Abstract The paper presents new studies about the removal efficiency of the biochemical treatment process of the Municipal Wastewater Treatment Plant from Constanta city, during 2008. Influent and effluent samples of biochemical treatment stage were collected and ammonium concentration, chemical oxygen demand (CODCr) and biochemical oxygen demand in five days (BOD5) were measured, aiming to study the evolution of the removal efficiency, during 2008. Additional analyses have been performed in ...
Autori: Elisabeta Chirilă, Camelia Draghici, Adriana Puhacel
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25458

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:The present paper presents an enhanced Activated Sludge Model No. 1 in which nitrification and denitrification are modelled astwo-step processes. The nitrification process is considered as a sequence of two steps carried out by two distinct genera ofbacteria, with nitrite as an intermediate product. For the denitrification process a parallel approach was used that considers nitrateand nitrite to be directly reduced to molecular nitrogen. The new model is compared to the original Activat...
Autori: George Simion Ostace, Paul Şerban Agachi, Vasile Mircea Cristea
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25786

The first part of this work presents the development and implementation in the Benchmark Simulation Model No 1 (BSM1) of a modified Activated Sludge Model No 3 (ASM3). The enhanced ASM3 presented in this study has three modifications compared to the original ASM3. The first modification is the representation of the simultaneous heterotrophic biomass growth on the primary substrate and on the internal storage products. Second, nitrification is modeled as a two-step process with nitrite as an inte...
Autori: George Simion Ostace, Paul Şerban Agachi, Vasile Mircea Cristea
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25865

AbstractPartial nitrification for the biological nitrogen removal (BNR) via nitrite has recently gained interest for treating high-strengthammonium wastewater with low organic matter content. However, stability of partial nitrification is still a challenge in activatedsludge system. In the present study, the technique of aerobic granulation was developed to produce granules for stable nitritation,treating ammonia-rich inorganic influent with 400 mg NH4+-N/L. The morphology, physical properties, ...
Autori: An-Jie Li, Xiang-Chun Quan, Xiao-Yan Li, Zhi-Feng Yang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25947

AbstractThis paper is an analysis of a case study which entails the assessment of pollution degree with nitrate in the Prut river basin, byanalysing 23 wells. The novelty of this work is the use of modeling done by GIS techniques, namely the Digital Terrain Model(DTM) interpolation technique, to obtain further information starting from discrete information.In the present paper, we emphasized the increasing tendency of nitrates and nitrites content in the underground waters, in directcorrelation ...
Autori: Florian Statescu, Gabriela Biali, Lucian Vasile Pavel
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26073

Abstract A set of 500 water samples collected from various sites of Tarnava Mare River, between Medias and Copsa Mica were analyzed, during three years (2010-2012). The physicochemical parameters like: temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), salinity, calcium (Ca2+), magnesium (Mg2+), sodium (Na+), lead (Pb2+), chloride (Cl-), sulfate (SO4 2-), ammonium (NH4 +), nitrite (NO2 -) and nitrate (NO3 -) were determined. The results were co...
Autori: Ioana Piştea
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26114

AbstractThis study aims to investigate the environmental impacts of the municipal waste disposal facility of Pata Rat, Cluj-Napoca, Romania during dry periods of the year. The environmental impact assessment on the landfill site was carried out on the basis of the measurements of environmental quality indicators. Environmental indicators were measured in the surface water, soil and air. For the assessment of the environmental impacts generated by landfill on surface water measurements were carri...
Autori: Ákos Rédey, Anca Gurzau, Antoanela Popovici, Constantin Măruţoiu, Fazekas Bence, , Ildiko Varga, Raluca Mariana Haţegan, Tatiana Yuzhakova
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26296

AbstractIn this work, the effect of the addition of some nutrients on fungal growth and removal of Cr(III) were investigated. Theconsidered fungi, isolated from real tanning factory environment were Phanerochaete chrysosporium, Aspergillus niger and A.oryzae. Firstly, the optimal conditions for fungal growth were determined as a function of pH, contact time, temperature andagitation speed. Secondly, the effect of the addition of some nutrients on fungal growth was examined. Without the addition ...
Autori: Abdeltif Amrane, Mansur Zarrabi, Mohammad Noori Sepehr
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26337

AbstractThe survival of Formosan landlocked salmon has been threatened by the change of habitat ambience. Because of the potentialtoxicity of nitrite (NO2-) and ammonium (NH4+) to salmonid fisheries, we studied the evolution of nitrogen compounddistributions in stream water and their relationship with ambient abiotic factors. The water was sampled at five sites surroundedwith various land-use types in bi-monthly intervals for seven years. The results indicated that a high NO2- concentration occu...
Autori: Wen-Hui Kuan, Yi-Lang Chen
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26351

AbstractIn this study, boron-doped diamond (BDD) electrode was tested in electrochemical oxidation and reduction processes using thesame vertical electrodes undivided cell in order to remove natural organic matter (NOM) and nitrogen compounds (NC) fromdrinking water. Boron-doped diamond-based electrochemical oxidation process has proven to be an efficient and versatilemethod suitable for NOM and NC in forms of nitrite and ammonium present in drinking water sources. However, the applicationof BDD...
Autori: Florica Manea
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26492

