Polycarbonate nuclepore membrane filter

Batch tests were conducted to evaluate the influence of remaining sorption and of different types of biomass on the TOC removal. Four batches were compared:i)

Biomass in suspension: water sample taken from the influent of the BAC filter with biomass in suspension;

ii)

Detached biomass: biomass detached by manual shaking from the GAC into 0.2 µm filtered (polycarbonate Nuclepore membrane filter, Whatman) influent water;

iii)

Schmutzdecke: biomass sampled with a steel needle and a glass syringe from the Schmutzdecke of the BAC filter;

iv)

Biomass on GAC: biomass with exhausted GAC from the sampling at 7 cm depth of the BAC filter.

To obtain comparable results, the same amount of biomass (quantified with ATP) was added to each batch: 1 L of the biomass in suspension, 1 g of GAC with biomass, detached biomass from 2 g of GAC, or 3 mL of Schmutzdecke. For all the samples except suspension, the BAC filter influent water was 0.2 µm filtered (polycarbonate Nuclepore membrane filter, Whatman) and added to provide the same nutrients to all batches. The samples were placed in an overhead shaker at room temperature for 5 days, and TOC and TCC samples were taken on days 1, 2, 4, and 5. All samples were done in duplicate and the glassware used was autoclaved.