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Aerated stabilization basins (ASBs) currently account for about one third of the pulp and paper industry's secondary treatment capacity. We surveyed mills with ASBs to analyze design and operating practices. Of the 19 mills that responded, 15 were kraft, reflecting the industry's overall use of ASBs. Biochemical oxygen demand (BOD) and total suspended solids (TSS) loading to the ASBs varied considerably and were factors in biotreatment performance. Problems identified with some ASBs included excessive solids accumulation resulting in the need for frequent dredging, high TSS discharge, and difficulty with nutrient management. Most ASBs have either two or three cells. An important parameter identified for these cells is the benthal settling area. Too small an area results in a higher dredging frequency, with limited nutrient feedback. In general, ASB systems that used the most intensive mixing and aeration in the upstream cells tended to have a smaller benthal settling area, resulting in the need to dredge more frequently. Ideally, some benthal settling should be designed into the upstream cells to allow nutrient feedback where it is needed most. [ABSTRACT FROM AUTHOR]

Presents a study that aimed to determine the levels at which phytosterols are present in Canadian pulp and paper mill effluents (PPME). Description of PPME; Chemicals that form the major fraction of plant sterols in PPME; Processes responsible for the observed removal of plant sterols across the biological wastewater treatment systems.

This study investigated the use of bark and combined paper sludge to develop a suitable plant growth substrate and to establish a vegetation cover on bark-covered land. Field experiments were established to determine the best plant growth medium, plant mixtures, and fertilization program. The best soil cover consisted of 2.5 cm of combined paper sludge on top of 2.5 cm of black bark. On this soil cover, the Savoureux mixture in combination with birdsfoot trefoil (Lotus corniculatus L.), Lab02 in mixture with MR77, and birdsfoot trefoil in mixture with bromegrass (Bromus inermis L.) gave good vegetation growth and yields. For birdsfoot trefoil over all soil covers, the phosphorus and potassium fertilizations were required at 140 kg P2O5/ha and 160 kg K2O/ha, respectively. These results suggest that combined paper sludge and black bark can be used as topsoil to favor plant establishment on bark-covered land. [ABSTRACT FROM AUTHOR]

Deinking by-product (DBP), a cellulose-rich by-product produced in the early stages of the paper recycling process, has been used as alternative material for the construction of cover systems for municipal waste disposal facilities and acid-producing mine residues. Because of the high organic content of this material, covers constructed with it are susceptible to biodegradation and, thus, to changes in their properties with time. With the goal of identifying the biodegradation parameters that could influence the long-term behaviour of DBP covers, an experimental laboratory program was developed and a series of 15 samples of DBP were monitored in biodegradation tests for 400 d. Periods of intermittent water percolation allowed for collection of leachate. The evolution of gas and leachate production was monitored in terms of quality and quantity. According to the results obtained, the hydraulic and geomechanical properties of importance for a cover do not seem to be adversely affected by the level of biodegradation of the DBP or by mass loss. [ABSTRACT FROM AUTHOR]

This phase of the study (Part II) investigates the application of a high-rate fluidized bed adsorber reactor (FBAR) process for biological denitrification of reverse osmosis (RO) brine concentrate. The companion paper (Part I) reported the first phase of the project, describing the batch and chemostat biokinetic studies employed for evaluating the process feasibility, and for optimizing the reaction conditions including the carbon and energy source, pH, temperature, and the carbon-to-nitrogen ratio. This paper describes the next stage of the study involving FBAR experiments using granular activated carbon (GAC) for denitrification and sulfate reduction conducted at different hydraulic retention times, and nitrate concentrations. These experiments showed that nitrate removal efficiencies in excess of 99% were achieved. Similar FBAR experiments conducted with sand showed that initially less nitrate removal was experienced, but under steady-state conditions