The potential of decentralised wastewater treatment in urban and rural sanitation in South Africa: lessons learnt from a demonstration-scale DEWATS within the eThekwini Municipality
| العنوان: | The potential of decentralised wastewater treatment in urban and rural sanitation in South Africa: lessons learnt from a demonstration-scale DEWATS within the eThekwini Municipality |
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| المؤلفون: | null Preyan Arumugam, null Lungiswa Zuma, null Susan Mercer, null Lloyd Govender, null Jonathan Pocock, null Christopher J Brouckaert, null Teddy Gounden |
| المصدر: | Water SA; Vol. 49 No. 1 (2023); 8-18 Water SA, Volume: 49, Issue: 1, Pages: 18-8, Published: JAN 2023 |
| بيانات النشر: | Water Research Commission (WRC), 2023. |
| سنة النشر: | 2023 |
| مصطلحات موضوعية: | decentralised sanitation, constructed wetlands, constructed wetlands DEWATS decentralised sanitation rural sanitation urban sanitation, DEWATS, rural sanitation, urban sanitation, Management, Monitoring, Policy and Law, Waste Management and Disposal, Applied Microbiology and Biotechnology, Water Science and Technology |
| الوصف: | The design principles of decentralised wastewater treatment systems (DEWATS) make them a practical sanitation option for municipalities to adopt in fast-growing cities in South Africa. Since 2014, a demonstration-scale DEWATS with a modular design consisting of a settler, anaerobic baffled reactor (ABR), anaerobic filter (AF), vertical down-flow constructed wetland (VFCW) and horizontal flow constructed wetland (HFCW) has been in operation in eThekwini. A performance evaluation after the long-term operation was undertaken in 2019 by comparing the final effluent with national regulatory requirements. Despite limitations in characterising the raw wastewater, a comparison of the settler and final effluent quality indicated high (≥ 85%) removal efficiencies of total chemical oxygen demand (CODt), ammonium-N (NH4-N) and orthophosphate-P (PO4-P), 75% removal of total suspended solids (TSS) and 83.3% log10 removal of Escherichia coli. Lack of exogenous and endogenous carbon and high dissolved oxygen (DO) concentrations (> 0.5 mg‧L−1) inhibited denitrification in the HFCW, resulting in 12.5% of the effluent samples achieving compliance for nitrate-N (NO3-N). Moreover, mixed aggregate media and low residence times in the HFCW may have also contributed to poor NO3-N removal. During the COVID-19 lockdown, an unexpected shutdown and subsequent resumption of flow to the DEWATS indicated a 16-week recovery time based on achieving full nitrification in the HFCW. Although design modifications are necessary for the HFCW, the installation of urine diversion flushing toilets at the household will reduce the nutrient loading to the DEWATS and potentially achieve fully compliant effluent. Alternatively, the application of two-stage vertical flow constructed wetlands to improve denitrification should also be explored in the South African context. With an improved design, DEWATS has the potential to fill the gap in both urban and rural sanitation in South Africa, where waterborne sanitation is still desired but connections to conventional wastewater treatment works (WWTWs) are not possible. |
| وصف الملف: | application/pdf; text/html |
| اللغة: | English |
| تدمد: | 0378-4738 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::99dcbda4f6a14bd259855386d9bcede3 https://www.ajol.info/index.php/wsa/article/view/240868 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....99dcbda4f6a14bd259855386d9bcede3 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 03784738 |
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