铬渣资源化处理的零排放工艺

采用氧化—还原法对某钢厂的粗铬渣进行提纯回收，对各项工艺参数进行了优化，探讨了铬渣零排放处理工艺的可行性。实验结果表明：在氧化温度80 ℃、氧化时间1.5 h、双氧水加入量2.35 mL/g（以铬渣计），还原时间15 min、还原pH 1.5、NaHSO₃加入量0.445 g/g（以铬渣计），沉淀pH 8.0，煅烧温度1 050 ℃、煅烧时间1 h的条件下，所得废渣的w（Cr）为1.29%，回收铬绿产品的w（Cr₂O₃）为97.20%，铬回收率为94.40%;处理后废水的ρ（总铬）约为0.06 mg/L，低于GB 13456—2012《钢铁工业水污染物排放标准》中规定的1.50 mg/L，既可作为循环用水，也可排放;处理后废渣中含大量硅元素，可作为生产水泥发泡节能砖或砌块的原料;整个回收过程清洁无污染，零排放，且具备一定的盈利空间。     

利用含铬污泥制备微晶玻璃关键技术开发

开发了冷轧含铬污泥中温脱硫保铬预处理工艺以及利用含铬污泥制备CaO-MgO-Al2O3-SiO2(CMAS)系统微晶玻璃的工艺,研究了晶核剂对微晶玻璃的物相、显微结构及性能的影响。所开发的工艺过程清洁环保,制品力学性能好、无浸出毒性。本技术不但实现了含铬污泥无害化处理,还发挥了污泥的资源价值,为冷轧含铬污泥的厂内安全低成本处置提供了技术解决方案。     

氯化焙烧法回收铬渣中的铬

以CaCl2为氯化剂,碳粉为还原剂,采用氯化焙烧—盐酸浸取的方法处理铬渣,铬渣中的铬以CrCl3的形式被回收。在m(铬渣)∶m(碳粉)为10∶2.0、m(CaCl2)∶m(铬渣)为0.4、焙烧温度为1 200℃、焙烧时间为50min的条件下,Cr(Ⅲ)回收率为91.2%。采用本方法处理1g铬渣可回收CrCl3约0.033g。     

炼油废水污泥脱水工艺条件的优化

采用化学除油降黏—污泥调理—离心脱水工艺处理某炼油厂废水处理系统的混合污泥，并对工艺条件进行优化。实验结果表明，最佳的工艺条件为：化学除油降黏阶段处理体系的pH=4，反应温度35 ℃，H₂O₂加入量 2 g/L，m（H₂O₂）∶ m（Fe²⁺）=4，反应时间 60 min；污泥调理反应阶段的CaO加入量7.0 g/L；离心脱水阶段在分离因数为1 558时脱水5 min。在此条件下，得到的泥饼的含水率为70.0%~75.0%（w），含油率小于2%（w），污泥比阻约为3.0×10⁷ s²/g。     

阴极射线管锥玻璃碱性浸出渣制备泡沫玻璃

以废弃的阴极射线管锥玻璃碱性浸出渣及屏玻璃混合粉末为原料烧制泡沫玻璃。考察了发泡温度、屏玻璃加入量、发泡剂种类、发泡剂加入量、稳泡剂添加量对所制备的泡沫玻璃密度及抗压强度的影响。实验结果表明：在发泡温度800 ℃、屏玻璃加入量50%（w）、稳泡剂硼酸加入量5%（以锥玻璃碱性浸出渣及屏玻璃粉末总质量为基准,下同）、发泡剂SiC加入量15%最佳条件下烧制的泡沫玻璃密度达417 kg/m³,抗压强度达1.09 MPa,可满足建筑用泡沫玻璃的Ⅳ型物理性能指标。本实验烧制的泡沫玻璃的Pb浸出量为1.27 mg/L,Ba浸出量为0.06 mg/L,均满足固体废物的浸出毒性标准。     

含铬（Ⅵ）废水治理新工艺

探索用活性粉煤灰处理含铬（Ⅵ）废水新工艺，探讨在不同条件下处理含铬（Ⅵ）废水的效果。实验结果表明：在pH＝2.00、铬（Ⅵ）含量为19．4mg·L－1，加入活性粉煤灰0．167L·g－1时，处理后水样中铬（Ⅵ）已检不出。同样在pH＝1.50，铬（Ⅵ）含量为40．1mg·L－1，加入活性粉煤灰达0．0667L·g－1时，铬（Ⅵ）去除率可达100％。     

锰矿浸渣中水溶性锰的回收

采用水洗—生石灰沉淀法回收锰矿浸渣中的水溶性锰，考察了液固比、水洗时间对锰矿浸渣中水溶性锰洗出率（洗出液与锰矿浸渣中水溶性锰的质量比）的影响，并探讨了n（生石灰）∶n（水溶性锰）、聚丙烯酰胺絮凝剂加入量、反应温度和反应时间对洗出液中水溶性锰回收率（沉淀与洗出液中锰的质量比）的影响。实验结果表明：水洗工段，在去离子水体积（mL）与锰矿浸渣质量（g）比为5∶1、水洗时间5 min的条件下，水溶性锰洗出率达到92%;生石灰沉淀工段，n（生石灰）∶n（水溶性锰）对水溶性锰回收率的影响最大，其次为反应温度、絮凝剂加入量和反应时间，在n（生石灰）∶n（水溶性锰）=1.8、絮凝剂加入量0.2 mg/L、常温、反应时间10 min的条件下，水溶性锰回收率达90%以上;锰矿浸渣中水溶性锰的总回收率达83%以上。     

絮凝沉淀-Fenton试剂氧化法处理含高浓度硫酸盐的洗涤剂生产废水

采用絮凝沉淀-Fenton试剂氧化法处理含高浓度硫酸盐的洗涤剂生产废水（简称废水），考察了各种因素对COD去除率的影响。实验结果表明：根据实际废水的水质情况，选用聚合氯化铝（PAC）为絮凝剂，PAC最佳加入量为0．3g／L，经絮凝处理后COD去除率为42．3％；Fenton试剂氧化的最佳操作条件为：n（H2O2）：n（Fe^2＋）=0．5、H2O2加入量为7mmol／L、反应时间为2h，不调节废水初始pH，经Fenton试剂氧化处理后COD去除率为70％以上。经絮凝沉淀-Fenton试剂氧化法处理后，废水COD由1950mg／L降至240mg／L，总的COD去除率为87．7％，废水处理效果良好。     

用废镍铝合金粉制备镍催化剂

研究了以废镍铝合金粉（废镍渣）为原料、H2SO4为浸出剂、尿素为沉淀剂制备镍催化剂的方法；考察了Ni浸出条件对其浸出率的影响，并通过催化加氢实验对镍催化剂的活性进行了评价。Ni的浸出条件：w（H2SO4）25％、酸浸时间3h、n（废镍渣）：n（H2SO4）=1．0：1．4。在该条件下，Ni的浸出率为92．85％。Ni的回收率在90％以上。催化加氢实验结果表明，在温度120～125℃、压力大于或等于1．2MPa、催化剂用量1％（质量分数）的条件下，可将异丙叉丙酮经一步液相催化加氢反应制备成甲基异丁基甲醇（MBC），异丙叉丙酮转化率为100％，MIBC的收率达99．3％。     

利用铬渣制备重铬酸钠

研究了采用焙烧—硫酸酸化法利用铬渣制备重铬酸钠的工艺.通过L16(44)正交实验得出铬渣焙烧—浸出的最佳工艺条件为:焙烧温度1 000℃,m(碳酸钠)∶m(铬渣)=0.18,液固比4,焙烧时间8h.在此条件下Cr(Ⅵ)回收率为99.3％.硫酸酸化制备重铬酸钠的最佳工艺条件为:浸出液pH为6.6,酸化液pH为3.5,浓缩液中重铬酸钠质量分数为83.1％.此条件下制备的产品重铬酸钠结晶率为44.5％,纯度为99.5％,符合GB1611-92《工业重铬酸钠》的一等品质量标准.处理1t铬渣可制备重铬酸钠约120 kg,增加收入660元.     

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.