over 99% removal was achieved. Additionally, this study examined the simultaneous denitrification and sulfate removal in a similar FBAR process. A second FBAR, employed to remove the remaining sulfate from the first FBAR, achieved over 99% removal. A biofiltration process was designed and operated to effectively eliminate hydrogen sulfide in the sulfate-reducing FBAR process. The sulfate reduction FBAR was also responsible for the removal of toxic metals and metalloids present in the brine concentrate by a combination of sulfide precipitation and sorption onto iron sulfides. Cette phase de l’étude (Partie II) examine l’application d’un procédé avec réacteur adsorbeur à lit fluidisé (FBAR) de haut débit à la dénitrification d’un concentré de saumure obtenu par osmose inverse. L’article complémentaire (Partie I) examine la première phase du projet et décrit les études en discontinu et de biocinétique des chémostats utilisés pour évaluer la faisabilité du procédé et pour optimiser les conditions de réaction, dont la source de carbone et d’énergie, le pH, la température ainsi que le rapport carbone-azote. Le présent article décrit la prochaine étape de l’étude impliquant des expériences par FBAR utilisant du charbon actif granulaire pour la dénitrification et la sulfatoréduction réalisées à divers temps de rétention hydraulique et concentrations de nitrates. Ces expériences indiquent que l’efficacité de dénitrification dépassait 99 %. Des expériences similaires avec FBAR effectuées avec du sable indiquent qu’au début une dénitrification inférieure mais que, sous des conditions stables, une élimination supérieure à 99 % est atteinte. De plus, cette étude examine la dénitrification et l’élimination simultanées des sulfates dans un procédé FBAR similaire. Un deuxième FBAR utilisé pour éliminer les sulfates résiduaires du premier FBAR a atteint une élimination supérieure à 99 %. Un procédé de biofiltration a été conçu et exploité pour éliminer efficacement les sulfures d’hydrogène dans le procédé sulfatoréducteur du FBAR. Le FBAR de sulfatoréduction élimine aussi les métaux et les métalloïdes toxiques présents dans le concentré de saumure grâce à une combinaison de précipitation des sulfures et la sorption sur des sulfures de fer. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A major technological concern with reverse osmosis in water purification, wastewater treatment, and water reclamation or recycling is the production of brine concentrates high in ammonia or nitrogen. This project addresses biological denitrification of reverse osmosis brine concentrates in a bioactive fluidized bed adsorber reactor (FBAR), accomplished in four stages. The first three stages are described in this paper, while the final stage is addressed in the companion paper (Ersever et al. 2007). The first stage optimized an FBAR to produce nitrified brine for subsequent denitrification studies. The second stage employed batch reactors to evaluate denitrification parameters such as temperature, pH, total dissolved solids, and carbon-to-nitrogen ratio. The specific denitrification rate was maximum at a temperature of 35 °C, pH of 8.0, and carbon-to-nitrogen ratio of 1.8. The third stage involved chemostats to determine Monod parameters under nitrate-, nitrite-, and carbon-limiting conditions. A biokinetic model was employed to simulate chemostat dynamics and to estimate the biological parameters. The final stage entailed FBAR denitrification experiments under different hydraulic retention times, nitrate concentrations, and packing media; simultaneous denitrification and sulfate reduction were addressed. A second FBAR used in series with the first achieved an overall sulfate reduction of 99%, and a biofilter effectively removed the hydrogen sulfide generated. Une préoccupation technologique important relié à l’utilisation de l’osmose inverse pour la purification de l’eau, le traitement des eaux usées et la récupération ou le recyclage de l’eau est la production de concentrés de saumure contenant beaucoup d’ammoniac ou d’azote. Le présent projet traite de la dénitrification biologique, en quatre étapes, des concentrés de saumure de l’osmose inverse dans un réacteur adsorbeur à lit fluidisé (FBAR). Les trois premières étapes sont décrites dans cet article alors que l’étape finale est traitée dans un article complémentaire (Ersever et al. 2007). La première étape optimise un FBAR afin de produire une saumure nitrifiée pour les études de dénitrification subséquentes. La deuxième étape utilise des réacteurs discontinus pour