scholarly journals Decentralized solar-powered drinking water ozonation in Western Kenya: an evaluation of disinfection efficacy

2020 ◽  
Vol 4 ◽  
pp. 56
Author(s):  
Colin Hendrickson ◽  
Jared Oremo ◽  
Oscar Oluoch Akello ◽  
Simon Bunde ◽  
Isaac Rayola ◽  
...  

 Background: Decentralized drinking water treatment methods generally apply membrane-based treatment approaches. Ozonation of drinking water, which previously has only been possible at large centralized facilities, can now be accomplished on a small-scale using microplasma technology. The efficacy of decentralized solar-powered drinking water treatment systems has not previously been described. Methods: We established a 1,000L decentralized solar-powered water treatment system located in Kisumu County, Kenya. Highly contaminated surface water is pumped to the treatment system, which includes flocculation and filtration steps prior to ozonation. Turbidity, total coliform bacteria, and E. coli were measured at various stages of water treatment, and bacterial log reduction values (LRVs) were calculated. Results: Forty-seven trials were conducted in which1000L of water were flocculated, filtered, and ozonated for 180 minutes. Baseline turbidity and E. coli concentrations were reduced from a median of 238 nephelometric turbidity units (NTU) and 2,419.7 most probable number/100mL, respectively, in surface water to 1.0 NTU and undetectable E. coli after ozonation for 180 minutes. The median E. coli LRV was 3.99. Conclusions: The solar-powered, decentralized water treatment system that utilizes ozonation for disinfection was founded to reduce E. coli by more than 3 log-orders of magnitude despite the high turbidity of the raw water. Further research is needed to characterize limitations, scalability, economic viability, and community perspectives that could help determine the role for similar systems in other settings.

2020 ◽  
Vol 4 ◽  
pp. 56
Author(s):  
Colin Hendrickson ◽  
Jared Oremo ◽  
Oscar Oluoch Akello ◽  
Simon Bunde ◽  
Isaac Rayola ◽  
...  

Background: Decentralized drinking water treatment methods generally apply membrane-based treatment approaches. Ozonation of drinking water, which previously has only been possible at large centralized facilities, can now be accomplished on a small-scale using microplasma technology. The efficacy of decentralized solar-powered ozonation for drinking water treatment is not known. Methods: We established a 1,000L decentralized solar-powered water treatment system located in Kisumu County, Kenya. Highly contaminated surface water is pumped to the treatment system, which includes flocculation and filtration steps prior to ozonation. Turbidity, total coliform bacteria, and E. coli were measured at various stages of water treatment, and bacterial log reduction values (LRVs) were calculated. Results: Nine trials were conducted treating 1000L of water in three hours. Baseline turbidity and E. coli concentrations were reduced from a median of 238 nephelometric turbidity units (NTU) and 2,752 most probable number/100mL, respectively, in surface water to 1.0 NTU and undetectable E. coli per100mL in finished drinking water. The nine trials yielded a mean E. coli LRV of 3.36 (2.71-4.00, 95% CI). Conclusions: Based on the observed reduction of E. coli, the solar-powered system shows promise as a means for producing safe drinking water. Further research is needed to characterize limitations, scalability, economic viability, and community perspectives that could help determine the role for similar systems in other settings.


2020 ◽  
Vol 19 (1) ◽  
pp. 22-29
Author(s):  
Yosua Natalianto ◽  
Eko Pujiyanto ◽  
Wahyudi Sutopo

SPAM (Sistem Pengolahan Air Minum or Drinking Water Treatment System) UNS was established in 2015 to meet the drinking water needs of the UNS academic community by providing 129 dispensers and water tap machines spread across buildings at UNS. A survey conducted by UNS students in 2017 showed that 54 % of students were not sure of the quality of UNS SPAM water. So the service quality questionnaire was distributed to 160 UNS students randomly and it was found that only 3 % of respondents stated that they used SPAM UNS water dispenser very often. Processing results shown the highest gap value is in the reliability dimension, with CTS namely cleanliness and flow of water. From the survey regarding the cleanliness and flow of the water carried out the DPMO value of the process was 332,589 (1, 930 sigma) . Recommendations for improvement are in the form of several SOPs to improve the cleanliness and quality of SPAM UNS water dispenser services.


2021 ◽  
Vol 14 ◽  
pp. 100103
Author(s):  
Ravindra Sewak ◽  
Dan Bena ◽  
Poonam Sewak ◽  
Shveta Mahajan

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 258 ◽  
Author(s):  
Huasheng Zou ◽  
Haoyuan Tang

The existing traditional drinking water disinfection technology relies mainly on chlorine disinfection alone, which has high disinfection efficiency and can effectively inactivate most of the microorganisms in the water. However, it produces a series of harmful disinfection by-products (DBPs). Therefore, it is very necessary to study an efficient and environmentally friendly disinfection technology for drinking water. For this purpose, a novel continuous-flow ultrasound (US)/chlorination water treatment system was designed and developed. Escherichia coli (E. coli), Bacillus subtilis (B. subtilis), and Staphylococcus aureus (S. aureus) were selected as indicators of water treatment effects to (1) investigate the disinfection effects of different bacteria by US treatment alone at different single or dual frequencies; (2) explore the disinfection effects of US pretreatment with 8 mg/L NaClO on different bacteria to assess the promoting effects of US pretreatment; and (3) identify the optimum system process to satisfy the national standard for drinking water quality. Results showed that the dual-frequency US had better inactivation effects compared with single-frequency US, although it could not achieve an ideal disinfection level (complete disinfection). Further, 17 + 33 kHz dual-frequency US pretreatment had obvious enhancement of the disinfection efficiency, where 3.85 (E. coli), 3.65 (S. aureus), and 3.52 (B. subtilis) log reduction were achieved when 8 mg/L NaClO disinfection lasted 10 min, and finally all three bacteria achieved 4 log reduction after 30 min. Moreover, the treated water satisfied the Chinese national standard for drinking water quality, in which the residual chlorine concentration was below 4 mg/L. The utilization efficiency of disinfectant was improved approximately 40% by 17 + 33 kHz US pretreatment.


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