Fabrication of Gd2O3/PSF Membranes via Aqueous Phase Inversion Method

This study aimed to investigate the effect of Gadolinium oxide (Gd2O3) concentration (0.5%, 1%, and 2%) on the performance of polysulfone (PSF) membrane. The membranes were fabricated by a common phase inversion method. The performance of membranes was determined based on pure water flux, bovine serum albumin (BSA) permeation test. These fabricated membranes were characterized by FTIR and contact angle measurements. The highest BSA rejection was 53%. The optimum membrane (2 % wt Gd2O3 /17 % wt PSF) in this study was determined by PSF 17% which successfully exhibited 53% rejection with filtrate flux for about 8.7 L/m2.h at a pressure of 10 bar

İndigo boyama atıksularının membran teknolojileri kullanılarak geri kazanımı veyeniden kullanımı.

The objective of this study is to develop a membrane-based generic treatment scheme for wastewaters of indigo dyeing process of denim industry, based on water reuse. For this purpose, firstly the performances of microfiltration (MF), coagulation, and ultrafiltration (UF) processes were evaluated as pretreatment alternatives and the best pretreatment alternatives appeared to be single stage 5 m MF and sequential 5 m MF followed by 100 kDa UF providing high permeation rate and high color retention. These two pretreatment alternatives were compared based on the performance of nanofiltration (NF) using NF 270 membrane, and the best pretreatment process was evaluated as 5 m MF that provided 87-92% color and 10% chemical oxygen demand (COD) retention. After the pretreatment tests, three different NF (NF 270, NF 90, Dow Filmtec, USA and NF 99, Alfa Laval, Denmark) and two different reverse osmosis (RO) membranes (HR 98 PP and CA 995 PE, Alfa Laval, Denmark) were tested to produce reusable water. Permeate COD and color performances of the tested NF and RO membranes were similar and satisfactory in meeting the relevant reuse criteria, while permeate conductivity was satisfactory only for HR 98 PP RO membrane and for NF 90 membrane. On the other hand, NF 270 membrane was superior to the other membranes in terms of permeation rate. For NF 270 membrane; cumulative color, COD and conductivity retentions were found to be 93 %, 92 %, and 60 %, respectively. When the developed process chain (5m MF+ NF 270) was also tested for a dilute indigo dyeing wastewater, it was found out that the developed scheme works similarly and is generic for indigo dyeing wastewaters.Ph.D. - Doctoral Progra

Removal of heavy metals from aluminum anodic oxidation wastewaters by membrane filtration

Aluminum manufacturing has been reported as one of the largest industries and wastewater produced from the aluminum industry may cause significant environmental problems due to variable pH, high heavy metal concentration, conductivity, and organic load. The management of this wastewater with a high pollution load is of great importance for practitioners in the aluminum sector. There are hardly any studies available on membrane treatment of wastewater originated from anodic oxidation. The aim of this study is to evaluate the best treatment and reuse alternative for aluminum industry wastewater using membrane filtration. Additionally, the performance of chemical precipitation, which is the existing treatment used in the aluminum facility, was also compared with membrane filtration. Wastewater originated from anodic oxidation coating process of an aluminum profile manufacturing facility in Kayseri (Turkey) was used in the experiments. The characterization of raw wastewater was in very low pH (e.g., 3) with high aluminum concentration and conductivity values. Membrane experiments were carried out with ultrafiltration (PTUF), nanofiltration (NF270), and reverse osmosis (SW30) membranes with MWCO 5000, 200-400, and 100 Da, respectively. For the chemical precipitation experiments, FeCl3 and FeSO4 chemicals presented lower removal performances for aluminum and chromium, which were below 35% at ambient wastewater pH 3. The membrane filtration experimental results show that, both NF and RO membranes tested could effectively remove aluminum, total chromium and nickel (> 90%) from the aluminum production wastewater. The RO (SW30) membrane showed a slightly higher performance at 20 bar operating pressure in terms of conductivity removal values (90%) than the NF 270 membrane (87%). Although similar removal performances were observed for heavy metals and conductivity by NF270 and SW30, significantly higher fluxes were obtained in NF270 membrane filtration at any pressure that there were more than three times the flux values in SW30 membrane filtration. Due to the lower heavy metal (< 65%) and conductivity (< 30%) removal performances of UF membrane, it could be evaluated as pretreatment followed by NF filtration to protect and extend NF membrane life. The water treated by both NF and RO could be recycled back into the process to be reused with economic and environmental benefits

