Silver nanoparticle removal from drinking water: flocculation/sedimentation or filtration?

2013 ◽  
Vol 13 (5) ◽  
pp. 1181-1187 ◽  
Author(s):  
Desmond F. Lawler ◽  
Anne M. Mikelonis ◽  
Ijung Kim ◽  
Boris L. T. Lau ◽  
Sungmin Youn

Silver nanoparticles are used in a wide variety of consumer products and are therefore rapidly becoming ubiquitous in the natural environment; they can be expected to be found in the natural waters used as drinking water supplies. This research investigated whether such particles could be expected to be removed in conventional water treatment plants such as flocculation and filtration. Both flocculation and granular media filtration experiments with citrate-capped silver nanoparticles were performed at different ionic strengths and in the presence and absence of natural organic matter. The results were generally consistent with theories of particle destabilization that have been developed for larger particles (greater than 1 μm), suggesting that silver nanoparticles are likely to be removed in conventional treatment processes.

2001 ◽  
Vol 1 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Don Bursill

On and follow Natural organic matter (NOM) derived from soil and vegetation in water catchments is the key factor influencing most, if not all water treatment processes. The structure of the NOM and its involvement in water treatment processes requires better understanding. It seems likely that a better understanding of NOM reactions could lead to far better predictive capacity for water treatment designers and operators. Certainly the removal of NOM as a first step to the production of drinking water has many attractions. This paper provides an overview of work done by the author and many of his colleagues to advance this issue.


2016 ◽  
Vol 3 (6) ◽  
pp. 1436-1446 ◽  
Author(s):  
Tongren Zhu ◽  
Desmond F. Lawler ◽  
Yunqi Chen ◽  
Boris L. T. Lau

Environmental transformations had different effects on self-aggregation and initial deposition in granular media filtration, contrary to traditional theory.


2015 ◽  
Vol 15 (3) ◽  
pp. 442-455 ◽  
Author(s):  
Yue Zhang ◽  
Xinhua Zhao ◽  
Xinbo Zhang ◽  
Sen Peng

In the past decades, natural organic matter (NOM), which is a complex heterogeneous mixture of organic materials that are commonly present in all surface, ground and soil waters, has had an adverse effect on drinking water treatment. The existence of NOM results in many problems in drinking water treatment processes, and the properties and amount of NOM can significantly affect the efficiency of these processes. NOM not only influences the water quality with respect to taste, color and odor problems, but it also reacts with disinfectants, increasing the amount of disinfection by-products. NOM can be removed from drinking water via several treatment processes, but different drinking water treatment processes have diverse influences on NOM removal and the safety of the drinking water. Several treatment options, including coagulation, adsorption, oxidation, membrane and biological treatment, have been widely used in drinking water purification processes. Therefore, it is of great importance to be able to study the influence of different treatment processes on NOM in raw waters. The present review focuses on the methods, including coagulation, adsorption, oxidation, membrane, biological treatment processes and the combination of different treatment processes, which are used for removing NOM from drinking water.


2015 ◽  
Vol 12 (6) ◽  
pp. 673 ◽  
Author(s):  
Rhys M. Goodhead ◽  
Blair D. Johnston ◽  
Paula A. Cole ◽  
Mohammed Baalousha ◽  
David Hodgson ◽  
...  

Environmental context Nanoparticles are present in growing volumes of consumer products and are suspected to be released into the environment at detectable levels. We focus on cerium dioxide nanoparticles and investigate their availability to fish from the water column, where we found increasing concentrations of natural organic material increased the ceria measured in the fish gills. This complex interaction between nanoparticle behaviour and uptake from environmentally relevant test systems is significantly understudied. Abstract Natural organic colloids affect the fate and behaviour of nanoparticles in the aquatic environment but how these interactions affect the bioavailability of nanoparticles to organisms is a major knowledge gap in risk-assessment analysis. Here, we investigated interactions of citrate-coated cerium dioxide (CeO2) nanoparticles with fulvic acids, representing natural organic matter, and assessed their bioavailability to fish (common carp, Cyprinus carpio) exposed chronically (32days) via the water. We show a fulvic acid concentration-related enhancement in the uptake of cerium (Ce) into gill tissues, with some evidence for an enhanced Ce uptake also into kidney and brain tissues in the presence of fulvic acids, but with more variable responses. We present evidence for differences in the aggregation behaviour for CeO2 nanoparticles in the different exposure scenarios, with reduced CeO2 particle aggregate size with citrate coating and fulvic acids, as determined from dynamic light scattering. We highlight that multiple analytical approaches are essential for understanding the dynamic nature of the particles and also that interpretations on measured particle sizes and characteristics may differ depending on the technique(s) employed. We conclude that conditions in natural waters are likely to play a fundamental role in affecting bioavailability and thus potential biological effects of CeO2 particles.


10.14311/334 ◽  
2002 ◽  
Vol 42 (2) ◽  
Author(s):  
A. Grünwald ◽  
B. Šťastný ◽  
K. Slavíčková ◽  
M. Slavíček

Recent drinking water regulations have lowered the standards for disinfection by-products and have added new disinfection by-products for regulation. Natural organic matter (NOM), mainly humic compounds, plays a major role in the formation of undesirable organic by-products following disinfection of drinking water. Many disinfection by-products have adverse carcinogenic or mutagenic effects on human health. This paper deals with the formation potencial of disinfection by-products in water samples taken from different places in the Flaje catchment.


2010 ◽  
Vol 10 (1) ◽  
pp. 59-68 ◽  
Author(s):  
I. Kristiana ◽  
B. P. Allpike ◽  
C. A. Joll ◽  
A. Heitz ◽  
R. Trolio

Water utilities have experienced increasing pressure to minimise the formation of disinfection by-products (DBPs), as reflected in the increasingly stringent regulations and guidelines for the concentrations of DBPs in drinking water. Understanding the disinfection characteristics and molecular weight (MW) distribution of natural organic matter (NOM) will assist in the optimisation of drinking water treatment processes to minimise the formation of DBPs. This study investigated the disinfection behaviour of MW fractions of NOM isolated from a Western Australian source water. The NOM was fractionated and separated using preparative size exclusion chromatography (SEC) and the fractions were chlorinated in the presence of bromide ion. The larger MW fractions of NOM were found to produce the highest concentrations of DBPs (trihalomethanes, haloacetic acids, haloacetonitriles, haloketones, and haloaldehydes), with the low MW fractions still producing significant amounts of these DBPs. The results also showed a trend of an increasing proportion of brominated DBPs with decreasing MW and aromatic character. Considering that the smaller MW fractions of NOM produce significant amounts of DBPs, with a higher relative contribution from brominated DBPs, water treatment processes need to be optimised for either bromide removal or the removal of aliphatic, small MW fractions of NOM, in order to meet DBP guidelines and regulations.


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