ISSN:0730-7268    

DOI:10.1002/etc.5620120601

出版商:Wiley Periodicals, Inc.    

年代:1993

数据来源: WILEY

摘要:

AbstractCompared were concentrations of Al, Cd, Ca, Cu, Fe, Hg, Pb, Mg, Mn, Ni, P, and Zn in water, plants, and aquatic insects of three acidified (pH ∼ 5.0) and three nonacidified (pH ˜ 6.5) constructed wetlands. Concentrations of Zn in water and bur‐reed (Sparganium americanum) were higher in acidified wetlands than in nonacidified wetlands. Floating nonrooted plants contained mean concentrations of Fe, Mg, and Mn that were higher than recommended maximum levels for poultry feed. The mean concentrations of all metals in insects were below recommended maximum levels for poultry feed and below levels that cause toxic effects in wild birds. Smaller than expected increases of metal concentrations in the water of acidified wetlands were probably due to limited mobilization of metals from the sediments and insignificant changes in sedimentation of aqueous metals. Calcium was lower in acidified than in nonacidified wetland water, but the Ca content of insects and bur‐reed was not lower. Low concentrations of Ca in aquatic insects from both groups of wetlands indicate that calcium‐rich crustaceans and mollusks are probably important to female waterfowl and their young during the spring, when invertebrates make up the majority of the diet. Although toxic effects from metal ingestion seem to be unlikely consequences of wetland acidification, the adverse effect of low pH on the occurrence of crustaceans and mollusks could threaten egg production and development

ISSN:0730-7268    

DOI:10.1002/etc.5620120602

出版商:Wiley Periodicals, Inc.    

年代:1993

数据来源: WILEY

摘要:

AbstractCompared were concentrations of Al, Cd, Ca, Cu, Fe, Pb, Mg, Mn, Hg, Ni, P, and Zn in water, plants, and aquatic invertebrates of wetlands, ponds, and small lakes in Maryland and Maine. The accumulation of metals by aquatic plants and insects and the concentration of metals in water were not greatly affected by pH. None of the metal concentrations in water significantly correlated with metals in insects. Plant metal concentrations poorly correlated with metal concentrations in water. Concentrations of metals exceeded acceptable dietary levels more frequently in plants than in invertebrates. Concerns about metal toxicity in birds that feed on invertebrates and plants from acidified waters seem to be unwarranted. Positive correlations among pH, Ca in water, Ca in insects, and Ca in plants imply that acidification can reduce the Ca content of aquatic biota. Aquatic insects were low in Ca, but crayfishes and snails, which are adversely affected by low pH, were very high. A concern for waterfowl is Ca deprivation from decreased Ca availability in low‐pH wetlands, ponds, and small lake

ISSN:0730-7268    

DOI:10.1002/etc.5620120603

出版商:Wiley Periodicals, Inc.    

年代:1993

数据来源: WILEY

摘要:

AbstractAn extensive monitoring study was conducted to determine the fate of linear alkylbenzene sulfonate (LAS) during wastewater treatment and in the environment. Results showed that LAS was highly removed during activated sludge (99.3 ± 0.6%), lagoon (98.5 ± 1.8%), oxidation ditch (98.0 ± 4.2%), and rotating biological contact (96.2 ± 6.1%) treatment, with poorer removals observed at trickling filter (77.4 ± 15.5%) facilities. Concentrations of LAS in anaerobically digested sludge (10,462 ± 5170 μg/g) were one to two orders of magnitude greater than those observed for aerobically digested sludge (152 ± 119 μg/g), illustrating that LAS is rapidly degraded during aerobic sludge treatment. Receiving water concentrations of LAS in rivers of low effluent dilution were generally<50 μg/L. Elevated river sediment concentrations of LAS were observed only below the outfall of trickling filter treatment plants (59.7‐182.1 μg/g). Alkyl chain lengths of LAS averaged 12.0 carbon units in most environmental compartments, with the exception of sludge solids and river sediments, in which an enrichment of longer chain lengths was observed. Measured concentrations of LAS in river waters under critical low flow conditions were in agreement with PG‐GRiDS model predictions [5], thus supporting the validity of the mod

ISSN:0730-7268    

DOI:10.1002/etc.5620120604

出版商:Wiley Periodicals, Inc.    

