生物滴滤塔处理甲苯废气

分别以生物陶粒和聚氨酯泡沫为生物滴滤塔填料，对甲苯废气进行处理，考察不同生物滴滤塔挂膜启动时间以及气体流量和甲苯质量浓度条件下生物滴滤塔对甲苯废气的去除效果。实验结果表明：生物陶粒为填料的生物滴滤塔所需要的挂膜启动时间更短；在气体流量为450L/h时，以生物陶粒为填料的生物滴滤塔甲苯去除率稳定在72%左右，聚氨酯泡沫为填料时甲苯去除率稳定在65%左右。以聚氨酯泡沫为填料时，随甲苯质量浓度提高，甲苯去除率下降幅度较小，甲苯质量浓度为1.80g/m3时，甲苯去除率仍在72%以上。     

改性膨润土对水中蒽的吸附和解吸

分别用长碳链季铵盐阳离子型表面活性剂溴化十六烷基三甲铵（HDTMAB）、短碳链季铵盐阳离子型表面活性剂四甲铵化溴（TMAB）及非离子型表面活性剂聚乙二醇（PEG）对天然膨润土进行改性。比较了不同类型改性膨润土对水中蒽的吸附性能，探讨了吸附机理。实验结果表明，天然膨润土及改性膨润土对水中蒽的吸附能力依次为HDTMAB改性膨润土〉PEG改性膨润土〉TMAB改性膨润土〉天然膨润土；吸附等温线均是直线，说明该吸附行为是分配作用的结果。不同蒽初始质量浓度下，各种改性膨润土对蒽的吸附量由大至小的顺序为HDTMAB改性膨润土〉PEG改性膨润土〉TMAB改性膨润土，而天然膨润土对蒽的吸附量随蒽初始质量浓度的变化很小。改性膨润土加入量为30～80g/L时，各种改性膨润土对水中蒽的去除率均可达到90％以上，且解吸率均在5％以下。     

废水处理用微电解规整化填料的制备

以黏土、铁屑和活性炭为原料，加入一定量的添加剂，以水为黏合剂造粒，在一定温度下焙烧制成颗粒状微电解规整化填料。实验结果表明：在黏土、铁屑、活性炭的体积比为2：4：4、氯化铵为添加剂、添加量为0．5％（质量分数）、焙烧温度为600℃的条件下，制备的微电解规整化填料具有最佳的废水处理效果。用该填料处理低浓度染料废水（废水COD为591．5mg／L），COD去除率可达75％以上。     

改性聚丙烯生物填料的制备与应用

对传统聚丙烯生物填料（简称普通填料）进行改性，考察了改性聚丙烯生物填料（简称改性填料）用于模拟废水生物处理的效果。实验结果表明，改性填料比普通填料具有更高的废水处理效率和更大的挂膜量，并能承受更高的气液比（体积比）及气流和水流的冲击。将模拟废水的COD（500mg／L）完全去除，用改性填料时需10.5h，而用普通填料时则需22．5h；在连续运行模式下，改性填料在气液比为40：1时可使废水COD的去除率最高（99％），而普通填料则在气液比为30：1时可使废水COD的去除率最高（79％）。     

负载型金属催化剂的制备及印染废水的催化氧化处理

采用浸渍沉淀法制备负载型金属催化剂，考察了载体种类、活性组分种类、活性组分配比（n（Fe2+）∶n（Mn2+））、浸渍液浓度（以Mn2+计）、煅烧温度和煅烧时间对催化剂性能的影响。实验结果表明：活性炭负载FexOy-MnOx型催化剂具有较高的活性；将在浸渍液浓度0.5 mol/L（以Mn2+计）、n（Fe2+）∶n（Mn2+）=1∶2、煅烧温度250 ℃，煅烧时间8 h条件下制备的催化剂用于印染废水（COD=584 mg/L、色度500倍）的处理，在臭氧流量0.8 L/min、废水pH 7、催化剂加入量40 g/L、反应时间60 min的条件下，印染废水COD的去除率为83.2%；该催化剂具有良好的稳定性，连续使用6次后的COD去除率仍可达到61.1%。     

生物膜填料塔净化工业废气用填料的研究

以净化低浓度甲苯废气为对象，采用实验室及工业化规模的 生物塔料塔对轻质陶块、瓷环、不锈钢环和塑料环4种填料进行选择研究，结果表明：轻质陶块是一种优质、廉价的废气处理用生物膜填料塔的填料；4种填料的净化性能及经济性的综合排序为：轻质陶块＞瓷环＞不锈钢环＞塑料环；用轻质陶块填充的工程应用生物膜填料塔，在生物挂膜约10d时，甲苯的净化效率可达90％以上，且设备运行稳定。     

水解酸化-好氧生物滤池处理炼油废水

以高炉水渣为填料,采用水解酸化-好氧生物滤池处理炼油废水。考察了好氧区气水比、水力停留时间对炼油废水处理效果的影响。实验结果表明：在水力停留时间为6h、温度为20～35℃、废水pH为6～9、好氧区气水比为10：1的条件下,该生物滤池对NH3-N,Ar-OH,COD的总去除率分别为100％,97％,85％,处理后出水水质达到国家《污水综合排放标准》一级标准。     

