Kostengünstige Chlorung für sicheres Wasser

Verunreinigte Trinkwasserquellen und die Rekontamination von sauberem Trinkwasser während des Transports und der Lagerung in den Haushalten sind in vielen einkommensschwachen Regionen nach wie vor ein grosses Problem und eine der Hauptursachen für Infektionskrankheiten. Auch die Wiederverwendung von Wasser kann die menschliche Gesundheit gefährden, wenn das Wasser nicht angemessen behandelt wird. Die Chlorung hat sich als einfache und wirksame Desinfektionsmethode erwiesen, um das Auftreten von durch Wasser übertragenen Krankheiten zu verringern, indem sie Krankheitserreger inaktiviert und durch einen Restgehalt an Desinfektionsmittel vor Rekontamination schützt.

Forschungsgruppen aus den Abteilungen Sandec, Verfahrenstechnik und Umweltmikrobiologie der Eawag evaluieren innovative Ansätze zur Verbesserung der kostengünstigen Chlorung als praktikable Option für die Wasseraufbereitung und -wiederverwendung in Regionen mit niedrigem Einkommen.

In mehreren Projekten dieser Abteilungen werden die Vorteile der Chlorung untersucht, darunter die Erschwinglichkeit, die Leistungsfähigkeit der technischen Lösungen, die Betriebs- und Wartungsanforderungen, die einfache Implementierung, der Bedarf und die Verfügbarkeit von Verbrauchsmaterialien und Ersatzteilen sowie der Schutz vor Rekontamination.

Desinfektion von Trinkwasser

Einer der zentralen Forschungsbereiche ist die kostengünstige Inline-Chlorung zur Trinkwasserdesinfektion in einfachen Leitungsnetzen und in Wasserkiosken. Im Vergleich zur Chlorung auf Haushaltsebene gewährleistet dieser Ansatz, dass das Wasser durchgängig gechlort wird, und ermöglicht einen zentraleren Betrieb und eine zentralere Wartung der Chlorungsanlage, wodurch die Belastung der einzelnen Haushalte verringert wird. Inline-Chlorungssysteme steuern die Chlordosierung automatisch und gewährleisten so eine kontinuierliche Behandlung des Wassers, während gleichzeitig der Arbeitsaufwand für die manuelle Dosierung reduziert wird.

Team

Loïc Fache Project Officer - Water Safety Management Tel. +41 58 765 5583 E-Mail senden

Wiederverwendung von Wasser vor Ort

Ein weiterer Schwerpunkt ist die Einführung einfacher Chlorungssysteme für die sichere Wiederverwendung von Wasser vor Ort. So ermöglichen beispielsweise Toiletten mit getrennter Sammlung von Wasser, Urin und Fäkalien die Aufbereitung und Wiederverwendung von Wasser zum Händewaschen oder für die Toilettenspülung. Darüber hinaus können Chlorungssysteme auch eine wichtige Rolle bei der dezentralen Wiederverwendung von Grauwasser spielen.

