Testing monolithic activated carbon adsorbers for in-line removal of organic micropollutants

2016 ◽  
Vol 16 (6) ◽  
pp. 1693-1699
Author(s):  
Inga Hilbrandt ◽  
Aki Sebastian Ruhl ◽  
Martin Jekel
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Cycle ◽  
Linear Increase ◽  
Low Flow ◽  
Organic Micropollutants ◽  
Gas Treatment ◽  
Flow Rates

Anthropogenic organic micropollutants (OMP) occur along the whole urban water cycle including drinking water. Various OMP can be efficiently adsorbed onto activated carbon. In the present study a commercial monolithic adsorber (MA), originally developed for gas treatment, was examined for the removal of OMP from drinking water. As a promising advantage, the adsorber can be introduced into existing pipes without causing substantial pressure losses. The MA was first characterized with scanning electron microscopy and energy dispersive X-ray spectroscopy. Weight loss during incineration at 550 °C indicated an activated carbon content of around 25%. Adsorption isotherms were recorded with milled material of the MA to estimate the capacity of the embedded adsorbent. Long-term flow-through experiments with two different flow rates were conducted to estimate the in-line removal efficiency. At low flow rates removals of 60% benzotriazole, 40% carbamazepine and 30% diclofenac were observed initially followed by a linear increase of effluent concentrations. Calculated loadings after 60 days of operation were e.g. 30 μg benzotriazole per g adsorber or 110 μg benzotriazole per g activated carbon as constituent of the adsorber. For specific applications, MA might be useful for the in-line elimination of OMP within drinking water distribution systems.

scholarly journals Disinfectant residuals in drinking water systems select for mycobacterial populations with intrinsic antimicrobial resistance

2019 ◽  
Author(s):  
Maria Sevillano ◽  
Zihan Dai ◽  
Szymon Calus ◽  
Quyen M Bautista-de los Santos ◽  
A. Murat Eren ◽  
...  
Keyword(s):  
Drinking Water ◽  
Antimicrobial Resistance ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Cycle ◽  
Water Systems ◽  
Intrinsic Resistance ◽  
Drinking Water Distribution Systems ◽  
The Impact ◽  
Drinking Water Systems

AbstractAntimicrobial resistance (AMR) in drinking water has received less attention than counterparts in the urban water cycle. While culture-based techniques or gene-centric PCR have been used to probe the impact of treatment approaches (e.g., disinfection) on AMR in drinking water, to our knowledge there is no systematic comparison of AMR traits between disinfected and disinfectant residual-free drinking water systems. We use metagenomics to assess the associations between disinfectant residuals and AMR prevalence and its host association in full-scale drinking water distribution systems (DWDSs). The differences in AMR profiles between DWDSs are associated with the presence or absence of disinfectant. Further, AMR genes and mechanisms enriched in disinfected systems are associated with drug classes primarily linked to nontuberculous mycobacteria (NTM). Finally, evaluation of metagenome assembled genomes (MAGs) of NTM indicates that they possess AMR genes conferring intrinsic resistance to key antibiotics, whereas such NTM genomes were not detected in disinfectant residual free DWDSs. Thus, disinfection may not only influence the AMR profiles of the drinking water microbiome but also select for NTM with intrinsic AMR.

Simulation of Constant Pressure and Flow Rate Through Mini-Channels Inserted Into Distribution Systems (WDS)

2012 ◽  
Author(s):  
Muinul H. Banna ◽  
Homayoun Najjaran ◽  
Rehan Sadiq ◽  
Manuel J. Rodriguez ◽  
Syed A. Imran ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Flow Rate ◽  
Distribution Systems ◽  
Water Distribution ◽  
Constant Pressure ◽  
Water Quality Monitoring ◽  
Quality Monitoring ◽  
Constant Flow ◽  
Flow Rates

The miniaturised online sensors that were developed in the laboratories were for atmospheric pressure and steady state flow, but in the water distribution network neither the pressure nor the flow is steady. Many of the state of the art drinking water quality monitoring sensors can be operated well below the drinking Water Distribution System (WDS) pressure. Moreover, each of the sensors requires different flow rates. This paper discusses simulation and design of an affordable constant flow and constant outlet pressure system and shows an easy way to provide different flow rates for different sensors. The other criterion which should be met is the flow rate of the water bled (leakage) from WDS which must also be low. To meet the above criteria a 2-D model was developed to represent the constant pressure constant flow system for online water quality monitoring (WQM) sensors. Different configuration of the system is considered and the optimum design includes 1.044 m/s flow velocity which is low enough for the flow to be steady.

