Développement d’une méthode d’extraction des contaminants émergents dans les solides particulaires par LDTD-APCI-MS/MS

Douze contaminants émergents (composés pharmaceutiques, pesticides et hormones) ont été quantifiés et extraits de l'eau de rivières et d’échantillons d'eaux usées municipales. La séparation des solides en suspension est effectuée par filtration des échantillons d'eau. L'effet de filtration sur les concentrations de contaminants dissous a été évaluée afin de minimiser les pertes de composés cibles. Les échantillons ont été lyophilisés et ont été extraits en deux cycles par ultrasons combinés avec une étape de nettoyage sur cartouche d’extraction de type C18. La quantification a été réalisée en utilisant la spectrométrie de masse. Les recouvrements de la méthode pour tous les composés ont varié de 68 à 112% dans toutes les matrices étudiées, sauf pour le sulfaméthoxazole et le diclofénac où des recouvrements plus modestes ont été obtenus (38 à 85%). Les limites de détection pour les 12 analytes dans les sédiments et particules en suspension (SPM) de la rivière variaient de 0,7 à 9,4 ng g-1 et de 21 à 92 ng g-1, pour les échantillons SPM de station d'épuration. Tous les contaminants émergents cibles ont été détectés à des concentrations variant de 3 à 5440 ng g-1 dans les matrices étudiées, les concentrations les plus élevées ont été observées dans les échantillons SPM de stations d'épuration. Une partie importante de certains de ces contaminants est clairement associée aux sédiments de rivière ou aux particules en suspension. L’optimisation des processus de traitement de l'eau et le devenir environnemental doit absolument tenir compte de la fraction de contaminants qui liée à des particules si on espère avoir un bilan de masse raisonnable.

Étude de la sorption et de la désorption de neuf contaminants émergents dans les boues usées

Des études de sorption/désorption ont été effectuées pour neuf contaminants émergents sélectionnés (caféine, sulfaméthoxazole, déséthylatrazine, carbamazépine, atrazine, estradiol, éthinylestradiol, noréthindrone et diclofénac) dans les boues usées provenant de trois systèmes différents. Les contaminants incluent une variété de classes de composés (pesticides, hormones et pharmaceutiques) qui possèdent des propriétés physicochimiques différentes. L’objectif de ces travaux est de modéliser leur comportement dans une station d’épuration, en présence d’une phase particulaire et d’une phase aqueuse, et du même coup, de mieux comprendre leur devenir lors de leur rejet dans l’environnement. Le coefficient octanol-eau (log Kow) permet de bien interpréter les résultats et nous permet de classer les composés selon deux types de comportements observés : les composés avec un log Kow inférieur à 3 montrent peu ou pas de sorption alors que les composés avec un log Kow supérieur à 3 montrent une sorption variant de 30 à 90 % durant les premières minutes, suivi d’une sorption lente durant les heures suivantes. Une augmentation du contenu organique favorise la sorption des composés hydrophobes alors qu’un changement de pH peut modifier la charge à la surface des particules et également la charge des analytes. Les résultats ont montré que seul le diclofénac était sensible aux variations de pH étudiés. Dans une telle situation, il est nécessaire d’utiliser le facteur d’hydrophobicité corrigé en fonction du pH (log Dow). Le coefficient de distribution solide-eau (log Kd) a été déterminé pour chaque composé à la fin de chaque expérience de sorption et se situe entre -0.3 et 2.6. Avec l’augmentation de l’hydrophobicité, la désorption diminue avec le temps et avec l’étape de rinçage. Pour simuler le relargage dans les systèmes aquatiques, les facteurs de rinçage ont été déterminés pour estimer le nombre de rinçages qui seraient nécessaire pour désorber 50 et 99 % de la concentration initialement sorbée. Les bilans de masse ont été effectués après chaque expérience dans le but de ne pas surestimer les capacités de sorption d’un composé et se situent entre 7 et 25 % pour l’estradiol, la noréthindrone et le sulfaméthoxazole et entre 44 et 103 % pour l’éthinylestradiol, l’atrazine, la déséthylatrazine, la carbamazépine, la caféine et le diclofénac.

