M. G. García

The influence of wastewater type and organic loading on the protozoan and metazoan population of a peat bed filter

Three peat bed filters treating wastewaters with differing proportions of industrial input were compared experimentally by analysis of their population strucrure. The plants were all full scale and served village communities around Madrid, Spain. AH three plants showed a high ciliated protozoan population density (> 105/1), but the least loaded system, which received only domestic wastewater, exhibited a 10 fold greater abundance and a predominance of Paramecium. The plants with an industrial input performed less well and showed a population structure predominated by Chilodonella and Colpidium as well as having substantial populations of nematodes and rotifers. Protozoans may contribute towards an enhanced BOD and COD removal efficiency and can be used as indicators of optimum oxygenation conditions with the peat bed.