İnce film kompozit membranlar ile enerji üretimi ve mikrokirletici giderimi

Bu tezin temel amacı, ince film kompozit membranların PRO prosesi ile enerji üretimpotansiyelini ve membranların mikrokirletici giderim performanslarınıdeğerlendirmektir. Bunun yanında, seçilen ticari membranların hidrofiliklik, membrandayanımı, su geçirgenliği, ters tuz akısı, basınç dayanıklılığı gibi özelliklerininiyileştirilmesi ve performanslarının arttırılması için L-DOPA ve nanomalzemeler ileyüzey modifikasyonu gerçekleştirilmiştir. BW30 ve SW30 membranlarının yüzeyleri LDOPA, L-DOPA+SiO2 ve L-DOPA+TiO2 nanomalzemeleri ile modifiye edilmiştir. Eldeedilen sonuçlara göre, membranların modifikasyonunun osmotik basınçtan enerjiüretimini arttırdığı tespit edilmiştir. Modifikasyon çalışmaları, membran enerji üretimpotansiyeli BW30 membran için 10 bar basınçta 0,18 W/m2’den 1,34 W/m2 ve SW30membran için 5 bar basınçta 0,07 W/m2’den 0,34’ W/m2 değerine arttığını ortayakoymuştur. Mikrokirletici giderimi çalışmalarında Yeşilırmak havzasında kirlilikoluşturan Irgarol 1051 ve Dikofol pestisitlerinin (1000 µg/L) BW30, SW30 ve GE-ADmembranlarla 2 farklı basınçta (10 ve 20 bar) giderim performansları test edilmiştir. TFCmembran filtrasyon ile Irgarol 1051 giderimi çalışmalarında en iyi arıtım 10 barda BW30membran ile %98,8 giderim verimi olarak elde edilmiştir. Benzer şekilde, Dikofol içinGE-AD membran ile 20 barda %99,1 giderim verimi gözlenmiştir. Sonuç olarak, TFCmembranlar PRO prosesi ile enerji üretiminde ve mikrokirletici gideriminde yüksekperformansa ile umut vaat etmektedir.&nbsp;&nbsp;</p

Life cycle sustainability assessment of a light rail transit system: Integration of environmental, economic, and social impacts

The transition toward sustainable urban transportation has gained importance in recent decades. However, urban transportation has not been addressed for all dimensions of sustainability. This study presents a life cycle sustainability assessment of a light rail transit system in Kayseri, Turkey, by integrating environmental, economic, and social aspects. The sustainability performance of the light rail transit system is evaluated using a cradle-to-grave approach to assess three aspects of sustainability. For the environmental evaluation, a life cycle assessment was applied using SimaPro 8.4.1 PhD version based on ISO 14040 and 14044. The method, which includes nine environmental impact categories, was employed to assess the environmental performance of the light rail transit system with a functional unit of 1 passenger-km. For the economic assessment, life cycle costing was utilized with the functional unit of USD for 1 passenger-km. A social life cycle assessment was applied to assess the social performance of the light rail transit system based on guidelines published by the United Nations Environment Programme in collaboration with the Society of Environmental Toxicology and Chemistry. For the determination of social impacts, 11 subcategories and 18 social indicators were selected. The results showed that the global warming potential and abiotic depletion potential of the light rail system per passenger-km were 2.4E - 02 kg CO2 eq. and 2.7E - 01 MJ, respectively, with a service life of 50 years. The total life cycle cost of the light rail system was calculated as 0.046 USD for 1 passenger-km. The results also revealed that the main contributor to the total life cycle cost was energy cost, with 92% (2.88E + 08 USD) of the total cost. In the social performance evaluation, it is found that the industry performs well for society, the local community, and workers but has a weaker social performance for the consumer due to a weak feedback mechanism. Integr Environ Assess Manag 2021;00:1-13. (c) 2021 SETA