Pollutant and microbe removal from dairy parlour wastewater using reed bed treatment

Mantovi, P., Iccinini, S.

Two horizontal subsurface flow reed beds (each 75m2), treating dairy parlour effluent (about 4.5m3) as well as domestic sewage (about 2m3), were set up in 1999 to verify the efficiency of this treatment system in reducing the polluting load of these kind of effluents. Throughout the first two trial years (fro Spring 2000), the two reed beds operated one after the other and wastewater inflows and outflows of the septic tank and reed beds were sampled more than 30 times. A high TSS average value of about 77 mg/l and COD and BOD average values of about 1200 mg 02 and 450 mg 02 respectively are characteristic of plant influent waters. Analyses showed that the reduction of suspended solids and organic load remained at levels greater than 90% while those of the nutrients nitrogen and phosphorus were about 50% and 60%, respectively. Nitrates, chlorides, sulphates, anioni and non-ionic surfactants and heavy metals Cd, Cr, Cu, Ni, Pb, Zn wer edetected in low concentrations in these effluents. The number of coliform bacteria, E. coli and faecal streptococci was reduced by 98-99%. Results demonstrated that reed beds can be appropriate treatment for dairy parlour wastewater.