Floating treatment wetlands using Vetiveria zizanioides and Heliconia psittacorum in aquaculture wastewater treatment

Abstract

The most important things needed in aquaculture are good quality and quantity of water resources. The residue from the use of pellets as additives and the results of the excretion of aquatic biota will produce liquid waste characteristics with high nutrient and organic matter content. One of the efforts to treat wastewater is using floating treatment wetlands (FTWs). This study aimed to analyze the changes in nutrients and organic matter concentrations and the removal efficiency using Vetiveria zizanioides and Heliconia psittacorum in a sewage treatment system using FTWs by grouping water quality parameters as observational variables whose linear correlations are in the line to become one main component using the PCA (Principal Component Analysis). The research was conducted on a laboratory scale using tarpaulin ponds with a batch system, the source of wastewater from catfish ponds with 12 treatment variations namely plant type, surface area, and pond depth, and observed for 30 days. Parameters monitored include total nitrogen (TN), total phosphorus (TP), nitrate (NO₃⁻), nitrite (NO₂⁻), ammonia (NH₄⁺), orthophosphate (PO₄^3-), chemical oxygen demand (COD), and in situ measurement of parameters such as dissolved oxygen (DO), pH, temperature, and conductivity. At the end of the experiment, it was seen that treatment pond 7 (Heliconia psittacorum, surface cover area 50%, depth 100 cm) effectively removed 75.35% of TN and 90.70% nitrate, treatment pond 1 (Vetiveria zizanioides, surface cover area of 100%, depth of 100 cm) effectively removed TP 92.55%, the treatment pond 5 (Heliconia psittacorum, the surface cover area of 100%, depth of 100 cm) effectively removed ammonia by 94.64% and nitrite by 97.93%. Almost all treatments tested can reduce COD concentrations, while the phosphate in the study showed a fluctuation until the end of the experimental period. Based on the PCA results on day 30, TN, TP, conductivity, phosphate, COD, nitrate, pH, and temperature can represent the characteristics of changes in the concentration of organic compounds and nutrients in aquaculture wastewater compared to other parameters.