Wastewater Treatment Potentials of Vegetated Beds with <i>Brillantaisia cf. bauchiensis</i> Hutch & Dalz and <i>Polygonum salicifolium</i> Brouss ex Wild in the Western Highlands of Cameroon

Abstract

The objective of this study was to evaluate the potentials of beds vegetated with medicinal species (Brillantaisia bauchiensis and Polygonum salicifolium) in a constructed wetland for domestic wastewater treatment in the Western Highlands of Cameroon. The study was carried out between March and September 2017 on plants collected from a natural wetland in Penka-Michel. The two plants species selected based on their ethnobotanical importance were transplanted and allowed to grow to maturity in a prepared natural wetland at Penka-Michel and a constructed wetland for domestic wastewater treatment on the campus of the University of Dschang. Growth parameters were followed for the two plants species in both wetlands. The physicochemical parameters and faecal bacteria concentrations were measured only for the vegetated and non-vegetated/control beds in the constructed wetland. Overall, the two plants species showed increased growth in height, diameter, leaf number and plants density. The change in diameter and density were very significantly influenced by species type in the constructed wetland than in the natural wetland. Generally, plant growth in height, diameter and density were higher with B. bauchiensis in the constructed wetland than with P. salicifolium in both wetlands. The mean faecal bacteria removal was higher in the vegetated beds for some bacteria than in the non-vegetated/control bed. There was a significant difference in the reduction efficiency of TSS, turbidity, BOD, Faecal streptococci and Total coliforms bacteria between the inflow and the outflow of some treatment beds especially the bed vegetated with Brillan

Eichhornia crassipes Efficacy in Secondary Wastewater Treatment in the Western Highlands of Cameroon

“…Te climate is equatorial with a four-month dry (mid-November to mid-March) and an eight-month rainy season (mid-March to mid-November) with a thermal amplitude of two (2). wastewater infow rate to the station is about 3 m 3 /day [33]. Te station has three compartments consisting of the pretreatment, primary, and secondary compartments (Figure 2).…”

“…Te physicochemical analyses were carried out following Hach [34] for the pH using CyberScan 1500 pH meter from Eutech Instruments, electrical conductivity (EC) and total dissolved solids (TDS) using conductivity/TDS 44600 ™ meter from Hach Company, total suspended solids (TSS); color; orthophosphates (PO Te purifcation performances were assessed based on the percentage reduction of parameters recorded at the outfow of each component: frst by comparing the outfow to the infow of the same lagoon and second by comparing the outfow of each lagoon to the main infow into the system to get the overall reduction of the parameter through the system up to that level. Te reduction efciencies were calculated for each stage of the process, using the following formula [33]:…”

Impact of the application of biochar previously used in domestic wastewater treatment on the growth of lettuce (Lactuca sativa)

“…The climate in this region is of equatorial type with two seasons: 4 months of the dry season from mid-November to mid-March and 8 months of the rainy season from mid-March to mid-November. Annual precipitations ranged between 1433 and 2137 mm, while the annual mean temperature was estimated at 20.8°C with a thermal amplitude of 2°C (Boyah et al, 2019). The dominant soil type was the oxisols which was characterized by an acidic pH (3 -5.5), high con-centration of heavy metal (Al and Fe) toxicities and low cation exchange capacity (Djousse, 2017).…”