UNIDIRECTIONAL FREEZING OF CUPRIC HYDROXIDES SLUDGE

Unidirectional freezing of cupric hydroxides sludge was conducted to i nvestigate the freezing speed effects on the sludge performance, inclu ding filterability, zone settling, and flee density versus size relati onship. With a high freezing speed, no global particle migration takes place. The sludge filterability is largely improved, however, the fle e morphology (whence the settleability) are little influenced. With a low freezing speed, nevertheless, global particle migration occurs. Th e sludge filterability and settleability are both markedly improved. T he flee morphology changes as well. The critical freezing speed that r equired for sufficient sludge performance improvement is suggested.