Ensuring microbial water quality for on-site water reuse: Importance of online sensors for reliable operation
A growing number of cities and regions are promoting or mandating on-site treatment and reuse of wastewater, which has resulted in the implementation of several thousand on-site water reuse systems on a global scale. However, there is only limited information on the (microbial) water quality from im...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2024-01-01
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| Series: | Water Research X |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2589914724000057 |
| _version_ | 1797265516419612672 |
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| author | Eva Reynaert Deepthi Nagappa Jürg A. Sigrist Eberhard Morgenroth |
| author_facet | Eva Reynaert Deepthi Nagappa Jürg A. Sigrist Eberhard Morgenroth |
| author_sort | Eva Reynaert |
| collection | DOAJ |
| description | A growing number of cities and regions are promoting or mandating on-site treatment and reuse of wastewater, which has resulted in the implementation of several thousand on-site water reuse systems on a global scale. However, there is only limited information on the (microbial) water quality from implemented systems. The focus of this study was on two best-in-class on-site water reuse systems in Bengaluru, India, which typically met the local water quality requirements during monthly compliance testing. This study aimed to (i) assess the microbial quality of the reclaimed water at a high temporal resolution (daily or every 15 min), and (ii) explore whether measurements from commercially available sensors can be used to improve the operation of such systems. The monitoring campaign revealed high variations in microbial water quality, even in these best-in-class systems, rendering the water inadequate for the intended reuse applications (toilet flushing and landscape irrigation). These variations were attributed to two key factors: (1) the low frequency of chlorination, and (2) fluctuations of the chlorine demand of the water, in particular of ammonium concentrations. Such fluctuations are likely inherent to on-site systems, which rely on a low level of process control. The monitoring campaign showed that the microbial water quality was most closely related to oxidation–reduction potential (ORP) and free chlorine sensors. Due to its relatively low cost and low need for maintenance, the ORP emerges as a compelling candidate for automating the chlorination to effectively manage variations in chlorine demand and ensure safe water reuse. Overall, this study underscores the necessity of integrating treatment trains, operation, and monitoring for safe on-site water reuse. |
| first_indexed | 2024-04-25T00:46:02Z |
| format | Article |
| id | doaj.art-2d7d686e1cee4af08b511f0ffb5cc60c |
| institution | Directory Open Access Journal |
| issn | 2589-9147 |
| language | English |
| last_indexed | 2024-04-25T00:46:02Z |
| publishDate | 2024-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Water Research X |
| spelling | doaj.art-2d7d686e1cee4af08b511f0ffb5cc60c2024-03-12T04:16:46ZengElsevierWater Research X2589-91472024-01-0122100215Ensuring microbial water quality for on-site water reuse: Importance of online sensors for reliable operationEva Reynaert0Deepthi Nagappa1Jürg A. Sigrist2Eberhard Morgenroth3Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; ETH Zürich, Institute of Environmental Engineering, Zürich 8093, SwitzerlandAshoka Trust for Research in Ecology and the Environment (ATREE), Bengaluru 560064, IndiaEawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, SwitzerlandEawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; ETH Zürich, Institute of Environmental Engineering, Zürich 8093, Switzerland; Corresponding author at: Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland.A growing number of cities and regions are promoting or mandating on-site treatment and reuse of wastewater, which has resulted in the implementation of several thousand on-site water reuse systems on a global scale. However, there is only limited information on the (microbial) water quality from implemented systems. The focus of this study was on two best-in-class on-site water reuse systems in Bengaluru, India, which typically met the local water quality requirements during monthly compliance testing. This study aimed to (i) assess the microbial quality of the reclaimed water at a high temporal resolution (daily or every 15 min), and (ii) explore whether measurements from commercially available sensors can be used to improve the operation of such systems. The monitoring campaign revealed high variations in microbial water quality, even in these best-in-class systems, rendering the water inadequate for the intended reuse applications (toilet flushing and landscape irrigation). These variations were attributed to two key factors: (1) the low frequency of chlorination, and (2) fluctuations of the chlorine demand of the water, in particular of ammonium concentrations. Such fluctuations are likely inherent to on-site systems, which rely on a low level of process control. The monitoring campaign showed that the microbial water quality was most closely related to oxidation–reduction potential (ORP) and free chlorine sensors. Due to its relatively low cost and low need for maintenance, the ORP emerges as a compelling candidate for automating the chlorination to effectively manage variations in chlorine demand and ensure safe water reuse. Overall, this study underscores the necessity of integrating treatment trains, operation, and monitoring for safe on-site water reuse.http://www.sciencedirect.com/science/article/pii/S2589914724000057On-site water reuseMicrobial water qualitySensorsOnline flow cytometryChlorination |
| spellingShingle | Eva Reynaert Deepthi Nagappa Jürg A. Sigrist Eberhard Morgenroth Ensuring microbial water quality for on-site water reuse: Importance of online sensors for reliable operation Water Research X On-site water reuse Microbial water quality Sensors Online flow cytometry Chlorination |
| title | Ensuring microbial water quality for on-site water reuse: Importance of online sensors for reliable operation |
| title_full | Ensuring microbial water quality for on-site water reuse: Importance of online sensors for reliable operation |
| title_fullStr | Ensuring microbial water quality for on-site water reuse: Importance of online sensors for reliable operation |
| title_full_unstemmed | Ensuring microbial water quality for on-site water reuse: Importance of online sensors for reliable operation |
| title_short | Ensuring microbial water quality for on-site water reuse: Importance of online sensors for reliable operation |
| title_sort | ensuring microbial water quality for on site water reuse importance of online sensors for reliable operation |
| topic | On-site water reuse Microbial water quality Sensors Online flow cytometry Chlorination |
| url | http://www.sciencedirect.com/science/article/pii/S2589914724000057 |
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