厌氧-好氧法处理聚氯乙烯离心母液废水

采用厌氧膨胀颗粒污泥床反应器与内循环式好氧生物膜反应器串联工艺对悬浮聚合法聚氯乙烯离心母液废水进行连续处理实验。在温度为35℃、厌氧反应器水力停留时间为8h、好氧反应器水力停留时间为6h条件下,TOC总去除率达95％以上,厌氧段为50％左右。结果表明：厌氧段还可提高其出水的可生化性;温度对厌氧及整个系统的处理效果影响较大;运行过程中须向离心母液废水中添加氮、磷等营养物质。     

用内循环式生物系统处理炼油废水

采用内循环式生物系统处理炼油废水，以内循环式水解酸化反应器、好氧流化床、模块化设计的生物接触氧化池作为生物反应器进行中试试验。在进水COD为1231．0mg／L、温度为45℃、水力停留时间为23．1～52．0h的条件下，COD去除率稳定在83．9％以上；在进水COD为296．9mg／L时，可通过切换至低负荷的模块化工艺使出水水质达标。该系统对一定范围内的水力负荷和有机负荷的冲击均有较好的缓冲能力和灵活处理能力。     

生物滤池处理炼油厂废水

采用活性炭、沸石、建筑陶粒及工程陶粒等作为生物滤池填料,考察了生物滤池对炼油厂废水中COD、NH_3-N、浊度的去除效果。实验结果表明,最佳的工艺条件为:水力停留时间1.5 h,进水有机负荷0.74～1.85 kg/(m~3·d),曝气量0.29 L/min。工程陶粒对COD和NH_3-N的去除效果最好,且出水浊度能达到废水回用标准,可作为生物滤池的填料。     

隔离曝气生物反应器处理含硫含酚碱渣

采用隔离曝气生物反应器（简称反应器）处理含硫含酚碱渣（简称碱渣）,探讨了碱渣中硫化物的去除机理．研究了反应器中的挂膜驯化过程,考察了水力停留时间、气水体积比（简称气水比）及反冲洗周期等对碱渣中硫化物、挥发酚、COD和油等污染物处理效果的影响。实验结果表明,在碱渣处理量为1m^3／h、气水比为36：1、水力停留时间为12．0h,反冲洗周期为3～5d的条件下,经过隔离曝气生物氧化工艺处理后碱渣的COD、硫化物、油和挥发酚的去除率分别为88％,99％,89％,85％,出水BOD,约为30mg／L,BOD,／COD小于0．1,处理1t碱渣的产泥量为0．17～0．26kg。     

用移动床生物膜反应器处理石化废水

采用悬浮填料移动床生物膜反应器处理石化废水,在水力停留时间大于6h、反应器填料投加率为50％的条件下,出水COD、NH3－N、SS、浊度等均达到国家排放标准,在水力停留时间大于8h时,能达到良好的硝化效果。     

混凝-间歇式活性污泥法处理炼油废水

采用混凝-间歇式活性污泥（SBR）法处理炼油废水，考察了混凝、SBR法对炼油废水的处理效果。实验结果表明：在硫酸铝、聚丙烯酰胺、CaCl2加入量分别为50，3，100mg／L的条件下，油去除率为82．7％，COD去除率为57．1％，BOD，／COD为0．24，混凝处理出水具有一定的可生化性；对混凝处理出水用SBR法进行厌氧水解2h、好氧曝气9h的生物处理后，出水COD低于150mg／L，COD去除率在80％左右。     

固定床三维电极反应器深度处理炼油废水

以不锈钢板为阴阳主电极,以柱状活性炭为感应粒子电极,构建固定床三维电极反应器,并用其深度处理炼油废水。考察了施加电压、水力停留时间、废水pH和曝气量对COD去除效果的影响。实验结果表明,在施加电压10 V、水力停留时间60 min、废水pH=7.0、曝气量120 L/h的优化工艺条件下,处理后出水的COD=27.1 mg/L,满足"超滤—反渗透"单元对进水COD的要求(COD30.0 mg/L)。     

用水解酸化池-膜生物反应器处理活性艳红X-3B废水

采用水解酸化池-膜生物反应器处理含活性艳红X-3B的模拟废水,研究了水力停留时间（HRT）对水解酸化池废水处理效果的影响,考察了水解酸化池-膜生物反应器对废水的处理效果及膜生物反应器中污泥沉降性能对膜污染的影响。实验结果表明：水解酸化池HRT为16h时,废水的可生化性最好,挥发性脂肪酸质量浓度与COD比值为0．5;HRT为17h时,废水脱色率达69％,而COD的去除率受HRT影响较小;膜生物反应器主要起去除废水中COD的作用;水解酸化池-膜生物反应器处理后废水的脱色率和COD去除率分别为83％和97％;膜生物反应器中活性污泥沉降性能的变化直接影响膜污染的速率。     

