scholarly journals Comparison of Different Bacteria Inactivation by a Novel Continuous-Flow Ultrasound/Chlorination Water Treatment System in a Pilot Scale

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 258 ◽  
Author(s):  
Huasheng Zou ◽  
Haoyuan Tang
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Continuous Flow ◽  
Treatment System ◽  
National Standard ◽  
Dual Frequency ◽  
Water Treatment System ◽  
E Coli ◽  
Log Reduction

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.

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 ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Surface Water ◽  
Drinking Water Treatment ◽  
Treatment System ◽  
Coliform Bacteria ◽  
Small Scale ◽  
Water Treatment System ◽  
E Coli ◽  
Solar Powered

 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.

scholarly journals Evaluating the Efficacy of Point-of-Use Water Treatment Systems Using the Water Quality Index in Rural Southwest China

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 867
Author(s):  
Zejin Zhang ◽  
Wei Zhang ◽  
Xi Hu ◽  
Kexin Li ◽  
Pengfei Luo ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Water Supply ◽  
Reverse Osmosis ◽  
Service Time ◽  
Filter Element ◽  
Treatment System ◽  
Water Treatment System ◽  
Point Of Use

Rural China faces a shortage of safe drinking water. There are significant challenges associated with small centralized water supply systems and decentralized water supply systems. Many rural residents use point-of-use water treatment systems to ensure the safety of their drinking water. The actual water purification effect and applicability of these water treatment systems in small centralized and decentralized water supply systems need to be determined urgently. In this study, the water quality index (WQI) method was applied for the first time in rural areas to evaluate the effectiveness of point-of-use water treatment systems. A total of 67 reverse osmosis water treatment systems were tested. The rate of compliance with drinking water standards of the decentralized water supply was low (37%). Compared with untreated water, the use of a reverse osmosis water treatment system improved the rate of compliance with drinking water standards, but this effect was not satisfactory (8%). Among the factors potentially affecting the purified water quality of point-of-use water treatment systems (e.g., service time of the water treatment system, service time of the filter element, and type of water source), the service time of the filter element had the most significant influence on the water quality. If the filter element had not been replaced for a long period, the removal effect of the water treatment system on the total hardness, sulfide, copper, and ammonia nitrogen was significantly affected, reducing the quality of the purified water. To ensure the safety of drinking water, it is recommended to replace the filter element of a reverse osmosis water treatment system at least once a year.

Improvement of Lake Water Quality by using Moving Rapid Water Treatment System

2018 ◽  
Vol 18 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Kwang-Hee Lee ◽  
◽  
Min-Ho Kim ◽  
Nam-Woo An ◽  
Chul-hwi Park
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Lake Water ◽  
Treatment System ◽  
Lake Water Quality ◽  
Water Treatment System

scholarly journals Designing The Improvement of SPAM UNS Water Dispenser Service Quality

2020 ◽  
Vol 19 (1) ◽  
pp. 22-29
Author(s):  
Yosua Natalianto ◽  
Eko Pujiyanto ◽  
Wahyudi Sutopo
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Service Quality ◽  
Drinking Water Treatment ◽  
Academic Community ◽  
Treatment System ◽  
Water Treatment System

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.

Ground-tested principles of designing a robust drinking water treatment system

2021 ◽  
Vol 14 ◽  
pp. 100103
Author(s):  
Ravindra Sewak ◽  
Dan Bena ◽  
Poonam Sewak ◽  
Shveta Mahajan
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Drinking Water Treatment ◽  
Treatment System ◽  
Water Treatment System
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