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％。     

萃取法处理萤光废水

采用萃取法处理萤光废水，最佳萃取工艺条件如下：ｐＨ为１，废水：萃取剂：稀释剂为２０：２：５。在此工艺条件下，萤光废水ＣＯＤ去除率可达９１％－９８％，色度去除率达９９．８％。萃取剂可再生回用，在萃取相中按萃取剂（包括络合物）的量加入等体积的浓度为２０％的ＮａＯＨ溶液，在９５－１０５℃加热回流５－１０ｍｉｎ，即可使萃取剂得到再生。     

废铁屑—H2O2法处理炼油厂含酚废水

用废铁屑作催化剂，Ｈ２Ｏ２作氧化剂，对炼厂汽提后含硫废水进行了除酚试验研究，考察了初始ＰＨ、Ｈ２Ｏ２投加量、废铁屑投加量对酚去除率的影响。对含酚量为３３１．５ｍｇ／Ｌ的废水，将其初始ＰＨ调至７．２，３０％Ｈ２Ｏ２的投加量为７．５ｍＬ／Ｌ，废铁屑的投加量为３－８ｇ／Ｌ，经２ｈ反应后，酚的脱除率可达９９．９％。     

多组分电镀污泥酸浸出液中铁的分离

研究了采用Ｐ５０７－煤油－Ｈ２ＳＯ４萃取体系分离电镀污泥酸浸出液中Ｆｅ＾３＋的工艺，确定了从含有多种上金属组分的硫酸溶液中萃取铁的最佳工艺条件以及负载有机相反萃取较优工艺条件，研究结果表明，以Ｐ５０７为萃取剂，硫酸为洗涤剂，经３级萃取、２级洗涤的分馏萃取后，可以从含有多种金属组分的硫酸溶液中分离出９９．９％的铁，其他金属的流失量小于１％，不影响后者的回收，铁在工艺过程中以ＦｅＣｌ３·６Ｈ２Ｏ的形式     

重力分离—NMC工艺处理对二氯苯生产废水

采用重力分离－ＮＭＣ（中和、混凝、吹脱）工艺处理对二氯苯生产废水，对工艺条件进行了选择试验，选定的最佳工艺条件为：废水静置分层时间５０－６０ｍｉｎ，中和至ＰＨ７，ＰＡＭ投加量５０－７５ｍｇ／Ｌ，空气流量１０ｌ／ｍｉｎ，反应温度５０－５５℃；反应时间６０ｍｉｎ。废水经处理后，苯和氯苯浓度可分别降至１．００ｍｇ／Ｌ和１．１０ｍｇ／Ｌ且可回收９０％以上的苯和氯苯。     

傅里叶变换红外光谱法测定废水中的酚

以三氯化碳萃取模拟含酚废水，再采用傅里叶变换红外光谱法（FTIR）测定废水中的酚含量。结果表明：废水中酚质量浓度大于100．0mg／L时，含酚废水与三氯化碳体积比为1：1，萃取效果最好，酚质量浓度测定的相对误差小于2％，检出限为11．95mg／L；废水中酚质量浓度为10．0～50．0mg／L时，含酚废水与三氯化碳体积比为10：1，萃取效果最好，酚质量浓度测定的相对误差小于5％，检出限为1．19mg／L。FTIR法的相对标准偏差平均为0．354％，加标回收率为101．7％～103．2％。采用FTIR法测定含酚工业废水中的酚质量浓度与GB7491-87《水质挥发酚的测定蒸馏后溴化容量法》测定结果非常接近。     

癸二酸生产中酚害治理——蓖麻油酸萃取中和液脱酚

本文采用外溢流-混合提升结构箱式萃取器,以蓖麻油酸为萃取剂,从癸二酸生产中和液中回收甲酚。改革了癸二酸的生产工艺,实现了酚的闭路循环,提高了产品质量和酚的回收率,改善了工作条件,减少了排入环境中的酚。     

缩合—电解法处理苯胺废水

采用缩合－电解法处理苯胺废水，缩合过程的最佳ＰＨ为５．０－６．０，甲醛的最佳投加量视废水中苯胺含量而定；电解过程中，ＮａＣｌ的最佳投加量为３％（ｗｔ），控制电解液ＰＨ为５．０－７．０、电解时间１２０－１４０ｍｉｎ、槽电压３Ｖ、电流密度０．９Ａ／ｄｍ＾２。在上述条件下，苯胺含量为１０００－１００００ｍｇ／Ｌ的废水经缩合－电解法处理后，ＣＯＤ＜２５０ｍｇ／Ｌ，苯胺＜０．１ｍｇ／Ｌ。     

含酚废水新型高效萃取处理设备及其应用

溶剂萃取法治理含酚废水已有很多年的历史 ,在工艺和设备方面已较为成熟。尽管如此 ,近年来对高效萃取设备的开发研究一直在不断进行中 ;在萃取剂方面 ,开发出新型络合萃取剂 ,可用于含酚废水的深度处理。传统塔式萃取设备因其级数的增加受到限制 ,应用受到挑战 ,而逐级操作的萃取设备水平布置级数不受限制 ,为含酚废水的深度处理创造了条件。我中心开发的圆筒式离心萃取器和混合澄清槽 ,为含酚废水的处理提供了新的有效设备。1　萃取设备1 .1　圆筒式离心萃取器　　圆筒式离心萃取器如图 1所示。转鼓置于有轻重两相收集室和进料管的外壳中 …     

湿式氧化法处理乐果废水

采用湿式氧化法对乐果生产废水进行预处理,氧化温度２３０－２４０℃,压力６．０－７．０ＭＰａ,废水停留时间１ｈ在此条件下,有机磷的去除率可达９５％以上,有机硫的去经可达８２％,废水经湿式氧化,回收磷酸盐后再经生化处理,保持ＣＯＤ与有机硫的比值大于２５：１,ＣＯＤ去除率可达９０％。     

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.     

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.     

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.