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1.
傅里叶变换红外光谱法测定废水中的酚   总被引:1,自引:1,他引:0  
以三氯化碳萃取模拟含酚废水,再采用傅里叶变换红外光谱法(FTIR)测定废水中的酚含量。结果表明:废水中酚质量浓度大于100.0mg/L时,含酚废水与三氯化碳体积比为1:1,萃取效果最好,酚质量浓度测定的相对误差小于2%,检出限为11.95mg/L;废水中酚质量浓度为10.0~50.0mg/L时,含酚废水与三氯化碳体积比为10:1,萃取效果最好,酚质量浓度测定的相对误差小于5%,检出限为1.19mg/L。FTIR法的相对标准偏差平均为0.354%,加标回收率为101.7%~103.2%。采用FTIR法测定含酚工业废水中的酚质量浓度与GB7491-87《水质挥发酚的测定蒸馏后溴化容量法》测定结果非常接近。  相似文献   

2.
研究了在聚乙二醇-200(PEG-200)活化下,Cu^2+催化H2O2氧化亚甲基蓝的褪色反应,建立了亚甲基蓝褪色催化动力学光度法测定痕量Cu^2+的方法。在25mL容量瓶中,加入1.00mL pH为11.68的氨水溶液、2.00mLH2O2溶液(质量分数15%)、1.00mL亚甲基蓝溶液(质量浓度0.20mg/mL)、3.00mL PEG~200溶液,76℃恒温反应5min后冷却,测定吸光度,根据加Cu^2+溶液和不加Cu^2+溶液的吸光度差值与Cu^2+质量浓度绘制了工作曲线,并由试样的吸光度差值确定痕量Cu^+含量。该法的测定波长为664nm,检出限为5.4×10^-6 g/L,最大相对标准偏差为2.58%,回收率为97.5%~104.5%。  相似文献   

3.
吴宏  张立新  赵长春 《化工环保》2007,27(6):576-578
采用流动注射在线富集分光光度法测定水样中痕量Cr(Ⅵ),考察了流路条件、显色条件和共存离子的影响。在H:SO。浓度为1.2mol/L、2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚溶液质量浓度为1.75g/L的条件下,试样富集4min,测定Cr(Ⅵ)的线性范围为0.01~0.60mg/L,检出限为3μg/L。连续10次测定质量浓度为0.20mg/L的Cr(Ⅵ)标准溶液相对标准偏差为0.4%。方法可应用于河水和工业废水中痕量Cr(Ⅵ)的测定,加标回收率为93.3%~106.4%。  相似文献   

4.
膜生物反应器处理显影废水   总被引:1,自引:0,他引:1  
研究了膜生物反应器对预处理后的显影废水的处理效果,考察了MLSS和DO对系统出水水质的影响。文验结果表明:在系统运行温度15~30℃、停留时间10—15h、曝气量4~10m^3/h的条件下,系统稳定后出水水质良好且稳定,COD去除率为85%~92%,Cu^2+去除率为90%~98%;生物反应池中的活性污泥对Cu^2+的去除起主要作用,使出水中Cu^2+质量浓度维持在0.5mg/L以下;考虑到废水处理效果和能耗两方面的因素,MLSS宜控制在6000mg/L左石,DO应控制存1.5~2.5mg/L。  相似文献   

5.
以桑色素作显色剂,采用流动注射分光光度法测定水中铝的含量。在桑色素质量浓度为0.8g/L、聚氧乙烯辛基苯基醚体积分数为1.0%、进样环体积为400μL、检测波长420nm的条件下,采用流动注射分光光度法对水中铝的含量进行测定,本方法的线性范围为2~300μg/L,检出限(信噪比为3)为0.124μg/L,相对标准偏差为2.9%,加标回收率为96.4%~101.8%。  相似文献   

6.
利用含铜蚀刻废液生产碱式碳酸铜   总被引:14,自引:0,他引:14  
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。  相似文献   

