? Denitrifying activity of activated sludge in suspension and in biofilm? Denitrifying potential of an activated sludge derived consortium? Biosorption of hexavalent chromium based on modified Y zeolites obtained by alkali-treatment? Identifying anaerobic digestion models using simultaneous batch experiments? Olive mill wastewater as a renewable resource? Influence of innoculum acclimation in the biodegradation rate and estimated biodegradbility of cow manure, food waste and oil? Studies on the ...
Autori:
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25378

Abstract A method based on measuring substrate depletion rate was developed to evaluate the denitrifying activity of activated sludge in suspension and in biofilm form in anoxic serum flasks. The adapted activated sludge inoculum was grown as biofilm in an anoxic rotating biological contactor (RBC). Acetate was used as external carbon source to obtain a carbon to nitrogen ratio (C/N) of 2. The results showed that the specific activity of cells in biofilm form was higher than in planktonic for...
Autori: Elba Vivanco, Juan Carlos Ruiz, Paola Poirrier, Rolando Chamy, Yves Lesty
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25617

Abstract The structural modification of external surface of NaY was investigated in order to enhance efficient biosorption systems consisting of a bacterial biofilm, Arthrobacter viscosus, supported on that zeolite, for removing hexavalent chromium from aqueous solutions. The supported bacterial biofilm reduces Cr(VI) to Cr(III) and this cation is then retained in the zeolite by ion exchange. NaY zeolite was modified by alkali-treatments using NaOH 2.0 M, with two different contact periods of...
Autori: Bruna Silva, Cristina Quintelas, Hugo Figueiredo, Isabel C. Neves, Manuel F.R. Pereira, Teresa Tavares
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25637

Abstract The aim of this work was the evaluation of the denitrification potential of a consortium of activated sludge adapted to anoxic conditions. As the carbon source is the main parameter influencing the denitrification process, in the first stage three carbon sources (acetate, citrate and glucose) were assayed in batch activity tests. The highest denitrification efficiency was ttained with acetate, being nitrate and nitrite completely reduced. The adapted sludge was then used as a potent...
Autori: Joana Azeredo, Pilar Teixeira, Rosario Oliveira, Zelia Fernandes
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25638

Abstract A method based on measuring substrate depletion rate was developed to evaluate the denitrifying activity of activated sludge in suspension and in biofilm form in anoxic serum flasks. The adapted activated sludge inoculum was grown as biofilm in an anoxic rotating biological contactor (RBC). Acetate was used as external carbon source to obtain a carbon to nitrogen ratio (C/N) of 2. The results showed that the specific activity of cells in biofilm form was higher than in planktonic for...
Autori: Manuel Mota, Pilar Teixeira, Rosario Oliveira, Susana Cortez
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25639

? STUDY OF BIODIESEL PRODUCTION FROM OILSEED PLANTS II. EVALUATION OF BIODISEL PRODUCTION FROM SOME CULTIVARS OF RAPES ? STUDY OF BIODIESEL PRODUCTION FROM OILSEED PLANTS I. EVALUATION OF THE GENETIC SIMILARITY OF SOME Brassica Napus CULTIVARS USING RAPD MARKERS ? STRUCTURAL CHARACTERIZATION AND IN VITRO CYTOTOXIC POTENTIAL OF COAL DUST IN A ROMANIAN POWER PLANT ? MUNICIPAL SOLID WASTE MANAGEMENT IN BENGHAZI (LIBYA): CURRENT PRACTICES AND CHALLENGES ? COMPARATIVE ENVIRONM...
Autori:
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25661

Abstract A one-stage aerobic moving bed biofilm reactor (MBBR) (Reactor A) and a combined reactor (Reactor B) involving an anoxicgravel-bed biofilm reactor (GBBR) and an aerobic MBBR were applied to the treatment of heavily polluted river water. Reactorperformance was investigated throughout the experiment for almost 200 days and molecular techniques including PCR-DGGE,FISH/CLSM and FISH/FCM were used to reveal the evolutions of bacteria community, abundance of nitrifying bacteria and their...
Autori: Linyun Gu, Xiangchun Quan, Yin Qian, Yuansheng Pei, Zhifeng Yang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25942

