The impact of loading frequency and copper as a biocide on biosand filter performance

August 20, 2013 · 0 comments

The impact of loading frequency and copper as a biocide on biosand filter performance. Journal of Water, Sanitation and Hygiene for Development, Aug 2013

Elizabeth M. Hyde and Laura W. Lackey

Mercer University School of Engineering, 1400 Coleman Ave., Macon, Georgia, 478-301-2552 E-mail: Lackey_l@mercer.edu

Biological sand filters (BSFs) can appropriately serve as point-of-use water treatment in developing nations. This study examined the benefit of adding copper to a BSF, and evaluated the impact of its addition in relation to extended pause times. Four 70-L BSFs were created – copper was incorporated in the packing of the two BSFs labeled Filter 1 and Filter 3. Filters 1 and 2 were loaded daily while Filters 3 and 4 were watered every third day. Source water was taken from the Ocmulgee River in Macon, Georgia. To investigate variation due to watering frequency and biocidal addition, BSF performance was quantified using coliforms, turbidity, solids, dissolved oxygen, pH, and copper analyses. E. coli removal efficiencies for Filters 1, 2, 3, and 4 averaged 90, 77, 87, and 80%, respectively. Paired t-tests at α = 0.05 indicate that effluent coliform concentrations from filters watered daily were significantly impacted by the presence of copper. Filters loaded every third day showed no significant performance effect from copper addition on coliform removal efficiency. Similar paired t-tests at α = 0.05 for turbidity, solids, and COD showed no significant difference between filter performance.

Factors Affecting Domestic Water Consumption in Rural Households

August 20, 2013 · 0 comments

Factors Affecting Domestic Water Consumption in Rural Households upon Access to Improved Water Supply: Insights from the Wei River Basin, China. PLoS ONE 8(8) 2013.

L Fan, et al.

Comprehensively understanding water consumption behavior is necessary to design efficient and effective water use strategies. Despite global efforts to identify the factors that affect domestic water consumption, those related to domestic water use in rural regions have not been sufficiently studied, particularly in villages that have gained access to improved water supply. To address this gap, we investigated 247 households in eight villages in the Wei River Basin where three types of improved water supply systems are implemented.

Results show that domestic water consumption in liters per capita per day was significantly correlated with water supply pattern and vegetable garden area, and significantly negatively correlated with family size and age of household head. Traditional hygiene habits, use of water appliances, and preference for vegetable gardening remain dominant behaviors in the villages with access to improved water supply. Future studies on rural domestic water consumption should pay more attention to user lifestyles (water appliance usage habits, outdoor water use) and cultural backgrounds (age, education).

The 6 domains of behavior change: the missing health system building block

August 20, 2013 · 2 comments

Editorial – The 6 domains of behavior change: the missing health system building block. Global Health Science & Practice, Aug 2013.

James Shelton.

Behavior is crucial throughout global health interventions. The discipline of behavior change offers distinct expertise needed across 6 different domains of behavior. Such expertise is in short supply, however. We will not have effective and sustainable health systems, nor achieve our ambitious global health goals, without seriously addressing behavior change.

Improving Access to Water and Sanitation: Is the Answer Individual Behavioral Change?

August 20, 2013 · 0 comments

Improving Access to Water and Sanitation: Is the Answer Individual Behavioral Change? | Source: Pacific Institute, June 2013 |

By Dr. John Akudago, Senior Research Affiliate. Pacific Institute.

Born and raised in rural Africa where I spent my youthful life, open defecation was not only the norm but preferred to outhouses that were poorly ventilated and unbearably hot. We did not understand the consequences of exposing human waste around our houses. At that time, the best practice for sanitation and hygiene was to use a hoe to excavate the ground and bury our feces during the farming season so that the food we grew in the wild did not get contaminated.

Our knowledge on water was even poorer. We drank any water we found in the streams and rivers with little understanding that the water source could be contaminated. The few hand-dug wells in the villages at that time were considered to be the best source of potable water because they appeared the cleanest. However, with an entire village relying on a few water sources, the demand for water from these wells was high and sometimes resulted in arguments over who got what water and how much of it. Not surprisingly, the lack of potable water in the villages led to a high prevalence of water related diseases. Guinea-worm and bilharzia were common water-related diseases suffered by most children, especially those of us who swam in rivers and streams.

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Impact of Regular Soap Provision to Primary Schools on Hand Washing and E. coli Hand Contamination

August 20, 2013 · 0 comments

Impact of Regular Soap Provision to Primary Schools on Hand Washing and E. coli Hand Contamination among Pupils in Nyanza Province, Kenya: A Cluster-Randomized Trial.  Am Jnl Trop Med Hyg, Aug 2013.

Shadi Saboori, et al.

