AbstractFlocculation performance of three chitosan samples with different viscosities (?§ = 400, 800 and 1000 mPas) and two strong synthetic polycations of integral type (PDADMAC and PCA5) on two model aqueous suspensions (kaolin and bentonite) was investigated. The flocculation results indicated that all the polycation samples were efficient in the kaolin flocculation, the turbidity being completely removed at approximately the same polycation dose; the flocculation window ranged between 2.7 an...
Autori: Ecaterina Stela Dragan, Luminita Ghimici, Marcela Mihai
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25201

Experiments in a Pilot Plant (PP) are extremely important and relevant for the substantiation of research. This is the way to set up the most suitable coagulation-flocculation reagents, optimum operating conditions (injection point, reaction times, etc.),compatibility with the processes at the actual Water Works and real possibilities for further improvement.The present work aimed at verifying the previously obtained results in laboratory under PP working conditions for optimizing the coagulatio...
Autori: Adina Pacala, Alina Anghelina, Dalila Marşavina, Ilie Vlaicu, Katalin Bodor, Mihaela Anghel
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25156

Contain all the articles from this issueICEEM/01 -- Environmental Engineering SectionThermodynamic and kinetic study of gas desulphurization by adsorption on zeolites  Ion Untea, Dan Brasoveanu, Madeleine Dancila, Szidonia Bocskor Mixed oxides derived from vanadium substituted layered double hydroxides as catalysts precursors for SO2 oxidationGabriela Carja, Ionel Popa, Gabriela Ciobanu, Nicolae Aelenei The impact of energy production on environment in RomaniaCarmen Zaharia, Mioara Sur...
Autori:
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25168

Include urmatoarele articole:� "Waste not, want not" a study of household attitude toward recycling of solid wastes� A kinetic model for the crystal violet mineralization in water by the electro- fenton process� Development of a coagulation/flocculation predictive model for turbidity removal from tehran water treatment plants� Removal of cadmium (II) from aqueous solutions by sphagnum moss peat: Equilibrium study� Environmental sustainability based on fuzzy models� Impact of dust emi...
Autori:
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25207

AbstractAluminum and ferric salts are widely used as coagulants in water and wastewater treatment. They are effective in removing a broad range of impurities from water, including colloidal particles and dissolved organic substances. As well as traditional additives, such as aluminum sulphate ("alum") and ferric chloride, other products containing prehydrolized metal ions such as polyaluminum chlorides are now commonly used. The aim of this study was to develop a model for coagulation/flocculati...
Autori: Avid Banihashemi, Manouchehr Nikazar, , Reza Maknoon
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25230

AbstractThe removal of formasine fines particles from water by precipitation with polyelectrolyte and surfactant complex of Polyacrylamide (industrial product Praestol 611 made by Degussa) and Sodium Lauryl Sulphate (SLS) was experimentally studied. Calcium oxide was added to initiate precipitation of the polyelectrolyte complex together with the fines particles. The experiments were carried out with complexes having the surfactants concentration higher then the critical aggregation concentratio...
Autori: Cristina Costache, Gabriel Dabija, Mihaela Mihai
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25238

AbstractThe removal of Acid Red 398 (AR398) dye from dye-containing solution using coagulation/flocculation process with polyaluminum chloride (PAC) and Alum was investigated. The effect of different parameters involving pH, dosage of coagulant, initial dye concentration, and bentonite as a natural coagulant aid was examined. According to the obtained results, the optimum pH, at which the maximum removal occurred, was about 4 and 5 for PAC and Alum, respectively. However, PAC performed efficient...
Autori: Maryam Hasani Zonoozi, , Mokhtar Arami
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25335

Include urmatoarele articole:� Composite membranes with cross-linked matrimid selective layer for gas separation� Determination of organic compounds from different types of coffee by Hplc and Gc-Ecd analysis� An integrated assessment of the suitability of domestic solar still as a viable safe water technology for India� Investigations on the possibility of natural hemp fibers use for Zn(II) ions removal from wastewaters� Removal of acid red 398 dye from aqueous solutions by coagulation...
Autori:
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25340

Abstract A prehydrolyzed aluminium chloride (PAC), commercial product selected from a previously studied series, and the electrochemically obtained PAC (E-PAC) were tested as coagulants, comparatively with the classical aluminium sulfate (alum). A new method for producing E-PAC has been applied. The level of turbidity, the amount of total organic carbon, the UV-254 absorbance and the residual aluminium were evaluated, for determining the efficiency of the coagulation process in all situations...
Autori: Adina Pacala, Ilie Vlaicu, Ciprian Radovan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25569

Abstract In this work the method for the treatment of industrial waste waters effluents containing hexavalent chromium in three companies during process of treating metal surface with chromic acid is described. Industrial water polluted with hexavalent chromium is collected in separate sewage system. Polluted water is collected in precipitation tanks which are directly connected with neutralization reservoirs. The treatment process includes pre-neutralization by lime-milk, sedimentation, floc...
Autori: Igor Creţescu, Mirjana Cvijovic, Predrag Djurdjevic, Slavica Cvetkovi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25596

? COMPARATIVE CONSIDERATIONS ON THE STRUCTURE OF SOME MOLYBDENUM/NIOBIUM DOUBLE PEROVSKITES OXIDES ? THE INFLUENCE OF THE STORAGE TIME ON THE STABILITY OF BUTTER ? CaCO3 CONTROLLABLE SYNTHESIS BY DOUBLE EXCHANGE METHOD USING CaCl2 RESIDUAL SOLUTIONS ? OPTIMIZATION OF COAGULATION-FLOCCULATION IN THE TREATMENT OF CANAL WATER ? ANODIC DETERMINATION OF PENTACHLOROPHENOL FROM WATER USING CARBON NANOFIBER-BASED COMPOSITE ELECTRODE ? STUDY OF PRECIPITATES GROWTH IN COAGULATION ...
Autori:
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25663

The main phenomenon of coagulation is that particles aggregate to form floc. The formation of floc and cluster was simulated with computer in two-dimensional space using particle-cluster aggregation model and the properties of floc were analyzed using fractal theory. The effect of sticking probabilities on floc structure, density and porosity were analyzed. With the sticking probability increases, the simulated floc structure is gradually loose, floc density is gradually lower, the porosity is g...
Autori: Wanchun Tan, Yunbo Wang, Changbo Jiang, Shiquan Sun, Hong Chen, Xiaobao Niehttp://www.ecozone.ro/reviste.php?RID=25675

Adding ferric or bio-ferric agent is method to improve membrane fouling and prolong membrane life.This paper analyses the influence of ferric content on treatment effect of printing and dyeing wastewater, through examining the change of COD and dyestuff content in supernatant with the change of ferric content in sludge and in supernatant. COD in supernatant is reduced with increase of ferric content in sludge, and the dyestuff content in supernatant is reversed, which might be due to the adsorpt...
Autori: Shifeng Ji, Chunmei Gao, Hong Yang, Ming Chu, Chunfeng Wanghttp://www.ecozone.ro/reviste.php?RID=25711

Abstract:The paper presents the results of a study carried out using the Artificial Neural Network (ANN) for prediction the coagulation/flocculation process of suspended solids in water treatment plant (WTP). In this research 5 kinds of Poly Aluminum Chloride (PAC) as coagulant were used to examine the impact of coagulant kinds, PAC dosage and influent turbidity for removal of suspended solids. Determination of optimal coagulant doses is vital, as insufficient dosing will result in undesirable t...
Autori: Gagik Badalians Gholikandi, Mohammad Delnavaz, Reza Riahi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25806

The aim of this work is the study of activated sludge floc samples stained with different dyes and imaged by Confocal Laser Scanning Microscopy (CLSM). Activated sludge flocs were stained for lipids, sugars and esterase enzyme producing bacteria. Images were acquired for different samples to analyze the structural characteristics of the bioaggregates. The analysis of the CLSM images allowed for the localization and estimation of the quantity of different build-up materials. The 3-D reconstructio...
Autori: Bela Abraham, Botond Raduly, Dan Niculae Robescu, Szabolcs Lanyi, Szabolcs Szilveszter, Szilard Bucs
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25937

This paper presents the physicochemical and rheological properties of some complex coagulants derived from the weak and medium anionic polymers and medium cationic surfactant in order to evaluate the opportunity to use them in destabilizing and removing the colloidal systems from water and wastewater. In this respect, weak anionic and medium anionic copolymers of acrylamide and sodium acrylate with commercial names of Preastol 2515 and Preastol 2540, and a medium cationic surfactant derived from...
Autori: Constantin Bobirică, Gabriel Dabija, Liliana Bobirica, Mihaela Mihai
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25850

An alternative preparation method for PAC (pre-hydrolyzed aluminium chloride with general formula Alm(OH)nCl3n-m) by electrochemical synthesis is presented in this paper. The electrochemically obtained PAC (E-PAC), in which the most effective species of the polymeric Al component were estimated by 27Al RMN method, with properties similar to the properties of a commercially available PAC solution, was successfully generated in a electrochemical reactor. For obtaining as much as Al13 polymer by el...
Autori: Adina Pacala, Ciprian Radovan, Ilie Vlaicu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25901

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

AbstractWastewater from butyl rubber production is causing an increasing environmental problem due to its large quantity and complexquality. In this paper, two types of wastewaters generated from rubber synthesis, i.e. alkaline wastewater (AW) and cleaning andflushing wastewater (CFW), were investigated. Coagulation and flocculation were firstly applied to remove suspended solids(SS) from the AW. By single factor experiment, the optimum operational conditions were obtained as pH 8, PAC dosage 40...
Autori: Lujun Chen, Rui Liu, Wei Li, Wei Zheng, Yan Zhang, Ying Li
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25950

AbstractEU policy on waste management stresses the importance of an integrated approach to waste management, which includesconstruction of waste disposal facilities with prevention of waste generation and recycling, in line with management hierarchy:prevention of waste and its negative impacts; recovery of waste through recycling, reuse, safe final disposal of waste where thereis no possibility of recovery.This paper address the issue of municipal waste management and the impacts generated into ...
Autori: Ana-Maria Şchiopu, Cristina Ghinea
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25987

AbstractThe aim of this work is to characterize the flocculation process of a bentonite synthetic suspension with characteristics close toBega River from Timisoara, Romania. The time stability of the synthetic suspension was firstly investigated. After a few days ofcontinuous mixing a stable suspension was reached, stability being confirmed by monitoring the main physicochemicalparameters (pH, temperature, turbidity, dissolved organic carbon and initial particle size). In order to determine the ...
Autori: Alain Liné, Cosmina-Mariana Militaru, Ligia Barna, Teodor Todinca
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26027

Abstract After any treatment process of wastewater results residual sludge that is characterized depending on the type of the wastewater or by the sludge treatment type. The sludge treatment process can be divided in three important stages: the preliminary stage (with the sludge thickening), the stabilization stage, and the dewatering stage. The paper shows the results of the research for the identification of the most efficient organic cationic flocculants, which might be used wit...
Autori: Mariana Turcu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26149

AbstractSecondary aluminium production inherently generates significant amounts of slag of variate composition and including dangerous compounds. Consequently, a care treatment of the resulted slag is imperatively necessary for preventing the environment pollution and for recovering valuable materials even if present in low amounts. The aluminium recovering procedure is based on a chemical and hydrometallurgical slag treatment, leading to the technical grade aluminium sulphate (AS), possible to ...
Autori: Carmen Tociu, Cristina Maria, Elena Diacu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26295

AbstractThe sludge treatment processes represent a priority when we refer to the municipal wastewater treatment, but can implicate verycomplex studies and applications if we consider the industrial wastewater recovery and treatment processes. Even if the industrialsludges are seen as wastes, they can represent an important resource if are properly managed in the storage, treatment andrecovery processes. This paper aims to identify some methods to optimize the coagulation and flocculation process...
Autori: Mariana Turcu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26444

AbstractThe performance of some complex coagulants derived from weak and medium anionic polymers and medium cationic surfactantin coagulation-flocculation process for water treatment was experimentally investigated by carrying out kinetic studies and bydetermining the optimum coagulant dose. The complex coagulants were prepared from weak anionic and medium anioniccopolymers of acrylamide and sodium acrylate with the commercial names Praestol 2515 and Praestol 2540, and mediumcationic surfactant ...
Autori: Constantin Bobirică
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26478

Abstract The biological removal of organic matter from a cosmetic wastewater by sequencing batch reactors has been optimized by analyzing the influence of the hydraulic retention time as well as the inclusion of anoxic and/or aerobic stages in the process sequence. Hydraulic retention time of 5 d led to the highest total organic carbon and chemical oxygen demand removal regardless the sequence used. Although a completely aerobic sequence can be used for cosmetic wastewaters treatment, the al...
Autori: Montserrat Tobajas
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26589

Abstract The performance of electrocoagulation (EC) process, a non-specific electrochemical technology, was investigated for the removal of carbamazepine (CBZ), an antiepileptic drug, from water. Experiments were carried out in synthetic wastewater in a batch cell. The respective influences of some key process parameters were studied, such as mixing conditions, initial pH, and current on aluminium electrodes. Experimental results showed that a CBZ removal efficiency of 62% was observed under...
Autori: Tania Yehya
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26683

Abstract In this study, Moringa oleifera seed extract was applied as coagulant under different pH values (2.5 - 9.5), coagulant dosages (200-600 mg/L), initial dye concentrations (50-300 mg/L) and different settling times (0- 60 minutes) for R. Blue 19 and R. Red 120 dyes removal. Results revealed that with increase in pH (from 2.5 to 9.5), removal efficiency decreased from 95% to 87.3% for R. Blue 19 and from 97.2% to 62% for R. Red 120. By increasing coagulant dosage to 400 mg/L, removal e...
Autori: Ali Jafari
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26864

The flocculation process is applied in wastewater treatment to separate the destabilized colloid particles (or the particles formed during the coagulation phase) by forming flocs. The scope of this research was to identify the predictability of the synthetic organic flocculants use for industrial wastewater treatment. The research was performed at small scale, in laboratory, but also at industrial scale, by applying the synthetic organic flocculants in a real industrial wastewater treatment p...
Autori: Mariana Turcu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26975

High contents of colloidal and organic materials in municipal wastewater sludge cause problems in the process of dewatering. The filtering efficiency can be improved by chemical conditioning, but the effectiveness of mechanical dewatering is limited because flocculated sludge is highly compressible. Physical conditioners such as bagasse can be used to facilitate mechanical dewatering. This paper describes the use of bagasse pith (cane sugar waste fiber) to improve the dewatering process of mu...
Autori: Nematallah Jaafarzadeh
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26995

Environment-friendly demulsifying strains could be applied in breakup of emulsion produced in the petroleum industry. The demulsifying strain Alcaligenes sp. S-XJ-1 was found to be capable of utilizing paraffin or certain pure n-alkane as its sole carbon source, and exhibited a strong cell surface hydrophobicity above 70% and demulsifying ability above 80%. A maximum biomass of 6.27 g/L was obtained when the demulsifying strain was cultured using eicosane as carbon source. A positive correlation...
Autori: Xiang-Feng Huang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27379

The paper deals with the demonstration of the technical and environmental advantages related to the use of a tannin based coagulant in textile wastewater treatments. The natural coagulant was tested to evaluate its performance in the coagulation/flocculation process, the level of biodegradability in both aerobic and anaerobic conditions and the eco-toxicological risks for aquatic systems. Results were compared with a common inorganic metal based coagulant. The findings at lab scale showed th...
Autori: Antonio Giuliano
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27407

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

Three different synthetic textile dyeing wastewaters were treated by a chemical coagulation/flocculation process, using ferric sulphate as coagulant. Polyacrylamide (Magnafloc 155) and polyamine (Superfloc C-573) based flocculants were applied. The influence of pH (between 3.5 and 10.4) and Fe3+ concentration (from 15 to 4000 mg/L) in both color and dissolved organic carbon (DOC) removal of polyester, cotton and acrylic dyeing wastewaters was assessed in the coagulation stage. As far as floc...
Autori: Carmen S.D. Rodrigues
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27427