Projekte

Publications

Wissenschaftliche Publikationen – Desinfektion von Trinkwasser

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   0 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=33456, pid=124)
      originalId => protected33456 (integer)
      authors => protected'Locher, J. M.; Tosi Robinson, D.; Canú, E. N.; San
         chez, G.; Herrera, N.; Muj, M. S.; Crider, Y. 
         S.; Marks, S. J.
' (178 chars) title => protected'Assessment of a local and low-cost passive inline chlorination device in rur
         al Guatemala
' (88 chars) journal => protected'PLoS Water' (10 chars) year => protected2024 (integer) volume => protected3 (integer) issue => protected'9' (1 chars) startpage => protected'e0000255 (19 pp.)' (17 chars) otherpage => protected'' (0 chars) categories => protected'' (0 chars) description => protected'Access to safe and affordable drinking water remains a major challenge world
         wide, especially in rural areas. While passive in-line chlorination offers a
          promising approach for providing consistent treatment of water supplies in
         resource-limited settings, little is known about the factors influencing the
          uptake and use of these technologies. This study used a controlled pre-post
          intervention design to evaluate the technical performance and user acceptan
         ce of a low-cost and locally constructed chlorinator (the A’Jín) in four
         water distribution systems in rural Guatemala. Data sources included househo
         ld surveys (N = 319) and operator interviews (N = 25), with regular monitori
         ng of faecal contamination, pH, temperature and free residual chlorine (FRC)
          at reservoir tanks, taps and households. Faecal contamination was significa
         ntly reduced in water systems actively using the A’Jín device. In these s
         ystems, the share of tap and household drinking water samples with detectabl
         e E. coli decreased from 28% to 1% and 25% to 15%, respectively. Chlorine do
         sing consistency with the A’Jín was low, with only 24% of tap samples mee
         ting the recommended minimal FRC threshold of 0.2 mg/L. Overall, the share o
         f users expressing satisfaction with their water increased by 14% in the wat
         er distribution systems with the A’Jín and stayed constant for users of c
         ontrol systems. While the device’s low cost and simple design offered adva
         ntages over other chlorinators on the market, operators reported challenges
         with high maintenance needs and frequent clogging. To ensure the future succ
         ess of passive in-line chlorination for small community supplies, we recomme
         nd prioritising ease of use combined with external support for addressing ma
         intenance needs.
' (1764 chars) serialnumber => protected'' (0 chars) doi => protected'10.1371/journal.pwat.0000255' (28 chars) uid => protected33456 (integer) _localizedUid => protected33456 (integer)modified _languageUid => protectedNULL _versionedUid => protected33456 (integer)modified pid => protected124 (integer)
1 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=24466, pid=124) originalId => protected24466 (integer) authors => protected'Bänziger, C.; Schertenleib, A.; Kunwar, B. M.; Bhatta,&
         nbsp;M. R.; Marks, S. J.
' (115 chars) title => protected'Assessing microbial water quality, users' perceptions and system functionali
         ty following a combined water safety intervention in rural Nepal
' (140 chars) journal => protected'Frontiers in Water' (18 chars) year => protected2022 (integer) volume => protected3 (integer) issue => protected'' (0 chars) startpage => protected'750802 (14 pp.)' (15 chars) otherpage => protected'' (0 chars) categories => protected'drinking water; water safety planning; microbial quality; piped systems; rur
         al communities; Nepal
' (97 chars) description => protected'Risk-based water safety interventions are one approach to improve drinking w
         ater quality and consequently reduce the number of people consuming faecally
          contaminated water. Despite broad acceptance of water safety planning appro
         aches globally, there is a lack of evidence of their effectiveness for commu
         nity-managed piped water supplies in rural areas of developing countries. Ou
         r research, in the form of a cluster-based controlled pre-post intervention
         analysis, investigated the impact of a combined water safety intervention on
          outcomes of microbial water quality, users' perceptions and piped system fu
         nctionality in rural Nepal. The study enrolled 21 treatment systems and 12 c
         ontrol systems across five districts of the Karnali and Sudurpaschim provinc
         es. Treatment group interventions included field laboratories for microbial
         analysis, regular monitoring of water quality including sanitary inspections
         , targeted treatment and infrastructure improvements, household hygiene and
         water filter promotion, and community training. In certain systems, regular
         system-level chlorination was implemented. Before and after the intervention
         s, the microbial water quality was measured at multiple points within the wa
         ter system. This information was complemented by household interviews and sa
         nitary inspections. The main result to emerge from this study is that chlori
         nation is the only identified intervention that led to a significant reducti
         on in <em>E. coli</em> concentration at the point of consumption. Secondly,
         the effectiveness of other interventions was presumably reduced due to highe
         r contamination at endline in general, brought about by the monsoon. All the
          interventions had a positive impact on users' perceptions about their water
