Disposal of Sludge from Municipal Wastewater Treatment Plants—Quality of Sludge Used in Brickmaking

This standard applies to the disposal of sludge from municipal wastewater treatment plants and its use in brickmaking. Before use, sludge shall be free of irritating odours and meet stabilization requirements; its pH shall be 5–10, moisture content shall not exceed 40%, and concentrations of total cadmium, mercury, lead, chromium, arsenic, nickel, zinc, copper and mineral oil shall not exceed specified limits. The mass ratio of sludge to total brickmaking raw materials should not exceed 10%; bottom ash and fly ash from separate sludge incineration may be used for non-fired bricks. Air pollution control during brickmaking, harmful substances in finished bricks and odour emissions shall comply with relevant standards. Sludge shall be sampled by batch and tested at least quarterly, with retesting required when influent sources or treatment processes change.