Nutrients removal from integrated multi-trophic aquaculture (IMTA) water using waste stabilization ponds (WSP)

Abstract

Nutrients enrichment due to waste from Keramba Jaring Apung (KJA) aquaculture is one of the main causes of eutrophication in Indonesian Lakes and Reservoirs. Integrated multi-trophic aquaculture (IMTA) is one of environmentally friendly aquaculture that currently being developed at the Research Center (RC) for Limnology - National Research and Innovation Agency (BRIN). This aquaculture would re-use its water, along with fish waste and leftover fish pellets, to grow Duckweed (Lemna sp.) in its ponds system as additional feed. However, due to closed water recirculation in IMTA ponds system, the water quality would eventually deteriorate which would be marked with high turbidity of organic solid waste and low dissolved oxygen (DO). This study aims to improve water quality from aquacultures activity, especially in nutrients (nitrogen and phosphorus) reduction, using a constructed wetland (CW) system. This system consists of waste stabilization ponds (WSP) and compartments of CW and adsorbent. During this initial stage, IMTA water was treated in the WSP for then observed for its improvements in the nutrients and other water quality parameters. This research was conducted from July to September 2019 in the Prototype Laboratory of RC for Limnology-BRIN. Parameters of DO, conductivity, pH, oxidation reduction potential (ORP), and salinity were observed using a calibrated water quality checker (WQC) Horriba