美国加强对ODS的控制

美国加强对ＯＤＳ的控制产业环境，２２［６］，７２（１９９３）根据新修订的大气清洁法，美国从１９９３年５月起加强对能破坏臭氧层物质（ＯＤＳ）的控制。凡生产ＯＤＳ的企业和含ＯＤＳ的制品必须附有ＯＤＳ标签，说明该制品使用了ＯＤＳ，并要制定ＯＤＳ废除的具体日...     

臭氧氧化法处理染料中间体1－氨基蒽醌和DSD酸生产废水

采用臭氧氧化法处理染料中间体１－氨基蒽醌和ＤＳＤ酸生产废水，能改善废水的可生化性，降低废水中有机物的水溶性，提高混凝处理的效率。研究结果表明，在原水ｐＨ条件下，当臭氧投加量为７．５ｇ／Ｌ时，ＤＳＤ酸氧化母液脱色率大于９０％，ＢＯＤ＿５／ＣＯＤ达到０．３。当臭氧投加量为６ｇ／Ｌ时，１－氨基蒽醌废水的ＢＯＤ＿５／ＣＯＤ达到０．３。１－氨基蒽醌废水经投加量为２．５ｇ／Ｌ的臭氧处理后，再进行两级混凝处理（ＦｅＳＯ＿４的投加量分别为５．０ｇ／Ｌ和１．０ｇ／Ｌ），ＣＯＤ和色度的去除率可分别达到９０％和９３％。     

臭氧氧化法处理染料中间体1—氨基蒽醌和DSD酸生产废水

采用臭氧氧化法处理染料中间体１－氨基蒽醌和ＤＳＤ酸生产废水，能改善废水的可生化性，降低废水中有机物的水溶性，提高混凝处理的效率。研究结果表明，在原水ＰＨ条件下，当臭氧投加量为７．５ｇ／Ｌ时，ＤＳＤ酸氧化母液脱色率大于９０％，ＢＯＤ５／ＣＯＤ达到０．３。当臭氧投加量为６ｇ／Ｌ时，１－氨基蒽醌废水的ＢＯＤ５／ＣＯＤ达到０．３。１－氨基蒽醌废水经投加量为２．５ｇ／Ｌ的臭氧处理后，再进行两级混凝处理，ＣＯ     

BOD5的应用与污水可生化性的判别

对水质参数ＢＯＤ５进行讨论，认为ＢＯＤ５仅反映污水排入水体后的耗氧状况，不反映污水本身的水质特性。建议采用可生化化学需氧量描述污水特性，以ＤＯＤＢ／ＣＯＤ作为判别污水可生化性指标，提出了测定ＣＯＤＢ的方法。     

消除DPD法测定水中臭氧浓度干扰因素的研究

研究了Ｈ_２Ｏ_２和其它氧化剂（以过氧化苯甲酰为例）对ＤＰＤ法测定水中臭氧浓度的干扰作用，结果表明，随着ＫＩ浓度或显色时间的增加，Ｈ_２Ｏ_２和其它氧化剂的干扰作用增加，当ＫＩ浓度为０．５ｇ／Ｌ时，可以基本消除这些干扰作用，且当臭氧浓度低于０．６ｍｇ／Ｌ时，不影响臭氧对ＤＰＤ的显色作用。     

生物接触氧化法处理甲胺磷生产废水

甲胺磷生产过程中排出的甲基氯化物废水,含盐量高（质量分数为１８％～２０％）,可生化性较差（ＢＯＤ／ＣＯＤ为０．１）,一般认为不宜直接进行生化处理。曾有农药厂采用低压酸性水解和湿式氧化等方法对其进行预处理,然后再进行生化处理,由于成本高或设备腐蚀等问题...     

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。     

土壤残留塑料的热降解脱附研究

针对土壤的塑料污染问题,提出一种采用热脱附降解技术修复污染土壤的方法。选取4种土壤中常见的残留塑料（聚乙烯（PE）、聚氯乙烯（PVC）、聚对苯二甲酸乙二酯（PET）、聚丙烯（PP））为研究对象,通过控制热解温度和土壤含水率对各污染土壤的修复效果进行探究。实验结果表明：在500 ℃的最佳热解温度下处理60 min,PE、PVC、PET和PP的去除率分别达到92.61%、91.73%、90.74%和93.42%;土壤含水率低于16%时对修复效果的影响不显著。表征结果显示,500 ℃热解后土壤中残留有机成分已得到充分挥发,热解油的主要组分为烷烃。     

AO1O2工艺处理染色废水

报导了豆腐营工业区污水集中控制示范工程，采用水解酸化（Ａ）－接触氧化（Ｏ１）－合建式氧化沟（Ｏ２）净化组合工艺处理染色废水的运行情况。该工艺具有处理效果好、运行稳定、投产快、操作管理简便、占地少、投资省、处理成本低等优点。     

化工废水CODCr与BOD5的相关关系和BOD5的快速计算

化工废水的ＣＯＤ与ＢＯＤ５之间具有相关性，存在着线性关系。在生产稳定的情况下，只需测定ＣＯＤＣｒ就可根据线性回归方程迅速计算出ＢＯＤ５。此值和实际值相比，相对误差≤±１０％。该方法省时，可用于生产控制。     

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.