          system, as measured by expectations for future functionality, satisfaction
         with the services received, and awareness of the potential health risks of d
         rinking contaminated water. For future applications we would recommend the m
         ore broadly applied use ...
' (2115 chars) serialnumber => protected'' (0 chars) doi => protected'10.3389/frwa.2021.750802' (24 chars) uid => protected24466 (integer) _localizedUid => protected24466 (integer)modified _languageUid => protectedNULL _versionedUid => protected24466 (integer)modified pid => protected124 (integer)
2 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=25904, pid=124) originalId => protected25904 (integer) authors => protected'Crider,&nbsp;Y.&nbsp;S.; Sainju,&nbsp;S.; Shrestha,&nbsp;R.; Clair-Caliot,&n
         bsp;G.; Schertenleib,&nbsp;A.; Kunwar,&nbsp;B.&nbsp;M.; Bhatta,&nbsp;M.&nbsp
         ;R.; Marks,&nbsp;S.&nbsp;J.; Ray,&nbsp;I.
' (193 chars) title => protected'Evaluation of system-level, passive chlorination in gravity-fed piped water
         systems in rural Nepal
' (98 chars) journal => protected'Environmental Science and Technology' (36 chars) year => protected2022 (integer) volume => protected56 (integer) issue => protected'19' (2 chars) startpage => protected'13985' (5 chars) otherpage => protected'13995' (5 chars) categories => protected'chlorine; safe drinking water; rural water supply; passive chlorination' (71 chars) description => protected'Over 2 billion people globally lack access to safely managed drinking water.
          In contrast to the household-level, manually implemented treatment products
          that have been the dominant strategy for gaining low-cost access to safe dr
         inking water, passive chlorination technologies have the potential to treat
         water and reduce reliance on individual behavior change. However, few studie
         s exist that evaluate the performance and costs of these technologies over t
         ime, especially in small, rural systems. We conducted a nonrandomized evalua
         tion of two passive chlorination technologies for system-level water treatme
         nt in six gravity-fed, piped water systems in small communities in the hilly
          region of western Nepal. We monitored water quality indicators upstream of
         the treatment, at shared taps, and at households, as well as user acceptabil
         ity and maintenance costs, over 1 year. At baseline, over 80% of tap samples
          were contaminated with <em>Escherichia coli</em>. After 1 year of system-le
         vel chlorination, only 7% of those same taps had <em>E. coli</em>. However,
         29% of household stored water was positive for <em>E. coli</em>. Per cubic m
         eter of treated water, the cost of chlorine was 0.06-0.09 USD, similar to th
         e cost of monitoring technology installations. Safe storage, service deliver
         y models, and reliable supply chains are required, but passive chlorination
         technologies have the potential to radically improve how rural households ga
         in access to safely managed water.
' (1478 chars) serialnumber => protected'0013-936X' (9 chars) doi => protected'10.1021/acs.est.2c03133' (23 chars) uid => protected25904 (integer) _localizedUid => protected25904 (integer)modified _languageUid => protectedNULL _versionedUid => protected25904 (integer)modified pid => protected124 (integer)
3 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=21855, pid=124) originalId => protected21855 (integer) authors => protected'Gärtner,&nbsp;N.; Germann,&nbsp;L.; Wanyama,&nbsp;K.; Ouma,&nbsp;H.; Meierh
         ofer,&nbsp;R.
' (89 chars) title => protected'Keeping water from kiosks clean: strategies for reducing recontamination dur
         ing transport and storage in Eastern Uganda
' (119 chars) journal => protected'Water Research X' (16 chars) year => protected2021 (integer) volume => protected10 (integer) issue => protected'' (0 chars) startpage => protected'100079 (8 pp.)' (14 chars) otherpage => protected'' (0 chars) categories => protected'chlorination; drinking water treatment; water kiosks; safe storage; drinking
          water recontamination; hygiene
' (107 chars) description => protected'Drinking water is frequently recontaminated during transport and storage whe
         n water is poured into jerrycans. To address this issue, three strategies ai
         ming at reducing these recontamination risks were implemented at water kiosk
         s in Eastern Uganda. In all three strategies, water at the kiosks was chlori
         nated to a free residual chlorine (FRC) concentration of 2 mg/L at the tap
          of the kiosk. In addition, water was collected in different containers for
         drinking water transport: a) uncleaned jerrycans, b) cleaned jerrycans, and
         c) cleaned improved containers with a wide mouth and a spigot. Water quality
          in the containers was compared to that of a control group collecting unchlo
         rinated water in uncleaned jerrycans. Water samples were collected at the ta
         p of the kiosk, from the containers of 135 households after they were filled
          at the tap, and from the same containers in the households after 24 h of
         water storage. The samples were analysed for counts of <em>E. coli</em>, tot
         al coliforms, and FRC. Household interviews and structured observations were
          conducted to identify confounding variables and to assess the influence of
         water, sanitation, and hygiene infrastructure and practices on recontaminati
         on.<br /> All three intervention strategies contributed to significantly low
         er <em>E. coli</em> recontamination levels after 24 h than in the control
         group (Median (Mdn) = 9 CFU/100 mL, Interquartile Range (IQR) = 
         25). Median <em>E. coli</em> counts and mean FRC consumption were higher in
         
