Wastewater Phytopurification Monitoring with Congolese Planted Filters, Republic of Congo

Abstract

The present study aimed to evaluate the purifying power of two Congolese plant filters or emerging macrophytes EP-F (Echinochloa pyramidalis (Lam) Hutch) and CA-F (Cyperus alternifolius L.) on wastewater coming from the Total market, the largest national market of Brazzaville in Congo. To do this, we set up an experimental device composed of gravel, fine sand and two plants. These plants were cultivated in an experimental pilot consisting of 8 tanks of 42,000 cm3 of wastewater at treat each one, in addition to 2 tanks used as controls. The purifying performance study of the system after 90 days of treatment showed a significant reduction in physical, organic and mineral pollution. Using the planted filter EP-F (Echinochloa pyramidalis (Lam)Hutch), we obtain reduction rates of almost 100% for turbidity and for suspended matter (SM), 75.42% for COD, 76.5% for NH4+ ions, 99.5% for NO3- ions and 99.73% for PO43- ions. In the case of the CA-F (Cyperus alternifolius L) planted filter, we obtain reduction rates of almost 100% for turbidity and SM, 80.94% for COD, 93% for ions. NH4+, 89.11% for NO3- ions and 98.93% for PO43- ions. Furthermore, we also noted an increase in organic and mineral pollutants concentrations in the two plants compared to the raw plants before wastewater passage. This study showed that Echinochloa pyramidalis (Lam) Hutch and Cyperus alternifolius L. are effective macrophyte filters to eliminate physical, organic and mineral pollution.