The influence of the active compound of Moringa oleifera Lam (MO) seeds was evaluated by different methods for the preparation of the natural coagulant in the treatment of surface water. Nine methods were analyzed, comprising samples of seed powder with different granulometry, aqueous and saline solutions, evaluated before and after oil extraction from MO seeds. Tests of coagulation/flocculation and sedimentation were accomplished using simple Jar Test. Natural coagulant dose of 50 mg.L-1 identi...
Autori: Karina Cardoso Valverde
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27588

The objective of the present study was to (i) compare different treatment options for greywater (GW) reuse, (ii) assess the potential of treated GW for reuse, and (iii) select the optimal treatment option by using Analytic Hierarchy Process (AHP). Raw GW was settled for 2 h. Five different treatment options were investigated simultaneously in parallel using the same influent (settled GW). The treatment options were (1) sand filtration, (2) sand/brick bat filtration, (3) alum coagulation/floc...
Autori: Dilip Machindra Ghaitidak
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27669

Algal bloom can represent a serious consequence of the eutrophication of surface water. Some of these algae, called cyanobacteria, are of particular interest for their effect on human health due to their capacity to produce cyanotoxins. In many countries, in fact, there are important problems of poisoning attributed to toxic cyanobacteria and contamination of water sources (specially lakes) resulting in increased cyanobacterial growth. Cyanobacteria can become particularly harmful for humans whe...
Autori: Sabrina Sorlini
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27800

In this study, the flocculating properties of different cactus juice preparations were assessed using synthetic and real industrial and leachate wastewaters. It was found that the crude CJ had a flocculating activity (FA) of 89 ± 2.2% which is significantly higher than that of a powdery sample derived from a 60°C oven-dried CJ sample and which was about 37.8 ± 2.5%. Interestingly, both crude and dried samples showed the ability to flocculate kaolin suspensions within a wide ...
Autori: Moncef Khadhraoui
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27887

In this work, the examination of separation of gypsum from wastewater generated during the machining of casts and the method of waste gypsum management have been presented. This waste gypsum is produced in Ortolab Poland facilities. Gypsum casts are cut and ground in water-cooled circular saws. Wastewater, with over-normative content of suspension, 10000 mg L-1 and sulphates, 1600 mg L-1 is produced in the process. The analysis of water and wastewater management in Ortolab Poland facilities l...
Autori: Ewa Liwarska-Bizukojc
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27910

Drinking water treatment aims to avoid or minimize some risks to human health and to provide adequate water quality by removing physical, chemical and biological contaminants. However, treatment processes require increasing efforts in terms of technology, chemicals and energy inputs, which generate increased secondary environmental impacts and added water production costs. The objective of this study is to evaluate the drinking water treatment plant (DWTP) in Iasi City (Romania) by life cycle...
Autori: George Barjoveanu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27922

The applicability of an electrocoagulation process with the biological treatment for the color removal of C.I. Basic Red 46 (BR46) dye was studied. It was shown that decolorization efficiency increased by increasing current density (j), pH, temperature (T) and agitation speed (ω) and decreased with the initial dye concentration [BR46]0. The optimal conditions in presence of a grid electrode (waste) used as cathode were found to be j=9 mA cm-², pH 8, T=35°C, [BR46]0=30 mg L-1 an...
Autori: Katia Madi
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27927

In recent years, so-called emerging contaminants (ECs) have attracted growing interest as they have been detected in reservoirs and even in drinking water. The new proposal Drinking Water Directive (2018) provides for the introduction of new parameters relevant to the ECs category. As these contaminants today tend to be present in a growing number of water sources, provide treatment systems that ensure compliance with regulatory limits and the protection of public health has become essential. Th...
Autori: Sabrina Sorlini
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28081

Sodium silicate, iron sulfate, magnesium sulfate, and zinc sulfate were used as the raw materials to prepare a new inorganic polymer flocculant, polysilicate ferric magnesium zinc (PSFMZ), using direct recombination. The effects of molar ratio of zinc to silicon, ratio of iron to magnesium, reaction temperature, and reaction time on deoiling rate were explored. The optimal synthesis conditions for the flocculant for the thermal-washing treatment of oily sludge were determined. Results showed tha...
Autori: Lanlan Yu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28165