Flux and retention analysis during micellar enhanced ultrafiltration for the removal of phenol and aniline

Removing Pollutants from Wastewater Using an Advanced Method

Purpose: Preparation of Nano cellulose from cotton lint and pear peels instead of  throwing it as waste and cause damage to environment and  Comparison between the efficiency of the product of  Nano cellulose prepared from cotton lint and NC prepared from pear peels through the characterization of both type of NC by using technique Field emission scanning electron microscopy (FESEM) . finally Applying  Murexide dye from the aqueous solution to the surface of both types of extracted Nano cellulose from cotton lint and pear peels for industrial Methodology: Agricultural wastes is the: cotton lint collected from Diyala, Iraq.   Linter is an important by product of the textile industry and pear peels collected from Local market of Iraq as raw material to synthesis of Nano cellulose compound  Extraction of cellulose from the cotton lint in several steps as follows: A: Purification step B: Grinding step preparation NC product: The product has been prepared by acid hydrolysis. Results and Discussion: In the present study, nanocellulose was successfully isolated from various plant fiber sources (cotton lint and pear peels) using acid hydrolysis . The results indicate that the FE-SEM formation of cellulose nano particles followed this method. However, the best results under sonication conditions used are coming from treatment of 30% acid hydrolysis sonicated for 120 min. Nanocellulose for cotton lint is more efficient than nanocellulose for pear peels in removing murexide dye from the aqueous solution, because percentage of the removal of murexide  dye from the aqueous solution by NC of cotton lint is higher than the percentage of the removal of murexide dye from the aqueous solution by pear peels. Therefore, nanocellulose for cotton lint will be more efficient in removing pollutants from water.

Ex situ soil washing of highly contaminated silt loam soil using core-crosslinked amphiphilic polymer nanoparticles

Non-ionic surfactants (Triton X-100 and Brij 30) and core-crosslinked amphiphilic polymer (CCAP) nanoparticles were used as extractants in the ex situ soil washing of silt loam soil contaminated with large quantities of petroleum oil, and their soil-washing performances were compared. Following washing with the surfactants, highly turbid aqueous solutions containing large numbers of soil and petroleum oil particles were produced. In contrast, the CCAP nanoparticles successfully extracted the petroleum oils from the soil samples without the formation of such a turbid aqueous solution. In addition, the CCAP nanoparticles extracted 96% of the petroleum oils, which is a significantly larger quantity than that by Brij 30 and Triton X-100 under equivalent conditions. Indeed, owing to their crosslinked micelle-like structure, the CCAP nanoparticles maintained their nanostructure even upon contact with a highly contaminated silt loam soil matrix, thereby resulting in the extraction of only the hydrophobic oily contaminants from the soil matrix and avoiding the formation of dispersions of soil particles and hydrophobic contaminants. As such, CCAP nanoparticles could be considered as suitable washing materials for highly contaminated silt loam soils.

Developmental and acute toxicity of cetylpyridinium chloride in Bombina orientalis (Amphibia: Anura)

In an effort to evaluate the toxicity of cetylpyridinium chloride (CPC), a cationic surfactant in amphibians, we examined the developmental and acute toxicity of CPC in Bombina orientalis embryos and tadpoles. Embryonic exposure to 2.0μM (0.72mg/l) CPC for 7 days significantly decreased the survival rates and increased DNA damage in the intestine of developed tadpoles. Exposure to 1.5μM (0.54mg/l) CPC significantly decreased the growth of embryos and increased developmental abnormalities. The 168-h LC50 and EC50 values of CPC were 1.95μM (0.697mg/l) and 1.48μM (0.531mg/l) in embryos, respectively. In an extended acute toxicity test using tadpoles, the 168-h LC50 value of CPC was 5.07μM (1.82mg/l). In terms of survival and growth rates, the lowest observed effective concentration of CPC was 1.5μM. At sub-lethal concentrations (1.0 and 2.0μM) CPC treatment to embryos increased lipid peroxidation in the intestine and gills of developed tadpoles, indicating that CPC can impose oxidative stress. At 2.0μM CPC, pro-apoptotic Bax and Bak mRNA levels were significantly increased together with DNA fragmentation, indicative of apoptotic cell death. CPC in freshwater system may threaten the normal development of amphibian embryos.