         
         = 2, ΔFRC = 1.6 mg/L) and the lowest in cleaned improved containers
          (Median = 0 CFU/100 mL, IQR = 0, ΔFRC = 1.2 mg/L). The F
         RC concentration at the tap of 2 mg/L was too low to protect water from <e
         m>E. coli</em> recontamination in uncleaned jerrycans over 24 h. Cleaning
         the jerrycans was inconv...
' (2599 chars) serialnumber => protected'2589-9147' (9 chars) doi => protected'10.1016/j.wroa.2020.100079' (26 chars) uid => protected21855 (integer) _localizedUid => protected21855 (integer)modified _languageUid => protectedNULL _versionedUid => protected21855 (integer)modified pid => protected124 (integer)
4 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=18600, pid=124) originalId => protected18600 (integer) authors => protected'Meierhofer,&nbsp;R.; Wietlisbach,&nbsp;B.; Matiko,&nbsp;C.' (58 chars) title => protected'Influence of container cleanliness, container disinfection with chlorine, an
         d container handling on recontamination of water collected from a water kios
         k in a Kenyan slum
' (170 chars) journal => protected'Journal of Water and Health' (27 chars) year => protected2019 (integer) volume => protected17 (integer) issue => protected'2' (1 chars) startpage => protected'308' (3 chars) otherpage => protected'317' (3 chars) categories => protected'chlorination; drinking water quality; drinking water treatment; low-income c
         ountry; recontamination; safe storage
' (113 chars) description => protected'The study assessed whether using clean containers that had been disinfected
         with chlorine at a water kiosk in the Kangemi slum in Nairobi reduced recont
         amination of treated water during drinking transport and storage. At the sam
         e time, the impacts of container handling and hygiene conditions at the hous
         ehold level on water quality changes during storage were evaluated. Data wer
         e collected during interviews with 135 households using either new, clean Ma
         ji Safi containers (MSCs) that had been disinfected with chlorine or normal
         uncleaned jerrycans (NJCs). Bacteriological water quality and free chlorine
         levels in both types of containers were measured after container filling at
         the kiosk and in the same containers after 24 h storage in households. The u
         se of MSCs significantly reduced the risk of recontaminating the treated wat
         er. After water filling at the kiosk, none of the MSCs contained <i>Escheric
         hia coli</i> bacteria, and 2.8% were contaminated after 24 h storage. In con
         trast, 6.2% of NJCs were contaminated after filling, and 15.2% after 24 h st
         orage. Multivariate logistic regression indicated that the use of a clean wa
         ter container and sufficient chlorine and the frequency of cleaning the cont
         ainer in the household mitigated recontamination. We suggest further investi
         gation of water container designs that facilitate cleaning.
' (1351 chars) serialnumber => protected'1477-8920' (9 chars) doi => protected'10.2166/wh.2019.282' (19 chars) uid => protected18600 (integer) _localizedUid => protected18600 (integer)modified _languageUid => protectedNULL _versionedUid => protected18600 (integer)modified pid => protected124 (integer)
5 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=22544, pid=124) originalId => protected22544 (integer) authors => protected'Dössegger,&nbsp;L.; Tournefier,&nbsp;A.; Germann,&nbsp;L.; Gärtner,&nbsp;N
         .; Huonder,&nbsp;T.; Etenu,&nbsp;C.; Wanyama,&nbsp;K.; Ouma,&nbsp;H.; Meierh
         ofer,&nbsp;R.
' (165 chars) title => protected'Assessment of low-cost, non-electrically powered chlorination devices for gr
         avity-driven membrane water kiosks in eastern Uganda
' (128 chars) journal => protected'Waterlines' (10 chars) year => protected2021 (integer) volume => protected40 (integer) issue => protected'2' (1 chars) startpage => protected'92' (2 chars) otherpage => protected'106' (3 chars) categories => protected'point-of-collection chlorination; water treatment; recontamination; GDM wate
         r kiosk; low-income country
