Pilot scale nanofiltration membrane fabrication containing ionic co-monomers and halloysite nanotubes for textile dye filtration.

Wastewater from the textile industry contains high concentrations of pollutants, so the wastewater must be treated before it is discharged. In addition, the reuse of treated wastewater should be considered from an environmental point of view, as large volumes of wastewater are produced. Since textile wastewater mainly contains dyestuffs, it must be treated effectively using environmentally friendly technologies. Membrane processes are widely used in textile wastewater treatment as they have distinct advantages over conventional wastewater treatment methods. This study reports the pilot-scale manufacturing and characterization of three different NF membranes. Three different types of membranes were fabricated. The fabricated membranes were compared through characterization by surface properties, chemical structure and morphology. Membranes were tested for pure water flux. Then the synthetic wastewater (SWW) was tested for flux and rejection. Lastly, the textile wastewater was tested. The textile wastewater flux of pure piperazine (PIP), 60% S-DADPS and 0.04% halloysite nanotubes (HNTs) were 22.42, 79.58 and 40.06 L m-2 h-1. It has been proven that the 60% s-DADPS membrane provides up to four times improvement in wastewater flux and simultaneously. In addition, NF membranes produced using HNT and sDADPS on a pilot scale have brought innovation to the literature with the good results obtained.

Ti2AlN MAX phase as a modifier of cellulose acetate membrane for improving antifouling and permeability properties.

The development of novel materials for the modification of filtration membranes is necessary to enhance their performance. In this study, the application of MAX phase-based material in the modification of cellulose acetate (CA) ultrafiltration membrane is reported to improve hydrophilicity, permeability, dye rejection and antifouling properties. Firstly, the Ti2AlN MAX phase was synthesized and exfoliated under ultrasonic to obtain nanosheets with an average width of 35 nm. Then, the influence of the prepared MAX phase on the CA membrane performance was assessed by blending different concentrations of it (0-1 wt%). The flux of pure water and bovine serum albumin protein solution was improved 27.5 % and 37.5 % by blending 0.5 wt% of the MAX phase into the matrix of the membrane. Moreover, the 0.5 wt% MAX/CA nanocomposite membrane represented ameliorated antifouling property with a flux recovery ratio of 86.3 %. This study showed that the MAX phase could be considered propitious additives to modify polymeric membrane performance.

Development of Ti2AlN MAX phase/cellulose acetate nanocomposite membrane for removal of dye, protein and lead ions.

To our knowledge, this study was carried out because there is no other study using Ti2AlN MAX phase material as an inorganic additive to improve the performance of the cellulose acetate (CA) membrane. In this research, the effect of titanium aluminum nitride (Ti2AlN) MAX phase on the performance of CA polymeric membrane was investigated. In the first step, the Ti2AlN MAX phase was synthesized via the reactive sintering method and characterized. The Successful synthesis of the MAX phase with high purity in the hexagonal crystalline structure was confirmed with the XRD pattern. The prepared MAX phase was used as a hydrophilic inorganic additive to improve the performance of the CA membrane. An improvement in hydrophilicity of the CA membranes was observed by incorporating the MAX phase into the matrix of membranes. The nanocomposite membrane containing optimum content of MAX phase (0.75 wt%) showed a threefold increase in permeability during filtration of pure water and dye solutions. In addition, the optimum nanocomposite membrane exhibited an improved flux recovery ratio of 92.7 % with a high removal efficiency of 70.7 % for reactive black 5, 93.5 % for reactive red 120, and >98 % for bovine serum albumin. Finally, the rejection of different salts was investigated, and the optimum nanocomposite showed high rejection for lead ions (97 %) with moderate rejection for Na2SO4 (>55 %) and NaCl (>30 %). The results of this research demonstrated the high potential of MAX phase-based materials for improving polymeric membranes.

Nanofiltration membranes for salt and dye filtration: effect of membrane properties on performances.

In this study, commercial nanofiltration membranes (Toray, NF 270, Desal 5 L) were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, optical profilometry, contact angle, mechanical strength and zeta potential measurements. Filtration performance tests were conducted with distilled water, MgSO4 solution and synthetic dye solutions, respectively. Among three commercial membranes, the Toray membrane was thought to be better choice. Additional experiments were carried out for a more detailed characterization of the selected membrane. Therefore, firstly, flux and removal efficiency was monitored by using dye solutions at different pH values, and then experiments were carried out to observe the effect of different temperatures. Also, another filtration test with NaCl solution was performed for the Toray membrane. As the main purpose of this study, we aimed to establish a significant correlation between the structural properties of membranes and their performances. In light of the results obtained, it was observed that the contact angle, mechanical strength and surface roughness values of the membrane significantly affected the membrane performance. It was concluded that the most important parameter in dye removal was the zeta potential. As a result of this work, a data set of commercial membranes was created and is available to all membrane users.

Polymer inclusion membrane applications for transport of metal ions: A critical review.

The co-existence of heavy metals in industrial effluents is a prevalent problem. Heavy metals are not biodegradable and can remain in the environment when left untreated. Therefore, metals must be removed from wastewater to protect people's health and the environment. Also, these pollutants usually have dissimilar compositions and properties. Generally, metal treatment is performed using traditional methods, but new processes have been developed due to the disadvantages of traditional methods. Especially in the last 20 years, studies on polymer inclusion membranes have been carried out and the transport performance of metal ions has been investigated. It is a more convenient process than both ion exchange and liquid-liquid extraction methods due to the potential and performance of polymer inclusion membranes. When the studies in the literature are examined, it is seen that the performance of polymer inclusion membranes is higher than expected and also when the production conditions are examined, polymer inclusion membrane is more advantageous than other processes. This review is a summary of the studies on the removal and transport of metal by using polymer inclusion membranes in the literature over the last 20 years.

