ISSN:0730-7268    

DOI:10.1002/etc.5620150901

出版商:Wiley Periodicals, Inc.    

年代:1996

数据来源: WILEY

ISSN:0730-7268    

DOI:10.1002/etc.5620150902

出版商:Wiley Periodicals, Inc.    

年代:1996

数据来源: WILEY

摘要:

AbstractThe concentration patterns of a number of compounds in the inlet water and wastewater from sprinkling of timber from Scotch pine and Norway spruce have been studied. The timber was separated with respect to species and sprinkled with water from a eutrophic or an oligotrophic receiving water for 18 weeks. Organic and inorganic compounds including dissolved organic carbon (DOC), distillable phenols, resin acids, bacterial phospholipid fatty acids, organic and inorganic phosphorus, nitrogen and sulphur, and a number of metal ions were monitored in the inlet water and wastewater. The toxicity of the wastewater was estimated during the first 2 weeks using a Microtox® test and appeared to decline in parallel with DOC. Most compounds showed both an environmental net load and an absorption by the timber, the loads being smaller and the absorption larger when using eutrophic water. At both sites the loads were generally largest during the first 2 weeks and larger in magnitude at the oligotrophic site and in the spruce wastewater. The initial growth of the bacterial biomass in the pile system was slower at the oligotrophic site, and the results indicated that a rapid growth of the bacterial biomass reduces the initial environmental loads and that this process is associated with the nutrient status of the receiving water

ISSN:0730-7268    

DOI:10.1002/etc.5620150903

出版商:Wiley Periodicals, Inc.    

年代:1996

数据来源: WILEY

摘要:

AbstractOur previous studies showed that dimethylsilanediol (DMD) was the main hydrolysis product of slicone (polydimethylsiloxane) polymer in soil. In the present study, volatilization of14C‐DMSD from soil (1 mg kg−1) was investigated in open tubes, with weekly remoistening. Losses of14C from Londo sandy clay loam and Pipestone sand were about 3.6 and 7.7% wk−1, respectively, and were attributed mostly to volatilization. For select samples, DMSD was trapped and identified as the volatilized compound. From 12 soils of variable properties, losses ranged from 1.4 to 6.4% wk−1, with higher rates correlated with sandier textures. An estimatedKdof 0.1 L kg−1in wet soil suggests potential mobility of DMSD, but increased bonding with soil drying means that mobility will be retarded under field conditions. Results suggest that volatilization will be a major route of loss of DMSD

ISSN:0730-7268    

DOI:10.1002/etc.5620150904

出版商:Wiley Periodicals, Inc.    

年代:1996

数据来源: WILEY

摘要:

AbstractThe thylakoid bioassay is used to determine the effect of herbicides in water. To avoid isolation for each bioassay, lyophilization of thylakoids for continuous, reproducible supply as bioassay material is descibed. This technique maintains the photosynthetic activity after lyophilization at 82 ± 9% (n= 5) of its original level

ISSN:0730-7268    

DOI:10.1002/etc.5620150905

出版商:Wiley Periodicals, Inc.    

年代:1996

数据来源: WILEY

摘要:

AbstractIn this study we evaluated the joint actions of cyanogenic toxicants with other organic chemicals using Microtoxx® tests. Experimental results indicated that greater than additive effect seldom occurred when these chemicals were mixed with nonreactive toxicants. However, the likelihood of synergistic effects exceeded 30% when reacting with a reactive chemical. Among the cyanogenic toxicants investigated in this study, malononitrile, lactonitrile, and α‐hydroxy‐isobutyronitrile have an approx. 50% likelihood of acting via synergism mode with other reactive toxicants. On the other hand, the joint actions related to acetonitrile and allyl cyanide are either additive or less than additive. Moreover, the likelihood of encountering synergistic effects markedly increases if the slopes of the dose–response curves for the two chemicals tested are small. Therefore, slope and certain characteristics of a chemical structure can apparently be used as indices to assess the potential hazard for a specific organic mixture. Furthermore, the complex joint action exerts a certain deterministic influence over the joint action mode of cyanogenic toxicants. This type of joint action, which quite frequently leads to an obvious antagonistic or even detoxification phenomena, could have some useful toxicological and pharmacological applications. Lastly, estimating the mixture toxicity on the basis of the concentration addition model is not always appropriate considering the high percentage of cases in this study showing sy

ISSN:0730-7268    

DOI:10.1002/etc.5620150906

出版商:Wiley Periodicals, Inc.    

年代:1996

数据来源: WILEY

摘要:

AbstractThe occurrence, sources, and fate of trichloroacetic acid (TCA) has been investigated in surface waters, ground waters, drinking waters, wastewaters, and rainwater in Switzerland. The concentrations found in surface waters varied between less than 27 ng/L (limit of quantification) and 340 ng/L, whereas the concentrations in ground water were always below 27 ng/L. It was found that the main sources of TCA in surface waters were the effluents of wastewater treatment plants (average concentration, 430 ng/L; range, 40‐1060 ng/L). The average TCA concentration in rainwater was 300 ng/L range, (90%), but they also show that about 60 to 80% of the TCA deposited by rain is eliminated, most probably in the

ISSN:0730-7268    

DOI:10.1002/etc.5620150907

出版商:Wiley Periodicals, Inc.    

年代:1996

数据来源: WILEY

摘要:

AbstractA modified procedure was developed for determining acid volatile sulfides (AVS) and simultaneously extracted metals (SEM) in freshwater sediments. A simple diffusion system employing relatively inexpensive glassware was compared to the more commonly utilized purge‐and‐trap system for generating AVS and SEM. Results obtained using the two different methods were generally compara

ISSN:0730-7268    

DOI:10.1002/etc.5620150908

出版商:Wiley Periodicals, Inc.    

年代:1996

数据来源: WILEY

摘要:

AbstractThe acute toxicity of wastewater generated during the extraction of bitumen from oil sands is believed to be due to naphthenic acids (NAs). To determine the factors that affect the rate of degradation of representative NAs in microcosms containing wastewater and the acute toxicity of treated and untreated wastewater, the effects of temperature, dissolved oxygen concentration, and phosphate addition on the rate of14CO2release from two representative naphthenic acid substrates, (linear) U‐14C‐palmitic acid (PA) and (bicyclic) decahydro‐2‐naphthoic acid‐8‐14C (DHNA), were monitored. Tailings pond water (TPW) contained microorganisms well adapted to mineralizing both PA and DHNA: PA was degraded more quickly (10–15% in 4 weeks) compared to DHNA (2–4% in 8 weeks). On addition of phosphate, the rate of NA degradation increased up to twofold in the first 4 weeks, with a concurrent increase in the rate of oxygen consumption by oil sands TPW. The degradation rate then declined to levels equivalent to those measured in flasks without phosphate. The observed plateau was not due to phosphate limitation. Decreases in either the dissolved oxygen concentration or the temperature reduced the rate. Phosphate addition also significantly decreased the acute toxicity of TPW to fathead minnows. In contrast, Microtox® analyses showed no reduction in the toxicity of treated or untreated TPW after incubation for up to

ISSN:0730-7268    

DOI:10.1002/etc.5620150909

出版商:Wiley Periodicals, Inc.    

年代:1996

数据来源: WILEY

摘要:

AbstractTriphenyltin (TPT) is a fungicide used on a variety of crops throughout the world. In this study, pecan orchards in central Georgia (USA) previously sprayed with commercial TPT hydroxide mixtures were found to have TPT concentrations of 8.5 to 37 μg/g dry weight in foliage and 1.2 to 12 μg/g dry weight in soil. Total phenyltin concentrations (monophenyltin [MPT] + diphenyltin [DPT]+ TPT) in foliage and soils immediately after application were up to 72 and 26 μg/g dry weight, respectively. Besides TPT, DPT and MPT were present in the leaves and soils, with MPT generally the predominant compound. The proportion of MPT to TPT in pecan leaves increased with time after spraying, which was indicative of photolytic degradation of TPT. Microbial degradation of radiolableled TPT in soil or sediment samples was slow, with only 5% degraded during a 14‐d incubation period. Triphenyltin was absent from the subsurface soils (2 to 15 cm depth) even though it had been sprayed eight to 10 times a year at a rate of 850 g/ha for the past 10 years. In an orchard where the last spraying was carried out approx. 2 years ago, TPT was absent, but MPT was present at approximately the same concentration as recently sprayed orchards. Fish (blue gill, largemouth bass, and channel catfish) from a pond near a recently sprayed pecan orchard had TPT as well as DPT and MPT. The predominate phenyltin in all fish was MPT, with 22 μg/g wet weight in the liver of catfish. Radiolabeled TPT was only slowly metabolized by the fathead minnow, with 2% of the TPT metabolized to DPT after 6 d of exposure via water. Photodegradation appears to be the major factor affecting the fate of TPT in

ISSN:0730-7268    

DOI:10.1002/etc.5620150910

出版商:Wiley Periodicals, Inc.    

年代:1996

数据来源: WILEY