IMPROVE FECAL COLIFORM DECAY IN INTEGRATED DUCKWEED AND ALGAL PONDS

The fecal coliforms (FC) decay in a series of five shallow algal ponds was compared to FC decay in an integrated system of algal and duckweed ponds. In the algal ponds of the conventional system the light attenuation by algal matter became rate-limiting for the FC decay. In the integrated system, the algal concentration in the algal ponds was reduced by the intermediary duckweed ponds. This was shown to increase the FC decay in the algal ponds of the integrated system considerabily. An improved system of duckweed and algal ponds is so proposed, that is expected to reduce the area requirements of ponds systems.