Halloysite nanotube blended nanocomposite ultrafiltration membranes for reactive dye removal.

In this paper, ultrafiltration (UF) flat sheet membranes were manufactured by introducing two diverse halloysite nanotubes (HNT) size (5 µm and 63 µm) and five different (0, 0.63, 1.88, 3.13, 6.30 wt %) ratios by wet phase inversion. Some characterization methods which are contact angle, zeta potential, viscosity, scanning electron microscopy (SEM) and Young's modulus measurements were used for ultrafiltration membranes. Synthetic dye waters which were Setazol Red and Reactive Orange were used for filtration performance tests. These dye solutions were filtered in three different pH conditions and three different temperature conditions for pH and temperature resistance to understand how flux and removal efficiency change. The best water permeability results were obtained as 190.5 LMH and 192 LMH, for halloysite nanotubes (HNT) sizes of 5 µm and 63 µm respectively. The best water and dye performance of UF membrane contains 1.88% w/w ratio of HNT, which showed increased water flux and dye flux of membranes according to different HNT concentrations including ultrafiltration membranes.

Effect of wetting agent on the dye filtration performance of ultrafiltration membrane.

In this study, the wet phase inversion method was used for fabrication of the flat sheet ultrafiltration (UF) membranes. Three different polymer types and two different wetting agents were used for the fabrication. The effect of polymer types and wetting agents were investigated on the structural and dye performance of casted membranes. Two different synthetic dyes, 100 ppm Setazol Red and 100 ppm Setazol Blue, were used for the performance test. Viscosity, contact angle, and molecular weight cut off (MWCO) of casted membranes were measured and an electro kinetic analyzer, dynamic mechanical analyzer (DMA) and scanning electron microscope (SEM) were used to determine the structural properties. While the highest water and dye permeability were obtained with PES-PEG membrane, PSf-plain membrane gave the highest removal efficiency for Setazol Red and Setazol Blue dyes, which was found to be 78.33% and 82.52%, respectively, in the conditions of neutral pH and ambient temperature. Addition of PVP and PEG wetting agents improved the structural properties and permeability of membranes, but the dye removal was decreased as against plain ones. As the retention of PEG and PVP-based PSf and PES membrane was calculated at an average of 50%, they could be used for dye retention separately or could be a candidate as a pretreatment membrane prior to nanofiltration or reverse osmosis to make their lifetime longer.

Treatment For The Large Aggressive Benign Lesions Of The Jaws.

OBJECTIVES: Our aim was to evaluate the clinical outcome of the conservative management of the significantly large benign aggressive lesions of the jaws. SUBJECTS AND METHODS: Twenty-two patients were reviewed regarding the demographic, radiographic, and operative findings. Patients were treated by decompression followed by curettage or only with curettage. RESULTS: No bone grafts were used. Mean follow-up time was 56.2 months. The mandible was more affected than the maxilla. Two of the ameloblastoma, two of the keratocystic odontogenic tumours, and one odontogenic myxoma were recurred. CONCLUSIONS: Despite the low number of the patients, it is concluded that the conservative management is predictable for the management of the benign aggressive lesions in order to reduce morbidity instead of directly performing radical surgery. The life during follow-up is mandatory in the situation of performing conservative surgery for the management of large aggressive lesions with high recurrence rate.

Effects of different suture materials on tissue healing.

PURPOSE: The purpose of this study was to investigate the healing differences in between four different widely used suture materials in the oral surgery practice, including silk (Perma- Hand; Ethicon, INC., Somerville, NJ, USA), polypropylene (Prolene; Ethicon, INC., Somerville, NJ, USA), coated polyglactin 910 (Ethicon, INC., Somerville, NJ, USA). and polyglecaprone 25 (Ethicon, INC., Somerville, NJ, USA ). MATERIALS AND METHODS: 20 male rats were randomly allocated into two groups depending on their sacrification days (post-operative 1st and the 7th days). Four longitudinal incision wounds, each 1cm in size, were created on the dorsum of each animal which were then primarily closed with four different types of sutures. RESULTS: The effects of these suture materials on soft tissue healing were compared histopathologically, by means of density of the cells, necrosis, fibrosis, foreign body reaction, the presence of cells of acute and chronic infection. No statistically significant difference was observed between the groups regarding the density of the cells, necrosis, fibrosis, foreign body reaction, and the presence of the cells of acute and chronic infections. Of note, propylene showed slightly less tissue reaction among the other materials. CONCLUSION: The results of our study showed that there is no only one ideal suture material for surgical practice. The factors related to the patient, the type of the surgery and the quality of the tissue are important to decide an appropriate suture material.

Investigation of the risk factors associated with the survival rate of dental implants.

PURPOSE: The propose of this article was to evaluate the risk factors associated with the survival rate of the dental implants. MATERIAL AND METHODS: This retrospective study evaluated the survival rate of 940 implants placed at the Faculty of Dentistry, Department of Oral and Maxillofacial Surgery, Istanbul University, from January 2003 to January 2011. The potential risk factors associated with the survival rate of the implants were investigated. RESULTS: Fifteen (1.5%) of the 940 implants failed during the follow-up period. Smoking did not affect the survival rate of the implants (log-rank, 1.5; P = 0.219). The survival rate of the implants placed in the maxilla was lower than that of the implants placed in the mandible (log-rank, 4.81; P = 0.028). The 5-year survival rate of the dental implants was 98.5%. CONCLUSIONS: There are still conflicting results about the risk factors associated with the survival rate of the implants. According to the results of this study, it is concluded that only the location of the implants is associated with the survival rates of the implants. All implant systems showed high survival rates.