scholarly journals Turbidity reduction in drinking water by coagulation-flocculation with chitosan polymers

2019 ◽  
Vol 17 (2) ◽  
pp. 204-218 ◽  
Author(s):  
Ampai Soros ◽  
James E. Amburgey ◽  
Christine E. Stauber ◽  
Mark D. Sobsey ◽  
Lisa M. Casanova
Keyword(s):  
Drinking Water ◽  
Functional Groups ◽  
Dose Range ◽  
Optimal Dose ◽  
Global Network ◽  
Point Of Zero Charge ◽  
Household Water ◽  
Generous Support ◽  
Higher Doses ◽  
Model Household

Abstract Turbidity reduction by coagulation-flocculation in drinking water reduces microbes and organic matter, increasing effectiveness of downstream treatment. Chitosan is a promising household water coagulant, but needs parameters for use. This study tested the effects of chitosan dose, molecular weight (MW), degree of deacetylation (DD), and functional groups on bentonite and kaolinite turbidity reduction in model household drinking water. Higher MW or DD produced greater reductions. Highest reductions were at doses 1 and 3 mg/L by MW >50,000 or >70% DD (residual turbidity <5 NTU). Higher doses did not necessarily continually increase reduction. For functional groups, 3 mg/L produced the highest reductions by lactate, acetate, and HCl, and lower reductions of kaolinite than bentonite. Doses where the point of zero charge was observed clustered around 3 mg/L. Chitosan reduced clay turbidity in water; effectiveness was influenced by dose, clay type, MW, DD, and functional groups. Reduction did not necessarily increase with MW. Bentonite had a broader effective dose range and higher reduction at the optimal dose than kaolinite. Chitosans with and without functional groups performed similarly. The best of the studied doses was 3 mg/L. Chitosans are promising for turbidity reduction in low-resource settings if combined with sedimentation and/or filtration. This article has been made Open Access thanks to the generous support of a global network of libraries as part of the Knowledge Unlatched Select initiative.

scholarly journals Does self-reported water collection time differ from observed water collection time? Evidence from the Upper West Region of Ghana

2020 ◽  
Vol 10 (2) ◽  
pp. 357-365
Author(s):  
Alfred Dongzagla ◽  
Abraham Marshall Nunbogu ◽  
Nicholas Fielmua
Keyword(s):  
Developing Countries ◽  
Drinking Water ◽  
Open Access ◽  
Global Network ◽  
Round Trip ◽  
Key Indicator ◽  
West Region ◽  
Water Collection ◽  
Generous Support ◽  
Collection Time

Abstract Water collection time is a key indicator in tracking access to drinking water. Over the years, water surveillance agencies have relied on water collectors for information on water collection time to measure progress of water supply. However, emerging evidence shows that water collection times reported by water collectors in developing countries are often imprecise. To contribute to knowledge about the validity or otherwise of self-reported water collection times, this study explored the association between self-reported water collection times and observed water collection times in the Upper West Region of Ghana. Data on water collection times were gathered from 412 water collectors in Daffiama-Issa-Bussie District and Lawra Municipality, first through interviews, and second by observation. From the results, self-reported water collection times were significantly (P < 0.01) lower than observed water collection times. The average round-trip water collection time reported by water collectors (32 minutes) was 8 minutes lower than observed water collection times (40 minutes). This implies that existing statistics on basic water coverage that are largely based on self-reported water collection times are overestimated. Going forward, we call on water surveillance agencies to collect data on water collection times through observation. This article has been made Open Access thanks to the generous support of a global network of libraries as part of the Knowledge Unlatched Select initiative.

scholarly journals Potable water supply among the physically challenged in selected homes for the disabled in Ibadan

2019 ◽  
Vol 9 (2) ◽  
pp. 225-236
Author(s):  
Ifiok P. Udofia ◽  
Elizabeth O. Oloruntoba
Keyword(s):  
Drinking Water ◽  
Potable Water ◽  
Well Being ◽  
Total Coliform ◽  
Global Network ◽  
Minimum Requirement ◽  
The Disabled ◽  
Potable Water Supply ◽  
Generous Support ◽  
Physically Challenged

Abstract There is paucity of information on accessibility to potable water in homes for the disabled in Nigeria. This study investigated access to potable water among physically challenged people in three homes for the disabled in Ibadan. Sixty-four physically challenged persons living at the Cheshire Home (CH), Sekinat Adekola (SAC) and Lawal Centre (LC) were surveyed. Quantity of Drinking Water (QDW) received daily was compared to the WHO minimum requirement of 2.5 litres/head/day. Drinking water samples were analysed for total coliform (TCC) and Escherichia coli counts (ECC). Respondents' ages were 22.4 ± 5.1 years in CH, 23.6 ± 7.4 years in SAC and 13.8 ± 5.6 years in LC. The QDW received was 5.3 ± 1.5 litres/head/day in CH, 4.5 ± 0.5 litres/head/day in SAC and 2.8 ± 0.8 litres/head/day in LC. Thirty-seven percent in CH, 55.0% in SAC and 22.0% in LC were very satisfied with QDW received. CH water had lower TCC (2.0 ± 0.6 cfu/100 mL) compared to SAC (378 ± 169.3 cfu/100 mL) and LC (357.3 ± 174.3 cfu/100 mL). Only LC water showed an ECC of 1.0 ± 0.4 cfu/100 mL. Not all individuals experienced adequate access within the homes. Water quality was poor across the homes and treatment was inadequate. Constant potable water is required for the well-being of disabled people in these homes. This article has been made Open Access thanks to the generous support of a global network of libraries as part of the Knowledge Unlatched Select initiative.