Polyphosphate Accumulation by Marine Bacteria

Phosphate (Pi) is one among the most important essential residues in maintenance and inheritance of life, with far diverse physiological role as structural, functional and energy transduction. Phosphate accumulation in wastewaters containing run off of fertilizers and industrial discharges is a global problem that results in algal blooms in bays, lakes and waterways. Currently available methods for removing phosphates from wastewater are based primarily on polyP accumulation by the activated sludge bacteria. PolyP plays a critical role in several environmental and biotechnological problems. Possible relation of interaction between polyP accumulation phenomenon, the low biomass, low Pi uptake, and varying results obtained in response to the impact of sodium chloride, pH, temperature, various inorganic salts and additional carbon sources studied, are all intriguing observations in the present investigation. The results of the present study have evidenced very clearly the scope for potential strains of bacteria from both sea water and marine sediments which could be exploited both for Pi removal in wastewater released by industries and intensive aquaculture practices in to the aquatic environment as well as to harness the potential strains for industrial production of polyP which was wide range of applications.

SUPPLY CHAIN MANAGEMENT IN INDIAN PETROLEUM REFINING INDUSTRY

Model development for selection of location for refinery in India and identification of characteristics to be looked into when configuring it and to develop models for integrated supply chain planning for a refinery. Locating and removing inbound, internal and outbound logistic problems in an existing refinery and overall design of a logistic information system for a refinery are the main objectives of the study. A brief description of supply chain management (SCM), elements of SCM and their significance, logistics cost in petroleum industry and its impacts, and dynamics of petroleum its logistic practices are also to be presented. Scope of application of SCM in petroleum refinery will also be discussed. A review of the investigations carried out by earlier researches in the area of supply chain management in general and with specific reference to petroleum refining.

Application of chitosan and PASS for the removal of turbidity and colour from water

The most common and conventional method for removing turbidity from water is by coagulating with alum or iron salts, and settling the precipitate in suitably designed clarifiers followed by filtration. But the sludge produced is bulky, difficult to dewater and accumulates in the dumping grounds causing environmental problems. Synthetic polymers such as polyacrylamide and polyethyleneoxide have been investigated for their ability to remove turbidity. They overcome many of the disadvantages of conventional methods, but are cost—effective only when rapid flocculation and reduction in sludge volume are demanded. Considering the aforementioned situation, it was felt that more easily available and eco-friendly materials must be developed for removing turbidity from water. The results of our studies in this direction are presented in this thesis. The thesis comprises of nine chapters, with a common bibliography at the end. Chapter 1 gives an introduction to the nature of turbidity and colour usually present in water. Chapter 2 discusses the nature and availability of the principal material used in these studies, namely chitosan. Chapters 3 to 8, which deal with the actual experimental work, are further subdivided into (a) introduction, (b) materials and methods, (c) results and discussion and (d) conclusions. Chapter 9 summarises the entire work so as to put the results and conclusions into proper perspective.

Algae in industrial effluent treatment

The present research is based on two broader aspects of pollution assessment ,and treatability of petroleum and petrochemical effluents by algae. The objectives of the investigation are to study the algal ecology and trophic status of an oil refinery effluent holding pond , isolate and identify pure cultures of algae, study the role of algae in petroleum and petrochemical effluent treatment, develop strains of algae tolerant to toxic effluents, study the biotreatment potential of the tolerant algal strains developed The thesis comprises of six chapters. The first chapter gives the significance and objectives of the present study. The second chapter describes the methodology, and results of studies on the algal ecology, and trophic status of the effluent holding pond of Cochin Refineries Ltd., Ambalamugal, Kochi. The third chapter deals with the isolation, and development of pure cultures of algae, the algal bioassay of the refinery effluent, and the analyses of Chitrapuzha river water. The analysis, and assessment of the algal growth potential of the petrochemical effluent of Hindustan Organic Chemicals Ltd., Ambalamugal, Kochi. are summarised in the fourth chapter The fifth chapter deals with the algal growth potential in phenol and phenolic effluent, and subsequent absorption of phenol and total dissolved solids. The summary and conclusion of the present study are given in the sixth chapter.

Development of bioreactors for nitrifying sewage

Nitrification is the biological oxidation of ammonium, first to nitrite and then to nitrate by two groups of aerobic, chemolithotrophic bacteria belonging to the family Nitrobacteriaceae. The biological nitrification in municipal wastewater treatment is important in those cases were ammonia removal requirement specially exist. In a trickling filter or in an activated sludge system nitrification is rate limiting and thus necessitates longer detention time. The combined carbon oxidation-nitrification processes generally have low population of nitrifiers due to a high ratio of BOD to total nitrogen in the effluent. This necessitates, separate carbon and nitrogen oxidation processes, which thus minimizes wash out ofthe nitrifiers. Therefore, a separate stage nitrification has become essential to achieve faster and efficient removal of ammonia from the wastewater. The present work deals with the development of bio reactor for nitrifying of sewage as the tertiary process so that the treated wastewater can be used for irrigation, algal culture or fish culture