' (103 chars) description => protected'Recontamination during transport and storage is a common challenge of water
         supply in low-income settings, especially if water is collected manually. Ch
         lorination is a strategy to reduce recontamination. We assessed seven low-co
         st, non-electrically powered chlorination devices in gravity-driven membrane
          filtration (GDM) kiosks in eastern Uganda: one floater, two in-line dosers,
          three end-line dosers (tap-attached), and one manual dispenser. The evaluat
         ion criteria were dosing consistency, user-friendliness, ease of maintenance
         , local supply chain, and cost. Achieving an adequate chlorine dosage (∼2
         mg/L at the tap and ≥ 0.2 mg/L after 24 h of storage in a container) was c
         hallenging. The T-chlorinator was the most promising option for GDM kiosks:
         it achieved correct dosage (CD, 1.5-2.5 mg/L) with a probability of 90 per c
         ent, was easy to use and maintain, economical, and can be made from locally
         available materials. The other in-line option, the chlorine-dosing bucket (4
         0 per cent CD) still needs design improvements. The end-line options AkvoTur
          (67 per cent CD) and AquatabsFlo® (57 per cent CD) are easy to install and
          operate at the tap, but can be easily damaged in the GDM set-up. The Ventur
         i doser (52 per cent CD) did not perform satisfactorily with flow rates &gt;
          6 L/min. The chlorine dispenser (52 per cent CD) was robust and user-friend
         ly, but can only be recommended if users comply with chlorinating the water
         themselves. Establishing a sustainable supply chain for chlorine products wa
         s challenging. Where solid chlorine tablets were locally rarely available, t
         he costs of liquid chlorine options were high (27-162 per cent of the water
         price).
' (1679 chars) serialnumber => protected'0262-8104' (9 chars) doi => protected'10.3362/1756-3488.20-00014' (26 chars) uid => protected22544 (integer) _localizedUid => protected22544 (integer)modified _languageUid => protectedNULL _versionedUid => protected22544 (integer)modified pid => protected124 (integer)
Locher, J. M.; Tosi Robinson, D.; Canú, E. N.; Sanchez, G.; Herrera, N.; Muj, M. S.; Crider, Y. S.; Marks, S. J. (2024) Assessment of a local and low-cost passive inline chlorination device in rural Guatemala, PLoS Water, 3(9), e0000255 (19 pp.), doi:10.1371/journal.pwat.0000255, Institutional Repository
Bänziger, C.; Schertenleib, A.; Kunwar, B. M.; Bhatta, M. R.; Marks, S. J. (2022) Assessing microbial water quality, users' perceptions and system functionality following a combined water safety intervention in rural Nepal, Frontiers in Water, 3, 750802 (14 pp.), doi:10.3389/frwa.2021.750802, Institutional Repository
Crider, Y. S.; Sainju, S.; Shrestha, R.; Clair-Caliot, G.; Schertenleib, A.; Kunwar, B. M.; Bhatta, M. R.; Marks, S. J.; Ray, I. (2022) Evaluation of system-level, passive chlorination in gravity-fed piped water systems in rural Nepal, Environmental Science and Technology, 56(19), 13985-13995, doi:10.1021/acs.est.2c03133, Institutional Repository
Gärtner, N.; Germann, L.; Wanyama, K.; Ouma, H.; Meierhofer, R. (2021) Keeping water from kiosks clean: strategies for reducing recontamination during transport and storage in Eastern Uganda, Water Research X, 10, 100079 (8 pp.), doi:10.1016/j.wroa.2020.100079, Institutional Repository
Meierhofer, R.; Wietlisbach, B.; Matiko, C. (2019) Influence of container cleanliness, container disinfection with chlorine, and container handling on recontamination of water collected from a water kiosk in a Kenyan slum, Journal of Water and Health, 17(2), 308-317, doi:10.2166/wh.2019.282, Institutional Repository
Dössegger, L.; Tournefier, A.; Germann, L.; Gärtner, N.; Huonder, T.; Etenu, C.; Wanyama, K.; Ouma, H.; Meierhofer, R. (2021) Assessment of low-cost, non-electrically powered chlorination devices for gravity-driven membrane water kiosks in eastern Uganda, Waterlines, 40(2), 92-106, doi:10.3362/1756-3488.20-00014, Institutional Repository