scholarly journals Adsorptive and Surface Characterization of Mediterranean Agrifood Processing Wastes: Prospection for Pesticide Removal

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 561
Author(s):  
José A. Fernández-López ◽  
Marta Doval Miñarro ◽  
José M. Angosto ◽  
Javier Fernández-Lledó ◽  
José M. Obón
Keyword(s):  
Functional Groups ◽  
Surface Characterization ◽  
Crystallinity Index ◽  
Zero Point ◽  
Cost Effective ◽  
Point Of Zero Charge ◽  
Waste Biomass ◽  
Global Challenge ◽  
Citrus Waste ◽  
Olive Mill

The sustainable management of biomass is a key global challenge that demands compliance with fundamental requirements of social and environmental responsibility and economic effectiveness. Strategies for the valorization of waste biomass from agrifood industries must be in line with sustainable technological management and eco-industrial approaches. The efficient bioremoval of the pesticides imazalil and thiabendazole from aqueous effluents using waste biomass from typically Mediterranean agrifood industries (citrus waste, artichoke agrowaste and olive mill residue) revealed that these residues may be transformed into cost-effective biosorbents. Agrifood wastes present irregular surfaces, many different sized pores and active functional groups on their surface, and they are abundant in nature. The surface and adsorptive properties of olive mill residue, artichoke agrowaste and citrus waste were characterized with respect to elemental composition, microstructure, crystallinity, pore size, presence of active functional groups, thermal stability, and point of zero charge. Olive mill residue showed the highest values of surface area (Brunauer–Emmett–Teller method), porosity, crystallinity index, and pH of zero point of charge. Olive mill residue showed the highest efficiency with sorption capacities of 9 mg·g−1 for imazalil and 8.6 mg·g−1 for thiabendazole.

scholarly journals The Effect of Administration of Silver Nanoparticles on the Immune Status of Chickens

2018 ◽  
Vol 18 (2) ◽  
pp. 401-416 ◽  
Author(s):  
Ewelina Kulak ◽  
Iwona Sembratowicz ◽  
Anna Stępniowska ◽  
Katarzyna Ognik
Keyword(s):  
Silver Nanoparticles ◽  
Dose Range ◽  
Control Treatment ◽  
Phagocytic Index ◽  
Immune Defence ◽  
Phagocytic Cells ◽  
Ag Nps ◽  
Nitroblue Tetrazolium Reduction ◽  
Higher Doses ◽  
Tetrazolium Reduction

AbstractThe purpose of the study was to verify the hypothesis that there are doses of silver nanoparticles (Ag-NPs) that improve immune defence in chickens without compromising their health. To verify this hypothesis, an attempt was made to determine which doses of Ag-NPs (5 nm) consumed by chickens as a result of administration of hydrocolloids during varying time periods at a concentration of 5 or 10 mg Ag/l stimulate immune defence. The experiment was performed on 296 chickens assigned to 3 treatments. Chickens from the control treatment received drinking water without experimental additives. Chickens from the T-5 and T-10 treatments received a hydrocolloid of Ag-NPs at a concentration of 5 mg/l (treatment T-5) or 10 mg/l (treatment T-10) from their second week of life. Blood for analysis was collected at the age of 42 days from 8 birds per treatment. Ceruloplasmin (Cp), leukocyte count (WBC), erythrocyte sedimentation rate (ESR), interleukin IL-6, immunoglobulins IgA, IgY, phagocytic cells (% PC), phagocytic index (PI), nitroblue tetrazolium reduction (NBT), and lysozyme content in the blood was determined. Application of Ag-NPs at a concentration of 5 mg/l or 10 mg/l in the dose range of 2.87-12.25 mg/bird (administration of Ag-NPs in concentration 5 mg/l in weeks: 2; 2 and 3; 2 and 4; 2 and 5; 2 and 6 or concentration 10 mg/l in week 2) resulted in an immunostimulatory effect expressed as an increase in heterophil respiratory burst and an increased concentration of lysozyme. Higher doses of Ag-NPs exerted a pro-inflammatory effect, as indicated by elevated levels of IL-6 and ceruloplasmin, as well as a high ESR. They also stimulated B lymphocytes to produce IgA and IgA immunoglobulins.

