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

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

An iron(Fe+3) oxide/hydroxide nanoparticles-based agglomerates (AggFe) suspension adsorbent was synthesized for efficient, cost-effective phosphate removal. A strong effect of AggFe concentration and pH level of water containing phosphate on removal efficiency was shown. It was found that phosphate adsorption onto the AggFe suspension may be described by pseudo-secondorder reaction kinetics and the Langmuir isotherm model. The unique adsorption properties of synthesized AggFe adsorbent are demon...
Autori: Grigori Zelmanov, Raphael Semiat
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25829

The performances of two types of multi-walled carbon nanotubes-based composite electrodes, i.e., MWCNT-Epoxy (CNTEpoxy) and Natural Zeolite-modified- MWCNT- Epoxy (NZ-CNT-Epoxy) are described in order to use them for electroanalytical application. Both electrodes were synthesized, electrically and electrochemically characterized and tested for the detection of ascorbic acid (AA) in aqueous solutions. The electrochemical characterization using classical potassium ferricyanide method showed a high...
Autori: Adriana Remes, Anamaria Baciu, Elida Ilinoiu, Florica Manea, Joop Schoonman, Stephen J. Picken
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=25877

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

Abstract The influence of exogenous form of heavy metals intake on their transformation in the soil is determined during model experiments. Distinctions in quantity of extracted mobile compounds of heavy metals in the soil depending on a form of addition various connections of Cu and Zn are established. The smallest mobility of Cu and Zn at addition of heavy metal oxides is observed. It is established that Cu accumulates mainly in the fraction connected with organic matter; Zn accumulates in...
Autori: Tatiana M. Minkina
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26662

In this work, coagulation features and characteristics of dissolved organic matter (DOM) in combined sewer overflow (CSO) wastewater were investigated. Ferric chloride (FeCl3) and polyaluminum chloride (PAC) were employed in the coagulation process. Results showed that both FeCl3 and PAC are effective in removing turbidity and total phosphorus (TP). Removal efficiencies were all above 90% when dosages were reasonable. Chemical oxygen demand (COD) removal efficiency was between 60% and 70%. T...
Autori: Wei-gang Wang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26931

Ferric sulfate and aluminum sulfate were applied to stabilize the available arsenic in solid waste residue (SWR) from the organic arsenic industry, previously pretreated by the semi-solid Fenton process. NaOH, Ca(OH)2, and MgO were introduced to adjust the matrix pH. Toxicity characteristic leaching procedure (TCLP), synthetic precipitation leaching procedure (SPLP), and sequential extraction procedure (SEP) were carried out to evaluate the effect and difference on the fixation treatments of ...
Autori: Li-Fang Hu
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26956

Drainage water and tailings impoundments water geochemistry (pH, EC, alkalinity, trace element concentrations, major ions) were studied at the Anjir Tangeh coal washing plant. The drainage water with neutral to alkaline pH values, high SO42- concentration and low metal content represented typical neutral alkaline mine drainage (NAMD). According to the Stiff and Piper diagrams, the majority of water samples classified into Ca-Mg-HCO3- type except drainage and processing water which were placed...
Autori: Majid Shahhosseini
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=26997

This study was conducted to evaluate the cyanide removal efficiency by coupled process of Fenton and coagulation/precipitation from aqueous solution. The study was performed at laboratory scale in a batch system. Variations of pH, Fenton and precipitation reagents (molar ratios of Fe2+/H2O2 and ferric chloride), contact time and initial concentration of cyanide were investigated, and the optimum conditions obtained from each of the Fenton and precipitation processes were followed in the coupl...
Autori: Ahmad Jonidi Jafari
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27426

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

Chemical oxidation of pyrite and chalcopyrite by ferric sulfate (Fe2(SO4)3) solution and biogenic ferric iron obtained by mixed culture of isolated thermotolerant Acidithiobacillus sp. 13Zn and Leptospirilum ferriphilum CC immobilized on natural carriers- zeolite and shungite was studied. Oxidation rate of sulfide minerals was estimated by the decrease of Fe3+ (oxidant) and increase of Fe2+ ions in the solution. It was revealed that chemical oxidation of chalcopyrite by biogenic ferric iron occu...
Autori: Arevik Vardanyan
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=27563

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

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

Arsenic-containing acid wastewater produced in the mining and smelting process will bring great harm to the environment, while to treat arsenic-containing wastewater with iron salt and lime is an economical and effective method. In this paper, iron salt was added to co-precipitate the arsenic and heavy metals, the pH value of arsenic containing acid leaching solution was adjusted by adding of lime. The stability of co-precipitates was also investigated in this study. The results show that the ir...
Autori: Yongliang Wang
ISSN: 1843 - 3707
http://www.ecozone.ro/reviste.php?RID=28121

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