scholarly journals Selective removal of cationic micro-pollutants using disulfide-linked network structures

RSC Advances ◽  
2017 ◽  
Vol 7 (42) ◽  
pp. 25969-25977 ◽  
Author(s):  
Mehmet Sahin Atas ◽  
Sami Dursun ◽  
Hasan Akyildiz ◽  
Murat Citir ◽  
Cafer T. Yavuz ◽  
...  
Keyword(s):  
Membrane Filtration ◽  
Water Sources ◽  
Selective Removal ◽  
Network Structures ◽  
Organic Polymers ◽  
Great Affinity ◽  
Micro Pollutants

Micropollutants are found in all water sources, even after thorough treatments that include membrane filtration. We have developed swellable di-sulfide covalent organic polymers (COPs) with great affinity towards cationic textile micropollutants.

Removal Mechanisms for Pharmaceuticals and Personal Care Products (PPCPs) in Water by NF/RO Membranes

2013 ◽  
Vol 726-731 ◽  
pp. 2502-2505
Author(s):  
Zhong Hua Huang ◽  
Zheng Li Liu ◽  
Li Jun Zhu ◽  
Guli Mira Akbar
Keyword(s):  
Human Health ◽  
Removal Efficiency ◽  
Aquatic Environment ◽  
Membrane Filtration ◽  
Personal Care Products ◽  
Separation Method ◽  
Ecological Environment ◽  
Personal Care ◽  
Removal Mechanisms ◽  
Micro Pollutants

Pharmaceuticals and personal care products (PPCPs) have been widely detected in aquatic environment in recent years; as emerging micro-pollutants, their influence on human health and ecological environment safety are of increasing concern. Membrane filtration is considered as the suitable separation method for PPCPs removal due to different removal mechanisms. This paper reviews the removal efficiency and removal mechanisms for PPCPs by NF/RO membranes.

Fate and transport of endocrine-disrupting compounds (oestrone and 17β-oestradiol) in a membranebio-reactor used for water re-use

2006 ◽  
Vol 53 (9) ◽  
pp. 123-130 ◽  
Author(s):  
Seojin Chang ◽  
Namjung Jang ◽  
Younghyun Yeo ◽  
In S. Kim
Keyword(s):  
Membrane Filtration ◽  
Membrane Bioreactor ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Fate And Transport ◽  
Endocrine Disrupting Compounds ◽  
Hollow Fibre ◽  
Incomplete Removal ◽  
Endocrine Disrupting ◽  
Micro Pollutants

Oestrogens have been detected in the effluents of sewage treatment plants (STPs) in several countries, as well as in surface water. This occurrence is fundamentally attributed to the excretion of oestrogen from humans and mammalian bodies, and the incomplete removal of these compounds from wastewater treatment plants. These micro-pollutants are causing great concern when it comes to water re-use. There is a lack information on endocrine-disrupting compounds (EDCs) such as oestrogen in water re-use systems, e.g. a membrane bioreactor (MBR). It is clear that there is a strong need for “EDCs in MBR for water re-use”. This study examined an E1 and E2 biodegradation batch test by an activated sludge and hollow fibre membrane filtration test with and without a bio-cake. E2 was effectively removed, even in high initial concentrations (1,000 ppb). E2 was oxidised into E1, and E1 had a lower adsorption rate than E2. The membrane with the bio-cake provided better removal than the virgin membrane.

scholarly journals Phosphorus and Emerging Micro-pollutants in Surface Waters: Challenges and Prospects for Water Quality Improvements

2014 ◽  
Vol 06 (1) ◽  
Keyword(s):  
Water Quality ◽  
Surface Waters ◽  
Membrane Filtration ◽  
Biological Effects ◽  
Sewage Treatment ◽  
Endocrine Disrupting Compounds ◽  
Agricultural Runoff ◽  
Phosphorus Recovery ◽  
Water Bodies ◽  
Micro Pollutants

An oversupply of Phosphorus in water bodies accelerates growth of algae and higher forms of plant life to produce undesirable impacts on overall water quality. Phosphorus inputs to surface waters arise from a variety of point and nonpoint sources. However much of the P is contributed by agricultural runoff and outfall of treated (or untreated) wastewater in receiving water-bodies. Point sourced-P inputs to waters have considerably decreased in recent years, at least partly driven by regulatory requirements, e.g. the EU Water Framework Directive. This has largely been achieved by removing P from treated wastewaters at sewage treatment works (STWs). Studies have shown that introducing an additional treatment step (“P-stripping”) can significantly reduce P in STW outfalls. Given P deposits are depleting, there is much interest in phosphorus recovery from wastewaters. A few STWs have already started to recover P as struvite (NH4MgPO4.6H2O) mineral – a substitute for commercially produced P-fertilizers. This requires major investment and is not economically viable at small STWs. Nonetheless it is a major breakthrough in terms of P recovery and its use. Effluents from sewage treatment works (STW) can often contain a complex mixture of residual microcontaminants, not removed during wastewater treatment. Organic micro-pollutants have been found in rivers receiving STW effluents. Such residual contaminants have become the focus of an emerging field of water quality study and are collectively referred to as pharmaceuticals and other personal healthcare products, PPHCPs. Many of these chemicals have the ability to effect the hormonal signaling of organisms and are called endocrine disrupting compounds (EDC). Such chemicals have shown some of the most damaging biological effects in aquatic organisms. Biological effects in the aquatic environment are typically related to the development of intersex in fish. Recent research shows the use of STW practices such as upgrading from using a combined trickling filter contact process to activated sludge treatment, ozonation, membrane filtration and use of suspended biofilm reactors reduces the amount of EDCs in waste effluent. It is thus possible to remove contaminants from STW effluents, but it will not be possible without major infrastructure improvements. This paper presents the challenges and prospects of P and micro-organic pollutants in surface waters.

