scholarly journals Impact of rock alum pretreatment on biosand filter performance in Cambodia

2020 ◽  
Vol 10 (1) ◽  
pp. 166-170 ◽  
Author(s):  
Kevin D. Curry ◽  
Christopher P. Bloch ◽  
Vantha Hem
Keyword(s):  
River Water ◽  
Flow Rate ◽  
Water Source ◽  
Drinking Water Source ◽  
Source Water ◽  
Filter Performance ◽  
Biosand Filter ◽  
Tonle Sap ◽  
Alum Treatment ◽  
Water Filters

Abstract Alum is often recommended by WASH agencies as a pretreatment flocculent to improve filtration in biosand filters (BSFs) for communities using a turbid drinking water source. Floating villages on the Tonle Sap Lake in Cambodia using BSFs encounter severe declines in filtration rates while using alum, resulting in reduced use of the BSF. We tested the effect of rock alum treatment on flow rate and turbidity. The flow rate of all BSFs declined over time, but degradation of flow was more rapid for alum-treated water than untreated water. Rock alum treatments significantly reduced the turbidity of borrow pit source water. Filters switched to untreated river water decreased in turbidity to levels ≤ rock alum-treated river water. Rock alum treatments increased aluminum in source water 4–15 times, but filtration by BSFs decreased levels of aluminum to near 0.05 mg/L. Though rock alum effectively reduces turbidity in source water, we believe it continues its coagulation inside the BSF during pause periods, negatively impacting flow rates.

Divergent responses of diverse microalgae commonly found in drinking water source water to UV-C treatment

2021 ◽  
Author(s):  
Jordan Roszell ◽  
Po-Shun Chan ◽  
Brian Petri ◽  
Ted Mao ◽  
Kathleen Nolan ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Source ◽  
Drinking Water Source ◽  
Source Water ◽  
Uv C

scholarly journals Quality of Ground and Surface Water of Rajshahi City Area for Sustainable Drinking Water Source

2010 ◽  
Vol 2 (3) ◽  
pp. 577 ◽  
Author(s):  
M. T. Rasul ◽  
M. S. Jahan
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Ground Water ◽  
River Water ◽  
Oxygen Demand ◽  
Water Source ◽  
Total Coliform ◽  
Drinking Water Source ◽  
City Area ◽  
Rajshahi City

An investigation was carried out to assess the water qualities and extents of impurities in groundwater and surface water (Padma river water) in Rajshahi City area. Water samples from a total of 330 tube wells and five spots of the river Padma were analysed for physicochemical, biological and hydrological parameters with standard methods. Among all considered parameters of ground water, concentrations of arsenic, iron, manganese, total hardness, and total coliform and faecal coliform bacteria were found above the permissible limits for potable water. In case of the river Padma, biochemical oxygen demand, chemical oxygen demand, total coliform, faecal coliform and suspended solids exceeded permissible limits. Both ground and river water must be treated properly before distribution for drinking purpose. Finally, the Padma is recommended as the most sustainable drinking water source for Rajshahi City Corporation area. Keywords: Rajshahi City; Ground water; Surface water; Quality control. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v2i3.4093                 J. Sci. Res. 2 (3), 579-586 (2010) 

scholarly journals Impact of surface maintenance on BioSand filter performance and flow

2017 ◽  
Vol 15 (2) ◽  
pp. 262-272 ◽  
Author(s):  
Sarah Singer ◽  
Brain Skinner ◽  
Raymond E. Cantwell
Keyword(s):  
Flow Rate ◽  
Recovery Period ◽  
Pause Time ◽  
Effluent Water ◽  
Removal Rates ◽  
Filter Performance ◽  
Biosand Filter ◽  
Slow Sand Filter ◽  
And Performance ◽  
Sr Method

The BioSand filter (BSF) is a household scaled, intermittently operated, slow sand filter. The BSF requires maintenance to remove trapped sediments. This study evaluated the effects of maintenance on the filter's flow rate and performance. Four concrete BSFs received three styles of maintenance: surface agitation (SA), stirring method (SM), and sand removal (SR). Effluent water was collected from the filter between 0–2 L effluent (0–2 L effluent) and between 15–20 L effluent (15 L+ effluent). After maintenance, effluent at 15 L+ (no pause time) showed a significant decrease in thermotolerant coliform removal rates by 0.66–0.91 log (SA), 0.57–0.67 log (SM) and 0.32–0.83 log (RM) (<0.001). Effluent water at 0–2 L (with pause time) did not significantly decrease in thermotolerant coliform removal rates (>0.17) for any maintenance method. The recovery duration after maintenance for all methods at 0–2 L effluent had a median recovery of <1.2 days. The effluent at 15 L+ had a longer recovery period (at least 3.9, 3.0 and 12.75 days for the SA, SM, and SR method, respectively). The flow rate recovery for SA (76%) and SM (82%) was lower compared to SR (138%).

