改性淀粉的合成及其对重金属离子的捕集效果

以玉米淀粉为原料，经过交联、间接醚化、胺化以及cs：亲核加成反应，得到二硫代氨基甲酸基（DTC）改性淀粉（DTCS），并对其合成条件进行优化；考察了交联度、醚化温度、氯含量及胺化剂对DTCS捕集重金属离子效果的影响。优化后的DTCS合成条件：交联淀粉（CS）沉降积为30—34mL，醚化温度为80℃，氯质量分数为7．82％，胺化剂为二乙烯四胺。实验结果表明，DTCS对Cu^2＋，Pb^2＋，Zn^2＋，Cd^2＋，Ni^2＋均有较好的去除效果，其对Cu^2＋，Pb^2＋，Zn^2＋，Cd^2＋，Ni^2＋的饱和吸附量分别为0．85，0．83，0．65，0．74，0．47mmol／g。     

阳离子淀粉-丙烯酰胺接枝共聚物絮凝剂的制备及其絮凝性能

研究了阳离子淀粉与丙烯酰胺接枝共聚反应制备阳离子型絮凝剂的工艺，并用硅藻土悬浊液及实际水样对产物的絮凝性能进行了考察。其最佳合成条件：阳离子淀粉与丙烯酰胺的质量比为1：4，引发剂加入量为丙烯酰胺质量的0．1％，反应温度50℃，反应时间3h。絮凝效果实验中，接枝共聚物絮凝剂的最佳加入量为4mg／L。与阳离子淀粉和阳离子聚丙烯酰胺絮凝剂相比，接枝共聚物絮凝剂对渭河水及造纸网下白水的絮凝效果更好。     

经济型阳离子淀粉絮凝剂的制备及其对印染废水的处理效果

采用玉米淀粉为原料、氯化缩水甘油三甲基铵（GTA）作阳离子化试剂、水-乙醇混合液作分散剂、NaOH作碱催化剂，制备了经济型阳离子淀粉絮凝剂（简称经济型阳离子淀粉）。实验结果表明：在淀粉加入量110g、GTA加入量30g、NaOH加入量1．6g、分散剂中m（水）：m（乙醇）=1：1、m（分散剂）：m（淀粉）=0．50：1、反应温度80℃、反应时间2．5h的条件下，可制得取代度（DS）为0．31的经济型阳离子淀粉；用该经济型阳离子淀粉与聚丙烯酰胺（PAM）联用处理印染废水，当经济型阳离子淀粉加入量为140mg／L、PAM加入量为4mg/L、废水pH为8时，印染废水的色度去除率和COD去除率分别达92％和82％。该方法絮凝效果好，药剂费用低，产生的污泥少。     

一种新型聚合物分散剂的制备及表征

以甲基丙烯酸和丙烯磺酸钠为单体、过硫酸铵溶液为引发剂合成聚合物分散剂（PMS）。最佳合成条件：单体总质量为60g，甲基丙烯酸和丙烯磺酸钠的摩尔比为3．0，过硫酸铵溶液加入量为12g，亚硫酸氢钠加入最为1g，反应温度为75℃。对最佳条件下制得的PMS进行应用实验，当100g陶瓷氧化铝粉末中PMS加入量为0．5g时，浆料的黏度较小，分散效果良好。PMS属于非品态聚合物，热稳定性良好，相对分子质量为2127。     

环保型脲醛树脂胶粘剂的合成研究

介绍了聚乙烯醇(PVA)、三聚氰胺在脲醛树脂胶粘剂合成过程中所起的改性作用,研究了反应温度、反应体系pH、甲醛与尿素摩尔比、PVA和三聚氰胺用量对脲醛树脂胶粘剂性能的影响。试验结果表明,在反应温度为80℃、反应体系pH为5．0、甲醛与尿素摩尔比为1．5、PVA和三聚氰胺用量分别为尿素与甲醛溶液总质量的1．0％和5％的条件下,合成的脲醛树脂胶粘剂的剪切强度为2．99MPa,游离甲醛的质量分数由传统工艺生产产品的0．6％～0．8％降低至0．063％,耐沸水时间为108min,且贮存稳定性好,达到了HJBZ-1998国家环境标志产品技术要求。     

化学沉淀与高级氧化法处理乙烯裂解废碱液的研究

采用化学沉淀与高级氧化(UV／H2O2)法去除乙烯裂解废碱液中的硫化物及有机物。考察了影响效果的各种因素。试验结果表明：化学沉淀在反应温度为20℃、反应时间为30min、CuO与Na2S的摩尔比为1．45：1;高级氧化反应温度为40℃、反应时间为120min、H2O2的加入量(H202／COD质量比)为0．8的条件下,废碱液中S^2-的去除率可达98％以上,COD总去除率可达87％,BOD5／COD由处理前的0．21提高至0．54。     

交联阳离子淀粉的合成及其对重金属离子的吸附

通过正交实验合成了取代度为0．568的交联阳离子淀粉。考察了溶液pH、螯合剂用量、重金属离子初始浓度对交联阳离子淀粉去除重金属离子效果的影响。当重金属离子初始质量浓度为50mg／L、螯合剂投加量为0．5g／U时,Pb^2 ,Cu^2 ,Cr^3 在溶液pH为6时的去除率达到最高,分别为97．94％,99．46％,84．30％,而Cd^ 在溶液pH为7时的去除率达到最高,为99．36％。实验结果表明,交联阳离子淀粉是一种有效去除废水中重金属的处理剂。     

衣康酸/苯乙烯磺酸共聚物的合成及其阻垢性能研究

以衣康酸(IA)和苯乙烯磺酸(SSA)为原料,合成IA／SSA共聚物阻垢剂,确定的最佳合成条件：反应温度为103℃,反应时间为2h,引发剂用量为7％(占单体总质量),IA：SSA质量比为2．8：1。在此工艺条件下合成的IA／SSA共聚物阻垢剂,其阻碳酸钙垢的阻垢率可达99％。     

改性多孔淀粉对Cu2+的捕集性能

以玉米淀粉为原料,采用糖化酶和α-淀粉酶复合酶解制成多孔淀粉,多孔淀粉经交联、间接醚化、胺化、黄原酸酯化反应得到二硫代氨基甲酸基改性多孔淀粉(DTCPS)重金属捕集剂.研究了DTCPS对Cu2+的捕集性能.实验结果表明:制得的多孔淀粉的比表面积为1.264 5 m2/g,比玉米淀粉的比表面积增大了138.5%;制得的多孔淀粉是一种中孔淀粉;Cu2+溶液pH为1-5时,DTCPS的Cu2+饱和捕集量均较高;Cu2+初始质量浓度为0～70 mg/L时,DTCPS对Cu2+的捕集性能很好,溶液中Cu2+的剩余质量浓度低于0.12 mg/L,Cu2+的去除率达99%以上.DTCPS对Cu2+的捕集性能明显优于二硫代氨基甲酸基改性淀粉(DTCS).     

利用钛白生产中的副产物制备聚合硫酸铁

以化工厂钛白副产物七水硫酸亚铁为原料，用过氧化氢作氧化剂，合成了絮凝剂聚合硫酸铁。研究结果表明：硫酸亚铁与过氧化氢的摩尔比达到1：0．6时，硫酸亚铁可完全被氧化；硫酸亚铁与浓硫酸的摩尔比为1:0.4时，制取的聚合硫酸铁可获得较高的碱化度。通过对产品絮凝性能的研究发现，自制聚合硫酸铁对人工模拟水样有较高的除浊率，与阳 离子高分子CPF－110絮凝剂配合使用，可达到相同的除浊效果，且投药量显著减少。     

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.     

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.     