Wissenschaftliche Publikationen – Wiederverwendung von Wasser

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      originalId => protected32681 (integer)
      authors => protected'Reynaert,&nbsp;E.; Nagappa,&nbsp;D.; Sigrist,&nbsp;J.A.; Morgenroth,&nbsp;E.' (76 chars)
      title => protected'Ensuring microbial water quality for on-site water reuse: importance of onli
         ne sensors for reliable operation
' (109 chars) journal => protected'Water Research X' (16 chars) year => protected2024 (integer) volume => protected22 (integer) issue => protected'' (0 chars) startpage => protected'100215 (8 pp.)' (14 chars) otherpage => protected'' (0 chars) categories => protected'on-site water reuse; microbial water quality; sensors; online flow cytometry
         ; chlorination
' (90 chars) description => protected'A growing number of cities and regions are promoting or mandating on-site tr
         eatment and reuse of wastewater, which has resulted in the implementation of
          several thousand on-site water reuse systems on a global scale. However, th
         ere is only limited information on the (microbial) water quality from implem
         ented systems. The focus of this study was on two best-in-class on-site wate
         r reuse systems in Bengaluru, India, which typically met the local water qua
         lity requirements during monthly compliance testing. This study aimed to (i)
          assess the microbial quality of the reclaimed water at a high temporal reso
         lution (daily or every 15 min), and (ii) explore whether measurements from c
         ommercially available sensors can be used to improve the operation of such s
         ystems. 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 irrigati
         on). These variations were attributed to two key factors: (1) the low freque
         ncy of chlorination, and (2) fluctuations of the chlorine demand of the wate
         r, in particular of ammonium concentrations. Such fluctuations are likely in
         herent to on-site systems, which rely on a low level of process control. The
          monitoring campaign showed that the microbial water quality was most closel
         y related to oxidation–reduction potential (ORP) and free chlorine sensors
         . Due to its relatively low cost and low need for maintenance, the ORP emerg
         es as a compelling candidate for automating the chlorination to effectively
         manage variations in chlorine demand and ensure safe water reuse. Overall, t
         his study underscores the necessity of integrating treatment trains, operati
         on, and monitoring for safe on-site water reuse.
' (1796 chars) serialnumber => protected'2589-9147' (9 chars) doi => protected'10.1016/j.wroa.2024.100215' (26 chars) uid => protected32681 (integer) _localizedUid => protected32681 (integer)modified _languageUid => protectedNULL _versionedUid => protected32681 (integer)modified pid => protected124 (integer)
1 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=31156, pid=124) originalId => protected31156 (integer) authors => protected'Reynaert,&nbsp;E.; Steiner,&nbsp;P.; Yu,&nbsp;Q.; D'Olif,&nbsp;L.; Joller,&n
         bsp;N.; Schneider,&nbsp;M.&nbsp;Y.; Morgenroth,&nbsp;E.
' (131 chars) title => protected'Predicting microbial water quality in on-site water reuse systems with onlin
         e sensors
' (85 chars) journal => protected'Water Research' (14 chars) year => protected2023 (integer) volume => protected240 (integer) issue => protected'' (0 chars) startpage => protected'120075 (13 pp.)' (15 chars) otherpage => protected'' (0 chars) categories => protected'online monitoring; machine learning; membrane bioreactor; chlorination; viru
         s removal; bacterial regrowth
' (105 chars) description => protected'Widespread implementation of on-site water reuse is hindered by the limited
         availability of monitoring approaches that ensure microbial quality during o
         peration. In this study, we developed a methodology for monitoring microbial
          water quality in on-site water reuse systems using inexpensive and commerci
         ally available online sensors. An extensive dataset containing sensor and mi
         crobial water quality data for six of the most critical types of disruptions
          in membrane bioreactors with chlorination was collected. We then tested the
          ability of three typological machine learning algorithms - logistic regress
         ion, support-vector machine, and random forest - to predict the microbial wa
         ter quality as "safe" or "unsafe" for reuse. The main criteria for model opt
         imization was to ensure a low false positive rate (FPR) - the percentage of
         safe predictions when the actual condition is unsafe - which is essential to
          protect users health. This resulted in enforcing a fixed FPR ≤ 2%. Maximi
         zing the true positive rate (TPR) - the percentage of safe predictions when
         the actual condition is safe - was given second priority. Our results show t
         hat logistic-regression-based models using only two out of the six sensors (
         free chlorine and oxidation-reduction potential) achieved the highest TPR. I
         ncluding sensor slopes as engineered features allowed to reach similar TPRs
         using only one sensor instead of two. Analysis of the occurrence of false pr
         edictions showed that these were mostly early alarms, a characteristic that
         could be regarded as an asset in alarm management. In conclusion, the simple
         st algorithm in combination with only one or two sensors performed best at p
         redicting the microbial water quality. This result provides useful insights
         for water quality modeling or for applications where small datasets are a co
         mmon challenge and a general advantage might be gained by using simpler mode
         ls that reduce the risk of overfitting, allow better interpretability, and r
         equire less computationa...
' (2008 chars) serialnumber => protected'0043-1354' (9 chars) doi => protected'10.1016/j.watres.2023.120075' (28 chars) uid => protected31156 (integer) _localizedUid => protected31156 (integer)modified _languageUid => protectedNULL _versionedUid => protected31156 (integer)modified pid => protected124 (integer)
2 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=33210, pid=124) originalId => protected33210 (integer) authors => protected'Reynaert,&nbsp;E.; Nagappa,&nbsp;D.; Morgenroth,&nbsp;E.' (56 chars) title => protected'Research brief: using sensors and automated chlorination to improve the micr
