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Journal ArticleDOI

Design of a Passive Biobarrier System for Chromium Containment in Confined Aquifers

TL;DR: In this paper, a procedure based on a simple mathematical model was developed for obtaining the interrelationship between these design variables for containing Cr(VI) in contaminated confined aquifers.
Abstract: Trench-type biobarrier is one of the commonly used in situ systems for bioremediation of contaminated aquifers. Design variables for such a system are the length of the biobarrier, L , initial microbial concentration, M0 , and inlet substrate concentration, S0 . In this work, a procedure, based on a simple mathematical model, was developed for obtaining the interrelationship between these design variables for containing Cr(VI) in contaminated confined aquifers. The microbial characteristics used in this study were obtained by batch and bench scale column studies. A simulation-optimization model is presented for obtaining the screening level optimal solutions, corresponding to a minimal cost. Variation of values of design variables are presented as a function of a nondimensional parameter π1 , which represents the relative magnitude of microbial growth rate and aquifer flow conditions. As π1 increases, the optimal length of the biobarrier and, hence, the cost of the treatment system is reduced. The screeni...
Citations
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01 Jan 2004
TL;DR: Under optimal local conditions, the rate of pollutant degradation might increase upon addition of an inoculant to remediate a chemical spill; however, the most successful cases of bioaugmentation occur in confined systems, such as bioreactors in which the conditions can be controlled to favour survival and prolonged activity of the exogenous microbial population.
Abstract: Microorganisms can degrade numerous organic pollutants owing to their metabolic machinery and to their capacity to adapt to inhospitable environments. Thus, microorganisms are major players in site remediation. However, their efficiency depends on many factors, including the chemical nature and the concentration of pollutants, their availability to microorganisms, and the physicochemical characteristics of the environment. The capacity of a microbial population to degrade pollutants within an environmental matrix (e.g. soil, sediment, sludge or wastewater) can be enhanced either by stimulation of the indigenous microorganisms by addition of nutrients or electron acceptors (biostimulation) or by the introduction of specific microorganisms to the local population (bioaugmentation). Although it has been practiced in agriculture and in wastewater treatment for years, bioaugmentation is still experimental. Many factors (e.g. predation, competition or sorption) conspire against it. However, several strategies are currently being explored to make bioaugmentation a successful technology in sites that lack significant populations of biodegrading microorganisms. Under optimal local conditions, the rate of pollutant degradation might increase upon addition of an inoculant to remediate a chemical spill; however, the most successful cases of bioaugmentation occur in confined systems, such as bioreactors in which the conditions can be controlled to favour survival and prolonged activity of the exogenous microbial population.

31 citations

Journal ArticleDOI
TL;DR: In this paper, single objective and multi-objective management models were developed by embedding the mathematical model describing the process in a simulation-optimization framework, which considered either cost minimization or minimization of time for treatment.

20 citations

Journal ArticleDOI
TL;DR: This study significantly assesses the speciation of dichromate by biogenic agents that are inherent and self-sustaining to treat the contaminated soil and suggests Cr (VI) speciation to Cr (III) by the influence of abiogenic factors are unlikely or less probable as studied in existing geogenic conditions.

2 citations

Journal ArticleDOI
TL;DR: In this paper, a biofilm coated clay composite adsorbent was synthesized and used in a reactive barrier to improve the treatment efficiency of river bank filtration (RBF).

1 citations

References
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Book
01 Sep 1988
TL;DR: In this article, the authors present the computer techniques, mathematical tools, and research results that will enable both students and practitioners to apply genetic algorithms to problems in many fields, including computer programming and mathematics.
Abstract: From the Publisher: This book brings together - in an informal and tutorial fashion - the computer techniques, mathematical tools, and research results that will enable both students and practitioners to apply genetic algorithms to problems in many fields Major concepts are illustrated with running examples, and major algorithms are illustrated by Pascal computer programs No prior knowledge of GAs or genetics is assumed, and only a minimum of computer programming and mathematics background is required

52,797 citations

01 Jan 1989
TL;DR: This book brings together the computer techniques, mathematical tools, and research results that will enable both students and practitioners to apply genetic algorithms to problems in many fields.
Abstract: From the Publisher: This book brings together - in an informal and tutorial fashion - the computer techniques, mathematical tools, and research results that will enable both students and practitioners to apply genetic algorithms to problems in many fields. Major concepts are illustrated with running examples, and major algorithms are illustrated by Pascal computer programs. No prior knowledge of GAs or genetics is assumed, and only a minimum of computer programming and mathematics background is required.

33,034 citations

Journal ArticleDOI
TL;DR: In this paper, a finite-difference approach is proposed for compressible flow conservation laws, involving more of the physics in the conservation laws and more attractive schemes are proposed for more efficient computations.

630 citations

Journal ArticleDOI
TL;DR: In this article, the capacity of a microbial population to degrade pollutants within an environmental matrix (e.g. soil, sediment, sludge or wastewater) can be enhanced either by stimulation of the indigenous microorganisms by addition of nutrients or electron acceptors (biostimulation) or by the introduction of specific microorganisms to the local population (bioaugmentation).

570 citations