我国电子废物回收处理产业政策及机遇与挑战分析

针对近年我国频繁出台的电子废物回收处理产业政策,系统论述了其发展脉络,并从循环经济角度出发,分析了我国电子废物产业发展的主体思路,同时还对我国电子废物回收处理产业发展机遇与存在的问题进行剖析,对如何稳定企业的电子废物来源、提升产业技术水平及降低企业运营成本进行建议性分析。     

Effect of Coconut, Sisal and Jute Fibers on the Properties of Starch/Gluten/Glycerol Matrix

Coconut, sisal and jute fibers were added as reinforcement materials in a biodegradable polymer matrix comprised of starch/gluten/glycerol. The content of fibers used in the composites varied from 5% to 30% by weight of the total polymers (starch and gluten). Materials were processed in a Haake torque rheometer (120 °C, 50 rpm) for 6 min. The mixtures obtained were molded by heat compression and further characterized. Addition of lignocellulosic fibers in the matrix decreased the water absorption at equilibrium. The diffusion coefficient decreased sharply around 5% fiber concentration, and further fiber additions caused only small variations. The thermogravimetric (TG) analysis revealed improved thermal stability of matrix upon addition of fibers. The Young’s modulus and ultimate tensile strength increased with fiber content in the matrix. The storage modulus increased with increasing fiber content, whereas tanδ curves decreased, confirming the reinforcing effect of the fibers. Morphology of the composites analyzed under the scanning electron microscope (SEM) exhibited good interfacial adhesion between the matrix and the added fibers. Matrix degraded rapidly in compost, and addition of increased amounts of coconut fiber in the matrix caused a slowdown the biodegradability of the matrix. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may be suitable.     

Nitrous oxide emission from some English and Welsh rivers and estuaries

Nutrient and N₂O concentrations in the water columns were measured seasonally over a full salinity range in the nutrified rivers Colne, Stour, Orwell, Deben, Trent, Ouse and Humber and their estuaries on the east coast of England between August 2001 and May 2002, and in the oligotrophic rivers Conwy, Dovey and Mawddach in North and West Wales between August 2002 and May 2003. Nutrient and N₂O concentrations in the nutrified English rivers and estuaries were much higher than those in the Welsh rivers. N₂O concentrations and % saturation in the estuaries were significantly correlated with nitrate, nitrite and ammonium concentrations in the water. The strongest correlation was with nitrite (r² = 0.56, p < 0.01), suggesting that nitrite was the most significant factor among the different nutrients in regulating N₂O concentration in the estuaries. N₂O concentrations in the English rivers and estuaries were supersaturated throughout the year with annual averages from 186.9 to 992.9%, indicating that these rivers and estuaries were sources of atmospheric N₂O, whereas in the Welsh rivers N₂O concentrations were much lower with annual averages from 113.6 to 137.4% saturation. Although the estuarine area in the Colne was almost the same as that in the Conwy, the annual N₂O emission from the Colne was much higher (937498 mol N yr^–1) than in the Conwy (23020 mol N yr^–1). On the east coast, riverine emissions of N₂O were only 0.5–12.5% of the total emission from rivers and estuaries. Thus rivers were negligible, but estuaries were significant contributors to the UK N₂O inventory.     

Trends in Fish Community Structure,Biomass, and Production in Three Algoma,Ontario, Lakes

Long-term (i.e. >10 years) whole community fish dataincluding catch-per-unit-effort, abundance, biomass, andproduction from three lakes were used: 1) to examine variabilityin fish population and community measures among years using wholelake assessments of fish populations derived from mark recaptureexperiments, 2) to assess implications arising from monitoringindividual species vs. the whole fish community, and 3) toascertain whether, in fisheries assessments (science) a commonlyused surrogate measure, [catch-per-unit-effort (CPUE)] reflectedannual changes in the fish assemblage, and thus may be a goodestimator of abundance. High, long-term variability was evident in the abundance andbiomass of a fish species in our lakes, yet the communityremained relatively stable in terms of its biomass andproduction. Changes in total fish community biomass appear drivenby large species, which, relative to small fish species, remainstable among years. Among years, species richness remainedstable; however, fish species changed in the community. AnnualCPUE was found to be a suitable surrogate for abundance (N) ofsmall fishes; CPUE x mean weight of the catch (bCPUE) was asuitable surrogate for biomass (B) of large fishes. Prior toconcluding that a change in a fish population has occurred as aresult of a stressor, care must be taken to critically examinethe level of population assessment in order to avoid acceptingpotentially invalid conclusions.