ISSN:0730-7268    

DOI:10.1002/etc.5620070401

出版商:Wiley Periodicals, Inc.    

年代:1988

数据来源: WILEY

ISSN:0730-7268    

DOI:10.1002/etc.5620070402

出版商:Wiley Periodicals, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractCarbonate radicals generated by the photolysis of H2O2at 313 nm in aqueous sodium bicarbonate (pH 8.3) or carbonate (pH 11.6) solution reacted with substituted aromatic amine derivatives. Particularly fast reactions (second‐order rate constants of 5 × 108to 2 × 109) were observed with anilines bearing electron‐donating substituents, either on the ring or at the nitrogen atom. The results suggest that carbonate radicals may play a significant role in the removal of some aromatic amines from the aquatic environment, particularly in carbonate‐rich

ISSN:0730-7268    

DOI:10.1002/etc.5620070403

出版商:Wiley Periodicals, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe environmental concentrations of nitrilotriacetic acid (NTA) resulting from its use in laundry detergents were monitored during a four‐year study conducted in central Indiana. The purpose of the study was to measure NTA concentrations in municipal wastewater, in surface waters that receive wastewater effluent and in finished drinking water from surface waters downstream from the outfalls of wastewater treatment plants. The 25 sampling sites were interdependent locations in and around Indianapolis, Indiana, an area that received laundry detergents containing Na3NTA at a level equivalent to 3.6% NTA in all detergents (w/w) during the last two years of the program. NTA removal during wastewater treatment averaged 91% (w/w) at activated sludge treatment plants and 65% at trickling filter plants. NTA concentrations averaged 0.008 μg/ml in river waters and 0.004 μg/ml in drinking waters when NTA‐containing detergents were in use. NTA concentrations in wastewaters, river waters and drinking waters were similar to or lower than concentrations predicted from usage levels and agreed, within a factor of 3, with the predicted values.Concentrations of six metals (Cu, Ni, Cd, Pb, Cr and Zn) were also measured in samples collected throughout the program. Concentrations of the metals in influent wastewater, their removal by wastewater treatment and their concentrations in river and finished drinking waters were comparable with values typical in the United States. Use of NTA in laundry detergents did not affect metals removal by wastewater treatment or metals concentrations in river and drinking w

ISSN:0730-7268    

DOI:10.1002/etc.5620070404

出版商:Wiley Periodicals, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractStudies were conducted to characterize the diversity of degradative abilities of microbial communities from pristine aquifer solids samples. Biodegradation was measured in aquifer solids slurries as both the conversion of radiolabeled substrate to 14CO2and the incorporation of label into cell biomass. Under aerobic conditions, the microbial community metabolized the following naturally occurring compounds: acetic acid, amino acids, cellulose, cinnamic acid, glucosamine and glucose. The xenobiotic compounds aniline hydrochloride, chlorobenzene,p‐chloro‐phenol,m‐cresol, ethylene dibromide, naphthalene, phenol, toluene and trichlorobenzene were also biodegraded. Several kinetic parameters were calculated from the uptake and mineralization data. First‐order rate constants (K1) ranged from 10−2to 10−4h−1for the natural compounds and from 10−3to 10−6h−1for the xenobiotic compounds. Turnover times ranged from 47 to more than 1,900 h for natural compounds and from 806 to 60,000 h for xenobiotic compounds. For some compounds, respiratory enzymes became saturated, whereas incorporation into biomass was first‐order. The results show that uptake into cell biomass represents a large fraction of total metabolism for many of the xenobiotic compounds.14C‐most‐probable‐number (MPN) of substrate degraders was calculated. MPNs for naturally occurring compounds ranged from 102to 106per gram of soil. There were generally fewer than 10 xenobiotic degraders per gram of soil. The biodegradative activity of the subsurface community appears to differ in both rate and product distribution from the activities of aquatic

ISSN:0730-7268    

DOI:10.1002/etc.5620070405

出版商:Wiley Periodicals, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe freshwater clam,Corbicula fluminea, was exposed during short‐ and long‐term toxicity tests to the anionic surfactant sodium dodecyl sulfate (SDS). Oxygen consumption, condition index, water content and the concentration of free amino acids (FAA) were measured in the clams after exposure. A significant increase in the total FAA concentration was measured in clams exposed for 96 h to 25 mg/L SDS. Exposure to sublethal concentrations (0.65 and 3.0 mg/L SDS) for 60 d caused both an increase in total FAA concentration and a change in the relative concentrations of individual amino acids. Sublethal chronic exposure also decreased oxygen consumption and condition index and increased water content. Alterations in FAA are a more sensitive indicator of toxicant exposure than more traditional measures such as respiration. The potential use of FAA as an in situ biochemical indicator of toxicant‐induced stress in freshwater invertebrates is disc

ISSN:0730-7268    

DOI:10.1002/etc.5620070406

出版商:Wiley Periodicals, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe effect of gaseous hydrogen fluoride (HF) on the loading of [14C]sucrose into phloem was studied because this response was a possible target site for F inhibition of translocation of photoassimilate in intact soybean plants. The active loading of [14C]sucrose into the minor veins of soybean leaf discs was inhibited by continuously exposing the plants to HF at nominal concentrations of 1, 3 and 5 μg F m−3for 8 to 11 d under both controlled‐environment and field conditions. The data suggest that phloem loading at atmospheric levels of HF greater than approximately 1 μg m−3was inhibited less in the plants grown and fumigated in the field than in the lab

ISSN:0730-7268    

DOI:10.1002/etc.5620070407

出版商:Wiley Periodicals, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractCadmium uptake by the early developmental stages of the sheepshead minnow,Cyprinodon variegatus, was studied over a 7.5‐d post‐hatch period. After chorionic hardening (about 4 h after fertilization), eggs were placed in filtered water from the Patuxent River, Maryland (diluted to 5%90 salinity), and dosed with cadmium concentrations of between 0.39 and 1,020 μg L−1. At the highest cadmium concentrations studied, hatching was delayed up to 3 d and larvae had spinal deformities. Growth inhibition was not clearly dose‐related, although larvae from all cadmium treatments were significantly shorter than controls. The lowest dry weights were recorded from the 5.8 and 1,020 μg Cd L−1treatment groups. Cadmium uptake peaked at 12 h after fertilization. Calcium levels in eggs and yolk‐sac larvae reared in 446 μg Cd L−1were greater than in controls after the first 2 d of development but fell behind thereafter, reaching only 50% of the control calcium level after 7.5 d. Inhibition of calcium uptake persisted even after cadmium levels had peaked and fallen to the control level. Phosphorus and sodium concentrations in eggs and larvae were not affected by cadmium exposure. Ninety‐three percent of the cadmium accumulated by the egg was associated with the chorion, and 68% of this could be removed b

ISSN:0730-7268    

DOI:10.1002/etc.5620070408

出版商:Wiley Periodicals, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractFathead minnows,Pimephales promelas, exposed to acidified water (pH = 5.0) for 72 h continued to respond normally to the alarm substance (Schreckstoff) contained in water extracts of conspecific skin. This result contrasts with an earlier finding that some behavioral responses to chemical feeding stimuli are lost at relatively high pH levels (pH = 6.0). In combination, the two sets of results indicate that different stimulus/response systems have different thresholds for interference by acidification.

ISSN:0730-7268    

DOI:10.1002/etc.5620070409

出版商:Wiley Periodicals, Inc.    

年代:1988

数据来源: WILEY