Suitability of the Modified Bardenpho process for faecal sludge treatment in Kumasi, Ghana
Open access
Autor(in)
Datum
2022Typ
- Master Thesis
ETH Bibliographie
yes
Altmetrics
Abstract
The Kumasi Wastewater Treatment Plant is a recently constructed faecal sludge treatment plant located in Kumasi, Ghana. It is designed to treat 1000 m3/d of faecal sludge. It is the first plant employing the Modified Bardenpho process for faecal sludge. A mixed-method approach was used to assess the suitability of the Bardenpho process for faecal sludge treatment. The characteristics of the received faecal sludge were examined, as well as the treatment performance in terms of removal efficiency and compliance with local effluent quality guidelines. Measurements were carried out to assess process functioning, and interviews were conducted with employees to investigate the impact of the following aspects on the performance: a) design and layout, b) operations and maintenance, c) quality control and d) data management. A high variability in quantity and quality was observed (median ± standard deviation: 917 ± 146.5 m3/d; 4208 ± 5007 mg/L COD; 628 ± 468 mg/L TN; 40 ± 42.8 mg/L TP). Critical parameters in terms of median compliance with the Ghana EPA effluent discharge guidelines were NH4+-N (10.7 mg/L), NO3--N (122 mg/L), TP (11.3 mg/L) and E. coli (>105 cfu/100mL). The median removal efficiencies were 95% for COD, 99% for TSS, 96% for NH4+-N, 73% for TN and 71% for TP. The Bardenpho process was not taking place as designed with no actual anaerobic zone, likely caused by a high return activated sludge flow. Some of the installed technologies were not performing as anticipated and poorly planned infrastructure resulted in disturbances. The dependence on the import of high-cost materials with insufficient supply chains was found to lead to frequent shortages of the required materials for operations, maintenance and quality control, causing inconsistent operation and an impaired treatment. A lack of training and technical knowledge was identified. Standard laboratory practices are not always followed, resulting in inaccurate measurements. Data recording and storage systems were found to be insufficiently organised. Collected data is not readily available for analysis and decision making. The Bardenpho process did not seem to provide the required flexibility under highly variable conditions and was found to be not suited for faecal sludge treatment, especially in a resource-limited setting. Further research is needed to identify strategies for a sustainable and effective operation of the plant and to investigate whether biological phosphorus removal is feasible. Mehr anzeigen
Persistenter Link
https://doi.org/10.3929/ethz-b-000626839Publikationsstatus
publishedVerlag
ETH ZurichThema
faecal sludge; wastewater treatment; Ghana; Limiting factors; Low income countries; global healthOrganisationseinheit
09746 - Tilley, Elizabeth / Tilley, Elizabeth
ETH Bibliographie
yes
Altmetrics