Design of a floating cage prototype with organic waste collector (food remains and excreta), produced by trout farming in lake Titicaca, Perú

Abstract

In Lake Titicaca, Peru, trout farming in floating cages has been a valuable opportunity for Andean residents, offering food and self-employment. However, this method has generated environmental problems by contaminating the bottom of the lake with large amounts of organic waste, such as excreta and remains of balanced feed. To address this challenge, a floating cage prototype was designed with an integrated organic waste collector, along with a vertical static settler and pump system. The objective of the research work was to mitigate the pollution of Lake Titicaca caused by the consumption of balanced feed in trout farming. A collecting cage model was built that trapped a significant amount of organic waste. 7 600 rainbow trout weighing an average of 800 g were used, fed with 300 kg day^-1 of balanced feed ad libitum for 30 days. After 16 hours from the feed supply, an average accumulation of organic waste of 6.9 ± 0.98 kg day^-1 was observed, which was transported to the settler using an electric pump. A water quality analysis was carried out, finding values of total phosphorus (TP) of 1.316 ± 0.059 mg L^-1, total nitrogen (TN) of 0.013 ± 0.001 mg L^-1 and total organic matter (MOT) of 55.60 ± 0.30 mg L^-1. L in the water column in the growing area. In conclusion, the design of the collecting cage proved to be an effective alternative to avoid the accumulation of organic waste at the bottom of the lake, and the recovered waste can be used as agricultural fertilizer, adding value to the process.