scholarly journals OPTIMIZATION OF THE DRINKING WATER TREATMENT PROCESS OF A SUGAR PLANT STATION IN COTE DIVOIRE

2021 ◽  
Vol 9 (01) ◽  
pp. 512-524
Author(s):  
Konan Lopez Kouame ◽  
◽  
Nogbou Emmanuel Assidjo ◽  
Andre Kone Ariban ◽  
◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Treatment Process ◽  
Polynomial Regression ◽  
Drinking Water Treatment ◽  
Optimal Dose ◽  
Raw Water ◽  
Water Treatment Process ◽  
Jar Test ◽  
Coagulation And Flocculation

This article presents an optimization of the drinking water treatment process at the SUCRIVOIRE treatment station. The objective is to optimize the coagulation and flocculation process (fundamental process of the treatment of said plant)by determining the optimal dosages of the products injected and then proposes a program for calculating the optimal dose of coagulant in order to automatically determine the optimal dose of the latter according to the raw water quality. This contribution has the advantage of saving the user from any calculations the latter simply enters the characteristics of the raw effluent using the physical interface of the program in order to obtain the optimum corresponding coagulant concentration. For the determination of the optimal coagulant doses, we performed Jar-Test flocculation tests in the laboratory over a period of three months. The results made it possible to set up a polynomial regression model of the optimal dose of alumina sulfate as a function of the raw water parameters. A program for calculating the optimal dose of coagulant was carried out on Visual Basic. The optimal doses of coagulant obtained vary from 25, 35, 40 and 45 mg/l depending on the characteristics of the raw effluent. The model obtained is: . Finally, verification tests were carried out using this model on the process. The results obtained meet the WHO drinkability standards for all parameters for a settling time of two hours.

scholarly journals The pursuit of good microbiological conditions in domestic softeners: a new improvement

2020 ◽  
Vol 18 (2) ◽  
pp. 200-206
Author(s):  
L. Bolelli ◽  
Elida Nora Ferri ◽  
Stefano Sangiorgi ◽  
Giuseppe Novelli ◽  
Stefano Girotti
Keyword(s):  
Pathogenic Bacteria ◽  
Microbiological Quality ◽  
Global Network ◽  
Plate Count ◽  
Bacteria Growth ◽  
Warm Environment ◽  
Quality Of Water ◽  
Softened Water ◽  
Generous Support

Abstract Effective resin disinfection is mandatory to ensure the microbiological quality of water treated by domestic softeners. The wet and sometimes warm environment inside the softener is ideal for bacteria growth. Our research was focused on the evaluation of the microbial quality of water from softeners sanitized by chlorine solutions or by electrolytic systems. We employed the heterotrophic plate count and specific tests to monitor the presence of opportunistic and pathogenic bacteria (Pseudomonas aeruginosa, Escherichia coli, enterococci, and coliforms). Completely new devices were equipped with a commercially available electrolytic system or with a newly patented one or sanitized by automatic or manual addition of chlorine solutions. In all cases, the contamination was reduced, not completely avoided. In particular, the patented electrolytic system significantly reduced bacterial proliferation in strongly contaminated devices. Our data confirm the difficulties encountered to solve the problem of microbiological quality of softened water and offer encouraging information on new possible solutions. This article has been made Open Access thanks to the generous support of a global network of libraries as part of the Knowledge Unlatched Select initiative.

scholarly journals Does the source of water for piped supplies affect child health? Evidence from rural Vanuatu

2019 ◽  
Vol 9 (3) ◽  
pp. 591-595
Author(s):  
Tim Foster ◽  
Emily Rand ◽  
Erie Sami ◽  
Brieana Dance ◽  
Jeremy Kohlitz ◽  
...  
Keyword(s):  
Water Supply ◽  
Water Source ◽  
Service Level ◽  
Water Systems ◽  
Global Network ◽  
Water Supply Systems ◽  
Piped Water ◽  
Generous Support ◽  
Year 2000 ◽  
Supply Systems

Abstract Piped water systems are considered to provide the highest service level for drinking water supplies; however, global monitoring of safe water access pays little attention to the type of water source that piped systems draw upon, even if the water is not treated prior to distribution. This study sought to understand whether the source of water for untreated piped supplies influences the prevalence of diarrhoea among children in rural Vanuatu. The analysis was based on a dataset integrating a Demographic and Health Survey and a nationwide water supply inventory. After adjusting for a range of potential confounders, the results revealed a significant association between diarrhoea and the type of water source supplying a piped system. Compared with borehole-supplied piped systems, spring-fed piped systems were significantly associated with increased odds of diarrhoea (adjusted odds ratio [AOR] 5.8, 95% confidence interval [CI] 1.1–31, p = 0.040). No significant association between diarrhoea and piped systems drawing on surface water was observed. Increased odds of diarrhoea were significantly associated with water supply systems constructed prior to the year 2000 (AOR 4.9, 95% CI 1.9–13, p = 0.001). The results highlight the need for improvements in spring protection as well as ongoing maintenance and periodic renewal of water supply infrastructure. This article has been made Open Access thanks to the generous support of a global network of libraries as part of the Knowledge Unlatched Select initiative.

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