Membrane filtration of high turbidity sources

2001 ◽  
Vol 1 (5-6) ◽  
pp. 325-330 ◽  
Author(s):  
M.A. Thompson
Keyword(s):  
Surface Water ◽  
Membrane Filtration ◽  
Suspended Solids ◽  
Water Sources ◽  
Feed Water ◽  
Membrane Systems ◽  
Water Supplies ◽  
High Turbidity ◽  
Large Water ◽  
Pressure Driven

Membrane filtration processes have become widely used for low turbidity water sources that require particle removal and disinfection. In cases where the feed water contains high turbidity levels or high fouling tendencies, pre-treatment has been required to allow the membranes to operate efficiently. Submersion membranes have allowed direct treatment on many of these water supplies but operate under vacuum. This presents limitations on operating flux and design conditions for incorporating into existing facilities. The treatment unit designs are also very expensive to implement for small water treatment applications. A recently developed pressure driven ultrafiltration (UF) membrane is being tested on several different water sources and has demonstrated exceptional operation on high turbidity feed water sources. The module design includes a single potted end with the membrane fibers looped on the bottom to allow draining of solids from the module. The UF membrane filters outside to inside and has been operated on feed water turbidity levels up to 200 ntu. The availability of a pressure driven hollow fiber membrane that can efficiently filter high suspended solids water sources can provide a cost effective solution for many small to medium sized water supplies. Conditioning the feed water with a coagulant or direct filtration of high turbidity feed water can be used depending on the organic material present without settling or other clarification process. This eliminates the need for additional structural pretreatment and reduces overall system cost and size. Current limitations include the module size that makes this cost prohibitive for very large systems. Larger membrane systems where high-suspended solids are present in the feed water have been utilizing immersion membrane technologies more and more over the past few years. These systems typically operate under a vacuum and can be used for large water treatment plants as their design allows large filtration modules such as Memcor's CMFS filter block at 880 m3/hr. This allows significant capital cost reductions and allows membrane filtration to be competitive to conventional filtration technologies for virtually all filtration applications. This paper will review the economics and performance of both pressure driven and immersion membrane systems for small to large water supply systems on feed water containing high-suspended solid levels. Actual testing data for the new pressure driven hollow fiber UF membrane and immersion membrane systems will be provided on different water supplies including unconditioned surface water, filter backwash water and coagulated surface water.

scholarly journals Investigations on Bacteriological Quality of Tap Water Sources within the University of Port Harcourt

2019 ◽  
pp. 1-5
Author(s):  
H. O. Stanley ◽  
C. J. Ugboma ◽  
P. C. Uzoaru
Keyword(s):  
Water Samples ◽  
Membrane Filtration ◽  
Heterotrophic Bacteria ◽  
Tap Water ◽  
Total Coliform ◽  
Water Sources ◽  
Filtration Method ◽  
Port Harcourt ◽  
The University

In this study, the sanitary quality of tap water sources within the University of Port Harcourt was investigated in order to determine its suitability for drinking and other domestic applications. Eight composite samples of tap water were collected from Eight different locations within the three campuses of the University of Port Harcourt using 300 ml-capacity sterile containers. These locations included NDDC Hostel, Sports Hostel, Medical Hostel, NUH Hostel, Dan Etete Hostel, Delta A Hostel, Delta B Hostel and Choba Campus. After collection, water samples were taken to the laboratory for enumeration and identification of Total heterotrophic bacteria (THB), Total coliform (TC) and Faecal coliform (FC) using the membrane filtration method. Result showed that the average THB, TC and FC counts recorded in the tap water samples across the eight locations ranged from 12.4 CFU to 36.7 CFU, 4.3 CFU to 10.1 CFU and 2.8 CFU to 5.2 CFU per 100ml respectively. Bacterial isolates were identified as probably belonging to genera such as Bacillus spp., Klebsiella spp., Enterobacter spp., Staphylococcus spp., Proteus spp., Citrobacter spp., Serratia spp. and Escherichia spp., respectively. Samples from Delta B hostel and Choba campus recorded the lowest and highest THB, TC and FC counts respectively. According to WHO standard, the result of THB, TC and FC counts indicated that the tap water in all eight locations were above the limit acceptable for drinking but within acceptable limit for other domestic use such as bathing and washing.

scholarly journals Processing nanoporous organic polymers in liquid amines

2019 ◽  
Vol 10 ◽  
pp. 1844-1850 ◽  
Author(s):  
Jeehye Byun ◽  
Damien Thirion ◽  
Cafer T Yavuz
Keyword(s):  
Elevated Temperatures ◽  
Carbon Film ◽  
Carboxyl Groups ◽  
Network Structures ◽  
High Porosity ◽  
Organic Polymers ◽  
Photo Catalysis ◽  
Nanoporous Polymers ◽  
Polymeric Chains ◽  
Fine Carbon

Rigid network structures of nanoporous organic polymers provide high porosity, which is beneficial for applications such as gas sorption, gas separation, heterogeneous (photo)catalysis, sensing, and (opto)electronics. However, the network structures are practically insoluble. Thus, the processing of nanoporous polymers into nanoparticles or films remains challenging. Herein, we report that nanoporous polymers made via a Knoevenagel-like condensation can be easily processed into nanoparticles (115.7 ± 40.8 nm) or a flawless film by using liquid amines as a solvent at elevated temperatures. FTIR spectra revealed that the carboxyl groups in the nanoporous polymers act as reactive sites for amines, forming new functionalities and spacing the polymeric chains to be dissolved in the liquid amines. The processed film was found to be CO2-philic despite the low surface area, and further able to be transformed into a fine carbon film by thermal treatment.

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