Abstract An activated sludge from SBBR (sequencing biofilm batch reactor) reactor filled with Fe0  as filler had been acclimated to Fe(III)rich environment aiming at secure an enrichment culture of iron-reducing bacteria. The dissimilatory Fe(III) reduction ability and its efficiency on the effect of nitrogen and phosphorous removal by dosing different Fe(III) under anaerobic condition were investigated. The mechanism was also proposed based on the results derived from the experiment a...
Autori: Jie Li, Juanjuan Feng, Siyuan Zhai, Ya’e Wang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25943

AbstractThe applications of biofilm treatment technologies for domestic wastewater are being increased in many parts of the world. Theaim of the study is to assess a compacted aerobic attached growth fix-film unit (termed Bio-cache) for treatment of small volumedomestic wastewater. The system consists of the miniature plastic packing matrix, which provides a large surface area of 300m2/m3, so as to maintain the high rate growth of viable organisms responsible for organic degradation. The study o...
Autori: Alireza Valipour
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26266

AbstractA deep understanding of the relationship between the solids deposition and head losses is vital to optimize the backwashing inbiological aerated filters (BAFs). In this article, the deposition solids were classified into four types: heterotrophic biomass,autotrophic biomass, inert biomass and extracellular polymeric substances (EPS). A concept model was developed to simulatethe solid deposition and the head loss development. The temporal and spatial distributions of the four types of sol...
Autori: Chengda He, Dongsu Bi, Jun Wu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26347

AbstractA lab-scale packed-bed biofilm channel reactor that operates as a plug-flow system equipped with top aeration modules wasconstructed and evaluated. To assess the reactor performance a microbial community able to degrade linuron was used. Changingthe fluid flow rates and the linuron concentrations in the inflowing medium the volumetric loading rates of linuron (BV,L) weregradually increased from 0.29 to 14.93 mg/Lh. During the operation of the reactor, an airflow rate of 0.15 ą 0.05 L/min...
Autori: Erick Marrón-Montiel
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26465

Abstract In this study we report the preparation and evaluation of the antimicrobial activity of a new hybrid material based on chitosan (CH), magnetite (Fe3O4) and phytocomponents from the Eugenia carryophyllata aqueous extract (AE). CH/Fe3O4 was prepared by chemical precipitation of Fe2+ and Fe3+ ions in aqueous solution of sodium hydroxide and CH. E. carryophyllata’s dried buds were hydrodistilled under microwave conditions. The AE was separated in three equal parts, one for the chl...
Autori: Ion Anghel
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26707

Abstract Poly(vinyl chloride) (PVC) is the most widely used material for the production of medical devices such as intravenous fluid bags and tubing, enteral feeding, dialysis equipment and catheters. Despite of their numerous advantages, the plastic medical devices are non biodegradable and prone to microbial colonization causing biofilm associated infections which are difficult to treat and tend to chronicisation. A possible solution to surpass these limitations could be the fabrication of...
Autori: Petruța Stoica
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26894

Moving bed biofilm reactor (MBBR) technique is a useful technology for the treatment of mature landfill leachate. The reactor start-up and acclimation processes illustrated that many factors, such as biomass, C/N ratio, and influent volumetric loading rates, could affect the ammonium-nitrogen (NH4+–N) and COD removal. The factorial experiments were carried out to determine the optimal reactor operational conditions, and the results demonstrated that when DO 2-4 mg/L, pH 7.5, and hydraul...
Autori: Wei Li
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26932

Heavy metal pollution is a major source of aquatic contamination and has deleterious effect on the environment, therefore treatment of the polluted sites and wastewater becomes very essential. Biofilm based bioremoval of heavy metals have been a new area of research. Bacterial strains belonging to the genus Bacillus, isolated from chromium polluted soil (Palar river basin, India) have been employed as consortium for Cr(III) removal from chrome tanning effluent. The bacterial isolates were fou...
Autori: Aafreen Fathima
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27086

