Nonliving macrophyte Salvinia sp. application for nutrient removal in starchy wastewater treatment of cassava industry

Abstract

The removal of nutrients (nitrogen, phosphorus, and COD) of wastewater from a local cassava industry wastewater was investigated. Dried (nonliving) biomass of the aquatic macrophyte Salvinia sp. was used in a batch system and experiments were all bench-top laboratory-scale in Erlenmeyer flasks. The kinetic behavior was evaluated and a statistical central composite design (CCD) was used to verify the influence of the parameters pH (5.0–9.0), initial biomass concentration (0.0–0.0067 g mL⁻¹), and agitation (0–150 rpm). After 24 h of contact with the macrophyte, about 98% of nitrogen was removed, coinciding to pH and COD/N ratio elevations. After 96 h, according to CCD results, the dried biomass of Salvinia sp. removed significantly the nutrients from cassava wastewater, suggesting it was irrespective of all the evaluated parameters. The nonliving macrophyte Salvinia showed potential for application in the starchy wastewater treatment as an alternative way for pollutant removal, since this macrophyte is found in aquatics environments.

Keywords:

• Salvinia
• Cassava industry
• Starchy wastewater
• Nutrient removal
• Statistical design
• Dried macrophyte