News Items Archive 2021
Please note that, for some of the older entries, links may no longer be functional.
Changes in Escherichia coli to enteric protozoa ratios in rivers - Implications for risk-based assessment of drinking water treatment requirements
Legionella and other opportunistic pathogens (OP) in full-scale chloraminated municipal drinking water distribution systems (DWDS).
This US study looks at how physicochemical parameters, mainly monochloramine residual concentration, hydraulic residence time (HRT), and seasonality, affected the occurrence and concentrations of four common OPs (Legionella, Mycobacterium, Pseudomonas, and Vermamoeba vermiformis)
in four full-scale DWDS in the US. Legionella
positively correlated with Mycobacterium
, and total bacteria. Multiple regression with data from the four drinking water distribution systems (DWDS) showed that Legionella
had significant correlations with total chlorine residual level, free ammonia concentration, and trihalomethane concentration. The study demonstrates how the significant spatiotemporal variations of OP concentrations in chloraminated DWDS correlated with critical physicochemical water quality parameters such as disinfectant residual levels. This work also indicates that Legionella
is a promising indicator of OPs and microbial water quality in chloraminated DWDSs.
In-situ fluorescence better than faecal indicator oganisms for estimating faecal contamination risk
This study carried out over 14 months in Uganda studied 40 groundwater sources and looked in depth at the statistical considerations. It concludes that Tryptophane-like fluorescence and Humic-like fluorescence
provide a more repeatable and temporally robust approach than faecal indicator organisms to ranking sources by faecal contamination risk across a community in order to strategise prioritisation of sources for drinking or interventions.
Hydrogel tablet can purify a liter of river water in an hou
US scientists and engineers have created a hydrogel tablet that can rapidly purify contaminated water
. One tablet can disinfect a liter of river water and make it suitable for drinking in an hour or less. The special hydrogels generate hydrogen peroxide to neutralize bacteria at an efficiency rate of more than 99.999%. The hydrogen peroxide works with activated carbon particles to attack essential cell components of bacteria and disrupt their metabolism.
Lead removal from water by shock electrodialyais
A process known as shock electrodialysis has been shonn at small scale to be effective at lead removal from water
. With filtration systems, for example, the costs are mainly for replacing the filter materials, which quickly clog up and become unusable, whereas in this system the costs are mostly for the ongoing energy input, which is very small. So far it has has only been demonstrated at small laboratory scale and at quite slow flow rates.
Monitoring biofiltration performance in drinking water treatment
ATP is often monitored as an index of biological acclimation of biological filters
but strong correlations between ATP concentration and filter performance (e.g., organic matter or disinfection by-product precursor removal) are not typically observed. This study evaluated the use of enzyme activity for monitoring biological processes within filters and showed that enzyme activity may be appropriate for monitoring biological processes within drinking water filters and may act as a surrogate for the removal of organic compounds.
DBPs and congenital malformations
This Swedish study based on national data over 10 years found TTHM exposure was associated with increased risk of malformations of the nervous system, urinary system, genitals, and limbs in areas exclusively using chloramine. No associations were observed in areas using exclusively hypochlorite as the primary water treatment method An association between chloramine-related chlorination by-products and congenital malformations has not previously been highlighted
PAC with chlorine can produce disinfection by-products
Water Research Austraalia has issued a factsheet on this compound, which can be produced by cyanobacteria
. This compound has been postulated as implicated in a neurodegenertive condition. The absence of reliable detection methods has led to many conflicting research studies, and has complicated efforts to compare findings across different studies despite the resources and intellectual efforts devoted to this topic, the effects of BMAA on public health continue to be heavily debated.
Risk assessment of loose deposits in drinking water distribution systems
This study of 12 distribution systems
known to be prone to discolouutation events found that although loose deposits could be visualized during water discoloration, toxicity risks could not be evaluated through aesthetic indicators although particle size showed a stronger correlation with toxicity than other properties.
Formation, analysis, and control of chlor(am)ination-derived odor problems.
This Chinese review provides a comprehensive overview
of the occurrence, detection, and control of odor substances derived from drinking water chlor(am)ination disinfection.
MALDI-TOF MS database for identification of water-related bacteria.
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a useful tool for identtification of bacterial isolates
but hitherto has been mostly used in a clinical environment. These workers have developed a database of 319 species which might be encountered in water intended for human consumption.
Influence of pipe materials on microbial community in water and biofilm.
These workers, having studied microbial communities in ccontact with a range of pipe materials
, concluded that pipe material is an important factor that influences the biomass concentration, abundance of specific microorganisms and the bacterial community composition in distribution systems with unchlorinated drinking water.
Domestic water requirement.
Focussing on personal water-use activities
rather than measured household consumption these workers concluded that a minimum target of 79 l/d/caapita during stringent water restrictions was appropriate. A more realistic expected value for non-wasteful, indoor-only water use was determined to be 175 l/d/capita/day.
Antibiotic resistance in hospital and municipal wastewater.
Chlor(am)ination derived odour problems
Lead in drinking water
Health Stream publication July 2021
The real cost of bottled water.