Microbial Fuel Cells (MFCs), the bioelectrochemical devices for conversion of waste into electricity through bacterial metabolic activity can use substrates with different complexity and strength. Wastewaters with moderate to high organic content can be exploited as MFC substrates. In this study, four different industrial wastewaters (from a chemical company, milk industry, soyabased food and soft-drink company and laundry) with different compositions were used as substrates in identical MFCs...
Autori: Deepak Pant
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27117

The objectives of this study were to investigate the composition of activated sludge biofilms and flocs in a sequential batch reactor (SBR) and in a sequential biofilm batch reactor (SBBR), and to evaluate the role of the extracellular polymeric substances produced in the reactors in comparison with the respective treatment efficiency of domestic wastewater, containing 1 to 40 mg/L phenol. Both reactors showed variable removal efficiencies. The SBR was found to contain more protistan species ...
Autori: Chrysi A. Papadimitriou
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27422

Wastewater treatment using sequencing batch reactor (SBR) has certain advantages over conventional activated sludge system. The performance of sequencing batch reactor in treating high C/N ratio was investigated with suspended polyurethane and polystyrene attached growth biomass configuration. A sequence of 4 hr HRT, 0.3 month SRT and 1kg COD/m3 was employed to study treatment efficacy. Treatment performance was assessed by means of chemical oxygen demand (COD), total nitrogen (TN) and total pho...
Autori: Beenish Saba
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27478

Three different hydraulic retention times (HRTs) were investigated for NH4+-N and Mn2+ removal using an upflow biological aerated system (BAF) as a new approach in drinking water treatment system. Currently in Malaysia, there is no specific treatment for NH4+-N and Mn2+ in drinking water treatment plant. BAF is a well known system in biological treatment for wastewater but not for drinking water treatment. This study showed that at 24 hours operation of BAF system, about 91.3% of COD, 94.4% of N...
Autori: Hassimi Abu Hasan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27543

The application of complex ecological approaches in biological wastewater treatment, assessment of its effect on the effectiveness of the process and comparison of the obtained data to the restrictions in the environmental legislation are key elements of the study. The processes in an anaerobic sequencing batch biofilm reactor, the first module from diphase anaerobic-aerobic biotechnology for dairy wastewater treatment, are investigated. The creation of highly specialized biological system by...
Autori: Irina Schneider
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27929

This study presents the influence of the storage recipients’ material and of the use and the type of stirring on the drinking water quality. The kinetics of drinkable water quality alteration under stationary conditions and under magnetic and sonical stirring have been monitored for a two weeks period. The microbiological parameters (total number of germs developed at 37°C and 22°C, lactose-positive and lactose-negative bacteria, coliform bacteria and Echerichia coli), as well a...
Autori: Laura Damian
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27999

Space exploration requires reliable, rapid, significant and safe methods for preventing, monitoring and controlling biocontamination risk in water loops and humid areas in manned Space habitats. Water is one of the most important resources of our everyday life. Its microbiological control in houses, public water dispensers and special conditions (e.g.: epidemics, catastrophes, isolation) is crucial. The presented solution is automated, compact and portable, and above all “integrated&rdquo...
Autori: Vincenzo Guarnieri
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28298

MABR (Membrane Aerated Biofilm Reactor) consists in an attached-growth process in which a gas permeable membrane is used as a biofilm carrier, and bubble-less oxygen transfer allows for a counter-diffusional mechanism where the electron donor (NH4+, biodegradable organics) and electron acceptor (O2) reach the biofilm from opposing sides. The paper reports results form the largest MABR installation in the world, demonstrating the beneficial impact of the technology in terms of improved process r...
Autori: Giuseppe Guglielmi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28299

The adoption of the Water Safety Plan (WSP) approach, as recommended by the World Health Organization, represents the most effective means to guarantee public health protection and improve drinking water safety. WSP is a risk assessment and management approach applied to all phases of the water supply chain. This study presents the development and implementation of the WSP for the municipality of Florence. The Florence drinking water supply system (DWSS) has two drinking water treatment plants ...
Autori: Roberta Muoio
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28303