant sites (PAH).     

循环式复合水解酸化—CASS—絮凝沉淀组合工艺处理化工园区废水

采用循环式复合水解酸化—CASS—絮凝沉淀组合工艺处理江苏省某化工园区污水厂的实际废水(COD260~815 mg/L、ρ(氨氮)19.15~40.41 mg/L、TN 22.51~50.66 mg/L、TP 0.79~3.21 mg/L),考察了污染物浓度的沿程变化,评价了各工段对主要污染物的去除效果。实验结果表明,组合工艺对废水有着较好的处理效果,平均COD、氨氮、TN、TP的去除率分别高达83.29%、95.34%、61.29%、82.70%,平均出水COD、ρ(氨氮)、TN、TP分别为56.2,1.27,14.34,0.33 mg/L,出水水质接近GB 18918—2002《城镇污水处理厂污染物排放标准》的一级A标准。     

电感耦合等离子体发射光谱法测定石化废水中的重金属

建立了硝酸加热消解后采用电感耦合等离子体发射光谱(ICP-OES)测定石化废水中重金属(As,Cd,Cr,Cu,Zn,Pb,Mn)的方法,优化了仪器工作参数,得到了线性回归方程,并对该方法进行了评价。优化后的仪器工作参数为射频功率1 150 W、雾化器流量0.70 L/min、辅助气流量0.50 L/min。各重金属元素回归方程的相关系数均在0.999 9以上,检出限为0.000 18~0.007 00 mg/L,相对标准偏差为0.1%~2.0%,加标回收率为96.3%~102.2%。该方法具有线性关系好、检出限低、精密度和准确度高、分析速度快等优点。     

Study of Pollution of the Plitvice Lakes by Water and Sediment Analyses

The process of eutrophication in form of intense plant growth has been observed in some lakes and water streams at the Plitvice Lakes National Park in central Croatia. Here we investigate whether this phenomenon is a consequence of anthropogenic pollution or due to naturally produced organic matter in the lakes. We applied chemical analysis of water at two springs and four lakes (nutrients, dissolved organic carbon (DOC), trace elements) and measurements of surface lake sediments (mineral and organic fraction analyses, trace elements) in four different lakes/five sites. The chemical composition of water does not indicate recent anthropogenic pollution of water because the concentrations of most trace elements are below detection limits. The concentrations of DOC and nutrients are slightly higher in the area of increased eutrophication-plant growth. Also the content of organic matter in the sediment is at the highest level in areas with highest C/N ratio indicating that the organic fraction of this sediment is mainly of terrestrial origin. There is no significant difference among the trace element concentration in the upper segment of all cores, deposited approximately during last 50 years when higher anthropogenic influence is expected due to development and touristic activity, and the lower part of the cores, corresponding to the period approximately 100–200 years before present. The content of trace elements and organic matter in sediments decreases from the uppermost lake downstream. According to our results there is no indication of recent anthropogenic pollution in water and sediment. Higher concentrations of DOC in water as well as phosphorus and some other elements in the lake sediment can be a consequence of input of natural organic matter to the lake water.     

Ecological Integrity: Concept,Assessment, Evaluation: The Traunsee Case

Definitions and concepts relevant to the evaluation of theEcological Integrity of lakes are discussed herein. Theirapplication to Traunsee, a deep lake located in the AustrianAlps which is affected by wastes of salt- and soda-producingindustries, is evaluated, based on 13 contributions published inthis special issue of Water, Air, and Soil Pollution.: Focus.     

Deposition and Storage of Spheroidal Carbonaceous Fly-Ash Particles in European Mountain Lake Sediments and Catchment Soils

Spheroidal carbonaceous particles(SCPs) are produced only from high temperaturecombustion of fossil-fuels. In mountain lakesystems, they provide an unambiguous indicator ofatmospheric deposition. In order to comparedepositional fluxes of SCPs between mountainareas experiencing various pollutant regimes,intensive bulk deposition sampling was undertakenat five sites across Europe. Catchment soil coresand lake sediment cores were also taken at eachsite to compare SCP storage over the post-industrial period. Atmospheric, sediment and soilSCP data showed similar patterns. Highestcontamination was found in Scotland, Slovakia andSpain with the Austrian site intermediate and themid-Norwegian site least contaminated. A highproportion of accumulated SCPs were found to bestored in catchment soils at each site.Therefore, a significant increase in soilerosion, possibly as a result of future climatechange, could lead to the input of largequantities of catchment stored SCPs and, byimplication, other atmospherically depositedcontaminants to the lake ecosystem.