In-home performance and variability of biosand filters treating turbid surface and rain water in rural Kenya

2013 ◽  
Vol 3 (2) ◽  
pp. 189-198 ◽  
Author(s):  
Erica R. McKenzie ◽  
Marion W. Jenkins ◽  
Sangya-Sangam K. Tiwari ◽  
Jeanie Darby ◽  
Wycliffe Saenyi ◽  
...  
Keyword(s):  
River Water ◽  
Low Income ◽  
Rain Water ◽  
Fecal Coliforms ◽  
Performance Study ◽  
Factors Affecting ◽  
Effluent Quality ◽  
Filter Performance ◽  
Biosand Filter ◽  
Households With Children

Thirty low-income Kenyan households using turbid river and relatively cleaner rain water participated in a 6 month in-home Biosand filter (BSF) performance study comprised of surveys and monthly monitoring of BSF influent and effluent water for turbidity and fecal coliforms (FC). River–river (influent–effluent) sample pairs (n = 155; 90% of observations) resulted in average BSF instantaneous FC and turbidity removals of 1.41 log10 (96.1%) and 32.5%, respectively. Cumulative distributions of influent and effluent quality demonstrated unambiguous improvement of river water but rain water improvement was limited and less reliable. Filter performance varied considerably within and across units. A hierarchical set of hypothesized factors affecting filter bacterial performance variability was assessed. BSF effluent FCs were positively correlated with influent (flush water) FCs and influent and effluent turbidity, and negatively correlated with turbidity applied to-date and days since maintenance. Interrupted use and moving the BSF negatively impacted effluent quality. Households with children age 6–10 collecting BSF filtered drinking water, or with more members, had higher effluent FCs. BSFs fed only river water performed better, on average, than mixed-source filters. Implications for BSF implementation in developing countries are discussed, including aqueous chemistry aspects of performance.

scholarly journals Identifying and Prioritizing Urban and Commercial Stormwater Concerns: City of Grants Pass, Oregon

2021 ◽  
Author(s):  
◽  
Amie Siedlecki ◽  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Best Management Practices ◽  
Management Practices ◽  
Water Source ◽  
Drinking Water Quality ◽  
Project Work ◽  
Drinking Water Source ◽  
Source Water ◽  
The City

For many communities, drinking water comes from surface water sources, or source water, such as rivers and creeks. Within the city of Grants Pass, Oregon, this is the case. The Rogue River, which spans 215 miles, beginning near Crater Lake and emptying into the ocean at Gold Beach, is Grants Pass’ drinking water source. While the capacity of the Rogue River, in relation to drinking water, is rarely an issue for the City of Grants Pass’ Public Works Department, the potential contaminant sources (PCS) from the urban, commercial, and industrial geographical areas of Grants Pass is a concern. In order to deploy treatment processes that are capable of targeting these PCS, it is important to have an idea of where and how these PCS are reaching the storm drains, creeks, and eventually the Rogue River. The purpose of this study was to identify area-specific risk components and how those components spatially aligned with PCS and their locations. Geographic Information System (GIS) analysis and a risk matrix were used to rank the PCS according to risk in relation to Grants Pass’ source water intake. PCS ranked as high priority, or exuding the highest risk to drinking water quality, were followed up with onthe- ground surveys. After surveying the high priority PCS, best management practices (BMP) recommendations were made to the City of Grants Pass to better protect the drinking water quality. Branching off of this initial project work came similar studies in many other Rogue Basin communities. With this continued work, improvements were made to streamline the processes, such as recording survey observations. Overall, this project work has led to many discoveries regarding threats to drinking water quality and how to best respond to certain types of threats.

Proactive optical monitoring of catchment dissolved organic matter for drinking water source protection

2020 ◽  
Author(s):  
John Weatherill ◽  
Elena Fernandez-Pascual ◽  
Jean O'Dwyer ◽  
Elizabeth Gilchrist ◽  
Simon Harrison ◽  
...  
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Water Source ◽  
Disinfection Byproducts ◽  
Catchment Management ◽  
Drinking Water Source ◽  
Source Water ◽  
Optical Monitoring ◽  
Water Supplies

<p>Ireland has a far greater number of regulatory exceedances for trihalomethanes (THMs) in public water supplies than the next highest European Union member state. In Ireland, 82% of public water supplies originate from surface water catchments which require disinfection to inactivate pathogens and prevent the spread of waterborne diseases. Since the 1970s, it has been known that the use of chlorine for disinfection leads to the formation of potentially harmful disinfection byproducts (DBPs) of which some are suspected carcinogens. THMs are one prominent class of at least 700 potentially harmful disinfection byproducts (DBPs) produced after chlorination of dissolved organic matter (DOM) present in source water which is not removed prior to disinfection.</p><p>We introduce a new research project, funded by the Irish Environmental Protection Agency entitled PRODOM: PRoactive Optical monitoring of catchment Dissolved Organic Matter for drinking water source protection. The overall aim of the research is to develop an integrated catchment-level understanding of the spatiotemporal dynamics of DOM precursors and associated DBP formation risk. The project will explore the relationship between optically-active DOM precursors and laboratory formation potentials for key DBPs including emerging classes of potentially more harmful nitrogenous DBPs. Through high-resolution spatial sampling we will develop geospatial DBP formation risk maps and identify risk-driving point and diffuse precursor sources. We will evaluate the potential of state-of-the-art UV fluorescence sensor technology to act as an early warning tool for proactive management of source water at sub-catchment scale. Using high-frequency time series monitoring of fluorescent precursors, we will identify high-risk periods in the catchment hydrograph and evaluate critical precursor sources and pathways to inform a series of catchment management measures designed to reduce DBP formation risk. </p>

scholarly journals Sustained use of a household-scale water filtration device in rural Cambodia

