Forschungsdaten – Titel und Zusammenfassungen von Publikationen, extrahierte Daten und Katalogeinträge – erscheinen in ihrer Originalsprache Englisch.
Sustainable Management of Chlorine Consumption in an Outdoor Swimming Pool: A Case Study of the Silpakorn University Swimming Pool
, Umarat Santisukkasaem
KI-Zusammenfassung
35 % KonfidenzThis paper reports optimization of chlorine dosing in an outdoor swimming pool through measurement-based control, reducing consumption from 2 kg to 1 kg daily while maintaining disinfection efficacy and water quality. Although focused on pool chemistry rather than bioelectrochemical systems, the work documents nitrogen species (ammonia, nitrite, nitrate) behavior under reduced oxidant stress, showing ammonia declined from 0.34 to 0.07 mg/L and nitrite became undetectable post-intervention. The study provides baseline data on how chlorine reduction affects nitrogen cycling in a real aquatic system, relevant to understanding trade-offs between oxidant dosing and nitrogen speciation in engineered water treatment.
Zentrale Erkenntnisse
Mechanismus Ammonia nitrogen decreased from 0.34 mg/L to 0.07 mg/L when chlorine dosing was halved from 2 kg to 1 kg daily, suggesting oxidant availability influences ammonia oxidation kinetics in pool water.
Was heißt das. In bioelectrochemical systems targeting ammonia recovery or nitrification, reducing cathode potential or current density may lower ammonia oxidation rates; operators should monitor ammonia accumulation if aiming to preserve it.
Mechanismus Nitrite nitrogen was undetectable (0.0008 mg/L pre-treatment) after chlorine reduction, indicating rapid conversion to nitrate rather than accumulation under lower oxidant stress.
Was heißt das. In MES denitrification cathodes, nitrite accumulation is a known problem at high current density; this pool result suggests that lower oxidant flux may favor complete reduction to N₂ rather than NO₂⁻ stalling, but mechanism differs from electrochemical control.
Schwellenwert Residual chlorine concentration remained in the range 3–5 mg/L during weeks 3–5 despite targeting 0.6–1.0 mg/L, exceeding WHO standard (<3 mg/L) due to uncontrolled environmental factors (rain, sunlight, debris, user load).
Was heißt das. Outdoor bioelectrochemical systems face similar uncontrolled disturbances; operators must design feedback control loops (e.g., potentiostat setpoint adjustment) to handle variable influent composition and environmental loading, not rely on fixed dosing.
Leistung Chlorine demand averaged 1.15±0.39 to 3.52±0.10 mg/L across days 14–35, with day 28 providing optimal residual chlorine (1.63–3.51 mg/L) closest to standard, enabling calculation that 1 kg daily chlorine addition was sufficient.
Was heißt das. In MES design, establish a transient response window (analogous to day 14–35 here) to identify the minimum applied potential or current density needed to achieve target product (e.g., nitrate reduction) without overshooting; use this to set steady-state operating point.
Leistung Total dissolved solids increased 18.11% from 836.28 to 1,021.28 mg/L post-intervention but remained within standard (1,000–2,000 mg/L), indicating chlorine reduction did not cause salt accumulation or precipitation problems.
Was heißt das. In bioelectrochemical systems, reducing applied potential or current may lower electrochemical salt generation (e.g., from water splitting); monitor TDS to confirm that lower oxidant dosing does not cause unintended ion accumulation from other sources.
Ansatzpunkte6
Konkrete Lücken in dieser Publikation, jeweils mit einem Experiment, das sie schließen würde.
Hoch No measurement of dissolved oxygen (DO) or redox potential (ORP) during the chlorine reduction phase; these would clarify whether ammonia oxidation and nitrite conversion are oxygen-limited or chlorine-limited.
The paper shows ammonia declined and nitrite disappeared post-intervention, but does not measure DO or ORP to distinguish whether lower chlorine reduced oxidant availability or whether microbial nitrification/denitrification was the driver. Section 3.3 states 'NO₂⁻ does not tend to accumulate in water but is rather converted into nitrate rapidly' but provides no mechanistic evidence.
Versuch. Measure DO (mg/L), ORP (mV), and chlorine residual simultaneously on days 1, 14, 21, 28, 35; correlate ammonia and nitrite trends with DO/ORP to identify the rate-limiting oxidant.
Hoch No characterization of microbial community (nitrifiers, denitrifiers, heterotrophs) before and after chlorine reduction; the decline in ammonia and nitrite may be due to microbial activity rather than chemical oxidation.
The paper attributes nitrite conversion to rapid chemical oxidation ('typical because NO₂⁻ does not tend to accumulate') but does not rule out biological nitrification or denitrification. Chlorine reduction may have allowed nitrifying bacteria to establish, explaining the ammonia decline and nitrite removal.
