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1.
Laundry wastewater treatment using coagulation and membrane filtration
Sonja Šostar-Turk, Irena Petrinić, Marjana Simonič, 2005, original scientific article

Abstract: This paper presents the results obtained from laundry wastewater treatment using conventional methods namely precipitation/coagulation and the flocculation process with adsorption on granular-activated carbon (GAC) and an alternative method, membrane filtrations, namely ultrafiltration (UF) and reverse osmosis (RO). Chemical analyses showed that parameter values of untreated wastewater like temperature, pH, sediment substances, total nitrogen and phosphorous, COD, BOD5, and the amount of anion surfactants had been exceeded in regard to Slovenian regulation. These regulations can be used as requirements for wastewater reuse and make treated wastewater an available source for the existing water supply. The study of conventional treatment was based on a flocculation with Al2(SO4)3 18H2O and adsorption on GAC. Membrane filtrations were studied on a pilot wastewater treatment plant: ultrafiltration (UF) and reverse osmosis (RO) units. The membranes used in this experiment were ceramic UF membrane and spiral wounded - polyethersulfone- RO membranes. The quality of the wastewater was improved by both methods and the specifications of a concentration limit for emission into water were confirmed. The disadvantage of GAC is that there is no possibility of any kind of selection, which is essential for recycling and re-use, while permeate coming from RO met the required regulation as well as requirements for reusing in washing process. However, the economical analyses showed that the membrane filtrations are more expensive compared to the GAC treatment process.
Keywords: laundries, washing of textiles, waste waters, advanced oxidation processes, membrane technology, membrane filtration, coagulation
Published: 01.06.2012; Views: 1706; Downloads: 92
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2.
Removal of vat and disperse dyes from residual pad liquors
Vera Golob, Alenka Ojstršek, 2005, original scientific article

Abstract: The efficiency of three wastewater treatment techniques, coagulation/flocculation, adsorption and ultrafiltration, has been studied for the removal of vat and disperse dyes from residual pad liquors. Three inorganic coagulants Al2(SO4)3 18H2O, FeSO4 7H2O, FeCl3 6H2O and commercial cationic flocculant, as individuals and in combination, were tested for the coagulation/flocculation methods. Granular activated carbon was used as an adsorbent in the adsorption technique. Ultrafiltration was performed using a polyethersulfone membrane with a molecular weight cut-off of 10 kDa. Dye removal was evaluated as the difference between concentrations of dyes in pad liquors before and after a particular treatment using absorbance measurements.The obtained results indicated over 90% of dye removal using appropriate coagulants and only 40% using activated carbon. The best results, dye removal over 98%, were achieved using the ultrafiltration technique.
Keywords: textile dyeing, disperse dyes, wastewater, decoloration, wastewater treatment, coagulation, flocculation, adsorption, ultrafiltration, vat dyes
Published: 01.06.2012; Views: 1476; Downloads: 81
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3.
Efficiency of the coagulation/flocculation method for the treatment of dyebath effluents
Vera Golob, Aleksandra Vinder, Marjana Simonič, 2005, original scientific article

Abstract: Textile dyeing processes are among the most environment-unfriendly industrial processes, because they produce coloured wastewaters that are heavily polluted with dyes, textile auxiliaries and chemicals. The coagulation/flocculation method was studied as a wastewater treatment technique for the decolourization of residual dyebath effluents after dyeing cotton/polyamide blends using reactive and acid dyes. It was discovered that acombination of aluminium sulphate and a cationic organic flocculant yields an effective treatment for residual dyebath wastewaters since almost complete decolourization was achieved, TOC, COD, AOX, BOD and the anionic surfactants were reduced and the biodegradability was increased.
Keywords: textile industry, reactive dyes, acid dyes, wastewater, čiščenje odpadnih vodwastewater treatment, flocculation, coagulation, ecological analyses, wastewater decoloration, Jar-tests
Published: 01.06.2012; Views: 1570; Downloads: 70
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4.
Substrate-induced coagulation (SIC) of nano-disperse titania in non-aqueous media : the dispersibility and stability of titania in N-methyl-2-pyrrolidinone
Angelika Basch, Simona Strnad, Volker Ribitsch, 2009, original scientific article