2009 ◽  
Vol 7 (3) ◽  
pp. 404-412 ◽  
Author(s):  
Joe Brown ◽  
S. Proum ◽  
M. D. Sobsey
Keyword(s):  
Water Treatment ◽  
Water Source ◽  
Drinking Water Source ◽  
Ceramic Water Filters ◽  
Hygiene Practices ◽  
Point Of Use ◽  
Sanitation And Hygiene ◽  
Water Filters ◽  
Over Time

The effectiveness of point-of-use water treatment may be limited by declining use over time, particularly when water treatment is introduced via targeted intervention programmes. In order to evaluate the long-term uptake and use of locally produced ceramic water filters in rural Cambodia, we visited households that had received filters as part of NGO-subsidized distribution programmes over a 4 year period from 2002 to 2006. Of the more than 2,000 filters distributed, we visited 506 randomly selected households in 13 villages spanning three provinces to assess filter time in use and to collect data on factors potentially correlated with long-term use. Results indicate that filter use declined at the rate of approximately 2% per month after implementation, largely owing to breakages, and that, controlling for time since implementation, continued filter use over time was most closely positively associated with: related water, sanitation and hygiene practices in the home; cash investment in the technology by the household; and use of surface water as a primary drinking water source.

Probing the mechanisms of NOM chlorination using fluorescence: formation of disinfection by-products in Alento River water

2004 ◽  
Vol 4 (4) ◽  
pp. 227-233 ◽  
Author(s):  
M. Fabbricino ◽  
G.V. Korshin
Keyword(s):  
Drinking Water ◽  
River Water ◽  
Emission Band ◽  
Total Yield ◽  
Water Source ◽  
Haloacetic Acids ◽  
Drinking Water Source ◽  
By Products

Experiments with Alento River water (a drinking water source in the province of Salerno, Italy) showed that considerable amounts of disinfection by-products, primarily chloroform and haloacetic acids, form in that water upon chlorination. The total yield of haloacetic acids was almost twice as high as that of chloroform. Chlorination also caused significant changes in the intensity of NOM fluorescence and the position of the emission band. To quantify the latter, the wavelength that corresponds to the position of the emission band at its half-intensity (λ0.5) was employed. Chlorination caused the λ0.5 values to decrease, while the THMs and HAAs concentrations were linearly correlated with the corresponding λ0.5 values. The strength of correlations between DBP concentrations and λ0.5 values indicates that the latter parameter can be employed in studies of DBP formation in drinking water.

scholarly journals Characteristics of packaged water production facilities in Greater Accra, Ghana: implications for water safety and associated environmental impacts

2020 ◽  
Vol 10 (1) ◽  
pp. 146-156 ◽  
Author(s):  
Maxwell D. K. Semey ◽  
Winfred Dotse-Gborgbortsi ◽  
Mawuli Dzodzomenyo ◽  
Jim Wright
Keyword(s):  
Water Demand ◽  
Water Source ◽  
Risk Scores ◽  
Drinking Water Source ◽  
Source Water ◽  
Water Production ◽  
Water Safety ◽  
Plastic Bags ◽  
Almost All ◽  
Sachet Water

Abstract Packaged water (sold in bags or bottles) is widely consumed in many countries and is the main drinking-water source for most urban Ghanaian households. There are, however, few studies of packaged water production. This study aims to assess the source water, treatment, and manufacturing characteristics of sachet water (vended in 500 mL plastic bags), together with point-of-manufacture risks to hygienic production. A sample of 90 sachets was collected of brands sold in four neighbourhoods in Accra, Ghana, their packaging and physical characteristics recorded, and a risk score calculated from these. Production processes were observed at 60 associated sachet factories, producers interviewed, and surrounding neighbourhoods surveyed for contamination hazards. 80% of producers packaged groundwater from boreholes and all treated water via reverse osmosis. Almost all manufacturers (95%) reported site visits by regulators in the previous year and few risks to hygienic production were observed at factories. Sanitary risk scores were 9.2% higher at the seven factories never visited by a regulator, though this difference was not significant (t = 1.81; p = 0.07). This survey suggests most Ghanaian sachet water originates from groundwater and is comparatively safe, though a minority remains unregulated. Groundwater governance policy could support this industry in meeting Greater Accra's growing water demand through the designation of protected municipal wellfields.

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