火电厂废水综合处理方法的研究

根据火电厂工业废水的特点，结合无机，有机高分子絮凝剂的絮凝特性，研究设计了高效去除油、SS、COD等的分离池及火电厂废水处理工艺，该工艺系统简单，运行可靠，占地面积小，可降低工程投资30％－80％，运行费用降低30％以上，0．7－2a即可收回投资，处理后的水质良好。     

絮凝—光氧化法处理染料废水的试验研究

以三氯化铁为絮凝剂，采用絮凝－光氧化二级串联法对模拟活性艳红Ｘ－３Ｂ染色料废水进行处理试验，取得了脱色率１００％、ＣＤＯＣＲ去除率８０％的效果。该方法具有一次性投药，投药量少，残渣少等优点。     

聚合氯化铝锌絮凝剂的制备及其性能

用在AlCl，与ZnCl2溶液中加NaOH溶液的方法制备无机高分子絮凝剂聚合氯化铝锌（PAZC），通过正交实验确定的最佳制备条件为：反应时间10min、碱化度2．2、氯化铝浓度0．5mol／L、NaOH溶液浓度0．5mol／L。在n（Zn）：n（Al）=0．6、水样pH=7．8、PAZC加入量为5mg／L的条件下，浊度和COD去除率分别为98．9％和88．2％。PAZC与聚合氯化铝对各种工业废水的处理效果比较结果表明，PAZC对各种工业废水的处理效果较好。从废水处理成本来看，PAZC具有较好的经济效益。     

阳离子淀粉-丙烯酰胺接枝共聚物絮凝剂的制备及其絮凝性能

研究了阳离子淀粉与丙烯酰胺接枝共聚反应制备阳离子型絮凝剂的工艺，并用硅藻土悬浊液及实际水样对产物的絮凝性能进行了考察。其最佳合成条件：阳离子淀粉与丙烯酰胺的质量比为1：4，引发剂加入量为丙烯酰胺质量的0．1％，反应温度50℃，反应时间3h。絮凝效果实验中，接枝共聚物絮凝剂的最佳加入量为4mg／L。与阳离子淀粉和阳离子聚丙烯酰胺絮凝剂相比，接枝共聚物絮凝剂对渭河水及造纸网下白水的絮凝效果更好。     

液膜萃取法处理有机磺酸工业废水

对含高浓度数－硝基甲苯－２－磺酸（ＮＴＳ）的工业废水采用液膜萃取法处理。研究了萃取过程膜溶剂、表面活性剂、外水相的ＰＨ、内水相氢氧化钠浓度、油内比的选择及它们之间的相互关系，以探讨去除ＮＴＳ的最佳条件。实验结果表明，外水相ＰＨ为４，内水相氢氧化钠浓度为５．０％－７．５％油内比为１：０．５－１．２５，表面话性剂复配使用可获得最佳的处理效果，ＮＴＳ和ＣＯＤ的去除率分别达９９．４％和９６．２％。     

聚合硅酸铝铁絮凝剂处理油井压裂废水

制备了聚合硅酸铝铁絮凝剂，并用于处理油井压裂废水。制备聚合硅酸铝铁絮凝剂的优化实验条件为：聚硅酸活化pH1~2，活化温度25~30℃，活化时间2.0h。在此条件下制备的聚合硅酸铝铁絮凝剂对油井压裂废水浊度和COD的去除率分别可达到97％和58％。与聚合氯化铝铁絮凝剂相比，聚合硅酸铝铁絮凝剂在浊度及COD去除方面有着更佳的处理效果，并且处理后废水的总溶解性固体含量较低。     

多菌灵及其中间体工业废水的处理

多菌录及其中间体工业废水含苯胺类物质和硝基苯，可物化性差，经凝聚－吸附预处理后，生物接触氧化处理效果大大提高。中试结果表明，预处理后废水经生化处理，ＣＯＤｃｒ平均去除率达８３％，出水ＣＯＤｃｒ，苯胺类、硝基苯和ＰＨ各项指标基本达到８９７８－８８污水综合排放标准。     

酸析法和碱析法处理草浆造纸黑液的效果对比

对比了酸析法和碱析法对碱法草浆造纸黑液中木质素的去除效果，并分析了聚合氯化铝(PAC)絮凝剂对酸析和碱析后木质素的絮凝效果。实验结果表明:酸析法和碱析法都能有效析出造纸黑液中的木质素，酸析法对色度的去除效果要优于碱析法;当造纸黑液pH为3时，COD去除率达到72.0%，色度去除率为97.7%;当造纸黑液pH为13时，COD去除率达到55.0%，色度去除率为22.3%;PAC对于酸析后木质素有较好的絮凝效果，当废水温度为55℃、PAC加入量为45mL/L时，COD去除率可以达到79.5%，色度去除率为98.5%;PAC絮凝剂对于碱析后的造纸黑液色度的去除效果较差。     

粉煤灰在废水处理中的最新应用研究

利用粉煤灰作为废水处理中的吸附剂或混凝剂,可取得良好的处理效果。以印染、造纸等工业的废水处理为例,综述了国内利用粉煤灰处理多种工业废水的最新研究成果。     

用高效菌种处理甲胺磷农药废水

用选育出的一种降解甲胺磷混合菌，在ＳＢＲ反应器中对预处理后的甲胺磷生产废水进行生化处理。结果表明，投加高效菌种后废水的处理效率较未加高效菌种时有明显提高：进水ＣＯＤ为１０００－１６００ｍｇ／Ｌ，去除率可达８４％左右，ＢＯＤ去除率为９０％￣９３％，甲胺磷的去除率为８８％－８９％，出水各项指标基本达到国家规定的有机磷农药工业废水排放标准。     

Distribution of Cd,Ck, Pb and Zn in Soil and Vegetation Compartments in Stands of Five Boreal Tree Species in N.E. Sweden

Concentrations and total quantity of cadmium (Cd), cupper (Cu),lead (Pb) and zink (Zn) were determined in biomass and soil compartments in a replicated tree species experiment with 27-yr-old stands growing on former farmland in N.E. Sweden. Sequentialextractions of soil samples were performed in order to estimate the exchangeable and an organically bound fraction of each element. The tree species included were Picea abies (L.)H. Karst., Pinus sylvestris L., Pinus contorta Dougl., Larix sibirica Ledeb., and Betula pendula Roth.Tree species influenced the rate of removal of Cu, Pb and Zn incase of stemwood harvesting, and of Cd, Cu and Zn in the case ofwhole-tree harvesting. B. pendula and P. abies had higher quantities and average concentrations of Zn in the biomass. For all species, >50% of the Zn in the stems was found in the bark. P. abies and L. sibirica had higher quantities of Cu in the biomass than the other species.P. abies and P. contorta had high quantities of Cd inthe biomass in relation to the other species. Branches and stembark contained high concentrations of Cd and Pb in relation to foliage and stemwood. Dead branches had especially high concentrations of Pb. The high accumulation rate of Zn in thebiomass of B. pendula was related to a low exchangeable amount of Zn in the A horizon. In the superficial centimeters ofthe A horizon, a depletion similar to that found for Zn was detected for Cu, whereas for Cd and Pb, no correlations were found between quantities of elements in the trees and element pools in the soil.     

Programs assessing implementation and effectiveness of state forest practice rules and BMPs in the West

The major forest nonpoint source control programs in the West are largely regulatory, either under forest practices acts (California, Idaho, New Mexico, Nevada, Oregon, and Washington) or a streamside management act (Montana). These programs and the specific rules they enforce continue to undergo intensive scrutiny. Still, the questions are the same for these regulatory programs as for states that base nonpoint source control on voluntary BMPs (Arizona, Colorado, Utah, Wyoming). Are the rules or BMPs being applied, and are they effective in reducing nonpoint source pollution to levels that protect beneficial uses of water? The level of debate about forestry in the West has resulted in detailed monitoring and research to answer these questions. In the past, state agencies have assumed levels of BMP compliance based on the percent of operations without enforcement actions. These estimates are being replaced by statistically valid and reproducible monitoring of forest practices rules and BMP compliance levels. BMP effectiveness is being assessed using both qualitative and quantitative methods. This can involve field assessments, process-based research, and control watershed studies. Some trend monitoring is also beginning. With the regional implementation rate for forestry BMPs at about 94% and rising, it is likely that effectiveness testing will continue to be a priority and consume the majority of assessment resources for this region.     

Hysteresis in Reversal of Central European Mountain Lakes from Atmospheric Acidification

Extremely high emissions of S and N compounds in Central Europe (both 280 mmol m^-2 yr^-1) declined by 70and 35%, respectively, during the last decade. Decreaseddeposition rates of SO₄ ^-2, NO₃ ^-, and NH₄ ⁺ in the region paralleled emission declines. The reduction in atmospheric inputs of S and N to mountain ecosystemshas resulted in a pronounced reversal of acidification in the Tatra Mountains and Bohemian Forest lakes. Between the 1987–1990and 1997–1999 periods, concentrations of SO₄ ^-2 and NO₃ ^- decreased (average ± standard deviation) by 22±7 and 12±7 mol L^-1, respectively, in theTatra Mountains, and by 19±7 and 15±10 mol L^-1, respectively, in the Bohemian Forest. Their decrease was compensated in part (1) by a decrease in Ca²⁺ + Mg²⁺ (17±7 mol L^-1) and H⁺ (4±6 mol L^-1), and an increase in HCO₃ ^-(10±10 mol L^-1) in the Tatra Mountains lakes, and (2) by a decrease in Al (7±4 mol L^-1), Ca²⁺ + Mg²⁺ (9±6 mol L^-1), and H⁺ (6±5 mol L^-1), in Bohemian Forest lakes. Despite the rapid decline in lake water concentrations of SO₄ ^-2 and NO₃ ^- in response to reduced S and N emissions, their present concentrations in some lakes are higher than predictionsbased on observed concentrations at comparable emission rates during development of acidification. This hysteresis in chemical reversal from acidification has delayed biological recovery of the lakes. The only unequivocal sign of biological recovery hasbeen observed in erné Lake (Bohemian Forest) where a cladoceran species Ceriodaphnia quadrangular has recentlyreached its pre-acidification abundance.     

Reconstruction of Long-Term Changes in Lake water Chemistry,Zooplankton and Benthos of a Small,Acidified High-Mountain Lake: Magic Modelling and Palaeolimnogical Analysis

Starolesnianske pleso is a small and shallow acid lake in the High Tatra Mountains, situated at 2000 m above sea level, on granitic bedrock, with sparse and thin soil cover. When detailed measurements began in the 1980s Starolesnianske pleso had pH below 5 and only one species of cladoceran zooplankton, the ubiquitous Chydorus sphaericusPalaeolimnological investigations show changes in cladoceran zooplankton and chironomid zoobenthic assemblages since about 1920 and a major change in 1970–1980. The dynamic acidification model MAGIC was used to reconstruct changes in water chemistry over the past 150 years. The results from MAGIC agree well with the sediment record; pH levels gradually decreased from 6.5 in the mid-1800s to about 5.6 in 1920 (first response in biota) to below 5.0 by 1970, and concentrations of inorganic aluminium rose dramatically beginning about 1960. In the 1990s the lake water chemistry showed clear signs of reversal in acidification brought about by a major decline in S deposition.     

Starch-plastic materials—Preparation,physical properties,and biodegradability (a review of recent USDA research)

Recent starch-plastic research at the National Center for Agricultural Utilization Research is reviewed and related worldwide efforts are noted. Properties of starch that influence its formulation and performance in plastics are discussed. Methods are given for preparation of starch-poly(methyl acrylate) graft copolymer, starch-poly(ethylene-co-acrylic acid), and starch-poly(ethylene-co-acrylic acid)-polyethylene plastics. Their physical properties are discussed, as is degradability by enzymes or amylolytic organisms from soil, ponds, and streams.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

Heavy Metals Removal by Biosorption and Flotation

The removal of a mixture of heavy (toxic) metal cations (copper, nickeland zinc) from liquid effluents was investigated in this study at pilotscale, using counter-current contact mode. The innovative processinvolved the abstraction of metal ions onto fungal biosorbents, followedby the application of flotation for the subsequent solid/liquid separationof biomass particles. The ability of microorganisms to remove metal ionsfrom aqueous solutions is a well-known phenomenon. Nevertheless,engineering considerations are very important in decisions, concerningthe commercial future of biosorption and practical solutions are neededfor certain problems, such as the efficient post-separation ofmetal-loaded biomass. The two processes (flotation and biosorption) caneffectively operate in combination, in what it was termed biosorptiveflotation process. The sorbents may be recycled, after appropriate elutionof metals, as well as the treated (clean) water.     