铁炭微电解-生化法处理电镀废水

采用铁炭微电解-生化法处理含铬电镀废水（简称废水），铁炭微电解法处理废水时，考察了进水pH、Cr^5浓度、废水停留时间对废水预处理效果的影响；生化法处理废水时，考察了搅拌转速、废水停留时间对废水处理效果的影响。在进水pH约为3、废水在铁炭微电解反应柱内的停留时间为30min、生物反应器内搅拌器的搅拌转速为40r／min、废水在生物反应器内的停留时间为3h的最佳工艺条件下，废水经铁炭微电解一生化法连续处理后，出水中Cr^6＋、Cu^2＋和Ni^2＋的质量浓度分别为0．05，0．08，0．06mg/L，其去除率分别为99．0％，99．7％，99．3％，出水水质达到GB8978-1996《污水综合排放标准》的要求，且不存在二次污染问题。     

用好氧-厌氧反复耦合固定床生物反应器处理肌苷生产废水

利用由多孔微生物载体构建的好氧-厌氧反复耦合固定床生物反应器进行了高浓度肌苷生产废水处理中试研究。连续84d的运行结果表明，当进水COD为1500-2700mg／L、水力停留时间为22．1h时，出水COD可维持在150mg／L左右，COD去除率达90％～95％。装置运行稳定后，未经沉淀的出水中的固体悬浮物质量浓度小于50mg／L，表明该反应器可避免剩余污泥的产生。中试结果验证了该反应器处理高浓度肌苷废水的可行性和优势，同时为装置放大提供了理论依据。     

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.     

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.     

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.     

四氮唑废水处理工艺设计

高浓度、高盐分的四氮唑生产废水通过三效蒸发浓缩，馏出液经铁炭氧微电解和混凝预处理，再采用水解酸化一接触氧化一反应二沉主体组合工艺进行处理。研究了该工艺所需构筑物和设备的设计与选型。该工艺在正常运行条件下，处理后出水pH6～9，COD 302mg／L，BOD5 108mg／L，SS30mg／L，色度36倍，水质达到GB8978--1996（污水综合排放标准》三级标准。     

Application of Cellulose Microfibrils in Polymer Nanocomposites

Cellulose microfibrils obtained by the acid hydrolysis of cellulose fibers were added at low concentrations (2–10% w/w) to polymer gels and films as reinforcing agents. Significant changes in mechanical properties, especially maximum load and tensile strength, were obtained for fibrils derived from several cellulosic sources, including cotton, softwood, and bacterial cellulose. For extruded starch plastics, the addition of cotton-derived microfibrils at 10.3% (w/w) concentration increased Young’s modulus by 5-fold relative to a control sample with no cellulose reinforcement. Preliminary data suggests that shear alignment significantly improves tensile strength. Addition of microfibrils does not always change mechanical properties in a predictable direction. Whereas tensile strength and modulus were shown to increase during addition of microfibrils to an extruded starch thermoplastic and a cast latex film, these parameters decreased when microfibrils were added to a starch–pectin blend, implying that complex interactions are involved in the application of these reinforcing agents.     

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.     

Does Soil Acidification Affect Spruce Needle Chemical Composition and Tree Growth?

In 1994, a large survey of soil chemistry was undertaken in thecounty of Värmland in central Sweden (Lundström et al., 1998).The southern part of the county was affected by soilacidification whereas there were no such indications in thenorthern part. To investigate the influence of soil chemistryon the trees at the specific sites, the survey was continued byan analysis of needle chemistry (Norway spruce) which wasundertaken at 150 of the 180 sites, and of tree growth at 65 ofthe 180 sites. Growth was expressed as a ratio between expectedgrowth, estimated with a national, empirical growth model, andthe growth observed in the field. In statistical analyses,using rank correlation, PCA and PLS, there were only weakindications of an influence of soil chemistry on needlechemistry and on tree growth. A moderate correlation betweennitrogen and sulphur in needles was found, which wasinterpreted as an effect of deposition and of processes in thetree canopy. No obvious regional pattern of the growth ratiowas found, in contrast to the clear pattern of soilacidification. The statistical analysis could not with anycertainty point out any of the soil chemistry variables asespecially important for the tree growth ratio.