évaluer les paramètres de dénitrification tels que la température, le pH, les matières totales dissoutes et le rapport carbone-azote. Le taux spécifique de dénitrification (SDR) a atteint son maximum à une température de 35  °C, un pH de 8,0 et un rapport C-N de 1,8. La troisième étape impliquait des chémostats afin de déterminer les paramètres de Monod dans des conditions limitant les nitrates, les nitrites et le carbone. Un modèle biocinétique a été utilisé pour simuler la dynamique des chémostats et estimer les paramètres biologiques. L’étape finale nécessitait des expériences de dénitrification par le FBAR sous différents temps de rétention hydraulique, concentrations de nitrates et de médium de garniture; la dénitrification simultanée et la sulfatoréduction ont aussi été abordées. Le deuxième FBAR utilisé en série avec le premier a atteint une sulfatoréduction globale de 99 %; un biofiltre a efficacement éliminé le sulfure d’hydrogène produit. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper introduces the fabrication procedure and evaluation method of an oxygen microelectrode applicable to environmental engineering and science research. The theory and development of an oxygen microelectrode technique are introduced. The fabrication procedure of a combined oxygen microelectrode with small-tip diameter (15–20 mm) is described in detail. This microelectrode was then evaluated by subjecting it to a polarization voltage of –0.8 V and calibrating against known dissolved oxygen concentrations from zero to air saturation. The results of the evaluation demonstrated that the fabrication procedure reported in this paper was successful. This microelectrode had a fast response time (<2 s), stable reading with good calibration linearity (R[sup 2] = 1), low residual current signal (6 pA), and low stirring effect (4%). No electromagnetic interference was observed when this combined oxygen microelectrode was used under both laboratory and field conditions. The combined oxygen microelectrode fabricated using this procedure can be used for in situ measurement of dissolved oxygen in wastewater biofilms under field conditions. Key words: microelectrode, microsensor, oxygen, fabrication, polarization, calibration, biofilm, wastewater.Cet article présente la procédure de fabrication et la méthode d'évaluation d'une microélectrode d'oxygène pouvant être appliquée aux domaines de recherche en ingénierie et en sciences de l'environnement. Nous présentons la théorie et le développement d'une microélectrode d'oxygène. La procédure de fabrication d'une microélectrode combinée d'oxygène avec un diamètre de pointe infime de 15 à 20 mm est décrite en détail. Cette microélectrode est évaluée par la polarisation à –0,8 V et l'étalonnage par rapport à des concentrations d'oxygène dissous connues entre zéro et la saturation en air. Les résultats de l'évaluation démontrent que la procédure de fabrication dont il est question dans cet article a réussi. Cette microélectrode possède un temps de réponse rapide (moins de 2 secondes), une lecture stable et une bonne linéarité de l'étalonnage (R[sup 2] = 1), un faible signal de courant résiduel (6 pA) et un faible effet d'agitation (4 %). Aucune interférence électromagnétique n'a été observée lors de l'utilisation de cette microélectrode d'oxygène sous des conditions de laboratoire et de terrain. La microélectrode combinée d'oxygène fabriquée en utilisant cette procédure peut être utilisée pour la mesure in situ d'oxygène dissous dans les biofilms d'eaux usées en conditions de terrain. Mots clés : microélectrode, microcapteur, oxygène, fabrication, polarisation, étalonnage, biofilm, eaux usées.[Traduit par la rédaction] [ABSTRACT FROM AUTHOR]

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A biological process for the removal of hydrogen sulphide (H2S) in digester biogas was investigated using nitrified municipal wastewater as a nutrient solution under anoxic conditions. Biogas was continuously fed into a 0.012 m3 biotrickling filter at an H2S loading rate of approximately 1.50 g/d, counter-current to the nutrient solution. A zero-order macro-kinetic process was established on the basis of the degradation and formation rates for N and S species. The process performance was dependent on the presence of nitrate at low concentrations (in the order of 20 mg N-NO3-/L) found to be sufficient to maintain maximum H2S removal efficiency (>99%) under steady-state conditions where nitrate degradation rate was constant. The developed process has the potential to be adopted