High Immobilization of NH4+ in Danish Heath Soil Related to Succession,Soil and Nutrients: Implications for Critical Loads of N

During recent decades heathlands havechanged into grasslands in regions with high atmosphericnitrogen deposition. In regions with intermediatedeposition level (e.g., Denmark) changes have been lesspronounced which may be due to delay or decrease inresponse of the ecosystem. The mor layer (O horizon) mayplay an important role for this delay due to high sinkstrength for N. In this study, the capacity for netNH₄ ⁺ immobilization and mineralization wasstudied during short- and long-term incubations (2–36 days)of mor samples from Danish dry inland heaths. High short-term capacity for net NH₄ ⁺ immobilization wasfound to be a general characteristic of Danish heath morlayers both under heather (Calluna vulgaris) andcrowberry (Empetrum nigrum ssp nigrum), the latterdominating late stages in heathland succession. The netNH₄ ⁺ immobilization was higher under youngcompared to old or dead vegetation, and higher on lessnutrient poor soils than on extremely nutrient poor soils.The addition of N, P and C stimulated CO₂ productionand net NH₄ ⁺ immobilization, but not net Nmineralization. The immobilization of ¹⁵NH₄ ⁺caused release of dissolved organic N, increased N anddecreased C/N ratio in the microbial biomass, and indicatedgrowth of microorganisms with other metabolic abilitiesthan the indigenous population. No evidence was obtained ofstabilization of immobilized ¹⁵NH₄ ⁺ intosoil organic matter during the experiment. On background ofthe results and current knowledge it was concluded that therecognition of the high capacity for net NH₄ ⁺immobilization in mor layers does not allow for a raiseof critical loads for N for northern dry inland heaths.     

Bioassessment of silvicultural impacts in streams and wetlands of the Eastern United States

Bioassessment is a useful tool to determine the impact of logging practices on the biological integrity of streams and wetlands. Measuring biota directly has an intuitive appeal for impact assessment, and biota can be superior indicators to physical or chemical characteristics because they can reflect cumulative impacts over time. Logging can affect stream and wetland biota by increasing sedimentation rates, altering hydrologic, thermal, and chemical regimes, and changing the base of food webs. Biotic impacts of logging on streams compared to wetlands probably differ, and in this paper we review some of those differences. In streams, invertebrates, fishes, amphibians, algae, and macrophytes have been used as indicators of logging impacts. In wetlands, bioassessment is just beginning to be used, and plants and birds are the most promising indicator taxa. Various best management practices (BMPs) have been developed to reduce the impacts of logging on stream and wetland biota, and we review quantitative studies that have evaluated the efficacy of some of these techniques in streams and wetlands in the eastern United States. Remarkably few studies that address the overall efficacy of BMPs in limiting biotic changes in streams and wetlands after BMP implementation have been published in scientific journals, although some work exists in reports or is unpublished. We review these works, and compile conclusions about BMP efficacy for biota from this body of research.     

Characterization of air emissions and residual ash from open burning of electronic wastes during simulated rudimentary recycling operations

Air emissions and residual ash samples were collected and analyzed during experiments of open, uncontrolled combustion of electronic waste (e-waste), simulating practices associated with rudimentary e-waste recycling operations. Circuit boards and insulated wires were handled separately to simulate processes associated with metal recovery. The average emissions of polychlorinated dibenzodioxins and dibenzofurans (PCDD/PCDFs) were 92 ng toxic equivalency (TEQ)/kg [n = 2, relative standard deviation (RSD) = 98%] and 11 900 ng TEQ/kg (n = 3, RSD = 50%) of the initial mass of the circuit boards and insulated wire, respectively. The value for the insulated wire is about 100 times higher than that for backyard barrel burning of domestic waste. The emission concentrations of polybrominated dibenzodioxins and dibenzofurans (PBDD/PBDFs) from the combustion of circuit boards were 100 times higher than for their polychlorinated counterparts. Particulate matter (PM) sampling of the fly ash emissions indicated PM emission factors of approximately 15 and 17 g/kg of the initial mass for the circuit boards and insulated wire, respectively. Fly ash samples from both types of e-waste contained considerable amounts of several metallic elements and halogens; lead concentrations were more than 200 times the United States regulatory limits for municipal waste combustors and 20 times those for secondary lead smelters. Leaching tests of the residual bottom ash showed that lead concentrations exceeded U.S. Environmental Protection Agency landfill limits, designating this ash as a hazardous waste.     

Selection of Autochthonous Plant Species from SE Spain for Soil Lead Phytoremediation Purposes

Mining activity in SE of Spain, in the west Mediterranean coast, originated more than two millenniums ago. It has generated huge areas affected by heavy metals contamination, especially of lead, which is possibly one of the most important. Investigations related to the selection of autochthonous plant taxa from a typical Spanish Mediterranean area, useful for phytoextraction and phytostabilization purposes in these polluted areas are shown. Under these edaphoclimatic conditions 12 interesting species were considered, from them six taxa were chosen for further studies. Some plant species have been proposed either for phytoextraction or phytostabilization purposes. Recommendations for further research have been discussed.