2015): Characterization, structure, and function of extracellular polymeric substances (EPS) of microbial biofilm in biological wastewater treatment systems: a review, Desalination and Water TreatmentTo link to this article: http://dx. A B S T R A C TA review concerning the definition, extraction, characterization, production, and functions of extracellular polymeric substances (EPS) of microbial aggregates in biological wastewater treatment reactors is given in this paper. EPS are a complex high-molecular-weight mixture of polymers excreted by microorganisms, produced from cell lysis and adsorbed organic matter from wastewater. The EPS fill and form the space between the biofilm constituents, e.g. prokaryotic and eukaryotic microorganisms which inhabit the aggregates. It seems that the EPS matrix may serve as a multipurpose functional element of microbial communities, including adhesion, structure, protection, recognition, and physiology. Due to the metabolic activity of the cells, gradients develop and create different habitats within small distances, allowing a wide variety of organisms to settle and grow in the aggregate. As many of these organisms produce their specific EPS, it is not surprising that an extremely wide variety of microbial aggregates result. All of them have in common their highly hydrated extracellular matrix which is the place the organisms shape their very own microhabitat in which they live. However, as EPS are very complex, the knowledge regarding EPS is far from complete and much work is still required to fully understand their precise roles in the biological treatment process.

This work is in the context of the management and recycling of solid urban waste. The evolution of the physicochemical and microbiological parameters during composting pilot scale household waste was studied. The maturity of the processes and the agronomic value of the finished product were examined. The results showed that the organic fraction of solid waste could be composted successfully in 60 days and revealing a vigorous microbial activity. The final compost has been satisfactory for its agricultural application. Phytotoxicity tests conducted on wheat and tomato crops, show that the incorporation of 25% culture support the compost allows a germination rate of up to 85% against 70% for the control for the variety of corn. In the case of tomatoes, we recorded a germination rate of about 67% against 58% for the control. Keywords:Waste, compost, recycling, maturity test European Scientific Journal December 2016 edition vol.12, No.35 ISSN: 1857 -7881 (Print) e -ISSN 1857-7431 248 RésuméLe présent travail s'inscrit dans le contexte de la gestion et la valorisation des déchets solides urbains. L'évolution des paramètres physicochimiques et microbiologiques au cours du compostage à l'échelle pilote des déchets ménagers a été étudiée. La maturité du process et la valeur agronomique du produit fini ont été examinées. Les résultats obtenus ont montré que la fraction organique des déchets solides pourrait être composté avec succès dans un délais de 60 jours et révélant une activité microbienne vigoureuse. Le compost final a été satisfaisant pour son application agricole. Les essais de phytotoxicité menés sur des cultures de blé et de la tomate, révèlent que l'incorporation de 25% du compost au supports de culture permet un taux de germination allant jusqu'à 85 % contre 70 % pour le témoin pour la variété du blé. Dans le cas de la tomate, nous avons enregistré un taux de germination de l'ordre de 67 % contre 58 % pour le témoin.

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Eighteen Erlenmeyer flask containing six different support media [pozzolan, polyvinyl chloride1 (PVC1), polyvinyl chloride2 (PVC2), foam, polyethylene terephthalate (PET) and polystyrene (PS)] were subject to identical volumetric organic loadings and hydraulic retention time in treating synthetic protein ± carbohydrate waste. The objective was to examine the influence of support media on performance of anaerobic denitrification and retention and their resulting impact on system performance and failure. According to the results relative to every control support media, it was noticed that the best support media were the ones in PVC1 and PVC2, with successive reduction rates of 68.33 and 61.93% for chemical oxygen demand (COD), and 55 and 49% for nitrate. On the other hand, in two submerged anaerobic biofilter reactor packed with the support media of PVC1 and PVC2, the reactor with PVC1 media exhibited 89.93% COD and 78.75% nitrate removal efficiency attributable to its higher production of EPSp and EPSc.

The Moroccan marine environment is threatened by several types of pollution. Indeed, the littoral zone knew an urban, industrial and agricultural development without precedent; moreover, coastal waters have served as discharges for almost all activities linked to this development. The aim of this study is to determine the biological, physicochemical and bacteriological quality of waters and bivalve shells in the Bouregreg estuary. Sampling was carried out at four stations (S1, S2, S3 and S4) located downstream to upstream of the estuary. Thus, we analysed the degree of contamination by total coliform, faecal coliform and faecal streptococci in the water and in the flesh of Mytilus galloprovincialis and Cardium edule and determined the physicochemical parameters of seawater samples, which included temperature, dissolved oxygen, electrical conductivity, pH, total hardness, biological oxygen demand for five days (BOD5), complete alkalimetric title, NO2−, NO3−, NH4+, Fe2+, K+, SO42−, HCO3−, Cl−, Na+, Mg2+and Ca2+. The S1, S2 and S3 stations were shown to have more or less homogeneous physicochemical properties. The evolution of faecal bacteriological contamination of water and bivalves has shown that faecal pollution of the environment varies according to the stations and according to the seasons. The degree of contamination is high in autumn and winter and comes from wastewater and runoff discharges which, by leaching agricultural land, bring a large number of microorganisms to the environment. This influences the quality of the aquatic fauna, in particular, the infestation of lamellibranch molluscs such as in Mytilus galloprovincialis and Cardium edule. We have noted that the contamination of mussels by these types of microorganisms follows, more or less, that of the biotope. It should also be noted that in summer, the faecal contamination of the environment increases with the arrival of summer visitors.