摘要:

The photolytic decomposition of tetraethyl lead (TEL) into the derivatives triethyl lead (TriEL), diethyl lead (DiEL) and into inorganic lead (Pb) in aqueous environment has been examined by using a single‐step dithizone extraction method. In cell‐free medium, TEL decomposes rapidly upon illumination to form TriEL, which accumulates in the medium. DiEL is formed in very small quantities only and without any significant accumulation, whereas the concentration of Pb increases slightly but continuously. In darkness the formation of TriEL amounts, as compared to light, to a maximum of 10 %, and DiEL as well as Pb are below the analytical threshold. There is a considerable loss of the initially added TEL: after 98 hr of incubation 96 % of the total lead are eliminated from the illuminated medium and 99.5 % from the non‐illuminated one. In illuminated tap water, where the creation of TriEL takes place much faster than in cultivation medium, the loss of total lead amounts to only 84 %. The formation kinetics for TriEL during the first 72 hr of incubation were determined as follows: tap water/ light: y = 0.18 x; cultivation medium/light: y = ln(l + 0.924 x); cultivation medium/darkness: y = ln(l + 0.006 x), with y being TriEL as ppm Pb and x the hours of incubation.

ISSN:0360-1226    

DOI:10.1080/10934528209375015

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Three herbicides, trifluralin, (α,α, α‐ trifluoro‐2, 6‐dinitro‐N,N‐dipropyl‐p‐toluidine), profluralin (N‐dyclopropylmeehyl)‐α,α,α,‐trifluoro‐2, 6‐dinitro‐N‐propyl‐p‐toluidine), and dinitramine (N4, N4‐diethyl‐α, α,α‐trifluoro‐3, 5‐dinitrotoluene‐2, 4‐diamine) were incubated in an Etowah silt loam soil under laboratory conditions. The herbicides were incubated at 0.5 ppmw herbicide concentrations at 73 and 95°F, and for a time period ranging from 7to17 days. Three pH levels (5.3, 6.4, and 7.5) and three moisture contents (0, 50, and 100% FC) were generally used.

ISSN:0360-1226    

DOI:10.1080/10934528209375016

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The utilization of a venting strategy to remove gasoline vapors from contaminated soil strata was investigated in this exper‐ment. A contained gasoline “leak”; was created in a large outdoor facility which simulated soil strata and a static water table. An air flow was established, and vapor samples taken before, during, and after venting were checked for hydrocarbon content. The effluent air was regularly sampled for carbon dioxide and total hydrocarbons. Carbon dioxide data were used to estimate the amount of microbiological activity, and total hydrocarbon data were used to calculate the total amount of gasoline removed by venting. Hydrocarbon condensates from the effluent air were collected periodically and the compositions of these condensates were compared to the compositions of the starting gasoline and the residual that remained in the soil.

ISSN:0360-1226    

DOI:10.1080/10934528209375017

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The elemental composition of Mount St. Helens ash samples and the amount of water‐leachable trace elements from the ash samples have been measured by inductively coupled plasma emission spectrometry and atomic absorption spectrometry. The leachable fraction of metals ranges from zero to 12 percent. It is speculated that the metals present in the leachates are mainly in colloidal form.

ISSN:0360-1226    

DOI:10.1080/10934528209375018

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Exposure of azadirachtin to sunlight caused a rapid decrease in antifeeding potency against newly emerged first instar (0.046 mg) fall armyworm,Spodoptera frugiperda(J. E. Smith), as compared to unexposed azadirachtin. Acetone solutions of azadirachtin exposed for seven days gave more than a 50 percent reduction in activity while azadirachtin exposed for sixteen days gave complete reduction in activity with destruction of the compound.p‐Aminobenzoic acid, a uv‐absorbing additive, gave slight protection to azadirachtin from photodegradation. Azadirachtin, mixed with various plant oils, was exposed to sunlight for two weeks. Bioassay of these mixtures showed that neem, angelica, castor, and calamus oils provided moderate protection (<25 percent) to azadirachtin from degradation by sunlight.

ISSN:0360-1226    

DOI:10.1080/10934528209375019

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0360-1226    

DOI:10.1080/10934528209375020

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The class of aromatic nitro compounds was studied in order to nominate chemicals to the National Cancer Institute as candidates for carcinogen bioassay. After application of several qualifying criteria relating to previous, current, or planned carcinogenicity tests and to commercial significance, the preliminary candidate list of 441 chemicals was reduced to a list of 210 chemicals. Based upon consideration of both the suspicion of possible carcinogenic activity and evidence indicating potential exposure, the following 14 chemicals were nominated: 4‐chloro‐2‐nitroaniline; 2,4‐dinitroaniline; 4‐nitroaniline; benefin; 2‐bromo‐4,6‐dinitro‐aniline; 2‐nitroanisole; nitrobenzene; 4,4'‐dinitro‐2,2'‐stilbene‐disulfonic acid; l,8‐dihydroxy‐4,5‐dinitroanthraquinone; C.I. Pigment Red 3; C.I. Pigment Orange 5; C.I. Pigment Red 23; C.I. Pigment Yellow 74; and 2‐amino‐6‐nitrobenzothiazole.

ISSN:0360-1226    

DOI:10.1080/10934528209375021

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0360-1226    

DOI:10.1080/10934528209375022

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The 3 tephritids in Hawaii of economic importance, namely the Mediterranean fruit fly (medfly),Ceratltls capltata(Wiedemann), the oriental fruit fly,Dacus dorsalisHendel, and the melon fly,D. cucurbitaeCoquillett, showed marked differences in species‐, age‐, and sex‐specific susceptibilities to CO2anesthetization. Mortalities for medflies exposed to CO2increased more with time than did mortalities for the other 2 species. Older medflies and oriental fruit flies were more susceptible to CO2exposure than were younger flies. Female medflies and oriental fruit flies were generally affected more by CO2exposure than were males. Melon files were the least affected of the tested species by anesthetization with CO2.

ISSN:0360-1226    

DOI:10.1080/10934528209375023

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0360-1226    

DOI:10.1080/10934528209375014

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor