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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 总被引:3,自引:1,他引:2
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。 相似文献
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耐高温反渗透膜在化工废水处理中的应用 总被引:1,自引:0,他引:1
以某化工工艺废水的超滤出水为原水,采用耐高温反渗透膜进行处理,考察了操作压力、废水pH、膜面流速及废水总铁质量浓度对耐高温反渗透膜产水通量及脱盐率(以电导率减小率计,下同)和TOC去除率的影响。实验结果表明,在操作压力为0.24 MPa、废水pH为7.60、膜面流速为2.0 m/s的最佳条件下运行4 200 min后,产水通量衰减约73%,反渗透系统的脱盐率为95%~97%,TOC去除率为83%~95%,出水电导率在50μs/cm左右,出水TOC为21~23 mg/L。 相似文献
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生物絮凝法与化学絮凝法处理洗毛废水的比较 总被引:1,自引:1,他引:0
分别采用生物絮凝法和化学絮凝法处理300 mL COD为20 000 mg/L、SS为4 000 mg/L的洗毛废水,最佳生物絮凝条件:生物絮凝剂加入量为5 mL,反应温度为30℃,先以120 r/min搅拌5 min、再以60 r/min搅拌35 min,洗毛废水pH为9.0.COD去除率达92%.最佳化学絮凝条件:化学絮凝剂加入量为30 mL,反应温度为40℃,先以120 r/min搅拌5 min、再以60 r/min搅拌25 min,洗毛废水pH为5.0.COD去除率达93%.生物絮凝剂和化学絮凝剂对洗毛废水的絮凝效果接近,但生物絮凝剂的加入量比化学絮凝剂少很多. 相似文献
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用水解酸化池-膜生物反应器处理活性艳红X-3B废水 总被引:1,自引:0,他引:1
采用水解酸化池-膜生物反应器处理含活性艳红X-3B的模拟废水,研究了水力停留时间(HRT)对水解酸化池废水处理效果的影响,考察了水解酸化池-膜生物反应器对废水的处理效果及膜生物反应器中污泥沉降性能对膜污染的影响。实验结果表明:水解酸化池HRT为16h时,废水的可生化性最好,挥发性脂肪酸质量浓度与COD比值为0.5;HRT为17h时,废水脱色率达69%,而COD的去除率受HRT影响较小;膜生物反应器主要起去除废水中COD的作用;水解酸化池-膜生物反应器处理后废水的脱色率和COD去除率分别为83%和97%;膜生物反应器中活性污泥沉降性能的变化直接影响膜污染的速率。 相似文献
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改性双氰胺-甲醛絮凝脱色剂的制备与应用 总被引:7,自引:0,他引:7
通过在原料中引入尿素,合成出了改性双氰胺-甲醛絮凝脱色剂,并应用到印染废水处理中。采用正交实验方法确定了最佳合成条件,实验结果表明,在反应温度65℃、反应时间3h、反应物配比n(双氰胺):n(尿素):n(氯化铵):n(甲醛)为0.714:0.286:0.9:1.4的最佳条件下,改性双氰胺-甲醛絮凝脱色剂具有优异的絮凝脱色性能,对实际印染废水的脱色率和COD去除率可分别达到99%和93.4%。 相似文献
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George Ice Liz Dent Josh Robben Pete Cafferata Jeff Light Brian Sugden Terry Cundy 《Water, Air, & Soil Pollution: Focus》2004,4(1):143-169
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. 相似文献
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Hysteresis in Reversal of Central European Mountain Lakes from Atmospheric Acidification 总被引:2,自引:0,他引:2
Kopáček Jiří StuchlÍk Evžen Veselý Josef Schaumburg Jochen Anderson Iris C. Fott Jan Hejzlar Josef Vrba Jaroslav 《Water, Air, & Soil Pollution: Focus》2002,2(2):91-114
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. 相似文献
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Stuchlík E. Appleby P. Bitušík P. Curtis C. Fott J. Kopáček J. Pražáková M. Rose N. Strunecký O. Wright R. F. 《Water, Air, & Soil Pollution: Focus》2002,2(2):127-138
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. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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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。 相似文献
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Elisângela Corradini Syed H. Imam José A. M. Agnelli Luiz H. C. Mattoso 《Journal of Polymers and the Environment》2009,17(1):1-9
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. 相似文献
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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. 相似文献