as an attractive alternative for biogas cleaning and, in some cases, with simultaneous wastewater denitrification. The information contained within this paper may be used as a basis for further research and (or) in the design of a scaled-up process. Un processus biologique anoxique pour l’enlèvement du sulfure d'hydrogène (H2S) dans le biogaz de digesteur a été étudié, en employant de l’eau usée municipale nitrifiée comme solution nutritive dans des conditions anoxiques. Le biogaz du digesteur a été alimenté en continu dans un biofiltre percolateur de 0,012 m3 à une charge de H2S d’environ 1,50 g par jour, à contre-courant de la solution nutritive. Un processus macro-cinétique d’ordre zéro a été établi sur la base des vitesses de dégradation et de formation des espèces à base de N et S. La performance du procédé a été dépendante de la présence de nitrates à des faibles concentrations (de l’ordre de 20 mg N-NO3-/L), avérées suffisantes pour maintenir le taux maximum d'enlèvement de H2S (>99 %) dans des conditions de régime permanent où la vitesse de dégradation du nitrate était constante. Le procédé développé a le potentiel d’être adopté comme alternative attrayante pour la purification des biogaz et, dans certains cas, simultanément avec le denitrification des eaux résiduaires. L'information contenue dans cet article peut être employée comme base pour la recherche dans ce domaine et (ou) dans la conception d'un procédé à grande échelle. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Activated sludge process is widely used for wastewater treatment throughout the world with various needful modifications. The hybrid modification of conventional activated sludge process utilizes a suspended media of appropriate inert material or fixed surface that serves as carrier material for growing active microorganisms on its surface. As a result the carrier media allows the biological reactor to operate at a higher biomass concentration, compared to the conventional activated sludge process. The hybrid modification of conventional activated sludge process can be configured either to provide additional capacity for biochemical oxygen demand (BOD) removal or to facilitate nitrogen control. The process is ideally suited for upgrading the existing system with a nominal modification. The present paper summarizes various research work towards the hybrid system to review the requirements and scope of modification, development and evolution of the hybrid modification. The review concludes with an assessment of financial viability of hybrid modifications. Le procédé de traitement par boues activées est largement utilisé pour le traitement des eaux usées dans le monde, requerrant cependant plusieurs modifications. La modification hybride du procédé traditionnel de traitement par boues activées utilise un matériau inerte adéquat en suspension ou une surface fixe qui sert de matière de charge pour la croissance de microorganismes actifs sur cette surface. Il en résulte que la matière de charge permet au bioréacteur de fonctionner à une concentration de biomasse supérieure à celle du procédé traditionnel de traitement par boues activées. La modification hybride du procédé traditionnel de traitement par boues activées peut être configurée pour fournir une capacité additionnelle pour l’élimination de la DBO (demande biochimique en oxygène) ou pour faciliter le contrôle de l’azote. Le procédé est parfaitement adapté aux mises à niveau des systèmes existants par une modification nominale. Cet article résume les divers travaux de recherche sur le système hybride afin de revoir les exigences et la portée des modifications, du développement et de l’évolution de la modification hybride. La revue se termine par une évaluation de la viabilité financière des modifications hybrides. [ABSTRACT FROM AUTHOR]

The ability of aerosolized disinfectant agents to reach exterior and interior spaces of walls and other difficult to access areas has potential as a remediation technique for contained biological contamination. Bacillus subtilis were evaluated against aerosolized solutions of distilled water (dH2O, control), 0.05% chlorine dioxide (ClO2), and 0.6% sodium hypochlorite (NaOCl). Bacillus subtilis endospores were inoculated onto commercially available gypsum board with paper facing. Aerosols generated from a collison nebulizer were directed into a sterile contact chamber housing the inoculated gypsum board for 4, 8, and 12 hour periods. Independent evaluations were conducted of the gypsum board where the organism B. subtilis