초록 ▼

The sewage treatment process combines physico-chemical clarification using fine material or clay particles with anaerobic digestion of a concentrated sewage. The particles are preferably magnetite. The sewage (10) is mixed with magnetite (12) having a hydroxylated surface layer in tanks (14, 16, 18,

The sewage treatment process combines physico-chemical clarification using fine material or clay particles with anaerobic digestion of a concentrated sewage. The particles are preferably magnetite. The sewage (10) is mixed with magnetite (12) having a hydroxylated surface layer in tanks (14, 16, 18, 20) in which acid, inorganic flocculant and polyelectrolyte may be added if necessary. The organic material in the sewage is adsorbed on the particles during the mixing contact and a clarified liquid effluent (28) is separated from the loaded particles in a clarifier (22). The organic material may be separated from the particles before or after treatment in an anaerobic digestion assembly (36). The particles are preferably cleansed and regenerated in a two stage countercurrent flow washing system (38, 40, 58, 60, 62) into which a dilute solution of caustic soda or lime (32) is introduced.

대표청구항 ▼

A sewage treatment process characterized in that it comprises the steps of: (a) mixing raw sewage or primary settled sewage with a coagulant/adsorbent which is finely divided particulate mineral or clay material the individual particles of which have a thin hydroxylated surface layer, under conditio

A sewage treatment process characterized in that it comprises the steps of: (a) mixing raw sewage or primary settled sewage with a coagulant/adsorbent which is finely divided particulate mineral or clay material the individual particles of which have a thin hydroxylated surface layer, under conditions whereby at least a substantial proportion of the organic material in the sewage becomes attached to the coagulant/adsorbent; (b) separating the coagulant/adsorbent with attached organic material from the mixture to leave a treated liquid effluent; and (c) subjecting the thus separated organic material to anaerobic digestion.