         obial water quality of on-site sewage treatment plants in Bengaluru
' (143 chars) journal => protected'' (0 chars) year => protected2023 (integer) volume => protected0 (integer) issue => protected'' (0 chars) startpage => protected'5&nbsp;p' (8 chars) otherpage => protected'' (0 chars) categories => protected'' (0 chars) description => protected'More than 3,000 on-site sewage treatment plants (STPs) recycle water for lan
         dscaping and toilet flushing in Bengaluru. Microbial water quality is essent
         ial to protect user health, even for non-potable water reuse applications. H
         owever, there is lack of information on short-term variability of the microb
         ial quality of the water. This research brief presents monitoring results fr
         om two on-site STPs in Bengaluru, and makes recommendations on how to optimi
         ze STP operation to ensure microbiologically safe water at all times.
' (525 chars) serialnumber => protected'' (0 chars) doi => protected'10.3929/ethz-b-000603755' (24 chars) uid => protected33210 (integer) _localizedUid => protected33210 (integer)modified _languageUid => protectedNULL _versionedUid => protected33210 (integer)modified pid => protected124 (integer)
3 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=30227, pid=124) originalId => protected30227 (integer) authors => protected'Reynaert,&nbsp;E.; Gretener,&nbsp;F.; Julian,&nbsp;T.&nbsp;R.; Morgenroth,&n
         bsp;E.
' (82 chars) title => protected'Sensor setpoints that ensure compliance with microbial water quality targets
          for membrane bioreactor and chlorination treatment in on-site water reuse s
         ystems
' (158 chars) journal => protected'Water Research X' (16 chars) year => protected2023 (integer) volume => protected18 (integer) issue => protected'' (0 chars) startpage => protected'100164 (13 pp.)' (15 chars) otherpage => protected'' (0 chars) categories => protected'online sensors; water reuse; chlorination; virus removal; bacterial regrowth
         ; risk-based monitoring
' (99 chars) description => protected'Widespread implementation of on-site water reuse systems is hindered by the
         limited ability to ensure the level of treatment and protection of human hea
         lth during operation. In this study, we tested the ability of five commercia
         lly available online sensors (free chlorine (FC), oxidation-reduction potent
         ial (ORP), pH, turbidity, UV absorbance at 254 nm) to predict the microbial
         water quality in membrane bioreactors followed by chlorination using logisti
         c regression-based and mechanism-based models. The microbial water quality w
         as assessed in terms of removal of enteric bacteria from the wastewater, rem
         oval of enteric viruses, and regrowth of bacteria in the treated water. We f
         ound that FC and ORP alone could predict the microbial water quality well, w
         ith ORP-based models generally performing better. We further observed that p
         rediction accuracy did not increase when data from multiple sensors were int
         egrated. We propose a methodology to link online sensor measurements to risk
         -based water quality targets, providing operation setpoints protective of hu
         man health for specific combinations of wastewaters and reuse applications.
         For instance, we recommend a minimum ORP of 705 mV to ensure a virus log-rem
         oval of 5, and an ORP of 765 mV for a log-removal of 6. These setpoints were
          selected to ensure that the percentage of events where the water is predict
         ed to meet the quality target but it does not remains below 5%. Such a syste
         matic approach to set sensor setpoints could be used in the development of w
         ater reuse guidelines and regulations that aim to cover a range of reuse app
         lications with differential risks to human health.
' (1646 chars) serialnumber => protected'2589-9147' (9 chars) doi => protected'10.1016/j.wroa.2022.100164' (26 chars) uid => protected30227 (integer) _localizedUid => protected30227 (integer)modified _languageUid => protectedNULL _versionedUid => protected30227 (integer)modified pid => protected124 (integer)
4 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=21700, pid=124) originalId => protected21700 (integer) authors => protected'Sutherland,&nbsp;C.; Reynaert,&nbsp;E.; Dhlamini,&nbsp;S.; Magwaza,&nbsp;F.;
          Lienert,&nbsp;J.; Riechmann,&nbsp;M.&nbsp;E.; Buthelezi,&nbsp;S.; Khumalo,&
         nbsp;D.; Morgenroth,&nbsp;E.; Udert,&nbsp;K.&nbsp;M.; Sindall,&nbsp;R.&nbsp;
         C.
' (230 chars) title => protected'Socio-technical analysis of a sanitation innovation in a peri-urban househol
         d in Durban, South Africa
' (101 chars) journal => protected'Science of the Total Environment' (32 chars) year => protected2021 (integer) volume => protected755 (integer) issue => protected'' (0 chars) startpage => protected'143284 (12 pp.)' (15 chars) otherpage => protected'' (0 chars) categories => protected'field test; water reuse; source separation; service delivery; social accepta
         nce; transdisciplinary research
' (107 chars) description => protected'The provision of water and sanitation for all that is safe, dignified, relia
         ble, affordable and sustainable is a major global challenge. While centraliz
         ed sewer-based sanitation systems remain the dominant approach to providing
         sanitation, the benefits of non-sewered onsite sanitation systems are increa
         singly being recognised. This paper presents the outcomes of the testing of
         the Blue Diversion Autarky Toilet (BDAT), a sanitation system providing hygi
         ene and dignity without relying on water and wastewater infrastructure, in a
          peri-urban household in Durban, South Africa. The BDAT was used by a single
          household as their only form of sanitation during three months of technical
          and social testing. An analysis based on technical data in combination with
          interpretive, qualitative research methods revealed that the BDAT functione
         d well and achieved high levels of social acceptance in the test household.
         The flushing, cleanliness and odour-free nature of the sanitation technology
         , its functionality, the household's previous sanitation experience, and the
         ir experience with and understanding of water scarcity, were the main factor