We assessed whether supplying soap to primary schools on a regular basis increased pupil hand washing and decreased Escherichia coli hand contamination. Multiple rounds of structured observations of hand washing events after latrine use were conducted in 60 Kenyan schools, and hand rinse samples were collected one time in a subset of schools. The proportion of pupils observed practicing hand washing with soap (HWWS) events was significantly higher in schools that received a soap provision intervention (32%) and schools that received soap and latrine cleaning materials (38%) compared with controls (3%).

Girls and boys had similar hand washing rates. There were nonsignificant reductions in E. coli contamination among intervention school pupils compared with controls. Removing the barrier of soap procurement can significantly increase availability of soap and hand washing among pupils; however, we discuss limitations in the enabling policy and institutional environment that may have prevented reaching desired levels of HWWS.

Access to Waterless Hand Sanitizer Improves Student Hand Hygiene Behavior

August 7, 2013 · 0 comments

Access to Waterless Hand Sanitizer Improves Student Hand Hygiene Behavior in Primary Schools in Nairobi, Kenya.  Am J Trop Med Hyg. 2013 Jul 8.

Pickering AJ, Davis J, Blum AG, Scalmanini J, Oyier B, Okoth G, Breiman RF, Ram PK.
Civil and Environmental Engineering and Woods Institute for the Environment, Stanford University, Stanford, California; Kenya Medical Research Institute, Centers for Disease Control and Prevention-Kenya, Nairobi, Kenya; University at Buffalo, State University of New York, Buffalo, New York.

Abstract – Handwashing is difficult in settings with limited resources and water access. In primary schools within urban Kibera, Kenya, we investigated the impact of providing waterless hand sanitizer on student hand hygiene behavior. Two schools received a waterless hand sanitizer intervention, two schools received a handwashing with soap intervention, and two schools received no intervention. Hand cleaning after toileting was 82% at sanitizer schools (N = 2,507 events), 38% at soap schools (N = 3,429), and 37% at control schools (N = 2,797), which was measured by structured observation over 2 months. Students at sanitizer schools were 23% less likely to have observed rhinorrhea than control students (P = 0.02); reductions in student-reported gastrointestinal and respiratory illness symptoms were not statistically significant. Providing waterless handsanitizer markedly increased student hand cleaning after toilet use, whereas the soap intervention did not. Waterless hand sanitizer may be a promising option to improve student hand cleansing behavior, particularly in schools with limited water access.
PMID: 23836575 [PubMed - as supplied by publisher] Free full text
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Impact of duration of structured observations on measurement of handwashing behavior

August 7, 2013 · 0 comments

Impact of duration of structured observations on measurement of handwashing behavior at critical times. BMC Public Health 2013, 2 August 2013

Amal K Halder, John W Molyneaux, Stephen P Luby and Pavani K Ram

Background – Structured observation is frequently used to measure handwashing at critical events, such as after fecal contact and before eating, but it is time-consuming. We aimed to assess the impact of reducing the duration of structured observation on the number and type of critical events observed.

Methods- The study recruited 100 randomly selected households, 50 for short 90-minute observations and 50 for long 5-hour observations, in six rural Bangladeshi villages. Based on the first 90 minutes in the long observation households, we estimated the number of critical events for handwashing expected, and compared the expected number to the number of events actually observed in the short observation households. In long observation households, we compared soap use at critical events observed during the first 90 minutes to soap use at events observed during the latter 210 minutes of the 5-hour duration.

Results – In short 90-minute observation households, the mean number of events observed was lower than the number of events expected: before eating (observed 0.25, expected 0.45, p < 0.05) and after defecation (observed 0.0, expected 0.03, p = 0.06). However, the mean number observed was higher than the expected for food preparation, food serving, and child feeding events. In long 5-hour observation households, soap was used more frequently at critical events observed in the first 90 minutes than in the remaining 210 minutes, but this difference was not significant (p = 0.29).

Conclusions- Decreasing the duration of handwashing significantly reduced the observation of critical events of interest to evaluators of handwashing programs. Researchers seeking to measure observed handwashing behavior should continue with prolonged duration of structured observation. Future research should develop and evaluate novel models to reduce reactivity to observation and improve the measurement of handwashing behavior.

Access to improved water and its relationship with diarrhoea in Kathmandu Valley, Nepal

August 7, 2013 · 0 comments

Access to improved water and its relationship with diarrhoea in Kathmandu Valley, Nepal: a cross-sectional study. BMJ Open. 2013 Jun 28;3(6).

Shrestha S, Aihara Y, Yoden K, Yamagata Z, Nishida K, Kondo N.
Interdisciplinary Graduate School of Medicine and Engineering, The University of Yamanashi, Chuo-shi, Yamanashi, Japan.

