摘要: DIRECT VS. CONVENTIONAL TREATMENT A general comparison between direct filtration and conventional treatment processes as to energy consuming factors is presented in Table 1. The table lists 14 different factors commonly involved in water or tertiary wastewater treatment. It indicates that, considering energy consumption, the major difference between conventional treatment and direct filtration is contributed by:(1) the elimination of the settling tank and its need for a sludge collector and separate sludge handling equipment,(2) the agitation required in the flocculation basin (or sludge blanket clarifier); and (3) the agitation required in the flash mixing or pre-mixing step when contact flocculationfiltration (direct in-line flocculant injection) takes place. Such a plant, treating water pumped from the Ohio River, has been previously described. 2