This study of water supply in Barcelona shows that if the whole population of Barcelona decided to shift to bottled water
, the production required would take a toll of 1.43 species lost per year and cost of 83.9 million USD per year due to extraction of raw materials. This is approximately 1,400 times more impact in ecosystems and 3,500 times higher cost of resource extraction compared to the scenario where the whole population would shift to tap water. However this would increase the overall number of years of life lost in the city of Barcelona to 309 (which equals approximately on average 2 hours of lost life expectancy if borne equally by all residents of Barcelona). Adding domestic filtration to tap water would reduce that risk considerably , lowering the total number of years of life lost to 36.
Novel material can remove PFAS from water
US workers incorporated fluorine into an amino acid and mixed it with a fluorinated oil. When added to water in a vial it formed a bead comprised of the fluorine droplet surrounded by an amino acid coating When inverting the vial to expose the bead to air, the bead's components rearranged to form a film
The film captured PFAS substances within two hours and was able to hold them for up to 24 hours
. From this stage, the film containing PFAS could be agitated to reform itself into a cohesive bead that could be easily collected from the now-purified water. This material could be implemented to remove PFAS from drinking water.
On-line microbiological monitoring of drinking water.
This study compared six commercially available microbiological devices
set up in a full-scale drinking water production plant. In order of sensitivity, enzymatic analysis, ATP measurement, and flow cytometric fingerprinting were the most performant for detection of rain- and groundwater contaminations (0.01 – 0.1 v%). On the other hand, optical classification and flow cytometric cell counts were shown to be more robust techniques. All techniques were more sensitive then plate counting.
In-situ creation of hydrogen peroxide
Workers at Cardiff University have shown that the reactive oxygen species—
which include hydroxyl, hydroperoxyl and superoxide radicals—formed over a AuPd catalyst during the synthesis of hydrogen peroxide from hydrogen and air are over 107 times more potent than an equivalent amount of preformed hydrogen peroxide and over 108 times more effective than chlorination under equivalent conditions when teted against E.coli
Hydrogen economy based advanced oxidation process
Interupted water supply impact on biofilms and water quality.
Green recovery from the COVID epidemic
Ofwat, DEFRA, the Environment Agency, DWI and the Consumer Council for Water have set out their ambition to build back greener from the pandemic
: delivering lasting environmental improvements for current and future generations, while meeting the economic and social challenges England faces. Formal proposals to enhance the environment and public health have been submitted from five companies: Severn Trent Water, South Staffs Water, South West Water, Thames Water, and United Utilities. Ofwat has published draft decisions on arrangements for providing fundingto companies, cost sharing rates, scheme delivery and reporting requirements,
Microplasticss remediaation in water systems
Removing salts and other materials from water.
Continuous v intermittent water supply.
Nitrate and spontaneous pre-term birth
Virus inactivating membrane
Removing endocrine disruptors using light
Workers in Germany have developed a new chemical process for removing hormones from water
. It takes advantage of the mechanisms of photocatalysis and transforms the pollutants into potentially safe oxidation products. It is not at the stage where it can be used in full scale water treatment.
Removing salts and other materials from water.
Researchers have created a molecule-sized water transport channel that can carry water between cells while excluding protons and undesired molecules
. These channels mimic the water transport functions of proteins in our bodies known as aquaporins. They could improve the ability of membranes to efficiently filter out unwanted molecules and elements, while speeding up water transport, making it cheaper to create a clean supply.
PFAS in US bottled waters.
39 of 101 products tested were positive for PFAS with purified water containing less than spring water
. Although no enforceable PFAS regulations exist for bottled water in the U.S., the finding that some products approach levels of concern justifies a framework for monitoring PFAS in bottled water production.
Risk of groundwater contamination widely underestimated because of fast flow into aquifers
This paper shows that in karst regions, which are characterized by an increased occurrence of cracks or fissures, the risk of pollution by degradable pollutants
such as pesticides, pharmaceuticals or pathogens is significantly higher than previously expected. Although pollutants are considered short-lived, up to 50 percent of them can still reach groundwater, depending on the period of their decomposition.
Fluoride in water and incidence of hip fracture in post-menopausal women.
This Swedish study population consisted solely of middle-aged to elderly women in Sweden, and thus its findings may not apply to other population subgroups or to women in other countries
However it suggest that long-term consumption of tap water with a fluoride concentration of 1mg/L, which is below the 1.5mg/L maximum concentration recommended by the WHO, may adversely affect bone health in postmenopausal women.
Effectiveness of methods for boiling water in domestic situations
Removal of antibiotic resistance genes by water treatment processes
This laboratory study looks at the effect of ozone, chlorine and u-v on bacterial cells and antibiotic resistance genes (ARG)
in water. While the impact of ozone was similar on bacterial cells and ARG, for chlorine and UV, inactivation of bacterial cells was observed at lower doses than those needed for the decrease of ARG copy numbers. Although UV and chlorine treatments were effective in the inactivation of bacterial cells, incomplete degradation of ARGs was observed. Therefore, plasmid-borne ARGs can potentially be transferred to other bacteria even after the disinfection.
Metformin as an endocrine disruptor.
Metformin no risk to aquatic life.