OBJECTIVE: To assess the associations between diarrhoea and types of water sources, total quantity of water consumed and the quantity of improved water consumed in rapidly growing, highly populated urban areas in developing countries.

DESIGN: Cross-sectional analysis using population-representative secondary data obtained from an interview survey conducted by the Asian Development Bank for the 2009 Kathmandu Valley Water Distribution, Sewerage and Urban Development Project.

SETTING:Kathmandu Valley, Nepal. PARTICIPANTS: 2282 households.

METHODS: A structured questionnaire was used to collect information from households on the quantity and sources of water consumed; health, socioeconomic and demographic status of households; drinking water treatment practices and toilet facilities.

RESULTS: Family members of 179 households (7.8%) reported having developed diarrhoea during the previous month. For households in which family members consumed less than 100 L of water per capita per day (L/c/d), which is the minimum quantity recommended by WHO, the risk of contracting diarrhoea doubled (1.56-fold to 2.92-fold). In households that used alternative water sources (such as wells, stone spouts and springs) in addition to improved water (provided by a water management authority), the likelihood of contracting diarrhoea was 1.81-fold higher (95% CI 1.00 to 3.29) than in those that used only improved water. However, access to an improved water source was not associated with a lower risk of developing diarrhoea if optimal quantities of water were not consumed (ie, <100 L/c/d). These results were independent of socioeconomic and demographic variables, daily drinking water treatment practices, toilet facilities and residential areas.

CONCLUSIONS: Providing access to a sufficient quantity of water-regardless of the source-may be more important in preventing diarrhoea than supplying a limited quantity of improved water.

Granular nanocomposites for affordable point-of-use water purification

August 7, 2013 · 0 comments

Biopolymer-reinforced synthetic granular nanocomposites for affordable point-of-use water purification. Proc Natl Acad Sci U S A. 2013 May 21;110(21):8459-64.

Sankar MU, Aigal S, Maliyekkal SM, Chaudhary A, Anshup, Kumar AA, Chaudhari K, Pradeep T. Unit of Nanoscience and Thematic Unit of Excellence, Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India.

Abstract - Creation of affordable materials for constant release of silver ions in water is one of the most promising ways to provide microbially safe drinking water for all. Combining the capacity of diverse nanocomposites to scavenge toxic species such as arsenic, lead, and other contaminants along with the above capability can result in affordable, all-inclusive drinking water purifiers that can function without electricity. The critical problem in achieving this is the synthesis of stable materials that can release silver ions continuously in the presence of complex species usually present in drinking water that deposit and cause scaling on nanomaterial surfaces.

Here we show that such constant release materials can be synthesized in a simple and effective fashion in water itself without the use of electrical power. The nanocomposite exhibits river sand-like properties, such as higher shear strength in loose and wet forms. These materials have been used to develop an affordable water purifier to deliver clean drinking water at US $2.5/y per family. The ability to prepare nanostructured compositions at near ambient temperature has wide relevance for adsorption-based water purification.

Apple Peels—A Versatile Biomass for Water Purification?

August 7, 2013 · 0 comments

Apple Peels—A Versatile Biomass for Water Purification? ACS Appl. Mater. Interfaces, 2013, 5 (10), pp 4443–4449

Ramakrishna Mallampati and Suresh Valiyaveettil. Department of Chemistry, National University of Singapore, Singapore 117543

The presence of anions such as chromate, arsenate, and arsenite in drinking water is a major health concern in many parts of the world due to their high toxicity. Removal of such anions from water using low cost biomass is an efficient and affordable treatment process. Owing to the easy availability and biodegradability, we chose to use apple peel as a substrate for our investigations.

Zirconium cations were immobilized onto the apple peel surface and used for the extraction of anions. Zirconium loaded apple peels were used to extract anions such as phosphate, arsenate, arsenite, and chromate ions from aqueous solutions. The presence of Zr cations on the apple peel surface was characterized using XPS. The modified adsorbent was characterized using SEM, EDS, and FT-IR. Zr treated apple peels showed efficient adsorption toward AsO2– (15.64 mg/g), AsO43– (15.68 mg/g), Cr2O72– (25.28 mg/g), and PO43– (20.35 mg/g) anions.

The adsorption and desorption studies revealed the adsorption mechanism involves electrostatic interactions. Anion removal efficiency was estimated by batch adsorption studies. Adsorption kinetic parameters for all anions at different concentrations were described using pseudo-first-order and pseudo-second-order rate equations. Langumir and Freundlich isotherms were used to validate our adsorption data. Arsenate and chromate anions were strongly adsorbed at the pH range from 2 to 6, while arsenite was extracted efficiently between pH 9 and 10. Overall, the Zr immobilized apple peel is an efficient adsorbent for common anionic pollutants.

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