Microbial Biosurfactants – Review

Biosurfactants are surface active compounds released by microorganisms. They are biodegradable non-toxic and eco-friendly materials. In this review we have updated the information about different microbial surfactants. The biosurfactant production depends on the fermentation conditions, environmental factors and nutrient availability. The extraction of the biosurfactants from the cell-free supernatant using the solvent extraction procedure and the qualitative and quantitative analysis has been discussed with appropriate equipment details. The application of the biosurfactant includes biomedical, cosmetic and bioremediation. The type of microbial biosurfactants include trehalose lipids, rhamnolipids, sophorolipids, glycolipids, cellobiose lipids, polyol lipids, diglycosyl diglycerides, lipoloysaccharides, arthrofactin, lichensyn A and B, surfactin, viscosin, phospholipids, sulphonyl lipids and fatty acids. Rhamnolipid biosurfactants produced by Pseudomonas aeruginosa DS10-129 showed significant applications in the bioremediation of hydrocarbons in gasoline spilled soil and petroleum oily sludge. Rhamnolipid biosurfactant enhanced the bioremediation process by releasing the weathered oil from the soil matrices and enhanced the bioavailability of hydrocarbons for microbial degradation. It is having potential applications in the remediation of hydrocarbon contaminated sites. Biosurfactants from marine microorganisms also offer great potential in bioremediation of oil contaminated oceanic environments

Microbial Treatment Of Rubber Latex Centrifugation Effluent

Many of the existing methods for the treatment of rubber latex centrifugation eflluent are not only unsatisfactory in their efliciency to effect near perfect treatment in bringing down the COD to optimum level, but also time consuming and need a large landspace. As the rate of effluent generation is extremely high (20 litres for kilogram of rubber) there is a need for development of efficient system,capable of rapid reduction of COD and BOD. Though the organic load of the rubber efiluent is very high, it does not contain much processed chemicals and therefore it can be considered as a ‘biological eflluent’. Further, the ratio of the Chemical Oxygen Demand to Biological Oxygen Demand (COD/BOD) of this effluent remain almost as a constant value. According to Montgomery (1967), estimation of BOD is not ideally suited for studies on process design, treatability, control of treatment plants, setting standards for treated effluents and assessing the effect of polluting discharges on the oxygen resources of receiving waters. Hence in the present study COD was measured to determine the impact of treatment system on the effluent. In the present study, attempts were made to evaluate the efficiencies of certain methods such as packed bed reactor using immobilized microbial cells, rotating biological contactor (RBC) and activated sludge process, for rapid and efficient treatment of natural rubber latex centrifugation effluent. In addition, studies were also carn'ed out to develop a suitable bioprocess for the coagulation of skim latex, as an alternative to the presently used acid coagulation process towards reducing the pollution load, besides recovering quality rubber

Barriers In TPM Implementation In Industries

This paper aims to highlight the difficulties faced by organizations in implementing Total Productive Maintenance (TPM). The authors with their experience in TPM and the refinery industry have attempted to understand the factors that hinder implementation of TPM. The paper first explains in brief the concepts of TPM and why TPM is a must for organizations in this complex dynamic business environment. It then takes up the various issues that hamper implementation of TPM in industries. Solutions to overcome the barriers are discussed briefly but will be taken up in detail in another paper with specific reference to refinery scenario

Influence of Major Operational Parameters on Aerobic Granulation for the Treatment of Wastewater

Effective solids-liquid separation is the basic concept of any wastewater treatment system. Biological treatment methods involve microorganisms for the treatment of wastewater. Conventional activated sludge process (ASP) poses the problem of poor settleability and hence require a large footprint. Biogranulation is an effective biotechnological process which can overcome the drawbacks of conventional ASP to a great extent. Aerobic granulation represents an innovative cell immobilization strategy in biological wastewater treatment. Aerobic granules are selfimmobilized microbial aggregates that are cultivated in sequencing batch reactors (SBRs). Aerobic granules have several advantages over conventional activated sludge flocs such as a dense and compact microbial structure, good settleability and high biomass retention. For cells in a culture to aggregate, a number of conditions have to be satisfied. Hence aerobic granulation is affected by many operating parameters. The organic loading rate (OLR) helps to enrich different bacterial species and to influence the size and settling ability of granules. Hence, OLR was argued as an influencing parameter by helping to enrich different bacterial species and to influence the size and settling ability of granules. Hydrodynamic shear force, caused by aeration and measured as superficial upflow air velocity (SUAV), has a strong influence and hence it is used to control the granulation process. Settling time (ST) and volume exchange ratio (VER) are also two key influencing factors, which can be considered as selection pressures responsible for aerobic granulation based on the concept of minimal settling velocity. Hence, these four parameters - OLR, SUAV, ST and VER- were selected as major influencing parametersfor the present study. Influence of these four parameters on aerobic granulation was investigated in this work

