خيارات البحث
النتائج 1 - 10 من 172
Volatile organic compounds in urban rivers and their estuaries in Osaka, Japan.
1997
Yamamoto K. | Fukushima M. | Kakutani N. | Kuroda K.
Polycyclic aromatic hydrocarbons in Norwegian forest soils: impact of long range atmospheric transport.
1996
Aamot E. | Steinnes E. | Schmid R.
Persistence and fate of polychlorinated biphenyls (PCBs) in sewage sludge-amended agricultural soils.
1996
Alcock R.E. | Bacon J. | Bardget R.D. | Beck A.J. | Haygarth P.M. | Lee R.G.M. | Parker C.A. | Jones K.C.
Chronic toxicity of an environmental contaminant mixture to young (or larval) striped bass.
1987
Mehrle P.M. | Cleveland L. | Buckler D.R.
Kinetic constraints on the in-situ remediation of soils contaminated with organic chemicals.
1995
Beck A.J. | Jones K.C.
Observations on long-term air-soil exchange of organic contaminants.
1994
Jones K.C.
Evidence for long-term changes in the soil composition of selected organic compounds, brought about by exchanges with the atmosphere, is briefly reviewed. In the case of some compounds - such as benzo(a)pyrene and octachlorodibenzo-p-dioxin, soils may be significant long-term environmental sinks for atmospherically-derived material. In other cases - such as phenanthrene and some of the lighter PCBs, de-gassing or volatilisation from soil back to the air can occur under certain conditions. Hence the soil may act as a "short-term" sink, and a potential source to atmosphere. Indeed, for some 'semi-volatile' compounds used in large quantities in the past - such as PCBs, soil outgassing may actually be an extremely important source to contemporary air. Furthermore, soil outgassing from areas of former high use may provide an important driving mechanism for continued "global cycling" of a range of semi-volatile organochlorine compounds.
اظهر المزيد [+] اقل [-]Microbiological remediation of waste-oil polluted soils -Ecotoxicological and toxicological considerations.
1994
Rippen G. | Held T. | Ripper P.
A waste-oil contaminated site situated near a river is supposed to be cleaned-up by means of different but complementary methods. On the basis of a research project, target values have been developed in close cooperation between the participant parties for the saturated and the unsaturated soil layers. The clean-up targets are introduced and discussed.
اظهر المزيد [+] اقل [-]The importance of total organic carbon and trihalomethane formation potential in monitoring of groundwater and surface water quality
1999
Ivancev-Tumbas, I. | Dalmacija, B. (Prirodno-matematicki fakultet, Novi Sad (Yugoslavia). Institut za hemiju)
Determination of total organic carbon content (TOC) and trihalomethane formation potential (THMFP) as well as correlation of those two parameters is recommended for monitoring of water bodies which are considered as drinking water resources. Those parameters would enable a categorization of water bodies from the protection point of view as well as from view of their usage as drinking water sources. Relationship between TOC and THMFP is dependent on the origin and the structure of organic matter in water. In this paper the correlation of TOC and THMFP is given for different kind of resources.
اظهر المزيد [+] اقل [-]High-rate anaerobic treatment of digestate using fixed film reactors
2019
Ülgüdür, Nilüfer | Ergüder, Tuba H. | Uludağ-Demirer, Sibel | Demirer, Göksel N.
The effluent stream of the anaerobic digestion processes, the digestate, accommodates high residual organic content that needs to be further treated before discharge. Anaerobic treatment of digestate would not only reduce the residual organic compounds in digestate but also has a potential to capture the associated biogas. High-rate anaerobic reactor configurations can treat the waste streams using lower hydraulic retention times which requires less footprint opposed to the conventional completely stirred tank reactors. This study investigated the high-rate anaerobic treatment performance and the associated biogas capture from the digestate of a manure mixture composed of 90% laying hen and 10% cattle manures in fixed-film reactors. The results indicated that it was possible to reduce total chemical oxygen demand content of the digestate by 57–62% in 1.3–1.4 days of hydraulic retention time. The corresponding biogas yields obtained were in the range of 0.395–0.430 Lbiogas/g VSadded which were found to be comparable to many raw feedstocks. Moreover, significant total phosphorus reduction (36–47%) and greenhouse gas capture (over 14.5–18.1 tCO2e/d per m3 digestate) were also recorded in the anaerobic fixed-film reactors.
اظهر المزيد [+] اقل [-]The organic molecular composition, diurnal variation, and stable carbon isotope ratios of PM2.5 in Beijing during the 2014 APEC summit
2018
Ren, Hong | Kang, Mingjie | Ren, Lujie | Zhao, Yue | Pan, Xiaole | Yue, Siyao | Li, Linjie | Zhao, Wanyu | Wei, Lianfang | Xie, Qiaorong | Li, Jie | Wang, Zifa | Sun, Yele | Kawamura, Kimitaka | Fu, Pingqing
Organic tracers are useful for investigating the sources of carbonaceous aerosols but there are still no adequate studies in China. To obtain insights into the diurnal variations, properties, and the influence of regional emission controls on carbonaceous aerosols in Beijing, day-/nighttime PM₂.₅ samples were collected before (Oct. 15th – Nov. 2nd) and during (Nov. 3rd – Nov. 12th) the 2014 Asia-Pacific Economic Cooperation (APEC) summit. Eleven organic compound classes were analysed using gas chromatography/mass spectrometry (GC/MS). In addition, the stable carbon isotope ratios (δ¹³CTC) of total carbon (TC) were detected using an elemental analyser/isotope ratio mass spectrometry (EA/irMS). Most of the organic compounds were more abundant during the night than in the daytime, and their concentrations generally decreased during the APEC. These features were associated with the strict regional emission controls and meteorological conditions. The day/night variations of δ¹³CTC were smaller during the APEC than those before the APEC the summit, suggesting that regionally transported aerosols are potentially played an important role in the loading of organic aerosols in Beijing before the APEC summit. The source apportionment based on the organic tracers suggested that biomass burning, plastic and microbial emissions, and fossil fuel combustion were important sources of organic aerosols in Beijing. Furthermore, a similar contribution of biomass burning to OC before and during the APEC suggests biomass burning was a persistent contributor to PM₂.₅ in Beijing and its surroundings.
اظهر المزيد [+] اقل [-]