AbstractThe purpose of this study was to investigate the immobilization of denitrifying bacteria on microbial cellulose (MC) for biological denitrification. A novel denitrifying bacterium, Pseudomonas stutzeri, was immobilized in microbial cellulose and introduced into an up flow packed bed reactor in order to remove nitrate from synthetic influent. The MC presented the high biomass concentration throughout the experiment, achieving 3.4 mg biomass/g support. The efficiency of the system for deni...
Autori: Abbas Rezaee, Hatam Godini, Hossein Bakhtou
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25302

Abstract The aim of this study was to assess nitrate removal using impregnated activated carbon (AC) with MgCl2. After impregnating of AC using heat treatment, the MgCl2 is converted to efficient MgO. The denitrification was conducted at pH 6.2, 25?C, and initial concentrations of 20 mg/L nitrate-N. The effects of the operating parameters including AC dosage, pH, and contact time have been investigated. Experimental data show that AC modified by MgCl2 was more effective than virgin AC for nit...
Autori: Abbas Rezaee, Hatam Godini, Sahand Jorfi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25618

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

Abstract Effects of the aeration rate on nutrient removal from synthetic domestic wastewater using an intermittently aerated sequencing batch reactor (IASBR) were studied at ambient temperature. Two aeration rates, 0.8 and 1 L air/min, were studied. At the aeration-rate of 0.8 L air/min, removals of COD, NH4+-N, total nitrogen (TN) and PO43--P were 84%, 96%, 75% and 99%, respectively. At the aeration rate of 1 L air/min, removals of COD, NH4+-N, TN and PO43--P were 90%, 99%, 70% and 66%, re...
Autori: Liam G. Henry, Liwen Xiao, Xinmin Zhan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25941

AbstractIn this study, a novel excess activated sludge (EAS) based nitrification and denitrification process was developed using EAS toprovide nitrifiers and denitrifers for nitrogen removal from the reject water of a municipal wastewater treatment plant (MWWTP).This can achieve a significant reduction in the nitrogen (N) loading in wastewater treatment plants. The results show that theammoniacal-nitrogen (NH4+-N) and total nitrogen (TN) removal efficiencies were in the range from 74.7% to 93.1%...
Autori: Wei Li, Xiaoxia Yang, Xinchao Guo, Yongzhe Yang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25946

AbstractGranular sludge technology – NEREDA is one of the most significant achievements in environmental biotechnology of the XXIstcentury. NEREDA is the latest innovative technology for biological wastewater treatment, which purifies water using the uniquecharacteristics of aerobic granular biomass. Unlike conventional processes, bacteria of the biological process naturally focus incompact granules with good settling properties.Due to the variety of biological processes that occur simultaneousl...
Autori: Ilinca Dinu, Ioan Crăciun, Teodora-Manuela Cornea
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26053

AbstractIn the conventional water flooding process of Daqing Oilfield in China, the occurrence of abundant sulfate-reducing bacterialpopulations has substantially affected the industrial production. This study was conducted from the perspective of ecologicalsuppression by operating anaerobic ABR reactors and dosing ecological inhibitors in a continuous-flow experiment. The practicaloperating efficacy was investigated and associated dynamic bacterial population succession was analyzed. Results sh...
Autori: Bin-song Wang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26165

AbstractA novel parallel A2O-MBR system was developed in this study based on the theory of denitrification with phosphorus removal.By utilizing the denitrifying phosphorus accumulating bacteria (DPB), the carbon source in the influent could meet the needs ofboth the denitrification and dephosphorization processes. Therefore, the carbon source restriction in conventional A2O processeswas resolved. The proposed system was inoculated with the sludge collected from the secondary settling tank in a m...
Autori: Liang Wang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26170

AbstractThis paper presents the full-scale treatment of nylon production wastewater in a wastewater treatment plant in Henan province, Central China. In this case, a 9600 m3/d capacity wastewater treatment plant was installed to treat the wastewater generated from the production of nylon-66 salt, based on the biological anaerobic filter (BAnF) combined with an anoxic/oxic (A/O) process. The performance of the biological combined system was monitored over a 75-day period. The results revealed tha...
Autori: Chunlian Xu, Haiming Huang, Jiankun Dai, Jianrong Qi, Qianwu Song, Shaowei Wu, Wenjun Wang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26276

AbstractTwo types of nanofiltration membranes had been used to study the influence of cross flow velocity on the membrane filtration ofdenitrification effluent (NF270 and NF90). Filtration had been conducted at constant transmembrane pressure of 5 bar andvariable cross flow velocity (0.03, 0.06, 0.15 and 0.39 ms-1). The obtained normal flux was 0.47, 0.58, 0.59 and 0.77for NF270membranes and 0.35, 0.38, 0.41 and 0.39 for NF90 membranes, the increase in cross flow velocity had enhanced fluxperfor...
Autori: Abdel Halim Fuqaha
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26523

AbstractWe reported the results of an isotopic study aimed at evaluating the medium to long-term effects of different water qualities anddeficit irrigation strategies on the ecophysiology of grapefruit in a 7-year-old plantation in SE Spain. For a better understandingof the interaction between nitrogen and salts from reclaimed water, RW, an experiment using natural abundance (δ) of 15N wasconducted. This study showed that in grapefruit crop irrigated with RW leaf δ15N value increased. ...
Autori: Cristina Romero-Trigueros
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26573