This very comprehensive paper concludes that based on predicted environmental concentrations and predicted no effect concentrations there is no risk to aquatic life
from metformin nor its metabolite guanylurea.
One step purification and desalination
Fast, selective, DNA‐based detection of Escherichia coli
A recombinase polymerase amplification (RPA) can amplify and detect E. coli
DNA in fewer than 3 min. Although the RPA method was less sensitive than qPCR, it was significantly more rapid
. The speed, selectivity and isothermal low temperature requirements of the RPA technique make it well‐suited for on‐site water quality testing. The current LOD for the method would limit its application to relatively high‐level contamination events, for example sewerage overflows/leaks. The authors suggest considering using mRNA primers to negate the impact of dead cells.
( this is very much “work in progress” but offers potential)
Legionellae in water systems in Spain
A Spanish survey was carried out on c.1750 samples from cooling towers and evaporative condensers (CTC), and water distribution networks
such as domestic hot water (DHW), cold water for human consumption (CW), sprinkler irrigation systems (SIS), fire sprinkler systems (FSS), and water from decorative fountains (DF). Legionellae were found in 15.79% of all samples and Legionella
was isolated from 13 of the 18 locations sampled with Legionella pneumophila
being isolated with similar frequency .High colonization was more frequently detected.
Toxic cyanobacteria in water
Waterborne Disease Outbreak Investigation Toolkit
Microplastics in fresh and drinkng water
Nitrate in drinking water and foetal development
Comparison of phosphate and silicate for reducing plumbosolvency.
Pilot scale studies showed that orthophosphate dosing with pH aadjustment was more effective than sodium silicate in reducing lead release from pipes
although silicate resulted in lower levels of biofilm accumulation on pipe walls.
Microbial community and pipe materials in unchlorinated water and biofilms.
Hydraulic transients can mobilise material from pipework
Viable but non-culturable bacteria(VBNC) in drinking water treatment plants
Metformin chlorination by-products
Mn in Drinking water and ADHD
This Danish study concludes that Mn in drinking water was associated with ADHD
, specifically the ADHD-Inattentive subtype. Its results support earlier studies suggesting a need for a formal health-based drinking water guideline value for Mn.
Cryptosporidium spp. and their detection in water
Accumulation of antibiotic resistnce genes (ARG) during backwash of biological activated carbon (BAC) filters.
This study was conducted to investigate the occurrence of ARGs in full-scale BAC filters during the backwash cycle
using high-throughput qPCR and high-throughput sequencing. After backwashing, the relative ARGs abundance increased by 1.5- to 3.8-folds and the absolute ARGs abundance increased by 0.90- to 1.12-logs in all biofilm samples during filter ripening, indicating that ARGs accumulated in filters during this period. The authors consider that given the high richness and relative abundance of ARGs in BAC filter and the ineffectiveness of backwashing in ARG removal, more stringent downstream disinfection strategies are deserved and more research is necessary to assess potential human health risks due to the persistence of ARGs in drinking water.
New Drinking Water Directive
On 16 December 2020 the European Parliament formally adopted a revised Drinking Water Directive
which came into force on January 12th 2021.After Brexit the UK is not obliged to adopt the new Directive but it is anticipated to have regard to it in future regulation.
Reactivity directed analysis
This critical review introduces the application of a novel approach called Reactivity-Directed Analysis (RDA)
to assess and identify organic electrophiles, the largest group of known environmental toxicants. In contrast to existing in vivo and in vitro approaches, RDA utilizes in chemico methodologies that investigate the re action of organic electrophiles with nucleophilic biomolecules, including proteins and DNA This summary is followed by an overview of existing RDA approaches and their application for the assessment of aqueous environmental matrices, with an emphasis on drinking water.
Harmful algal blooms in the USA.
18 US states entered 421 reports on the One Health Harmful Algal Bloom System
during 2016–2018, including information about 389 human illnesses and at least 413 animal illnesses associated with harmful algal bloom events. The report recognises a number of limitations in its content but further developments can be anticipated.
Waterborne disease in the USA.
This very comprehensive study by no less than 21 authors looks at data from 2000 to 2015 and shows that domestic waterborne transmission of 17 diseases in the United States
caused ≈7.15 million (95% CrI 3.88–12.0 million) waterborne illnesses to occur annually during the study period, including 601,000 ED visits (95% CrI 364,000–866,000), 118,000 hospitalizations (95% CrI 86,800–150,000), and 6,630 deaths (95% CrI 4,520–8,870), and incurred $3.33 billion (95% CrI $1.31–$8.71 billion) in hospitalization and ED visit costs. This estimate includes drinking, recreational, and environmental water exposures. The report however contains many caveats and its findings shouldbe viewed with caution.
Sodium silicate and plumboslvency
This paper suggests that as a corrosion control treatment
for lead, sodium silicate is inferior to orthophosphate in circumneutral pH water with low alkalinity. and, as with polyphosphate, excess silicate can be highly detrimental to controlling lead release.
Rapid detection of cyanobacteria
This thesis describes the application of in situ fluorometers for monitoring algal blooms in water supply systems, giving results in minutes facilitating the timely adjustement of PAC and coagulant dosing.