Resorcinarene Cavitand Polymers for the Remediation of Halomethanes and 1,4-Dioxane

2019 ◽  
Author(s):  
Luke Skala ◽  
Anna Yang ◽  
Max Justin Klemes ◽  
Leilei Xiao ◽  
William Dichtel
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
High Capacity ◽  
The United States ◽  
Water Sources ◽  
Disinfection Byproducts ◽  
Porous Polymer ◽  
Organic Micropollutants ◽  
Executive Summary ◽  
Regulatory Limits

<p>Executive summary: Porous resorcinarene-containing polymers are used to remove halomethane disinfection byproducts and 1,4-dioxane from water.<br></p><p><br></p><p>Disinfection byproducts such as trihalomethanes are some of the most common micropollutants found in drinking water. Trihalomethanes are formed upon chlorination of natural organic matter (NOM) found in many drinking water sources. Municipalities that produce drinking water from surface water sources struggle to remain below regulatory limits for CHCl<sub>3</sub> and other trihalomethanes (80 mg L<sup>–1</sup> in the United States). Inspired by molecular CHCl<sub>3</sub>⊂cavitand host-guest complexes, we designed a porous polymer comprised of resorcinarene receptors. These materials show higher affinity for halomethanes than a specialty activated carbon used for trihalomethane removal. The cavitand polymers show similar removal kinetics as activated carbon and have high capacity (49 mg g<sup>–1</sup> of CHCl<sub>3</sub>). Furthermore, these materials maintain their performance in real drinking water and can be thermally regenerated under mild conditions. Cavitand polymers also outperform activated carbon in their adsorption of 1,4-dioxane, which is difficult to remove and contaminates many public water sources. These materials show promise for removing toxic organic micropollutants and further demonstrate the value of using supramolecular chemistry to design novel absorbents for water purification.<br></p>

The assessment of biofilm community composition on plumbing materials in filtered and unfiltered water distribution systems

2003 ◽  
Vol 3 (1-2) ◽  
pp. 187-191
Author(s):  
M.M. Critchley ◽  
N.J. Cromar ◽  
H.J. Fallowfield
Keyword(s):  
Drinking Water ◽  
Fatty Acid ◽  
Community Composition ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Polymer Materials ◽  
Fatty Acid Profiles ◽  
Water Supplies ◽  
Drinking Water Distribution Systems

Biofilms have been extensively characterised within drinking water distribution systems. However, the significance of materials on biofilm species diversity is not established. This study investigated the community composition of biofilms on plumbing materials receiving filtered and unfiltered water supplies. Biofilms were extracted from polybutylene, polyethylene, cross-linked polyethylene, unplasticised polyvinyl chloride and copper tubes in sampling rigs receiving Murray-Onkaparinga water before or after filtration. Biofilms were extracted and analysed for fatty acid composition using the FAME™ methodology. There were differences in the fatty acid profiles of biofilms and the respective water supplies, indicating differences in the attached and planktonic communities. The results also showed significant differences in the fatty acid profiles of biofilms on the polymer materials compared to copper, suggesting variations in biofilm populations on the different materials. The potential for materials to select for microbial populations has significant implications for the ecology of drinking water biofilms.

scholarly journals Identification of Aminoglycoside Resistance Genes From Bacteria Isolated From Selected Municipal Drinking Water Distribution Systems in Southwestern Nigeria

2020 ◽  
Vol 41 (S1) ◽  
pp. s255-s255
Author(s):  
Ayodele T. Adesoji ◽  
Adeniyi A. Ogunjobi
Keyword(s):  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Southwestern Nigeria ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution

Background: Multidrug-resistant bacteria can lead to treatment failure, resulting in infectious diseases being transferred through nonpotable water. Aminoglycosides are an important class of antibiotics that are abused in Nigeria. Few studies have investigated aminoglycoside-modifying genes (AMGs) that are likely responsible for resistance in Nigeria bacteria isolates. Therefore, we aimed to characterize AMGs from isolates in drinking water distribution systems (DWDS) in southwestern Nigeria. Methods: Multidrug-resistant bacteria (n = 181) that had been previously characterized by 16S rDNA sequencing and that were positive for resistance to at least 1 aminoglycoside antibiotic were selected from 6 treated and untreated water distribution systems. Strains were PCR genotyped for 3 AMGs: aph(3)c, ant(3)b and aph(6)-1dd. Results: Of 181 MDR bacteria tested, 69 (38.12%) were positive for at least 1 of the AMGs. The most common was ant(3)c (27.6%), followed by aph(3")c (18.23%). Both aph(3)c and ant(3")b were found in 7.73% of tested isolates, ant(3)b was most commonly found in Alcaligenes spp (50%). Furthermore, aph(3")c was most commonly detected in Proteus spp (50%). Other genera positive for AMGs included Acinetobacter, Aeromonas, Bordetella, Brevundimonas, Chromobacterium, Klebsiella, Leucobacter, Morganella, Pantoae, Proteus, Providencia, Psychrobacter, and Serratia. Conclusions: High occurrence of ant(3)c and aph(3)c among these bacteria call for urgent attention among public health workers because these genes can be easily disseminated to consumers if present on mobile genetic elements like plasmids, integrons, and transposons.Funding: NoneDisclosures: None

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