邻氨基苯甲醚的清洁生产工艺

采用清洁生产的理论与思维模式,对合成邻氨基苯甲醚的传统工艺进行了改造,开发出以质量分数5％的Pd／C为催化剂、加氢制备邻氨基苯甲醚的清洁生产工艺。最佳生产工艺条件为：100g邻硝基苯甲醚中加入0．9g催化剂、溶剂与邻硝基苯甲醚的质量比0．75、反应压力0．7MPa、反应温度80℃。与传统的硫化钠还原工艺相比,该工艺使反应时间由6h缩短到1．75h,产品收率由90．5％提高到93．8％,解决了原工艺产生大量含硫废水的问题,每吨产品的生产成本可降低1650元。     

铜铈复合金属氧化物催化剂催化分解N2O

以蜂窝陶瓷为载体,采用浸渍法制备了负载型铜铈复合金属氧化物催化剂.研究了n(Cu):n(Ce)、活性组分负载量、焙烧温度及O2气氛对催化剂分解N2O活性的影响.实验结果表明:CeO2的掺入可以明显提高CuO催化剂催化分解N2O的活性,当n(Cu):n(Ce)=1:1时,N2O分解率最高,反应温度为500 ℃时,N2O分解率达85.8％;对于n(Cu):n(Ce)=1:1的催化剂,最佳活性组分负载量为18％,最佳焙烧温度为500 ℃;当反应气氛中有O2存在时,会抑制催化分解N2O反应的进行.     

用废杂铜制备碱式碳酸铜

以废杂铜为原料,用稀硝酸浸出硝酸铜溶液,与碳酸氢钠反应得到碱式碳酸铜粗品,漂洗后得到高纯度碱式碳酸铜。实验结果表明,废杂铜与质量分数为30％的硝酸反应,开始比较平缓,后期反应剧烈,有少量红棕色的NO：生成,采用碱液吸收方式处理生成的NO：可减少其对大气的污染。碳酸氢钠与硝酸铜进行合成反应,反应温度50～80℃,反应液pH6．5～7．0,产品中铜的质量分数为55％-56％,产品质量较好。     

臭氧氧化法制备晶体乙醛酸的清洁生产工艺

以顺丁烯二酸酐为原料、水为溶剂，用臭氧氧化法制备晶体乙醛酸的最佳条件为：反应时间8h，反应温度30℃，顺丁烯二酸质量分数30％。减压蒸馏出的甲酸水溶液可循环利用。中试试验结果表明，合成的晶体乙醛酸中乙醛酸的质量分数为97．2％～97．7％，达到了市售工业乙醛酸的要求。晶体乙醛酸的收率为95．5％-96．1％，熔点为51～53℃，用红外光谱技术对其结构进行表征的结果表明，晶体乙醛酸的红外谱图与乙醛酸标准谱图基本吻合。该工艺过程无三废污染，可实现清洁生产。     

制备条件对Mn-Fe/TiO2催化剂低温脱硝性能的影响

通过浸渍法制备了一系列Mn-Fe/TiO2催化剂,并采用XRD技术对其进行了表征,考察了锰前体种类、负载量（活性组分质量占载体质量的百分比）、Fe含量（Fe物质的量占活性组分物质的量的百分比）、焙烧温度等因素对催化剂低温选择性催化还原NO性能的影响。实验结果表明：以乙酸锰为前体制备的催化剂的脱硝活性明显高于以硝酸锰为前体制备的催化剂;负载量的增加有利于脱硝活性的提高,而Fe的添加对提高催化剂的活性有重要作用,但Fe含量超过15%后,对催化剂脱硝性能的影响并不明显;焙烧温度超过650 ℃时会使活性组分的结晶度提高,导致脱硝活性的降低。在锰前体为乙酸锰、负载量为15%、Fe含量为15%、焙烧温度为500 ℃、焙烧时间为6 h、反应温度为200 ℃的条件下,Mn-Fe/TiO2催化剂的NO转化率约为95%。     

蚀刻液水合肼还原除铜

将电路板厂废弃的蚀刻液,经氢氧化铜沉淀法回收大部分铜后,再采用水合肼还原,进一步除铜。反应温度为50℃,水合肼质量分数为3．0％,溶液pH为6．0,废液中铜的去除率可达98.5％,处理后废液中铜的质量浓度低于0．2g／L,可作为碱性蚀刻液重复利用。     

废变换催化剂中铬和铁的回收利用

一氧化碳变换催化剂广泛应用于合成氨及制氢工业中。催化剂由于中毒、粉化、衰老等原因失去活性,需要经常更换。以中温变换催化剂为例,我国每年生产约２万ｔ用以更换失效的催化剂。更换出的催化剂未经任何处理就排弃掉,其中的铬会对环境造成污染。消除废变换催化剂的铬污染,使废催化剂变废为宝,是一项有重要意义的工作。目前国内已有无铬催化剂的试验报道,尚没有废变换催化剂处理的报道。本文简要介绍我们进行的从废变换催化剂中回收铬和铁用于制造新变换催化剂的试验研究结果。１　试验方法一氧化碳变换催化剂主要由铁、铬的氧化物组…     

废油脂制备生物柴油的清洁生产工艺

在固定床反应器中，采用自制固体催化剂催化废油脂与甲醇发生酯交换反应制备生物柴油。最佳反应条件为：甲醇与废油脂摩尔比6，液态空速2h，反应温度290℃。废油脂预处理简单，酸值为180mg／g时，生物柴油的产率可达85％。所制备的，仨物柴油各项物性数据均符合我国轻柴油的标准，也完全达到德国和美国生物柴油的指标要求。该生物柴油制备方法属清洁生产工艺，无废水产生。     

利用含铜蚀刻废液生产碱式碳酸铜

介绍了利用含铜蚀刻废液生产碱式碳酸铜的生产工艺、技术特点、工艺流程和产品质量。以碳酸钠作蚀刻废液的除杂剂,对其进行除杂前处理,控制反应液的pH为3．5～4．0、反应液中碳酸钠的浓度为0．02～0．03mol／L。可除去其中大部分杂质。用碳酸钠与含铜溶液中的铜进行合成反应,控制反应温度为70～80℃、pH为8～9、碳酸钠和含铜溶液中铜的浓度均为1mol／L,反应生成碱式碳酸铜,此产品中铜的质量分数为56％,产品质量优于木材防腐用碱式碳酸铜国内外同类产品。     

气体中硫化氢催化焚烧催化剂的制备和性能研究

考察了制备方法对催化剂活性的影响，评价了活性组分的添加量，操作温度和空速对催化剂活性和选择性的影响，在温度290℃，空速5000h^-1条件下，催化剂连续使用200h性能稳定，H2S转化率为SO2生成率在99．9％以上，该催化剂具有优良的性能，适合在硫化氢焚烧装置上使用。     

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.     

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.     

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.     

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.     

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。     

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.