Versuch. 16S rRNA gene sequencing or qPCR for ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB), and denitrifiers on water samples from days 1 and 35; correlate abundance with nitrogen species changes.
Mittel No investigation of N₂O or N₂ production; the paper measures NO₃⁻, NO₂⁻, and NH₃ but does not close the nitrogen mass balance or detect gaseous nitrogen loss.
If ammonia declined 79% and nitrite was removed, the nitrogen must go somewhere. The paper shows nitrate only declined 10.7%, leaving ~70% of the ammonia unaccounted for. This could be N₂O or N₂ emission, but is not measured.
Versuch. Measure headspace N₂O (gas chromatography) and estimate N₂ loss via isotope pairing or acetylene inhibition assay on days 1, 14, 28, 35 to quantify denitrification and N₂O yield.
Mittel No variation of chlorine dose below 1 kg/day or above 2 kg/day to establish a dose–response curve for ammonia oxidation and nitrite formation kinetics.
The paper tested only two chlorine doses (2 kg and 1 kg daily) and found that 1 kg was sufficient for disinfection. However, no intermediate doses (1.5 kg, 0.75 kg) were tested to map the relationship between chlorine availability and nitrogen species speciation.
Versuch. Conduct a 4-week trial with chlorine doses of 0.5, 0.75, 1.0, 1.5, 2.0 kg/day; measure ammonia, nitrite, nitrate, and residual chlorine daily to establish a dose–response curve and identify the threshold for ammonia oxidation.
Niedrig No measurement of pH-dependent speciation of ammonia (NH₃ vs NH₄⁺) or hypochlorous acid (HOCl vs OCl⁻); the paper measures pH but does not calculate the fraction of each species.
Section 3.1 discusses how pH affects HOCl⁻ vs OCl⁻ disinfectant efficiency, but does not calculate the speciation. Similarly, ammonia speciation depends on pH and temperature; the paper does not report whether the 0.34 mg/L is NH₃ or NH₄⁺ or a mixture.
Versuch. Calculate ammonia and hypochlorous acid speciation using Henderson–Hasselbalch equations for each day; plot speciation against residual chlorine and ammonia concentration to identify whether HOCl⁻ availability or pH-dependent ammonia form drives oxidation kinetics.
Mittel No long-term (>5 weeks) monitoring of nitrogen species or microbial regrowth after chlorine reduction; the paper does not assess whether the system reaches a new steady state or whether ammonia/nitrite accumulation resumes.
The intervention lasted 5 weeks (days 1–35). The paper states in Section 4 (Conclusion) that 'the long-term microbial risks due to the reduced amount of chlorine added should be monitored' as a future recommendation, indicating this is a known gap.
Versuch. Extend monitoring to 12–24 weeks post-intervention; measure ammonia, nitrite, nitrate, and total/fecal coliform bacteria weekly to confirm that the system does not revert to higher ammonia or nitrite levels and that microbial regrowth does not occur.
Erstellt von der MESSAI-Extraktionspipeline · mit dem Quell-PDF abgleichen
Was gemacht wurde
- Systemtyp
- not_BES
Was funktioniert hat
Noch keine Ergebniskennzahlen extrahiert.
Zusammenfassung
The general daily maintenance of outdoor swimming pools includes the addition of chlorine for disinfection. Chlorine is a potentially hazardous chemical that is harmful to users, and its excessive addition could lead to health effects in swimmers while insufficient levels may result in inadequate disinfection. This study aimed to optimize chlorine management at the Silpakorn University swimming pool by analyzing the physical and chemical characteristics of outdoor pool water. Initial sampling revealed an unacceptably high residual chlorine concentration of 20 mg/L, exceeding regulatory standards. To address this, a chlorine management strategy was implemented. Chlorine adjustment was conducted by measuring the residual chlorine concentration and calculating the chlorine demand. Post-intervention results indicated that residual chlorine and pH levels were successfully brought within acceptable limits. Further analysis confirmed that parameters such as hardness, ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, suspended and dissolved solids, and total and fecal coliform bacteria met safety standards. Recommendations were given to the pool caretaker, including the use of personal protective equipment (PPE) while handling chlorine, a precise measurement of chlorine (1 kg daily), and regular filtration tank maintenance at least twice a month. Besides improving social and environmental aspects, the optimized chlorine usage resulted in an estimated annual cost saving of $1,213.26 (1 USD ≈ 36.065 THB). This study highlights the importance of sustainable chlorine management in swimming pools, offering a practical approach that can be replicated in similar facilities.
Schlagwörter
Kennungen
- Zeitschrift
- Environment and Natural Resources Journal
- Jahr
- 2025
Dieser Publikation ist noch kein 3D-Modell zugeordnet. Die Parameterbereiche oben ordnen die berichteten Werte trotzdem in die Literaturverteilung ein.