Study of the Effectiveness of Domestic Wastewater Treatment in the City of Brazzaville Using Vertical-Flow Artificial Marshes Planted with Cyperaceae (Cyperus alternifolius L.)
Diele Mouko Gavin-Rolin *
Faculty of Sciences and Technics, University of Marien N'GOUABI Uni, Plant and Life Chemistry, BP 69, Brazzaville, Republic of Congo.
Mbemba Kiélé Molingo
Faculty of Sciences and Technics, University of Marien N'GOUABI Uni, Plant and Life Chemistry, BP 69, Brazzaville, Republic of Congo.
Okeni-Boba Judicaël Gabriel
Faculty of Sciences and Technics, University of Marien N'GOUABI Uni, Plant and Life Chemistry, BP 69, Brazzaville, Republic of Congo.
Ngoulou Jeansval Rossam Cédrick
Faculty of Sciences and Technics, University of Marien N'GOUABI Uni, Plant and Life Chemistry, BP 69, Brazzaville, Republic of Congo and Faculty of Applied Sciences, University of Denis SASSOU-N'GUESSO, Kintélé, Republic of Congo.
Mabiala Loubilou Mithé Brice
Faculty of Sciences and Technics, University of Marien N'GOUABI Uni, Plant and Life Chemistry, BP 69, Brazzaville, Republic of Congo.
Litebe Aimé Claude
Faculty of Sciences and Technics, University of Marien N'GOUABI Uni, Plant and Life Chemistry, BP 69, Brazzaville, Republic of Congo.
Kaya-Kaya Phys Alhen Consolat
Faculty of Sciences and Technics, University of Marien N'GOUABI Uni, Plant and Life Chemistry, BP 69, Brazzaville, Republic of Congo.
Ngoma Tsaty Véronique Junior
Faculty of Sciences and Technics, University of Marien N'GOUABI Uni, Plant and Life Chemistry, BP 69, Brazzaville, Republic of Congo and National Polytechnic Institute of Félix Houphouët-Boigny, Ivory Coast.
*Author to whom correspondence should be addressed.
Abstract
Domestic wastewater can cause environmental pollution if it is discharged into the environment without prior treatment, particularly because of its high organic load. In this study, the experimental pilot consisted of two basins: the first was planted with Cyperus alternifolius L., and the second was unplanted and used as a control to monitor the effectiveness of phytoremediation. The system was regularly supplied with municipal wastewater from Brazzaville at a frequency of once every seven (7) days. Thirteen (13) physicochemical parameters were measured before and after treatment. The assessment of removal performance showed that the system achieved a marked decrease in the mean concentrations of several measured parameters from the feedwater, including TSS (372.2, 8.16 and 16.70 mg/L), turbidity (85, 6.5 and 11.41 NTU), and COD (291.37, 92.97 and 69.94 mg/L). \(NO_3^-\) (124.7, 26.01 and 20.32 mg/L), \(PO_4^3-\) (74, 17.41 and 12.06 mg/L), nickel (6.3, 0.71 and 0.16 mg/L), and copper (3.35, 0.10 and 0.13 mg/L) were measured in the feedwater, control filter and Cyperus alternifolius L. planted filter, respectively. Multivariate analysis of means and standard deviations revealed a statistically significant difference in more than twelve (12) parameters in the filtrates from the two filters, with p-value < 0.001. The Cyperus alternifolius L. planted filter contributed to the assimilation of pollutants present in wastewater, resulting in improved treatment performance under the experimental conditions.
Keywords: Treatment, Cyperus alternifolius L., domestic wastewater, Brazzaville, phytoremediation, physicochemical parameters, chemical oxygen demand, total suspended solids, nutrient removal, trace metals