7.
探索催化双氧水氧化去除间甲酚对开发炼油厂碱渣废水处理新技术意义重大。采用钛硅分子筛催化双氧水氧化水中间甲酚,考察了反应时间、反应温度、双氧水加入量、催化剂加入量和初始溶液pH对间甲酚去除率的影响。实验结果表明:钛硅分子筛对双氧水氧化间甲酚具有显著的催化作用;在反应时间为90 min、反应温度为80 ℃、n(H2O2)∶n(间甲酚)为4、催化剂加入量为1.5 g/L、初始溶液pH为1.0~11.0的条件下,间甲酚去除率约为94%,间甲酚溶液的BOD5/COD从氧化前的0.26提高到氧化后的0.38,可生化性显著提高。  相似文献   

8.
《化工环保》2008,28(6)
该发明涉及一种利用污泥和废石墨制备活性吸附材料的方法,其特征在于从城市污水处理厂取剩余污泥,干化、研磨、过筛后按固液质量比1:(2.5~4.5)加入氯化锌和硫酸溶液,静止放置20~24h,烘干20~24h,处理后的污泥加入废石墨,加入量为污泥总质量的3%~10%;然后放入热解炉中进行热解,利用氮气隔绝空气,氮气流量控制在0.4~0.5L/min,加热速率控制在10~15℃/min,热解温度为500~800℃,热解时间为1.5~2.5h;热解后的产物先用浓度为3mol/L的盐酸溶液漂洗,促使其中的氧化物充分溶解,同时洗脱杂质,  相似文献   

9.
次氯酸钙法处理发泡剂生产废水   总被引:6,自引:0,他引:6  
蔡闽 《化工环保》2004,24(6):440-443
采用废漂白液(次氯酸钙)处理发泡剂偶氮二甲酰胺生产废水。废水pH为8~9时,加入质量分数3%~5%的漂白液和1‰PAM絮凝剂,反应2h,沉淀澄清。实验室试验中COD去除率为88%,工业处理试验中COD平均由626mg/L降为105mg/L,去除率为83.2%。该法工艺简单,以废治废,费用低,处理效果好。  相似文献   

10.
对上海石洞口发电厂1000t/h直流炉柠檬酸酸洗废水和该厂生活污水用活性污泥法进行联合处理。在室温下,控制污泥沉降比30%~35%,pH7.0~7.5,溶解氧4.0~4.5mg/L。停留时间1.5~2.0小时,CODcr和BOD5的去除率均可达90%以上,效果显著。当进水CODCr浓度控制在800~850mg/L范围内时,出水CODCr将小于100mg/L,BOD5小于30mg/L,可达标排放。  相似文献   

11.
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   

12.
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.  相似文献   

13.
Application of Cellulose Microfibrils in Polymer Nanocomposites   总被引:1,自引:0,他引:1  
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.  相似文献   

14.
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。  相似文献   

15.
Bioassessment is a useful tool to determine the impact of logging practices on the biological integrity of streams and wetlands. Measuring biota directly has an intuitive appeal for impact assessment, and biota can be superior indicators to physical or chemical characteristics because they can reflect cumulative impacts over time. Logging can affect stream and wetland biota by increasing sedimentation rates, altering hydrologic, thermal, and chemical regimes, and changing the base of food webs. Biotic impacts of logging on streams compared to wetlands probably differ, and in this paper we review some of those differences. In streams, invertebrates, fishes, amphibians, algae, and macrophytes have been used as indicators of logging impacts. In wetlands, bioassessment is just beginning to be used, and plants and birds are the most promising indicator taxa. Various best management practices (BMPs) have been developed to reduce the impacts of logging on stream and wetland biota, and we review quantitative studies that have evaluated the efficacy of some of these techniques in streams and wetlands in the eastern United States. Remarkably few studies that address the overall efficacy of BMPs in limiting biotic changes in streams and wetlands after BMP implementation have been published in scientific journals, although some work exists in reports or is unpublished. We review these works, and compile conclusions about BMP efficacy for biota from this body of research.  相似文献   

