A mathematical model of the sealing of earth-banked tanks for animal slurry

Experimental validation of the model was undertaken by constructing a laboratory-scale test column, 2 m high and 0.074 m diameter. The soil liner was simulated in the laboratory by a filter paper. Two suspensions were tested: inorganic waterworks aluminium hydroxide sludge and organic cattle slurry. The experimental results show that the mathematical model predicts a reduction in seepage due to the formation of a suspended solids 'cake' at the suspension/filter-membrane interface. The model is conservative i.e. it under predicts the extent of membrane sealing by cake formation. Only membrane sealing, resulting from advection of suspended solids, is accounted for. Sealing due to sedimentation of solids is not incorporated into the proposed simple model.