Abstract: Dispersions of 1 wt% titandioxide (titania or TiO2) were investigated with respect to their stability in non-aqueous media. The objective of this work was to find conditions for the substrate-induced coagulation (SIC) process in N-methyl-2-pyrrolidinone (NMP). The SIC process is a dip-coating process that enhances adsorption of fine dispersed particles on a pre-conditioned surface. The wetting behavior of titania and NMP was investigated by the powder contact angle method. The absorption process of the polar solvent NMP on the acid oxide TiO2and Aerosol OT (AOT) (bis-2-ethylhexyl sodium sulfosuccinate) was also investigated and a polar or hydrophilic interaction was found. The stability of titania in NMP dispersions and the influence of the solvent AOT and the electrolyte LiCl was investigated. By studying the electrophoretic mobilities of titania particles in NMP and the influence on solutes by the electrophoretic method phase analysis light scattering (PALS) and the electroacoustic method this paper explores suitable conditions for non-aqueous substrate-induced coagulation of titania.
Keywords: contact angle, non-aqueous dispersions, electrophoretic mobilities, substrate-induced coagulation, titandioxide, zeta potential
Published: 01.06.2012; Views: 1442; Downloads: 63
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5.
Compost leachate treatment using polyaluminium chloride and nanofiltration
Marjana Simonič, 2017, original scientific article

Abstract: Laboratory scale filtration tests utilizing leachate were conducted to investigate fouling and filtration performance of nanofiltration membranes. The work presented in this study is conducted on real samples rather than model water. Physico-chemical analyses showed that the leachate contained a lot of organic substances, exceeding 20000 mg/L O2 expressed as chemical oxygen demand. Proper pre-treatment method must be chosen in order to reduce fouling index. Coagulation pre-treatment using poly-aluminium chloride was chosen. Two thin film polysulfone membranes were used, purchased by Osmonic Desal. The focus of this research is to assess the influence of the particle size and zeta-potential of the colloidal fraction in leachate on nanofiltration performance. The isoelectric point of both membranes was 4.7 and 4.3, respectively. The fouled membranes were negatively charged over the pH range with isoelectric point shifting to the left (lower pH) indicating the foulant material mainly not charged. It was confirmed by its zeta-potential, measured at -2 mV.
Keywords: compost leachate, coagulation, nanofiltration, zeta potential
Published: 29.06.2017; Views: 773; Downloads: 227
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6.
Reduction of sludge volume in waste waters at the end of the drinking water treatment process
Rebeka Fakin, 2018, master's thesis

Abstract: Water treatment at Seierstad drinking water treatment plant is done by chemical coagulation using aluminum-based coagulant. The quality of the drinking water source – Lake Farris, has decreased throughout the years, that is why more and more particles, organic matter and dissolved minerals must be removed. That contributes to the volume of sludge being produced at the end of the process. The main objective of the assignment is to reduce sludge volume by coagulation and flocculation in the sedimentation basins using a coagulant/flocculent. In order to choose the right coagulant tests have been performed in the laboratory and on the actual process. The laboratory analyses showed great potential and one of the coagulants has been chosen and tested on the actual process. The testing was followed up for the entire summer of 2016 and then compared to the year before. We have been following the pH and Al3+ content in the water being released back to the environment and visibility in the top water layer in the sedimentation basin. Cost analysis, including the cost of chemicals and electricity usage, has been done. The sludge reduction was successful, and it was approximately 49% less than the year before.
Keywords: Water treatment, lake Farris, sludge treatment using coagulation and flocculation, effects of aluminum on the environment.
Published: 09.03.2018; Views: 475; Downloads: 63
.pdf Full text (2,97 MB)

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