年代:1993

数据来源: WILEY

摘要:

AbstractMirror carp were exposed to Rotterdam Harbor sediment, highly contaminated with polychlorodibenzo‐p‐dioxins (PCDDs), polychlorodibenzofurans (PCDFs), and polychlorobiphenyls (PCBs) (0.5 μg 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin [TCDD] equivalents per kilogram dry weight). In two additional separate experiments rainbow trout (Oncorhynchus mykiss) and mirror carp (Cyprinus carpio) received a single intraperitoneal injection of approximately 0.01, 0.03, 0.06, 0.3, 0.6, or 3.0 μg TCDD per kilogram body weight. In all three experiments induction of hepatic P450 1A was measured with immunochemical and enzymatic methods. The polyclonal antibodies anticod (Gadus morhua), anti‐perch (Perca fluviatilis), and anti‐rainbow trout P450 1A all cross‐reacted with the P450 1A orthologue of the carp and rainbow trout. In most cases high correlations were found between 7‐ethoxyresorufinO‐deethylation (EROD) activity and cytochrome P450 1A protein contents, the latter measured by the enzyme‐linked immunosorbent assay (ELISA) and protein blot methods. However, the correlations between EROD activity and P450 1A protein levels were higher within the separate sampling periods (i.e., 3, 6, and 12 weeks after dosage) than with the total data set, especially in the dose‐effect study with the rainbow trout. This was probably caused by a difference in time‐dependent relationships between P450 1A protein content and EROD enzyme activity: 12 weeks after dosage the P450 1A protein was still increased, although EROD activity had returned to background level. In addition, there were higher correlations of the EROD activity and P450 1A protein content with total P450 content in rainbow trout and carp treated with a single dose of TCDD, than with total P450 content in carp exposed to contaminated sediment. In our study, the ELISA method appeared to be more useful than the protein blot technique, because the ELISA is faster and has higher reproducibility. In addition, in all our experiments EROD activity showed a higher induction than the P450 1A protein, indicating a higher sensitivity of the EROD assay. Our results strongly indicated that determination of the P450 1A protein content and EROD activity provides complementary information. Thus we recommended the use of both the ELISA and the EROD activity assay in order to understand the

ISSN:0730-7268    

DOI:10.1002/etc.5620120605

出版商:Wiley Periodicals, Inc.    

年代:1993

数据来源: WILEY

摘要:

AbstractChromosomal puffing in the salivary glands of larvalChironomus tentanswas developed as a biomarker for genotoxic substances. Reduced chromosomal puffing was considered an indication of decreased RNA synthesis. Third‐ or fourth‐instar larvae were exposed to test chemicals in an artificial substrate under static conditions. Chromosomes from glands of individual larvae were stained with methyl green and pyronin Y. The widths of Balbiani rings I and II (large puffs on chromosome IV) were measured. Three carcinogens with different mechanisms of action were tested, benzo[a]pyrene (BaP), actinomycin D (Act D), and dimethylnitrosamine (DMN). Puff size was statistically reduced by all three chemicals with varying potency. Lowest‐observable‐effect levels (LOEL) were 0.5 nmol BaP, 6.0 nmol Act D, and 243,000 nmol DMN. The degree of response was influenced by exposure time, applied dose, individual sensitivity, and possibly chemical hydrophobicity. Biomarker specificity was determined by testing a weak carcinogen, benzo[e]pyrene (BeP), and an acutely toxic noncarcinogen, naphthalene (NP). The effective dose of BeP (LOEL = 250 nmol) was four orders of magnitude higher than that of BaP. Only lethal doses of NP had statistically significant effects on puff size, LD50 = 25,000 (34,300‐15,700) nmol. Approximately 40% of the larvae in our laboratory population appeared tolerant to the effects of BaP. Advantages of this biomarker were its association with a known mechanism of action and measurement of the whole‐organism integrat

ISSN:0730-7268    

DOI:10.1002/etc.5620120606

出版商:Wiley Periodicals, Inc.    

年代:1993

数据来源: WILEY

摘要:

AbstractImmobilized bacteria technology (IBT) utilizes inert biocarriers to support high concentrations of chemical‐degrading bacteria in reactors designed to provide optimal conditions for microbial activity. This study evaluated IBT performance in packed bed reactors (PBRs) using a porous inorganic biocarrier (diatomaceous earth), nonporous biocarriers (glass beads), and organic biocarriers having carbon adsorption properties (granular activated carbon) with different porosity. Each reactor was challenged with high chemical loading, acid, dryness, and heat shock conditions. Benchtop PBRs inoculated with ap‐nitrophenol‐ (PNP)‐ degradingPseudomonassp. and fed a synthetic waste containing 100 to 1,300 mg/L of PNP showed removal of PNP from effluents within 24 h of start‐up. Chemical loading studies showed maximum PNP removal rates of 6.45 to 7.35 kg/m3/d for bacteria in PBRs containing diatomaceous earth beads, glass beads, and activated coconut carbon. A lower PNP removal rate of 1.47 kg/m3/d was determined for the activated anthracite carbon, and this PBR responded more slowly to increases in chemical loading. The PBR containing bacteria immobilized on activated coconut carbon showed exceptional tolerance to acid shocking, drying, and heat shocking by maintaining PNP removal rates>85% throughout the entire study. The other biocarriers showed nearly complete loss of PNP degradation during the perturbations (except for drying), but all recovered high rates of PNP degradation (>98% removal) within 48 h after an acid shock at pH 2, within 8 d after an acid shock at pH 1.0, within 24 h after drying for 72 h, and within 48 h of heat shocking. The resiliency and high chemical removal efficiency demonstrated by immobilized bacteria in this study support the concept of using IBT for the biotreatment of industri

ISSN:0730-7268    

DOI:10.1002/etc.5620120607

出版商:Wiley Periodicals, Inc.    

年代:1993

数据来源: WILEY

摘要:

AbstractAnaerobic biotransformation of polychlorinated biphenyls of Hudson River sediment microorganisms was investigated using the commercial mixture Aroclor 1242 in the laboratory at six different concentrations: 120, 300, 500, 800, 1,000, and 1,500 μg/g (on a sediment dry‐weight basis). Dechlorination was concentration dependent. No change in congener composition was found at 1,000 and 1,500 μg/g during seven months of incubation, but significant shifts were observed in sediments with concentrations below 800 μg/g. A mass balance of the transformation indicated that, despite the shifts, the total molar concentration remained the same. An optimum concentration, based on the decrease of Cl per biphenyl, was 500 μg/g, but based on Cl removed per gram sediment it had a range from 500 to 800 μg/g. Dechlorination (total Cl removed per biphenyl) at 300 and 500 μg/g appeared to be first order, with rate constants of —0.039 and —0.059 per month, respectively. The rate also varied with the substitution position; it was faster form‐Cl, followed byp‐Cl, but noo‐Cl was removed. However, the faster rate ofm‐dechlorination in Aroclor 1242 was probably due to a high concentration of congeners in the Aroclor with Cl substitution patterns favoring its removal, rather than the m

ISSN:0730-7268    

DOI:10.1002/etc.5620120608

出版商:Wiley Periodicals, Inc.    

年代:1993

数据来源: WILEY

摘要:

AbstractThe effect of electron acceptors and biphenyl on reductive dechlorination was investigated using the commercial polychlorinated biphenyl mixture Aroclor 1242 and sediment microorganisms from the Hudson River. Polychlorinated biphenyl‐ (PCB‐) free sediments spiked with the Aroclor at 700 μg/g and anaerobically incubated for six months, with and without biphenyl enrichment, showed that dechlorination was most advanced with CO2without biphenyl enrichment. A small amount of methane was detected. However, methane production per se was not essential for dechlorination, because addition of the inhibitor of methane production, 2‐bromoethane sulfonate, did not affect dechlorination. On the other hand, dechlorination was inhibited partly by sulfate and completely by nitrate. Biphenyl enrichment initially inhibited dechlorination under both methanogenic and sulfidogenic cond

ISSN:0730-7268    

DOI:10.1002/etc.5620120609

出版商:Wiley Periodicals, Inc.    

年代:1993

数据来源: WILEY

摘要:

AbstractBiotransformation of a series of organophosphorus compounds by the 9,000‐g supernatant of rainbow trout (Oncorhynchus mykiss) liver was tested in an in vitro system fortified either with NADPH‐generating cofactors or with reduced glutathione (GSH). Elimination rate constants for both systems were calculated from linear decay curves when substrate concentrations were used that were considerably lower than theKmvalues of the concerned enzymatic reactions. The results reveal a large variation in both the oxidative and the glutathione‐mediated biotransformation rate of the organophosphorus compounds. Half‐lives ranged from 25 to 1,216 min in the NADPH system and from 18 to 381 min in the GSH system. Elimination rate constants in the GSH system were related to Hammett σ constants or reactivity toward 4‐nitrobenzylpyridine, which substantiates the assumption that electrophilicity is the controlling variable for the reaction with GSH within this particular class of compounds. A remarkable analogy was observed between compounds that were metabolized relatively quickly by glutathioneS‐transferases and compounds that showed a reduced bioconcentration factor in guppies. A significant improvement of the relationship between the bio‐concentration factor in guppies and the octanol/water partition coefficient was obtained when the rate constant with GSH was introduced in this relationship. Such an improvement was not obtained with the rate constants from the oxidative system. These observations are discussed in view of the differences in the activities of the involved enzyme systems in the test species and in view of the possible relevance of the different biotransformation pathways for the in

ISSN:0730-7268    

DOI:10.1002/etc.5620120610

出版商:Wiley Periodicals, Inc.    

年代:1993

数据来源: WILEY