16.
Air emissions and residual ash samples were collected and analyzed during experiments of open, uncontrolled combustion of electronic waste (e-waste), simulating practices associated with rudimentary e-waste recycling operations. Circuit boards and insulated wires were handled separately to simulate processes associated with metal recovery. The average emissions of polychlorinated dibenzodioxins and dibenzofurans (PCDD/PCDFs) were 92 ng toxic equivalency (TEQ)/kg [n = 2, relative standard deviation (RSD) = 98%] and 11 900 ng TEQ/kg (n = 3, RSD = 50%) of the initial mass of the circuit boards and insulated wire, respectively. The value for the insulated wire is about 100 times higher than that for backyard barrel burning of domestic waste. The emission concentrations of polybrominated dibenzodioxins and dibenzofurans (PBDD/PBDFs) from the combustion of circuit boards were 100 times higher than for their polychlorinated counterparts. Particulate matter (PM) sampling of the fly ash emissions indicated PM emission factors of approximately 15 and 17 g/kg of the initial mass for the circuit boards and insulated wire, respectively. Fly ash samples from both types of e-waste contained considerable amounts of several metallic elements and halogens; lead concentrations were more than 200 times the United States regulatory limits for municipal waste combustors and 20 times those for secondary lead smelters. Leaching tests of the residual bottom ash showed that lead concentrations exceeded U.S. Environmental Protection Agency landfill limits, designating this ash as a hazardous waste.  相似文献   

17.
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.  相似文献   

18.
The solubility and potential mobility of heavy metals (Cd, Cu,Hg, Pb and Zn) in two urban soils were studied by sequential andleaching extractions (rainwater). Compared to rural (arable) soils on similar parent material, the urban soils were highlycontaminated with Hg and Pb and to a lesser extent also with Cd,Cu and Zn. Metal concentrations in rainwater leachates were related to sequential extractions and metal levels reported fromStockholm groundwater. Cadmium and Zn in the soils were mainly recovered in easily extractable fractions, whereas Cu and Pb were complex bound. Concentrations of Pb in the residual fractionwere between two- and eightfold those in arable soils, indicatingthat the sequential extraction scheme did not reflect the solidphases affected by anthropogenic inputs. Cadmium and Zn conc. inthe rainwater leachates were within the range detected in Stockholm groundwater, while Cu and Pb conc. were higher, whichsuggests that Cu and Pb released from the surface soil were immobilised in deeper soil layers. In a soil highly contaminatedwith Hg, the Hg conc. in the leachate was above the median concentration, but still 50 times lower than the max concentration found in groundwater, indicating the possibilityof other sources. In conclusion, it proved difficult to quantitatively predict the mobility of metals in soils by sequential extractions.  相似文献   

19.
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.  相似文献   

20.
Injection molded specimens were prepared by blending poly (hydroxybutyrate-co-valerate) (PHBV) with cornstarch. Blended formulations incorporated 30% or 50% starch in the presence or absence of poly-(ethylene oxide) (PEO), which enhances the adherence of starch granules to PHBV. These formulations were evaluated for their biodegradability in natural compost by measuring changes in physical and chemical properties over a period of 125 days. The degradation of plastic material, as evidenced by weight loss and deterioration in tensile properties, correlated with the amount of starch present in the blends (neat PHBV < 30% starch < 50% starch). Incorporation of PEO into starch-PHBV blends had little or no effect on the rate of weight loss. Starch in blends degraded faster than PHBV and it accelerated PHBV degradation. Also, PHBV did not retard starch degradation. After 125 days of exposure to compost, neat PHBV lost 7% of its weight (0.056% weight loss/day), while the PHBV component of a 50% starch blend lost 41% of its weight (0.328% weight loss/day). PHB and PHV moieties within the copolymer degraded at similar rates, regardless of the presence of starch, as determined by 1H-NMR spectroscopy. GPC analyses revealed that, while the number average molecular weight (Mn) of PHBV in all exposed samples decreased, there was no significant difference in this decrease between neat PHBV as opposed to PHBV blended with starch. SEM showed homogeneously distributed starch granules embedded in a PHBV matrix, typical of a filler material. Starch granules were rapidly depleted during exposure to compost, increasing the surface area of the PHBV matrix.  相似文献   

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