| 摘要 |
<p>In cleaning the oil tanks of ships, esp. oil tankers, a suspension is pumped in, contg. (i) sewage sludge from the activated sludge process, (ii) activated bentonite and (iii) adipic acid. The sludge contains 80-95% water, and its pH is set between 6 and 9, if necessary by adding quicklime. Pref. proportions are 100kg (i): 10 kg(ii): 1kg(iii). The mixt.remains in the tanks during the return voyage to the loading port, and the oil residues are attacked by the microorganisms in the sludge. After discharge, the suspension is used as fertiliser. Sludge from the coastal towns of the oil-importing countries is disposed of. Fertiliser becomes available for the usually barren regions round the oil-exporting ports. There is no environmental damage through discharge of spent cleaning fluids.</p> |
