Flocculation effects on bound water in sludges as measured by nuclear magnetic resonance spectroscopy.

Nuclear magnetic resonance relaxation times (T(1) and T(2)) were measured for flocculated and unflocculated samples of activated sludge. The weight of water and solids in the sludge samples was found and related to T(1) to find the relative percentage of bound water. The results suggest that the amount of bound water increases as the samples become more unflocculated. The values of T(1) and T(2) also indicate that unflocculated individual particles are characterized by loose packing of shorter molecules and that the addition of larger molecules may induce flocculation.