         s underpinning their positive response to this innovation in sanitation. The
          testing process resulted in broader developmental benefits for the househol
         d, including improved basic services due to the upgrading of the electrical
         and existing sanitation system, social learning, and improved relationships
         between household members and the local state. A transdisciplinary research
         process, which emerged through the assessment, enabled the integration of di
         fferent forms of knowledge from multiple actors to address the complexity of
          problems related to the development of socially just sanitation. The benefi
         t of engaging with societal actors in sanitation innovation and assessing it
         s outcomes using both the technical and social sciences is evident in this p
         aper.
' (1905 chars) serialnumber => protected'0048-9697' (9 chars) doi => protected'10.1016/j.scitotenv.2020.143284' (31 chars) uid => protected21700 (integer) _localizedUid => protected21700 (integer)modified _languageUid => protectedNULL _versionedUid => protected21700 (integer)modified pid => protected124 (integer)
5 => Snowflake\Publications\Domain\Model\Publicationprototypepersistent entity (uid=23229, pid=124) originalId => protected23229 (integer) authors => protected'Sutherland,&nbsp;C.; Reynaert,&nbsp;E.; Sindall,&nbsp;R.&nbsp;C.; Riechmann,
         &nbsp;M.&nbsp;E.; Magwaza,&nbsp;F.; Lienert,&nbsp;J.; Buthelezi,&nbsp;S.; Kh
         umalo,&nbsp;D.; Dhlamini,&nbsp;S.; Morgenroth,&nbsp;E.; Udert,&nbsp;K.&nbsp;
         M.
' (230 chars) title => protected'Innovation for improved hand hygiene: field testing the Autarky handwashing
         station in collaboration with informal settlement residents in Durban, South
          Africa
' (159 chars) journal => protected'Science of the Total Environment' (32 chars) year => protected2021 (integer) volume => protected796 (integer) issue => protected'' (0 chars) startpage => protected'149024 (13 pp.)' (15 chars) otherpage => protected'' (0 chars) categories => protected'community participation; hand hygiene; WASH; technology field test; water re
         cycling; transdisciplinary research
' (111 chars) description => protected'Safe and accessible water services for hand hygiene are critical to human he
         alth and well-being. However, access to handwashing facilities is limited in
          cities in the Global South, where rapid urbanisation, service backlogs, lac
         k of infrastructure and capacity, and water scarcity impact on the ability o
         f local governments to provide them. Community participation and the co-prod
         uction of knowledge in the development of innovative technologies, which are
          aligned with Water, Sanitation and Hygiene (WASH) principles, can lead to m
         ore sustainable and socially-acceptable hand hygiene systems. This paper pre
         sents the outcomes of the testing of the Autarky handwashing station, a tech
         nology that provides onsite treatment and recycling of handwashing water, in
          an informal settlement in Durban, South Africa. The transdisciplinary resea
         rch approach adopted enabled the participation of multiple stakeholders with
          different knowledge systems in the framing, testing and evaluation of the s
         ystem. The process of co-producing knowledge, as well as the outcomes of the
          testing, namely high levels of functionality and social acceptability of th
         e technology, supported the WASH principles. The evaluation revealed that th
         e Autarky handwashing station is a niche intervention that improved access t
         o safe and appealing handwashing facilities in an informal settlement. Its n
         ovel design, socially desirable features, reliability and ability to save wa
         ter increased its acceptance in the community. The testing of the system in
         a real-world context revealed the value of including communities in knowledg
         e production processes for technology innovation. Further work is required t
         o ensure that real-time monitoring of system function is feasible before suc
         h systems can be implemented at larger scale.
' (1793 chars) serialnumber => protected'0048-9697' (9 chars) doi => protected'10.1016/j.scitotenv.2021.149024' (31 chars) uid => protected23229 (integer) _localizedUid => protected23229 (integer)modified _languageUid => protectedNULL _versionedUid => protected23229 (integer)modified pid => protected124 (integer)
Reynaert, E.; Nagappa, D.; Sigrist, J.A.; Morgenroth, E. (2024) Ensuring microbial water quality for on-site water reuse: importance of online sensors for reliable operation, Water Research X, 22, 100215 (8 pp.), doi:10.1016/j.wroa.2024.100215, Institutional Repository
Reynaert, E.; Steiner, P.; Yu, Q.; D'Olif, L.; Joller, N.; Schneider, M. Y.; Morgenroth, E. (2023) Predicting microbial water quality in on-site water reuse systems with online sensors, Water Research, 240, 120075 (13 pp.), doi:10.1016/j.watres.2023.120075, Institutional Repository
Reynaert, E.; Nagappa, D.; Morgenroth, E. (2023) Research brief: using sensors and automated chlorination to improve the microbial water quality of on-site sewage treatment plants in Bengaluru, 5 p, doi:10.3929/ethz-b-000603755, Institutional Repository
Reynaert, E.; Gretener, F.; Julian, T. R.; Morgenroth, E. (2023) Sensor setpoints that ensure compliance with microbial water quality targets for membrane bioreactor and chlorination treatment in on-site water reuse systems, Water Research X, 18, 100164 (13 pp.), doi:10.1016/j.wroa.2022.100164, Institutional Repository
Sutherland, C.; Reynaert, E.; Dhlamini, S.; Magwaza, F.; Lienert, J.; Riechmann, M. E.; Buthelezi, S.; Khumalo, D.; Morgenroth, E.; Udert, K. M.; Sindall, R. C. (2021) Socio-technical analysis of a sanitation innovation in a peri-urban household in Durban, South Africa, Science of the Total Environment, 755, 143284 (12 pp.), doi:10.1016/j.scitotenv.2020.143284, Institutional Repository
Sutherland, C.; Reynaert, E.; Sindall, R. C.; Riechmann, M. E.; Magwaza, F.; Lienert, J.; Buthelezi, S.; Khumalo, D.; Dhlamini, S.; Morgenroth, E.; Udert, K. M. (2021) Innovation for improved hand hygiene: field testing the Autarky handwashing station in collaboration with informal settlement residents in Durban, South Africa, Science of the Total Environment, 796, 149024 (13 pp.), doi:10.1016/j.scitotenv.2021.149024, Institutional Repository

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