were exposed to the aerosolized disinfectant. Treatment effects were evaluated through the collection of surface samples before and after exposures. The aerosolized 0.6% sodium hypochlorite solution was the only treatment successful in reducing the total concentration of B. subtilis. Treatment with sodium hypochlorite solution reduced B. subtilis organisms by 1.55-log after 4 h, 1.92-log after 8 h, and 2.50-log after 12 h of exposure, though the difference in log-reduction between exposure periods were not statistically significant. La capacité des désinfectants vaporisés à atteindre les surfaces extérieures et intérieures des murs et d’autres zones difficiles d’accès leur confère le potentiel de remédier à une contamination biologique en milieu fermé. Bacillus subtilis a été évalué contre diverses solutions vaporisées d’eau distillée (contrôle), de dioxyde de chlore à 0,05 % (ClO2), et d’hypochlorure de sodium à 0,6 % (NaOCl). Les endospores de B. subtilis ont été inoculés sur des plaques de plâtre cartonnées disponibles sur le marché. Les aérosols générés par un nébuliseur Collison ont été dirigés dans une salle de contact stérile comprenant les plaques de plâtre cartonnées inoculées pour des durées de quatre, huit et douze heures. Des évaluations indépendantes ont été réalisées sur les plaques de plâtre cartonnées où B. subtilis a été exposé au désinfectant vaporisé. Les effets des traitements ont été évalués par la collecte d’échantillons de surface avant et après les expositions. La solution vaporisée d’hypochlorure de sodium à 0,6 % a été le seul traitement ayant réussi à réduire la concentration totale de B. subtilis. Le traitement avec la solution vaporisée d’hypochlorure de sodium a réduit les organismes B. subtilis de 1,55log après 4 heures, de 1,92log après 8 heures et de 2,50log après 12 heures d’exposition, bien que la différence dans la réduction logarithmique entre les périodes d’exposition n’était pas significative statistiquement. [ABSTRACT FROM AUTHOR]

Drinking water filtration systems should be as robust as possible to consistently provide finished water of high quality to protect public health. The quantification of robustness makes it possible to evaluate the status of a given system. This paper introduces a newly developed turbidity robustness index, which differentially weights average performance and deviations from average. A second new robustness evaluation method - the probability method - was also developed. This method provides the basis to implement almost real-time online monitoring of filtration robustness as the filter cycle develops. This may be particularly useful in smaller systems, which usually have less direct operator oversight. Both of the newly developed robustness approaches were applied to assess filtration turbidity performance at selected full-scale water treatment plants. Les systèmes de filtration d’eau potable devraient être aussi robustes que possible afin de fournir constamment de l’eau prête au débit de haute qualité dans le but de protéger la santé du public. La quantification de la robustesse rend possible l’évaluation de l’état d’un système donné. Le présent article introduit un indice de robustesse développé récemment qui pondère de manière différentielle le rendement moyen et les déviations de la moyenne. Une deuxième méthode d’évaluation de la robustesse - la méthode probabiliste - a également été développée. Cette dernière méthode fournit la base pour implanter un suivi en temps quasi réel en ligne de la robustesse de filtration lors du développement du cycle de filtration. Cela peut être particulièrement utile pour les systèmes plus petits que les opérateurs surveillent moins directement. Les deux nouvelles approches de la robustesse ont été appliquées à l’évaluation du rendement de la filtration de la turbidité dans des usines sélectionnées de traitement des eaux pleine échelle. [ABSTRACT FROM AUTHOR]