Removal of Ni(II) from aqueous solution by using micellar enhanced ultrafiltration

To explore the potential of micellar enhanced ultrafiltration (MEUF) process for the treatment of industrial effluent, herein, we report the surfactant-based separation of a metal ion [Ni(II)] from the aqueous solution using two different anionic surfactants viz. dioctyl sodium sulfosuccinate (DSS) and sodium dodecyl sulfate (SDS). By following a systematic investigation, we utilized two membranes with different pore sizes viz. 10,000 MWCO (molecular weight cutoff) and 30,000 MWCO and determined the rejection coefficient and permeate flux of the Ni(II) from aqueous at 1.5 bar trans-membrane pressure. The experimental results showed higher percentage of Ni(II) retention upon using the micellar solution of SDS compared with the solution containing DSS surfactant. In addition, the retention of Ni(II) ions incorporated in the micelles of surfactants was also found to be higher upon using 10,000 MWCO membrane compared with 30,000 MWCO membrane. Hence, we suggest that the combination of SDS surfactant and 10,000 MWCO membrane is a potent solution for the removal of metal ions from aqueous solutions via MEUF process.

Studies of membrane fouling mechanisms involved in the micellar-enhanced ultrafiltration using blocking models

Micellar-enhanced ultrafiltration (MEUF) is a promising technology to remove organic contaminants from wastewater.

Determination of residual nonsteroidal anti-inflammatory drugs in aqueous sample using magnetic nanoparticles modified with cetyltrimethylammonium bromide by high performance liquid chromatography

A simple and sensitive solid-phase extraction method for separation and preconcentration of trace amount of four nonsteroidal anti-inflammatory drugs (naproxen, indomethacin, diclofenac, and ibuprofen) using Fe₃O₄ magnetic nanoparticles modified with cetyltrimethylammonium bromide has been developed. For this purpose, the surface of MNP_s was modified with cetyltrimethylammonium bromide (CTAB) as a cationic surfactant. Effects of different parameters influencing the extraction efficiency of drugs including the pH, amount of salt, shaking time, eluent type, the volume of solvent, amount of adsorbent, sample volume, and the time of desorption were investigated and optimized. Methanol has been used as desorption solvent and the extracts were analysed on a reversed-phase octadecyl silica column using 0.02 M phosphate-buffer (pH = 6.02) acetonitrile (65 : 35 v/v) as the mobile phase and the effluents were measured at 202 nm with ultraviolet detector. The relative standard deviation (RSD%) of the method was investigated at three concentrations (25, 50, and 200 ng/mL) and was in the range of 3.98–9.83% (n = 6) for 50 ng/mL. The calibration curves obtained for studied drugs show reasonable linearity (R² > 0.99) and the limit of detection (LOD_s) ranged between 2 and 7 ng/mL. Finally, the proposed method has been effectively employed in extraction and determination of the drugs in biological and environmental samples.

Removal of phenol from synthetic waste water using Gemini micellar-enhanced ultrafiltration (GMEUF)

Comprehensive studies were conducted on the phenol wastewater ultrafiltration (UF) with the help of various concentrations of cationic Gemini surfactant (N1-dodecyl-N1,N1,N2,N2-tetramethyl-N2-octylethane-1,2-diaminium bromide, CG), conventional cationic surfactant (dodecyl trimethyl ammonium bromide, DTAB), anionic surfactant (sodium dodecyl sulfate, SDS) and nonionic surfactant ((dodecyloxy)polyethoxyethanol, Brij35). A flat sheet module with polyethersulfone (PES) membrane was employed in this investigation. The effects of feed concentration (phenol and surfactant) on the retention of phenol and surfactant, permeate flux and membrane fouling by micelles were evaluated. The distribution coefficient (D), the loading of the micelles (L(m)) and the equilibrium distribution constant (K) were also utilized to estimate the micellar-enhanced ultrafiltration ability for phenol. Scanning electron microscope (SEM), Fourier transform infrared spectrometer with attenuated total reflectance accessory (ATR-FTIR) and mercury porosimeter were applied to analyze membrane surface morphology, membrane material characteristics and membrane fouling for the original and fouled membranes. Based on the above analysis, the performance of the selected Gemini surfactant was proved superior in the following aspects: retention of phenol/surfactant (peak value is 95.8% for phenol retention), permeate flux and membrane fouling with respect to other conventional surfactants possessing equal alkyl chain length. These results demonstrated that CG surfactant with exceptional structure has favorable prospects in the treatment of phenol wastewater by the micellar-enhanced ultrafiltration.

Simulation of micellar enhanced ultrafiltration by multiple solute model

Multiple solute ultrafiltration models in micellar enhanced ultra filtration (MEUF) have been studied, for experimental results of selective separation of Cu (II) and Co (II) with anionic surfactant, sodium dodecyl sulfate (SDS) and imino diacetic acid (IDA) as chelating agent using synthetic waste water. This model is based on mass balance analysis coupled with the filtration theory, resistance-in-series model and gel polarization model. This model is characterized by the parameters, membrane resistance R(m), membrane permeability P(m), back transport coefficient K(b), K(bi) and mass transfer coefficient k(i). These parameters are estimated by using the Levenberg-Marquardt method coupled with the Gauss-Newton algorithm. Due to cross currents caused by the superficial velocity, some solutes are removed from the membrane surface and go into the bulk known as back transport effect. Hence back transport coefficient plays significant role in explaining the extent of micellization. The simulation results show a good agreement with the experimental data of permeate quality and flux. The consideration of negligible gel thickness is suitable for dilute solutions.