Abstract The adaptation of commercially available ion-selective electrodes (ISEs) for use in wastewater matrices was demonstrated using multivariate analysis and optimization with the Microsoft Excel Solver tool. The electrodes were characterized in pure analyte solutions, and their parameters were estimated using multivariate analysis and Solver optimization. The ammonium, nitrate, and nitrite ions were measured in model systems that were designed to simulate wastewater. The accuracy of the...
Autori: Natalija Koprivanac
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26687

Abstract In this study, the electrocoagulation process using aluminium anodes was tested as alternative for coagulation process for the drinking water treatment using two types of real groundwater sources, characterized by low turbidity, moderate and high organic load, and nitrite and ammonium species for one of them. The optimum operating conditions determined to be pH 6.5, current density (i) 25A/m2 at 30 min resulted in removal efficiency of over 70 % for total organic carbon (TOC) parame...
Autori: Anamaria Baciu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26756

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

This study examines the impact of the chemical oxygen demand to nitrogen ratio (COD:N) on nitrous oxide (N2O) emissions during N removal via a nitrite (NO2−) pathway for synthetic livestock wastewater treatment. Based on typical cycle operations, 1.07 ± 0.07% of the incoming N load was emitted as N2O at a COD:N ratio of 3:1. This was higher than the 0.83 ± 0.08% emitted at a COD:N ratio of 6:1. The low COD:N ratio in the synthetic livestock wastewater may thus cause increa...
Autori: Qiang Kong
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27157

Groundwater originating from two rural communities from Cluj and Bistrita Nasaud counties was analyzed using parallel ion chromatography, the focus being on major anions (chloride, nitrite, nitrate, phosphate and sulphate) and cations (potassium, sodium, ammonium, calcium and magnesium). These analytes were determined simultaneously using a Shimadzu two-channel instrument with non-suppressed conductivity detection, separations being carried out using an Allsep Anion 7u column and an Universal Ca...
Autori: Edward Muntean
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27211

Water quality is a very important aspect in the perspective of durable, urban and rural development. At European level, several directives were implemented, with the purpose of regulating the degree of pollution for water sources. Both surface and underground water resources in Romania are being affected by pollutants, such as nitrites, phosphorus, generated through irrational usage of chemical fertilizers, but also through the discharge of urban waste water directly into river courses. The spat...
Autori: Andrei Enea
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27280

Water is the source of life and a high water quality leads to a harmonious development of the surrounding environment (biotic and abiotic) and of humans. When water is loaded with various chemicals due to erosion, corrosion and human activities, the pollution phenomenon appears, causing harmfull effects over plant and animal organisms. The presence in water of substances derived from agriculture or mismanagement of manure organic obtained from various species of domestic animals affects the envi...
Autori: Alina Simionică Bădilă
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27285

The partial nitrification bioreactor (PNBR) was operated at a constant temperature and an influent synthetic wastewater pH of 35°C and 8.5, respectively. The effects of dissolved oxygen concentrations (DO), hydraulic retention times (HRT), and the nitrogen loading rates (NLR) on the ammonium removal efficiencies and the NO2-N/NOx-N ratio were investigated. The activity of nitrite oxidizing bacteria was stimulated at high DO concentrations. The highest NO2-N/NOx-N ratio of 0.76 was obtained a...
Autori: Sukru Aslan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27455

The performance and microbial community of an anoxic-aerobic sequencing batch reactor (SBR) treating saline wastewater were investigated at different influent COD/N ratios. The average COD removal efficiencies at steady states were 87.46%, 73.75%, 64.87% and 88.34% at the COD/N ratios of 20, 10, 6 and 30, respectively. The average NH4+-N removal efficiencies were 79.74%, 74.34%, 64.55% and 89.29% at the COD/N ratios of 20, 10, 6 and 30, respectively. No obvious accumulation of NO2--N and NO3--N ...
Autori: Sen Wang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27592

One of the main challenges for the development of biomass algal system production is the high operational and capital costs for these technologies. A great opportunity to overcome these challenges may however exist in the integration of wastewater treatment with algal biomass production. The algae are used for treatment of industrial wastewater, for purification of effluent originating from livestock production, while the studies concerning the use of algae species for the treatment of aquacultu...
Autori: Katya Velichkova
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27684

Evaluation of spatial/ temporal water quality data at reservoirs has shown differences after the dam construction as well as long-term changes of water chemistry. One of the most recent reservoirs created in Europe is Ilarion Reservoir in Western Macedonia – Greece (2012). In this work, the water physicochemical characteristics of this young reservoir and the spatiotemporal water quality variation of the feeding river and its main tributaries have been studied, and statistically interprete...
Autori: Elisavet Amanatidou
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27737

The main objective of the research was to study the efficiency of the glyphosate amine pesticide mineralization in wastewaters (real and model type of wastewaters respectively) using ozonation treatment as an advanced oxidation processes (AOP). The wastewater samples (model wastewater) were obtained by mixing a given volume of the stock solution prepared from glyphosate isopropyl-amine in different volumetric ratios with distillated water and with real wastewater obtained from a domestic wastewa...
Autori: József Németh
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28050

Inorganic ceramic materials is receiving more attention in recent times due to their unique characteristics which include different pore structures, hydrophilic surfaces, high chemical, thermal and mechanical stabilities that offer avenues for application in water treatment. In the present work, cost-effective clay ceramic water filters of different designs were developed from clay (50, 60, and 70) %, sawdust (15, 20, 25, and 35) %, grog (5, 10 and 15)% ratios plus 5% bone char by volume and ...
Autori: Enyew Amare Zereffa
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28196