In North America, the rapid movement away from the direct discharge of water treatment plant (WTP) residual streams to receiving environments has resulted in considerable benefits to the drinking water industry in terms of enhancing environmental stewardship practices and supporting source water protection strategies. Over the past 20 years, application based research on appropriate technologies to treat residual streams such as filter backwash water (FBWW) has promoted the development of integrated process design that presents recycling as a viable residual management option. However, as utilities continue to develop and expand their main process lines to comply with more stringent government regulations encompassing both water quality and residual disposal practices, the development of sustainable residual management practices is expected to become a more prominent issue for this industry. The purpose of this paper is to present, from a critical point of view, the matrix of issues that currently exist regarding WTP residual streams and strategic pathways that would enhance future decision making processes for achieving long-term residual management solutions for the drinking water industry. En Amérique du Nord, l’abandon rapide de la décharge directe des effluents des usines de traitement des eaux dans les milieux récepteurs a grandement profité à l’industrie de l’eau potable en termes d’amélioration des pratiques de gérance environnementale et de soutien des stratégies de protection des sources d’eau. La recherche des 20 dernières années, appliquée aux technologies appropriées de traiter les effluents, tels que l’eau de lavage des filtres à contre-courant, a favorisé le développement d’une conception de procédé intégrée qui présente le recyclage comme une option viable de gestion des matières résiduelles. Toutefois, à mesure que les services publics continuent de développer et d’étendre leurs chaînes de procédé principales pour rencontrer les règlements gouvernementaux plus sévères touchant la qualité des eaux et les pratiques d’élimination des matières résiduelles, le développement de pratiques de gestion durable des matières résiduelles devrait revêtir plus d’importance pour cette industrie. L’objectif de cet article est de présenter de manière critique la matrice des enjeux existants dans les effluents des usines de traitement des eaux et les chemins stratégiques qui pourraient améliorer les prises de décisions futures pour arriver à des solutions de gestion des matières résiduelles à long terme pour l’industrie de l’eau potable. [ABSTRACT FROM AUTHOR]

Solid waste management systems currently receive wide attention, from both economic and environmental planners, because of their complexity during coordination of various management strategies. The efficiency and cost effectiveness of route optimization and disposal site selection depend largely upon the appropriate placement of storage bins and their corresponding command area for waste contribution. The present paper illustrates a geographic information system (GIS) based algorithm for optimal location and number of storage bins, considering p-median constrained model, based on Indian guidelines for Municipal Solid Waste Rules. The algorithm also computes the contributing command area of solid waste to a particular bin, based on the shortest distance, with descending slope for ease in solid waste collection. Les systèmes de gestion des déchets solides attirent présentement beaucoup l’attention des planificateurs économiques et environnementaux en raison de leur complexité durant la coordination de diverses stratégies de gestion. L’efficacité et la rentabilité de l’optimization de route et la sélection du site d’enfouissement dépendent en grande partie de l’emplacement approprié des bacs de stockage et leur zone desservie correspondante pour la collecte de déchets. Le présent article présente un algorithme basé sur un système d’information géographique (SIG) utilisé pour déterminer l’emplacement et le nombre optimaux de bacs de stockage, compte tenu d’un modèle p-médian contraint, basé sur les directives concernant la réglementation des déchets solides municipaux en Inde. L’algorithme calcule également la zone de collecte de déchets solides desservie par un bac de stockage particulier en se basant sur la plus courte distance, avec une pente descendante pour faciliter la collecte des déchets solides. [ABSTRACT FROM AUTHOR]

Air sparging represents an innovative groundwater remediation technology, which has been proved to be capable of restoring aquifers that have been polluted by volatile and (or) biodegradable contaminants, such as petroleum hydrocarbons. This paper presents the design, the installation, and the pulsed operation of an in-well air sparging system at the site of a Greek petroleum refinery. The geographical position, the hydrologeoly, and the contamination features of the chosen study area develop special conditions that, along with the fact that the existing refinery is still active, greatly determine the applicability and the effectiveness of the specific technology. The area that was used for the application of the technology covered