Dulces Nombres Wastewater Treatment Plant

Location: Monterrey, Mexico

Client: Desarrollo y Construcciones Urbanas SA (DYCUSA)

Completion Date: 1996

Burns & McDonnell, in association with DYCUSA Y ASOCIADOS, was retained for the design and construction of the Dulces Nombres Wastewater Treatment Plant in Monterrey, Mexico. This plant was designed for a current peak flow of 216 million gallons per day (MGD) with provision to expand capacity to 432 MGD within two years.

The peak solids production following anaerobic digestion:

  • Primary sludge — 250,000 pounds per day
  • Secondary sludge — 136,000 pounds per day
  • Total — 386,000 pounds per day

Primary sludge is blended with pure oxygen waste-activated sludge, which is thickened to 6 percent solids on gravity belt thickeners. Digested sludge is pumped to eight 2-meter belt filter presses. Sludge is dewatered from 4 percent to 6 percent solids to a minimum of 29 percent solids. Dewatered sludge is then conveyed on two belt conveyors to two elevated live bottom sludge storage hoppers, which serve as truck loading stations. Dewatered sludge is then trucked to a landfill for final disposal.

  • Design-build
  • Anaerobic digestion
  • Sludge thickening/dewatering
  • Sludge landfill

The solids handling system is designed for:

  • Number of BFPs — 8
  • Belt width — 2 meters
  • Hydraulic loading — 120 gpm/unit (60 gpm/m)
  • Solids loading — 1,800 pounds/hour/unit (900 pounds/hour/meter)
  • Solids feed concentration — 4% to 6%
  • Cake solids concentration — 24%
  • Polymer consumption — 8-12 pounds/day ton
  • Bulk polymer storage — 9,000 gallons
  • Belt conveyor — 30-ton/hour
  • Sludge storage hoppers — 1,500 cubic feet
  • Sludge flow metering — magnetic