Abstract The results of batch tests of anaerobic dechlorination on groundwater samples collected downgradient from an industrial site in Northern Italy are presented and discussed. The experiments were carried out using sucrose as electron donor at equimolar concentration and at selected excess with respect to the total reducible species. The purpose of the study was to investigate the effectiveness of sucrose to achieve a complete chlorinated solvents degradations at the specific site, and ...
Autori: Luca Di Palma
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26895

The pickling liquor used in the stainless steel manufacturing process is a mixture of nitric and hydrofluoric acid which generates wastewater with nitrate concentrations ranging between 500 and 6000 mgNO3--N/L. In the present study, laboratory-scale anoxic Sequencing Batch Reactors (SBRs) were used to treat high nitrate wastewaters. Two different sludge inocula were tested: one from a Municipal Solid Waste Leachate Treatment Plant (LTP), and the other from a Sewage Treatment Plant (STP). Meth...
Autori: Ana Isabel Pelaez
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26933

Sequencing Batch Biofilter Granular Reactors (SBBGRs) represent an innovative technology; coupling granular and attached biomass and operating in a batch mode. These systems allow good removal rates with low sludge production and space requirement. A particular application, consisting of an aeration unit and an upflow SBBGR in series, has been tested at pilot scale. The pilot system was installed at a conventional activated sludge plant and fed with average-strength urban wastewater after pre...
Autori: Paolo Cirello
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27123

The direct measurement of the nutrients largely contributes to understand how the quality of the information, coming from the instruments, may improve the performances of the plants. The advanced knowledge acquired on the meaning of the signals gives new possibilities to control the biological processes and estimate the operational state of the plant, improving the quality of the effluent and keeping the operational costs as low as possible. Such information, furthermore, can be used to under...
Autori: Carmine Fiorentino
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27127

A combined system of up-flow cyclic sludge bed (UCSB) and aerobic nitrification reactor (ANR) was designed for organic matter and ammonia nitrogen (NH4-N) removals of swine wastewater. The UCSB had one acidogenic zone for hydrolytic acidification to solve the problem of poor carbon source in swine wastewater, and the other zone for denitrification. Results showed that average removals of the chemical oxygen demand (COD) and NH4-N were 92% and 95%, respectively, under the following conditions...
Autori: Jie Zhang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27160

Three pilot-scale biofilters consisting of 1 m aerobic woodchip layers and 0.5 m submerged woodchip layers were constructed to treat the separated pig manure anaerobic digestate (SAD). Reductions of 54% dry matter, 80% of chemical oxygen demand (COD), 93% of 5-day biochemical oxygen demand (BOD5), 86% of total nitrogen (TN) and 79% of total phosphorus (TP) were achieved. The study results confirm the occurrence of nitrification in the aerobic woodchip layers and denitrification in the submer...
Autori: Kathy Carney
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27161

Aerobic treatment processes using attached media have been studied extensively to remove organic matter from wastewater and also denitrification process. The objective of this study was to assess the ability of down flow anaerobic up flow oxic submerged bio-film reactor (DAUOSBR) to remove phosphorus, nitrogen compounds, BOD5, COD, turbidity and total suspended solids from the Farabi Hospital wastewater. The present work involved designing and building a reactor loaded with down flow anaerobic u...
Autori: Meghdad Pirsaheb
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27622

The presence of nitrogen in its reduced forms serves as an indicator of natural aquatic system degradation. The excessive concentrations of nitrogen in reduced forms (NH4+, NO2-) found in the sections of the the Shireutsi (of the Prut River) and the Olaneshti (of the Nistru River) prove that these sites are areas to focus efforts on improving water quality. Laboratory simulations indicate a good environmental buffer action of natural waters to potential pollution in Sculeni and Ungheni sections ...
Autori: Petru Spataru
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27698

The scarcity of water resources, especially in the agricultural sector, is an increasing problem both in developing and industrialized countries. Recent studies and reports have shown the high potential of wastewater reuse mostly in South European countries. In this paper, we study the possibility to reuse wastewater from the Santerno full-scale wastewater treatment plant located in Imola (Bologna, Italy). Specific monitoring campaigns have been carried out in Basin 1 of the natural finishing tr...
Autori: Carmine Fiorentino
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28085

The aim of this research was to improve the removal of organic matter and nutrients from wastewater from pig farms in a combined batch reactor performed as anaerobic-aerobic sequential. For this purpose, it was suggested to include recirculation cycles of wastewater in a sequentially pulsed manner in the anaerobic treatment followed by intermittent aeration in the aerobic-anoxic treatment. This novelty implemented in both sequential reactors was studied under pilot scale conditions. The process ...
Autori: Jorge Alonso Cortes-Esquivel
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28101

Biological ammonium removal from wastewater requires coupling of nitrification and denitrification processes in respective aerobic and anaerobic conditions. This difference in environmental requirements pose a big challenge in the design of systems intended to effect both nitrification and denitrification processes. Alcaligenes faecalis strain No. 4, however, has both heterotrophic nitrification and aerobic denitrification abilities in aerobic conditions, eliminating the need to provide anaerobi...
Autori: Hung-Soo Joo
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28186