VICKREY & WEHMAN
PROJECT DEVELOPERS - PLANNERS - DESIGNERS - CONSTRUCTION MANAGERS-
BUILDERS - CIVIL & ENVIRONMENTAL ENGINEERS - SURVEYORS - MARKETERS
7334 Blanco Road - Suite 109
San Antonio, Texas 78216, United States of America
INFORMATION BRIEF ON
THE ADVANCED WASTEWATER TREATMENT PLANT
Description: This Advanced Wastewater Treatment Plant (AWTP) (see photos) is permitted by the State of Texas Natural Resource Conservation Commission (TNRCC) for treatment capacity of up to 6.5 Million Gallons per Day or 2,372.5 Million Gallons per Year. This AWTP is very unusual because the sewage in the plant does not have the odor or sewage since it is being treated throughout the AWTP aerobically. This allows the plant to be a good neighbor (no odors) and the AWTP can be placed directly adjacent to large populations thus reducing piping, pumping and maintenance costs to the utility. Note: 1 U.S. Gallon = 3.785 Liters.
In the U.S.A. we design the AWTP to treat approximately 100 gallons of domestic sewage per person per day in the plant service area. This AWTP would routinely serve from 65,000 to 80,000 people per day that are connected to a U.S. standard domestic sewage collection system. This same plant could serve 100,000 people in Asia with some minor modifications. The AWTP shown in the associated pictures provides a routine wastewater treatment efficiency (solids and organics) of over ninety-five percent (typically 95-99%) each day throughout the year. The AWTP process consists of: (a) head works that distribute the sewage flow to the oxidation racetracks, (b) oxidation racetracks (large ovals) that aerobically treat the sewage, (c) solids concentrating racetrack (large oval) that continues to treat the sewage and concentrate solids, (d) standard primary clarifiers/gravity settlers (circular areas) to settle out the solids, (e), belt filter presses to dewater and dry the sludge, (f) disinfection chambers) and (g) the discharge channel to the river. The water coming from the AWTP has a much higher water quality (lower organics and suspended solids) than a typical natural unpolluted river in Texas, U.S.A..
The AWTP process is highly reliable while treating conventional domestic sewage. The AWTP does not require costly air compressors, air piping networks, air diffusers and their associated high maintenance costs for the waste water utility operating the AWTP. The AWTP needs seven (7) people each working an eight (8) hour work shift throughout the year or employees typically 21-22 people/AWTP per day. The AWTP process results in a wastewater treatment facility having high treatment efficiency, low annual operating costs, and low maintenance cost for the entire facility because of no requirements for highly trained operating personnel and extensive maintenance, repair, or equipment replacement. Because of the high cost of labor (typically $US9-16/work hour plus 25% employee benefits) in the U.S.A., the plant has an annual operation and maintenance cost of approximately $US 1.2 Million; this is approximately one-third the annual operating cost of other U.S.A. comparable wastewater treatment plant systems achieving the same degree of treatment (95%) and daily wastewater treatment capacity of 6.5 Million Gallons per Day. This AWTP plant is easily upgradable to 8.5 Million Gallons per Day by increasing the disinfection capacity of the plant, increasing the recirculation pumping capacity and increasing the solids belt filter press capacity. An AWTP needs 10 hectares of land area.
Typical Characteristics of Incoming Domestic Sewage Being Treated in AWTP:
Carbonaceous Biochemical Oxygen Demand (CBOD) 218-264 mg/l
Total Suspended Solids (TSS) 265-295 mg/l
Total Kjeldahl Nitrogen (TKN) 28-42 mg/l
Ammonia Nitrogen (NH3 as Nitrogen) 22-35 mg/l
Total Phosphates (TPO4) 8.3-11.4 mg/l
Typical Characteristics of Treated Domestic Sewage Leaving AWTP:
Carbonaceous Biochemical Oxygen Demand (CBOD) 2.0-3.0 mg/l
Total Suspended Solids (TSS) 1.8-2.5 mg/l
Total Kjeldahl Nitrogen (TKN) 0.65-0.80 mg/l
Ammonia Nitrogen (NH3 as N) 0.10-20 mg/l
Total Phosphate (TPO4) 0.06-0.25 mg/l
A range of 33-74 dry tons (average of 47 dry tons) of aerobically digested sludge solids (belt filter pressed) is processed monthly (approximately 1.53 dry tons per day.