Anàlisi comparativa dels processos emergents sharon i anammox per al tractament d’aigües amb una alta càrrega de nitrogen

Estudi de tractaments innovadors en aigües residuals amb elevada concentració de nitrogen mitjançant la tecnologia ANAMMOX (Anaerobic Ammonium Oxidation) i SHARON i posterior anàlisi teòrica de la gestió dels fangs residuals d’una EDAR

Valor diagnostico de la colangioresonancia para la detección de coledocolitiasis en pancreatitis aguda Hospital Mederi-Bogotá

La pancreatitis aguda (PA) es una patología clínica común que abarca un espectro desde leve hasta fatal, donde se produce una inflamación del páncreas por auto digestión enzimática con grado variable de compromiso sistémico. Es una emergencia abdominal grave con una mortalidad del 9-23%. En el 40% de los casos de pancreatitis aguda se encuentra que es de origen biliar. La prevalencia de enfermedad biliar a nivel mundial en adultos varía entre 5,9% y 21,9%, con grandes variaciones geográficas y regionales, se encuentran en el 12% de los hombres y el 24% de las mujeres. La prevalencia aumenta con la edad. Latinoamérica es una región con alta prevalencia. En pacientes con colelitiasis del 5-15 % tienen coledocolitiasis. La alta prevalencia de la patología biliar en nuestro país hace que esta sea una causa frecuente de consulta médica por dolor abdominal. El factor común presente en la gran mayoría de las enfermedades de la vía biliar es la Colelitiasis. La complicación más frecuente, la Coledocolitiasis, se ha reportado con cifras hasta de un 20% y como complicación de esta la pancreatitis. La pancreatitis aguda de origen biliar (PAB) es causada por una obstrucción transitoria o persistente de la ampolla de Váter por barro biliar o por cálculos. En el diagnostico de la PAB se emplean métodos invasivos como la colangiopancreaticografia endoscópica retrograda (CPRE) la cual trae consigo morbilidad y mortalidad asociada y métodos no invasivos como la colangiopancreaticografia magnética (CRM) que emerge como modalidad prometedora en el diagnostico y manejo de la PAB en centros de tercer y cuarto nivel de complejidad. El manejo actual de la PAB es la remoción de la obstrucción del conducto biliar común (CBC) seguida de su tratamiento definitivo, la colecistectomía o CPRE con papilotomia. En nuestro país no se han publicado estudios con datos locales acerca de la utilidad de la CRM para la detección de coledocolitiasis, en las guías de manejo de coledocolitiasis de la asociación colombiana de cirugía publicadas en el año 2004, hace referencia de la utilidad de la CRM para el diagnostico de esta entidad tomando como base una revisión sistemática de estudios publicados en Medline, Pubmed y Cocrane los cuales no incluyen experiencia a nivel nacional. En este estudio pretendimos determinar cuáles son los pacientes que se benefician de la realización de CRM temprana en el marco de la PAB leve para la detección de coledocolitiasis.

Análisis prospectivo del mineral de cobre en el mundo, Latinoamérica y Colombia

Se presenta un análisis prospectivo del comportamiento de la oferta y la demanda del Mineral de Cobre en el Mundo, en Latinoamerica y en Colombia, creando diferentes escenarios con futuros posibles, consientes y detallados que servirán para entender la dinámica de mercado y la creación de estrategias de penetración, disminución de costos y aumento de productividad en compañías que operan tanto en países donde la industria del cobre se encuentra muy desarrollada, como en aquellos donde la explotación del mineral es todavía muy incipiente (Colombia).

Prediction of the bulking phenomenon in wastewater treatment plants

The control and prediction of wastewater treatment plants poses an important goal: to avoid breaking the environmental balance by always keeping the system in stable operating conditions. It is known that qualitative information — coming from microscopic examinations and subjective remarks — has a deep influence on the activated sludge process. In particular, on the total amount of effluent suspended solids, one of the measures of overall plant performance. The search for an input–output model of this variable and the prediction of sudden increases (bulking episodes) is thus a central concern to ensure the fulfillment of current discharge limitations. Unfortunately, the strong interrelation between variables, their heterogeneity and the very high amount of missing information makes the use of traditional techniques difficult, or even impossible. Through the combined use of several methods — rough set theory and artificial neural networks, mainly — reasonable prediction models are found, which also serve to show the different importance of variables and provide insight into the process dynamics