Produced water treatment by micellar-enhanced ultrafiltration

A water treatment approach combining ultrafiltration (UF) and micellar-enhanced ultrafiltration (MEUF) techniques was used for the removal of organic contaminants in field produced water samples from Canada and the United States. Free oil droplets and suspended solids were separated by initial UF treatments while MEUF was necessary for the removal of dissolved organics. It was shown that the amphiphilic characteristics of some organics commonly existing in produced water contributed to lowering the critical micelle concentration (CMC) of the surfactant employed. Lower surfactant concentrations could, therefore, be employed leading to lower fouling and back contamination and higher permeate flux. In addition, the incorporation of organic contaminants into the structure of cetylpyridinium chloride (CPC) micelles resulted in larger size and higher dissolution capacity of the "mixed micelles". The performance of polymeric and ceramic membranes of different molecular weight cutoffs (MWCOs) was evaluated by analyzing the permeate flux, recovery ratio, and solute percent rejection as functions of trans-membrane pressure (TMP). A mathematical model based on Darcy's law and the resistance in-series model successfully described the flux decline as a function of TMP for the two field samples and the two membranes studied.

Removal of Eriochrome Blue Black R from wastewater using micellar-enhanced ultrafiltration

Micellar-enhanced ultrafiltration (MEUF) represents a potentially attractive tool for the removal of different contaminants from wastewater. In this study, MEUF was carried out to investigate the retention of Eriochrome Blue Black R (EBBR), an anionic dye, from aqueous stream. N-Alkyltrimethylammonium bromide i.e. dodecyltrimethylammonium bromide (C(12)TAB), tetradecyltrimethylammonium bromide (C(14)TAB), cetyl-trimethylammonium bromide (C(16)TAB) and octadecyltrimethylammonium bromide (C(18)TAB) were taken as cationic surfactants, and NaCl, Na(2)SO(4), Na(2)HPO(4) as electrolytes. A hydrophilic membrane made of cellulose (molecular weight cut-off 10000 Da) was used in a cross-flow ultrafiltration unit. The removal of EBBR was studied as a function of dye and surfactant concentrations, ionic strength, transmembrane pressure and pH. The MEUF experiments showed that the highest dye rejection was about 99% for the used range of dye and surfactant concentrations. This retention depended slightly on dye and surfactant concentrations, ionic strength, pH and transmembrane pressure. However, permeate flux changed significantly with those parameters due mainly to concentration polarisation and osmotic pressure.

Extraction and recovery of methylene blue from industrial wastewater using benzoic acid as an extractant

Liquid-liquid extraction (LLE) of methylene blue (MB) from industrial wastewater using benzoic acid (extractant) in xylene has been studied at 27 degrees C. The extraction of the dye increased with increasing extractant concentration. The extraction abilities have been studied on benzoic acid concentration in the range of 0.36-5.8x10(-2) M. The distribution ratio of the dye is reasonably high (D=49.5) even in the presence of inorganic salts. Irrespective of the concentration of dye, extraction under optimal conditions was 90-99% after 15 min of phase separation. The extracted dye in the organic phase can be back extracted into sulphuric acid solution. The resultant recovered organic phase can be reused in succeeding extraction of dye with the yield ranging from 99 to 87% after 15 times reused, depending on the concentration of the initial feed solution. Experimental parameters examined were benzoic acid concentration, effect of diluent, effect of pH, effect of initial dye concentration, effect of equilibration time, various stripping agents, aqueous to organic phase ratio in extraction, organic to aqueous phase ratio in stripping and reusability of solvent.

Filtration by a novel nanofiber membrane and alumina adsorption to remove copper(II) from groundwater

The elevated level of heavy metals in groundwater poses a substantial risk potentially to local resource users and the natural environment. Micellar-enhanced filtration (MEF) and alumina adsorption are considered from the viewpoint of copper(II) removal in groundwater, by taking copper(II) as an example. In MEF, copper(II) cations are collected electrostatically on micelles of sodium dodecyl benzene sulfonate (SDBS) and separated from the mother liquor by filtration using a novel nanofiber membrane prepared from chloridized polyvinyl chloride by high-voltage electrospinning process. After MEF with 10-layer filtration and SDBS concentration of 5 mmol/L, the removal of copper(II) in groundwater is above 70%. However, the final solution contains a large amount of surfactant causing serious second contamination in groundwater. This problem is overcome by alumina adsorption, where negatively charged surfactants are adsorbed on positively charged alumina particles and then recovered by conventional filtration. The hybrid process of MEF and alumina adsorption is successfully applied to removing almost 100% of copper(II) from groundwater. Finally, the characterization of the membrane and filtration mechanism are presented here.