石墨毡电极预处理模拟邻甲酚废水

采用聚丙烯腈基石墨毡电极，以NaCl为电解质，在恒流电解的条件下，对质量浓度为1 000 mg/L、COD=3 672 mg/L的模拟邻甲酚废水进行预处理。研究了电解时间、初始废水pH、NaCl加入量、电流密度对邻甲酚去除率的影响，考察了废水的COD变化，并探讨了反应机理。实验结果表明：石墨毡电极具有较好的导电性、吸附性，对邻甲酚具有较好的电化学氧化性能;常温常压下，初始废水pH为6~7、电流密度为90 A/m2、向300 mL废水中加入0.5 g NaCl时，经4 h电解，邻甲酚的去除率达到97.1%，COD的去除率达到47.3%;处理后废水的BOD5/COD由0.04提高至0.33，可不经稀释直接进行生物处理。     

生物絮凝剂MBFGA1预处理乳制品加工废水

用生物絮凝剂MBFGA1预处理乳制品加工废水（简称废水）。实验结果表明，废水处理的水力条件为：以150r／min的转速搅拌30S，再以30r／min的转速搅拌20min；MBFGA1的最佳加入量为15mg／L；废水pH为4．0时，MBFGA1对废水的絮凝处理效果最好；废水温度对浊度、COD去除率有一定的影响，在20～45℃时，废水浊度的去除率始终保持在85％以上；30℃时，COD去除率达到最大值65．0％。     

改性粉煤灰吸附-高级氧化法处理奥里油废水

将氯化铁改性粉煤灰（简称改性粉煤灰）吸附处理与高级氧化和生物处理等技术进行优化组合，以期得到简便而有效的处理奥里油废水（简称废水）的组合工艺。研究结果表明：在废水COD平均为4600mg／L、改性粉煤灰加入量为50g／L、废水pH为7～9、吸附时间为1h的条件下，COD去除率达30％。采用“改性粉煤灰一次吸附-湿式均相催化氧化-厌氧生物过程-改性粉煤灰二次吸附”组合工艺处理废水时，改性粉煤灰不但具有较好的预处理效果，且还有较好的后处理能力；湿式均相催化氧化的催化剂用量少（Cu（NO3）2为2．0g／L）、操作条件温和（2．5MPa，180℃，pH5—7，1h）；厌氧生物过程中不需特殊筛选的菌种，易操作控制；经该组合工艺处理后，废水COD从4600mg／L降至55mg／L，COD去除率为98．4％，达到GB8978-1996《污水综合排放标准》的一级排放标准。     

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.     

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.     

Concentrations and Pools of Heavy Metals in Urban Soils in Stockholm,Sweden

The concentrations of heavy metals (Cd, Cr, Cu, Hg, Ni, Pb andZn) and arsenic (As) were surveyed and the metal pools estimatedin soils in Stockholm Municipality. The sampling sites were distributed all over the entire municipality with a higher sampling density in the city centre. Soils were sampled to a maximum depth of 25 to 60 cm. Soil texture, total-C content, electrical conductivity and pH were analysed. Heavy metal concentrations were determined after wet digestion with boiling7 M HNO₃.The results showed a wide range in heavy metal concentrations, as well as in other soil properties. The city centre soils constituted a rather homogeneous group whereas outside this areano geographical zones could be distinguished. These soils were grouped based on present land use, i.e. undisturbed soils, public parks, wasteland (mainly former industrial areas), and roadside soils. The city centre and wasteland soils generally hadenhanced heavy metal concentrations to at least 30 cm depth compared to park soils outside the city centre and rural (arable)soils in the region, which were used to estimate background levels. For example, the mean Hg concentration was 0.9 (max 3.3)mg kg^-1 soil at 0–5 cm and 1.0 (max 2.9) at 30 cm depth in the city centre soils, while the background level was 0,04 mg kg^-1. Corresponding values for Pb were 104 (max 444) and135 (max 339) mg kg^-1, at 0–5 and 30 cm, respectively, while the background level was 17 mg kg^-1.The average soil pools (0–30 cm depth) of Cu, Pb and Zn were 21,38 and 58 g m^-2 respectively, which for Pb was 3–4 timeshigher and for Cu and Zn 1.5–2 times higher than the backgroundlevel. The total amount of accumulated metals (down to 30 cm)in the city centre soils (4.5^*10 ⁶ m² public gardens and green areas) was estimated at 80, 1.1, 120 and 40 t for Cu, Hg, Pb and Zn, respectively. The study showed (1) thatfrom a metal contamination point of view, more homogeneous soilgroups were obtained based on present land use than on geographicdistance to the city centre, (2) the importance of establishing a background level in order to quantify the degree of contamination, and (3) soil samples has to be taken below the surface layer (and deeper than 30 cm) in order to quantify theaccumulated metal pools in urban soils.