Showing papers in "Critical Reviews in Environmental Science and Technology in 1994"
TL;DR: In this paper, the physical and chemical frameworks for the attenuation processes are discussed in terms of dilution/dispersion and redox zones in the plume, respectively, and a separate section focuses on the occurrence of bacteria in plumes, the fate of pathogens, and microbial mediation of redox processes.
Abstract: Landfill leachate contains a variety of pollutants that may potentially contaminate the ground water and affect the quality of surface waters and well waters. The literature has been critically reviewed in order to assess the attenuation processes governing the contaminants in leachate‐affected aquifers. After an introductory section on leachate composition, the physical and chemical frameworks for the attenuation processes are discussed in terms of dilution/dispersion and redox zones in the plume, respectively. A separate section focuses on the microbiology in terms of the occurrence of bacteria in plumes, the fate of pathogens, and microbial mediation of redox processes. In individual sections, the attenuation of dissolved organic matter, anthropogenic‐specific organic compounds, inorganic macrocomponents as anions and cations, and heavy metals are discussed. The focus is on laboratory experiences and field investigations. The review shows that most leachate contamination plumes are relatively ...
467 citations
TL;DR: While some of the world's most productive agriculture is on artificially drained soils, drainage is increasingly perceived as a major contributor to detrimental off-site environmental impacts as discussed by the authors, which is a concern.
Abstract: While some of the world's most productive agriculture is on artificially drained soils, drainage is increasingly perceived as a major contributor to detrimental off‐site environmental impacts. Howe...
449 citations
TL;DR: A search of the literature concerning the influence of commercial surfactants and biosurfactants on microbial metabolism has been conducted in this paper, where factors pertaining to surfactant-substrate interactions such as emulsification, solubilization, and partitioning of hydrocarbons between phases, all of which can influence accessibility of substrates to microorganisms, are of concern.
Abstract: Surfactants have the ability to increase aqueous concentrations of poorly soluble compounds and interfacial areas between immiscible fluids, thus potentially improving the accessibility of these substrates to microorganisms. However, both enhancements and inhibitions of biodegradation of organic compounds in the presence of surfactants have been reported. The mechanisms behind these phenomena are not well understood. To better understand the factors involved and the current state of knowledge in this field, a search of the literature concerning the influence of commercial surfactants and biosurfactants on microbial metabolism has been conducted. Factors pertaining to surfactant‐substrate interactions such as emulsification, solubilization, and partitioning of hydrocarbons between phases, all of which can influence accessibility of substrates to microorganisms, are of concern. Also, due to the direct interaction of surfactants with microorganisms, it appears that steric or conformational compatibi...
232 citations
TL;DR: There have been few significant advances in our knowledge of evaporation on an environmental scale during the past 4 decades, a state of affairs linked to the concurrent sterility of research in hydrology and the related environmental sciences as discussed by the authors.
Abstract: There have been few significant advances in our knowledge of evaporation on an environmental scale during the past 4 decades, a state of affairs linked to the concurrent sterility of research in hydrology and the related environmental sciences. Furthermore, almost none of the advances have been used successfully in practice. This means that we can provide only trivial or dubious answers to important environmental questions. A critical review, based on a quarter century of research on evaporation, has indicated that much of the superficiality of the environmental sciences can be attributed to inappropriate methodologies and the application of linear cause‐and‐effect ways of thinking to the cybernetic feedback mechanisms that prevail in environmental systems. The resultant problems are particularly evident in the application of small‐scale processes to large, environmentally significant areas and in the application of mechanistic concepts to the interactions between plants and their environments. A...
62 citations
TL;DR: A review of the currently available incinerator systems in the light of basic combustion theory can be found in this paper, which provides potential users with sufficient background to evaluate the various technologies for application to their specific waste stream.
Abstract: A major control strategy for dilute waste streams of volatile organic compounds (VOCs) in air is incineration. However, no single incineration technology will likely serve as the optimal solution for all applications. In addition, with increasing VOC regulation, more variations of incineration or oxidation systems are appearing in the marketplace. This review presents a description of the currently available incinerator systems in the light of basic combustion theory. It is intended that this overview provide potential users with sufficient background to evaluate the various technologies for application to their specific waste stream. The discussion is presented in two parts. The first deals with thermal or gas‐phase oxidation reactions and those incinerators that employ the thermal pathway for VOC destruction. Both recuperative and regenerative systems are described in this part of the review. The second part treats catalytic incinerators with the same emphasis on underlying principles. The disc...
34 citations
TL;DR: This study reviews data on the extent of HAV prevalence and persistence in the environment and water and finds that HA is highly prevalent in low socioeconomic populations as determined by seroepidemiologic studies.
Abstract: Hepatitis A virus (HAV) is a major waterborne disease agent with worldwide distribution. The main transmission route of HAV is direct person‐to‐person contact. However, hepatitis A (HA) outbreaks associated with the consumption and use of fecally contaminated water were reported from many countries. Studies on the environmental behavior of HAV were feasible only after developing techniques for its cultivation and enumeration in tissue culture. This study reviews data on the extent of HAV prevalence and persistence in the environment and water. HA is highly prevalent in low socioeconomic populations as determined by seroepidemiologic studies. HAV is excreted for long periods by infected individuals, but it is also shed by healthy persons. HAV has been detected in concentrated wastewater and natural waters. However, in most cases the natural waters were monitored for the presence of HAV after the occurrence of HA outbreak. HAV persists for months at temperatures below 10°C and for at least 1 month ...
21 citations
TL;DR: Bikini and Enewetak Atolls in the Marshall Islands were selected for various reasons discussed in this article, and sixty-six nuclear devices of various types were detonated from 1945 through mid-1958 at these atolls.
Abstract: Following the end of World War H, the U.S. Government decided to commence nuclear weapons testing and consequently searched for a suitable test site. Bikini and Enewetak Atolls in the Marshall Islands were selected for various reasons discussed in this manuscript. Sixty‐six nuclear devices of various types were detonated from 1945 through mid‐1958 at these atolls. During this period and for an extended period thereafter, extensive endeavors to rehabilitate these atolls occurred. In addition to physical rehabilitation, scientists were involved in basic investigations on the cycling of radionuclides and the effects of ionizing radiation on the atoll environment. Further, a limited number of observations were made on the cultural impacts of removal and possible return of the Bikini and Enewetak Marshallese to their home atolls. The extensive but obscure literature as well as unfamiliarity by many people of the health aspects of ionizing radiation and fundamentals of radiation ecology encouraged the ...
7 citations