摘要:

A study was conducted to determine the effects of ozonation on pH, heavy metals, and COD of four sludges, i.e., return activated sludge, thickened sludge, anae‐robically digested sludge, and bottom sediments of lake as a control sludge. It was found that heavy metals were released from the sludges after ozonation. Total COD decreased considerably and dissolved COD increased as a result of ozonation. Slight changes in pH values were observed during ozonation, and odor was completely eliminated from all sludges.

ISSN:0360-1226    

DOI:10.1080/10934528209375065

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The noxious, submersed aquatic plantHydrilla verticillatahas not thrived in certain lakes, including Lake Starvation, northwest Hillsborough County, Florida. Aqueous extracts of sediment from that lake were inhibiting the growth of hydrilla in the laboratory (Co, organic carbon,ca. 0.4 ppm). In contrast, similar concentrations of active fractions did not inhibit the growth of the freshwater algaS.obliquus, though at higher concentrations, cultures were stimulated (6–12 ppm, Co), and inhibition was noted for the highest concentration studied (18 ppm Co, 0.01 ppm Fe).

ISSN:0360-1226    

DOI:10.1080/10934528209375066

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Application of Avadex BW or triallate {(S‐(2,3,3‐trichlorallyl)‐diisopropylthiocarbamate} to soils subject to water ponding or temporary flooding may present some problems in wild oat (Avena fatua L.) control. Both wild oat and domestic oat (Avena sativa L.) are susceptible to triallate. Laboratory incubations of triallatetreated soils at 25°C showed the response of domesticated oat (cultivar ‘Harmon') to triallate was related to soil moisture content and to the length of incubation time. Triallate activity decreased more slowly at a soil water content of 5% below field capacity than for incubations at field capacity. Triallate treated soils incubated under water saturation conditions generally retained a higher level of phytotoxicity than those incubated at moisture contents of field capacity or less. Soils containing trial late incubated at a moisture content mid‐way between saturation and field capacity did not differ in activity to those incubated at field capacity. These results suggest that with soil moisture contents at or above field capacity but not saturated, trial late in‐activation may be more rapid than at more normal moisture levels for agricultural soils.

ISSN:0360-1226    

DOI:10.1080/10934528209375067

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Danio malabaricusandPuntius tictowere exposed to Cu, Hg, and Cd under static bio‐assay conditions. The results shows that Cu was more toxic toD.,malabaricusthan the fishes treated with Hg and Cd. The Hg was more toxic toP. tictothan the fishes treated with Cu and Cd. The 24 h LC 50 value of 0.5 mg/l with Cu. forD. malabaricusand 3.0 rag/l forP. tictowere recorded, while the 24 h LC 50 values with Hg forD,malabaricuswas 2 mg/l and 0.38 mg/l forP. ticto. The Cd, at the concentrations tested did not affect till 24 h. The LC 50 values at 96 h with Cd. forD. malabaricuswere 25 mg/l and 32 mg/l forP. ticto.

ISSN:0360-1226    

DOI:10.1080/10934528209375068

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Twenty natural and synthetic substances, known or reported to be repellent to insects, were evaluated for repellency to adult house flies,Musca domesticaL., by a new laboratory test method. Fourteen materials completely repelled the flies during a 30‐min test period. The most active material was 2‐phenylethanol.

ISSN:0360-1226    

DOI:10.1080/10934528209375069

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0360-1226    

DOI:10.1080/10934528209375070

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A total of 72 male Sprague‐Dawley rats were assigned to three groups using a 3 X 3 factorial design. Animals were injected IP every three days for 29 days with 0, 1.0 or 2.5 mg CdCl2/kg of body weight. Total cumulative CdCl2doses were 0. 9.0 or 22.5 mg/kg of body weight. Animals were sacrificed on day 1, 7 or 21 following injections. Liver and kidney tissues were collected and analyzed for Cd concentrations.

ISSN:0360-1226    

DOI:10.1080/10934528209375071

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Concentrations of ten known or suspected toxic and/or carcinogenic volatile organic compounds, including benzene, chloroform, carbon tetrachloride, trichloroethylene, tetraehloroethylene, ortho‐ and para‐diehlorobenzene, 1,2‐dichloroethane, 1,1,1‐trichloroethane, and nitrobenzene were measured in ambient air. Samples were taken in three sections of northeastern New Jersey for purposes of discerning whether high concentrations of these species existed in selected areas of the state. The pollutants were collected by trapping on porous polymer (Tenax), thermal desorption, and high resolution gas chromatographic analysis. Concentrations in the low and sub‐part‐per billion range were found. Differences in the concentration levels of these pollutants were detectable when urban, suburban residential, and industrial areas were compared. The results obtained in this work prove to be comparable with those of researchers in other locations.

ISSN:0360-1226    

DOI:10.1080/10934528209375072

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Selected volatile organic species, including chloroform, 1,2‐dichloroethane, 1,1,1‐trichloroethane, benzene, carbon tetrachloride, trichloroethylene, tetrachloroethylene, p‐dichlorobenzene, o‐dichlorobenzene, and nitrobenzene, are determined in ambient air by collection and concentration on Tenax‐filled traps. The samples are recovered for analysis by a novel thermal desorption system which allows the injection of an aliquot of the sample into a 50M fused silica methyl silicone gas chromatographic column, which is programmed from ‐90 to 140° C. A standard addition process for qualitative analysis and an external standard method for quantitation are described, both using compressed gas standards. GC/MS is used for confirmation of sample identity on approximately 10% of the samples.

ISSN:0360-1226    

DOI:10.1080/10934528209375073

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The perennial submersed noxious aquatic plantHydrilla verticillata(Royle) was treated with well water solutions of methylene blue, hematoporphyrin, and Eosin Y, and compared with control systems. Statistically significant reductions in growth were observed for treatments with all three dyes at initial dye concentrations of 10‐4M. Typically, reductions in growth of 30 percent on a relative basis for the test systems were observed. Methylene blue was adsorbed onto the plant, raising the possibility that shading could be affecting plant growth. Similar adsorption was not noted for the other two dyes. Though two dyes are used as redox indicators, the third — hematoporphyrin — is not but a common mechanism of action may be proposed: that the dyes are involved in photodynamic action. It is possible that natural products may act in a similar manner to manage hydrilla through photodynamic action, and the implications of this hypothesis are considered.

ISSN:0360-1226    

DOI:10.1080/10934528209375074

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor