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Gerson, et al.

which operate in parallel to allow flexible hydraulic 2.2. Methods
distribution and enhance treatment performance under 2.2.1. Sampling strategy
variable loading conditions. This configuration enables To evaluate the stage-wise and overall performance
the ponds to accommodate fluctuating industrial flows of the Kalobe WSP system, a structured sampling
by distributing influent across multiple units rather than strategy was developed to assess influent and effluent
operating strictly in series. quality across each treatment stage. Composite grab
Figure 1 presents the location of the study area. samples were collected from four critical points within
Photographs of the anaerobic, facultative, and maturation the system: The inlet point, located just upstream of
ponds are provided in Figure 2 to enhance visualization the anaerobic ponds, representing untreated domestic
of the treatment process. In addition, Figure 3 illustrates and industrial influent; the anaerobic pond outlet,
the layout of the Kalobe WSP system. reflecting conditions after primary sedimentation and
The treatment process comprises three unit anaerobic digestion; the facultative pond outlet, situated
operations arranged as parallel trains, with serial flow downstream of the aerobic–anaerobic hybrid treatment
within each train: Two units of anaerobic ponds (for zones; and the maturation pond outlet, representing the
primary sedimentation and anaerobic digestion under final effluent before environmental discharge.
oxygendeficient conditions), four units of facultative Sampling followed the guidelines outlined by the
ponds (for combined aerobic–anaerobic treatment, American Public Health Association (APHA) for
further organic degradation, suspended solids removal, wastewater quality monitoring. A total of 12 composite
17
and algal–bacterial oxygen transfer), and one unit of samples per point were collected over 4 weeks
maturation pond (for final polishing and pathogen (May–June), covering Monday, Wednesday, and
reduction before discharge). In addition, a screening Friday each week, to account for weekly fluctuations
chamber, a grit channel, sludge drying beds, and a and peak industrial discharges, a practice supported
natural wetland serve as preliminary and tertiary by previous WSP studies. 6,16 This 4-week monitoring
treatment components. This layout supports flexible period corresponds to the dry season baseline; while it
influent distribution across ponds while maintaining provides robust insights under relatively stable hydraulic
stage-wise treatment within each train. Figure 3 shows conditions, it does not capture wet-season variability.
the schematic layout of WSP. This limitation is therefore explicitly acknowledged

Figure 1. Location of Mbeya municipal waste stabilization ponds

Volume 22 Issue 6 (2025) 200 doi: 10.36922/AJWEP025320249