Intermolecular packing of sugar-based surfactant and phenol in a micellar phase

Surfactants have been used to enhance the removal of phenol from aqueous system; therefore, the interaction between surfactants and phenol is important for selection of the surfactant and understanding the process. In this work, sugar based surfactant, n-dodecyl-beta-D-maltoside (DM), was utilized to separate phenol from aqueous solution using ultrafiltration. 2-D NMR and Cryo-TEM techniques were employed to obtain information on the orientation of phenol molecules in the micellar phase and the shape transition of the micelles. The flux was found to decrease linearly with the solute concentration and the equilibrium constant was found to be constant. 2-D NMR spectra have shown that phenol molecules reside in the palisade layer of the DM micelles with the benzene ring interacting with the hydrocarbon chain of DM molecules, especially the first methylene group. Cryo-TEM results have shown the shape transition from spherical to worm-like due to the presence of phenol. The results will help understand the interaction between surfactants and phenol and the select the optimum surfactant reagents and operational conditions for micellar enhanced ultrafiltration process.

Micellar enhanced ultrafiltration of phenolic derivatives from their mixtures

Micellar enhanced ultrafiltration (MEUF) of different phenolic derivatives including meta-nitrophenol (MNP), catechol (CC), para-nitrophenol (PNP), and beta-napthol (BN) in their binary mixture has been studied. A 1:1 ratio of the mixture of (i) MNP with CC and (ii) PNP with BN is taken for the MEUF experiments using a cationic surfactant, namely, cetyl(hexadecyl)pyridinium chloride (CPC). An organic polyamide membrane with molecular weight cutoff of 1000 is used. Experiments are conducted using an unstirred batch cell and a continuous cross-flow cell. The effects of various operating conditions, e.g., concentrations of surfactant and solute in the feed, transmembrane pressure drop, and cross-flow rate (for cross-flow experiments) on the permeate flux and the observed retention of each solute have been studied in detail. The retention of solutes without using the surfactant varies from 3 to 15% only at a typical feed solute concentration of 0.09 kg/m3, whereas, under the same operating pressure (345 kPa), retention at the end of the experiment increases to about 66 to 99.8% depending on the nature of solute in the batch cell using surfactant micelles (10 kg/m3). Retention of solutes is less in the case of the two-component feed solution compared to the single-component feed solution. An increase in flux to the range of 9 to 16% is realized in cross-flow experiments compared to batch cell flux after one hour of operation.

Micellar-enhanced ultrafiltration process (MEUF) for removing copper from synthetic wastewater containing ligands

The effects of the type and concentration of ligands on the removal of Cu by micellar-enhanced ultrafiltration (MEUF) with the help of either anionic or cationic surfactants were investigated. The removal efficiency of copper by anionic surfactant-(SDS-) MEUF depends on the ligand-to-Cu ratio and the ligand-to-Cu complexation constant. At fixed ligand-to-Cu ratio, the Cu removal efficiency decreases in the order of citric acid>NTA>EDTA, which is the reverse order of Cu-ligand complexation constants for these ligands. Increasing SDS-ligand ratios from 12 to 60 at fixed ligand concentration did not improve copper removal efficiency. The cationic surfactant, CPC, enhances Cu removal efficiency in systems with condition of ligand-copper ratios higher than 1.0, where Cu removal is not very efficient using SDS-MEUF process. The Cu removal efficiency with CPC-MEUF depends on both the ligand-to-Cu ratio and the type of ligands.

Removal characteristics of anionic metals by micellar-enhanced ultrafiltration

Surfactant-based separation of Fe(CN)(6)(3-) and CrO(4)(2-) using regenerated cellulose membrane was studied in order to assess the potential of micellar-enhanced ultrafiltration for the remediation of wastewater or groundwater polluted with ferriccyanide and chromate. In the ferriccyanide/octadecylamine acetate (ODA) and chromate/ODA systems, removal of ferriccyanide increased from 73 to 92% and to 98%, and that of chromate from 64 to 97% and to >99.9% as the molar ratio of ODA to ferriccyanide and to chromate increased from 1 to 2 and to 3, respectively. In the ferriccyanide/chromate/ODA system, while the removal of ferriccyanide increased from 62 to 72% and to 93%, the removal of chromate from 20 to 38% and to 68% as the molar ratio of ferriccyanide:chromate:ODA increased from 1:1:1 to 1:1:2 and to 1:1:4, respectively. With the molar ratio of 1:1:6, the removal was >99.9 and 98% for chromate and ferriccyanide, respectively. Ferriccyanide ions were more easily bound to ODA micelles because the binding power of ferriccyanide was greater than that of chromate.