almost 600 m2 and included five air injection wells and four additional monitoring wells. The pulsed operation of the installed system lasted about 5 months and the results of frequent groundwater sampling and analysis indicate an important decline in total petroleum hydrocarbons (TPH) and benzene-toluene-ethylbenzene-xylene (BTEX) concentrations (up to 99%). However, prior to any attempt to expand the application of air sparging within the facilities of the refinery, special attention should be given to the eccentricities of the site and the ability of the technology to confront more persistent contaminants, such as methyl tertiary-butyl ether (MTBE). Le barbotage à l’air est une technologie d’assainissement innovatrice pour l’eau souterraine et il s’est avéré adéquat pour restaurer les aquifères pollués par des contaminants volatils et (ou) biodégradables, tels que les hydrocarbures pétroliers. Cet article présente la conception, l’installation et le fonctionnement pulsé d’un système de barbotage à l’air dans un puits d’une raffinerie de pétrole en Grèce. L’emplacement géographique, l’hydrogéologie et les caractéristiques de la contamination de la zone à l’étude ont conduit à des conditions spéciales qui, ajoutées au fait que la raffinerie est toujours en opération, déterminent grandement l’applicabilité et l’efficacité de la technologie spécifique. La zone d’utilisation de la technologie couvrait environ 600 m2 et comprenait cinq puits d’injection et quatre puits de surveillance additionnels. Le fonctionnement pulsé du système installé a duré environ cinq mois; les résultats de l’échantillonnage fréquent de l’eau souterraine et des analyses indiquent une diminution importante des concentrations en hydrocarbures pétroliers totaux et en benzène-toluène-éthylbenzène-xylène (BTEX) (jusqu’à 99 %). Toutefois, avant de penser à étendre l’utilisation du barbotage à l’air à d’autres secteurs de la raffinerie, il faut porter une attention spéciale aux conditions spéciales du site et à la capacité de la technologie à faire face à des contaminants plus persistants, tels que l’éther méthyltertiobutylique (MTBE). [ABSTRACT FROM AUTHOR]

The paper presents a novel atmospheric free-radical thermochemical oxidation (TCO) process in an aqueous phase for decontamination of industrial liquid effluents from organic toxic substances, in particular the refractory organic pollutants such as phenols. Its original concept is based on a direct contact between a contaminated liquid stream and the flame of a gas-fired burner containing free radicals such as OH·, H·, CH3·, and CHO·. Despite a direct contact of the contaminated liquid with the flame, the evaporation was less than 6% at the separator outlet where liquid temperatures ranged from 60 to 70 °C. A prototype of the 50 kW reactor operated in a continuous mode with the phenol concentration ranging from 200 to 20 000 mg/L was proven to process from 200 to 300 L/h of the contaminated model liquid. Experimental results show a final destruction efficiency of over 98%. Kinetics of phenol oxidation in TCO shows that the induction period can be avoided by injection of a small amount of hydrogen peroxide in the contaminated effluent feeding tank. L’article présente un nouveau procédé d’oxydation radicalaire thermochimique (OTC) en phase aqueuse pour la décontamination d’effluents liquides industriels contaminés par des substances organiques toxiques, plus spécifiquement par des polluants organiques récalcitrants tels les phénols. Son concept original est fondé sur le contact direct entre l’effluent liquide contaminé et la flamme d’un brûleur au gaz contenant des radicaux libres tels OH·, H·, CH3· et CHO·. Malgré le contact direct de l’effluent liquide contaminé avec la flamme du brûleur, le taux d’évaporation n’excédait pas 6 % à une température du liquide à la sortie du séparateur de 60 à 70 °C. Un prototype de réacteur de 50 kW de puissance nominale, opéré en continu avec des concentrations de phénol variant de 200 à 20 000 mg/L, a été utilisé avec succès pour le traitement de 200 à 300 L/h d’un effluent liquide modèle contaminé. Les résultats expérimentaux montrent une efficacité finale de destruction supérieure à 98 %. La cinétique d’oxydation du phénol dans le procédé OTC montre que la période d’induction peut être éliminée par l’ajout d’une faible quantité de peroxyde d’hydrogène dans le réservoir contenant l’effluent contaminé. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Environmental Engineering & Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)