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 ◽  
...  

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.

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.


2003 ◽  
Vol 1 (2) ◽  
pp. 73-84 ◽  
Author(s):  
Philip F. Souter ◽  
Graeme D. Cruickshank ◽  
Melanie Z. Tankerville ◽  
Bruce H. Keswick ◽  
Brian D. Ellis ◽  
...  

Contamination of drinking water by microorganisms and arsenic represents a major human health hazard in many parts of the world. An estimated 3.4 million deaths a year are attributable to waterborne diseases. Arsenic poisoning from contaminated water sources is causing a major health emergency in some countries such as Bangladesh where 35 to 77 million people are at risk.The World Health Organization (WHO) has recently recognized point-of-use water treatment as an effective means of reducing illness in developing country households. A new point-of-use water treatment system that is based on flocculation, sedimentation and disinfection was evaluated for the removal of bacterial, viral and parasitic pathogens as well as arsenic from drinking water to estimate its potential for use in developing countries.Tests were conducted with United States Environmental Protection Agency (EPA)-model and field- sample waters from developing countries. Samples were seeded with known numbers of organisms, treated with the combined flocculation/disinfection product, and assayed for survivors using standard assay techniques appropriate for the organism.Results indicated that this treatment system reduced the levels from 108/l to undetectable (<1) of 14 types of representative waterborne bacterial pathogens including Salmonella typhi and Vibrio cholerae. No Escherichia coli were detected post-treatment in 320 field water samples collected from five developing countries. In addition, the water treatment system reduced polio and rotavirus titres by greater than 4-log values. Cyrptosporidium parvum and Giardia lamblia inocula were reduced by greater than 3-log values following use of this water treatment system. Arsenic, added to laboratory test waters, was reduced by 99.8%, and naturally occurring arsenic in field samples from highly contaminated Bangladeshi wells was reduced by 99.5% to mean levels of 1.2 µg/l.This water treatment system has demonstrated the potential to provide improved drinking water to households in developing countries by removing microbial and arsenic contaminants.


Author(s):  
Simón Mostafa ◽  
Mónica N. Camacho-Galván ◽  
Héctor E. Castelán-Martínez ◽  
Ane Galdos-Balzategui ◽  
Fermín Reygadas

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

2008 ◽  
Vol 80 (8) ◽  
pp. 703-707 ◽  
Author(s):  
Steven J. Wright ◽  
Jeremy D. Semrau ◽  
David R. Keeney

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.


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