臭氧氧化法处理染料中间体1－氨基蒽醌和DSD酸生产废水

采用臭氧氧化法处理染料中间体１－氨基蒽醌和ＤＳＤ酸生产废水，能改善废水的可生化性，降低废水中有机物的水溶性，提高混凝处理的效率。研究结果表明，在原水ｐＨ条件下，当臭氧投加量为７．５ｇ／Ｌ时，ＤＳＤ酸氧化母液脱色率大于９０％，ＢＯＤ＿５／ＣＯＤ达到０．３。当臭氧投加量为６ｇ／Ｌ时，１－氨基蒽醌废水的ＢＯＤ＿５／ＣＯＤ达到０．３。１－氨基蒽醌废水经投加量为２．５ｇ／Ｌ的臭氧处理后，再进行两级混凝处理（ＦｅＳＯ＿４的投加量分别为５．０ｇ／Ｌ和１．０ｇ／Ｌ），ＣＯＤ和色度的去除率可分别达到９０％和９３％。     

美国加强对ODS的控制

美国加强对ＯＤＳ的控制产业环境，２２［６］，７２（１９９３）根据新修订的大气清洁法，美国从１９９３年５月起加强对能破坏臭氧层物质（ＯＤＳ）的控制。凡生产ＯＤＳ的企业和含ＯＤＳ的制品必须附有ＯＤＳ标签，说明该制品使用了ＯＤＳ，并要制定ＯＤＳ废除的具体日...     

臭氧氧化法处理染料中间体1—氨基蒽醌和DSD酸生产废水

采用臭氧氧化法处理染料中间体１－氨基蒽醌和ＤＳＤ酸生产废水，能改善废水的可生化性，降低废水中有机物的水溶性，提高混凝处理的效率。研究结果表明，在原水ＰＨ条件下，当臭氧投加量为７．５ｇ／Ｌ时，ＤＳＤ酸氧化母液脱色率大于９０％，ＢＯＤ５／ＣＯＤ达到０．３。当臭氧投加量为６ｇ／Ｌ时，１－氨基蒽醌废水的ＢＯＤ５／ＣＯＤ达到０．３。１－氨基蒽醌废水经投加量为２．５ｇ／Ｌ的臭氧处理后，再进行两级混凝处理，ＣＯ     

BOD5的应用与污水可生化性的判别

对水质参数ＢＯＤ５进行讨论，认为ＢＯＤ５仅反映污水排入水体后的耗氧状况，不反映污水本身的水质特性。建议采用可生化化学需氧量描述污水特性，以ＤＯＤＢ／ＣＯＤ作为判别污水可生化性指标，提出了测定ＣＯＤＢ的方法。     

消除DPD法测定水中臭氧浓度干扰因素的研究

研究了Ｈ_２Ｏ_２和其它氧化剂（以过氧化苯甲酰为例）对ＤＰＤ法测定水中臭氧浓度的干扰作用，结果表明，随着ＫＩ浓度或显色时间的增加，Ｈ_２Ｏ_２和其它氧化剂的干扰作用增加，当ＫＩ浓度为０．５ｇ／Ｌ时，可以基本消除这些干扰作用，且当臭氧浓度低于０．６ｍｇ／Ｌ时，不影响臭氧对ＤＰＤ的显色作用。     

生物接触氧化法处理甲胺磷生产废水

甲胺磷生产过程中排出的甲基氯化物废水,含盐量高（质量分数为１８％～２０％）,可生化性较差（ＢＯＤ／ＣＯＤ为０．１）,一般认为不宜直接进行生化处理。曾有农药厂采用低压酸性水解和湿式氧化等方法对其进行预处理,然后再进行生化处理,由于成本高或设备腐蚀等问题...     

萃取法处理萤光废水

采用萃取法处理萤光废水，最佳萃取工艺条件如下：ｐＨ为１，废水：萃取剂：稀释剂为２０：２：５。在此工艺条件下，萤光废水ＣＯＤ去除率可达９１％－９８％，色度去除率达９９．８％。萃取剂可再生回用，在萃取相中按萃取剂（包括络合物）的量加入等体积的浓度为２０％的ＮａＯＨ溶液，在９５－１０５℃加热回流５－１０ｍｉｎ，即可使萃取剂得到再生。     

化工废水CODCr与BOD5的相关关系和BOD5的快速计算

化工废水的ＣＯＤ与ＢＯＤ５之间具有相关性，存在着线性关系。在生产稳定的情况下，只需测定ＣＯＤＣｒ就可根据线性回归方程迅速计算出ＢＯＤ５。此值和实际值相比，相对误差≤±１０％。该方法省时，可用于生产控制。     

AO1O2工艺处理染色废水

报导了豆腐营工业区污水集中控制示范工程，采用水解酸化（Ａ）－接触氧化（Ｏ１）－合建式氧化沟（Ｏ２）净化组合工艺处理染色废水的运行情况。该工艺具有处理效果好、运行稳定、投产快、操作管理简便、占地少、投资省、处理成本低等优点。     

生物接触氧化处理电厂生活污水的试验研究

建立了一套生物接触氧化动态模拟台，针对电厂生活污水水质特点，在低浓度下培养并驯化生物膜，开展了用于低浓度生活污水处理的试验研究。结果表明生物膜在较低的有机负荷下仍能保持良好的活性。对ＣＯＤ、ＢＯＤ５去除率分别达到７５％和８５％，并具有较高的耐水力负荷的冲击能力，操作简便，运行管理方便。     

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.     

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.     

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。     

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.     

Bioassessment of silvicultural impacts in streams and wetlands of the Eastern United States

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.     

Characterization of air emissions and residual ash from open burning of electronic wastes during simulated rudimentary recycling operations

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.     

Does Soil Acidification Affect Spruce Needle Chemical Composition and Tree Growth?

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.     

Solubility and Potential Mobility of Heavy Metals in Two Contaminated Urban Soils from Stockholm,Sweden

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.     

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.     

Biodegradation of Injection Molded Starch-Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) Blends in a Natural Compost Environment

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.