Industrial Wastewater - General
Wet Air Oxidation: A Review of Commercial Sub-critical Hydrothermal Treatment
by Clayton B. Maugans and Claude Ellis, Siemens Water Technologies
Wet air oxidation (WAO) is a hydrothermal treatment process that has been commercialized for approximately 50 years. Over 200 industrial or municipal WAO systems have been constructed. The process is operated in a pressurized hydrothermal reactor in the sub-critical water temperature and pressure range with the system conditions usually under 320°C and 214 bar (608°F/3100 psig). This process is usually applied for the treatment of high strength wastewaters with components that are difficult or uneconomical to treat via conventional biological treatment or incineration. WAO has also been used for the treatment of municipal sludge to minimize the consumption of landfill capacity. In the majority of WAO wastewater applications, subsequent biological treatment of the WAO effluent is required. Another application of WAO includes the integration into industrial processes for insitu removal of impurities, such as in crystallization.
This paper discusses the process in more detail.
Use of the PACT® System to Treat Industrial Wastewaters for Direct Discharge or Reuse
by John Meidl - Siemens Water Technologies
For many years, there has been a real concern over the discharge of industrial pollutants into our world's waterways because of their complex chemical structure and their long-term persistence in nature. One wastewater treatment technology that can treat both conventional and complex organic pollutants from industry is the PACT system.
This paper discusses the PACT system and its merits in treating industrial wastewaters.
Improvement of Industrial Synthesis of Methyl Methacrylate Application of a Wet Air Oxidation Process
by Dario Giudici - ATOFINA; and Clayton Maugans - Siemens Water Technologies
A process in which the blow down from an ammonium sulfate crystallizer is treated in a wet air oxidation system has been developed by ATOFINA Italia and Siemens Water Technologies (formerly USFilter). The process has been installed and operated at ATOFINA Italia's methyl methacrylate production facility in Rho, Italy, and eliminates the need for off-site disposal of a crystallizer blow down stream, as well as increases ammonium sulfate recovery.
This paper discusses the MMA process and by-product generation, application of wet air oxidation to the stream, and treatment results.
The Use of Wet Oxidation and PACT® for the Treatment of Propylene Oxide/Styrene Monomer (PO/SM) Industrial Wastewaters at the Repsol PO/SM Plant in Tarragona, Spain
by Juan Pedrerol Gallego - Repsol Quimica, S.A.; Salvador Ruiz Lopez - Repsol Quimica, S.A.; Clayton B. Maugans - Siemens Water Technologies
In 1999, Repsol YPF constructed a sophisticated industrial wastewater treatment plant in Tarragona, Spain to accommodate the new 678,000 tons per year propylene oxide/styrene monomer (PO/SM) and derivatives chemical production plants. The high strength aromatic and polyol compounds in the PO/SM wastewater are unaffected by conventional biological treatment processes and a more sophisticated wastewater treatment approach was necessary.
This paper describes the wastewater treatment plant in detail, and use of the wet air oxidation and PACT systems.
Pharmaceutical Wastewater
The Challenges of Treating a Complex Pharmaceutical Wastewater
by Terrence Virnig, Joel Melka - Synthetech, Inc.; and John Meidl - Siemens Water Technologies
Synthetech, Inc., Albany, Oregon, produces peptide building blocks and specialty amino acids that are globally distributed to major pharmaceutical companies. Chemical manufacture occurs in batches that contribute to large swings in waste production, and because Synthetech uses a wide range of chemicals within production, they get a large fluctuation in variety and concentration of contaminants in the wasteater requiring treatment, generating wastes that represent a challenge to be treated safely and reliably.
This paper discusses Synthetech's use of the PACT system to treat their wastewater.
Wet Air Oxidation of a Pharmaceutical Waste Stream
by David J. Best - Sterling Organics
In early 1990, ministers of the European countries on the North Sea declared that ocean disposal of industrial wastes should cease by the end of 1992. To comply with the mandate, the Sterling Organics' facility at Dudley, Northumberland, England, had to investigate treatment of a high-strength, highly colored para-aminophenol (PAP) wastewater generated in the production of the pain reliever Paracetamol.
They chose to use a wet air oxidation from Siemens Water Technologies (formerly USFilter). This paper discusses the treatment challenge, the decision to use wet air oxidation, and the treatment results.
Spent Caustic Treatment
Wet Air Oxidation of Ethylene Plant Spent Caustic
by Claude E. Ellis, Robert J. Lawson, Bruce L. Brandenburg - Siemens Water Technologies
Spent caustic scrubbing liquor is commonly the most problematic waste stream generated by an olefin plant. The most effective means for on-site treatment of spent caustic is wet air oxidation which can achieve the oxidation of reactive sulfide to soluble thiosulfate, sulfite and sulfate. This treated stream is then suitable for biotreatment in the plant's wastewater treatment system.
This paper provides insight into the design of a wet air oxidation system as it is applied on a full scale basis for spent caustic treatment.
Wet Air Oxidation of Refinery Spent Caustic: A Refinery Case Study
by Tania Mara S. Carlos - Refinaria de Petroleos de Manguinhos; and Clayton B. Maugans - Siemens Water Technologies
In 1995, a wet air oxidation system was put into operation for treatment of refinery spent caustic from gasoline sweetening, gasoline and LPG prewashing and from gasoline and LPG mercaptans extraction at the Refinaria de Petroleos de Manguinhos, S.A. (RPDM) in Rio de Janeiro. RPDM is a producer of liquid fuels and is located near residential property within Rio de Janeiro.
This paper discusses the technology selection process as well as performance of the wet air oxidation system.