Using the Comprehensive Performance Evaluation Approach to Optimize Industrial Waste Treatment Facilities

The Comprehensive Performance Evaluation (CPE) process presented by Hegg, DeMers and Barber (1) has been successfully used for over a decade in the municipal wastewater treatment sector to establish the actual hydraulic and organic treatment capacity of a facility and identify the factors that lead to poor performance. Once the poor performance factors have been identified, a Composite Correction Program (CCP) can be developed to improve the performance of the treatment facility. The CPE defines the CCP and determines whether the facility improvement will require operational changes, minor facility modification, major facility modification or a combination of these.RTW has modified this approach and applied it to industrial wastewater treatment facilities. While there are thousands of municipal waste treatment plants and the characteristics of municipal wastewater and biological treatment processes are relatively well understood, significantly less is known about the myriad of different industrial wastes and their associated treatment processes. However, the same biological, physical and chemical laws apply to both municipal and industrial waste treatment. Even though we may not understand each industrial waste or process to the degree that we understand municipal waste treatment, we can still apply the CPE approach to minimize the factors leading to poor performance and can optimize treatment at existing industrial wastewater treatment facilities.This paper presents an example of the use of this approach. At the invitation of the wastewater treatment staff, the consultant and operations staff formed a team to improve performance at a chemical wastewater treatment plant treating formaldehyde and related compounds at a location in the central United States. The results of that team effort are shown in data from January 1995 through December 2001. With the project starting in February 1997, 26 pre-project months of data were evaluated and compared with 58 months of data following project initiation. Pre-project effluent BOD and TSS values were 39 mg/L and 100 mg/L respectively, and within permitted limitations. However, after the project was initiated, effluent BOD and TSS averaged 11 mg/L BOD and 33 mg/L TSS for the 58 months of data. Dramatic savings, average over 66%, in cost of polymer required for sludge settleability has also been maintained during that time period. These results were attained with modified process control and utilization of existing treatment units, and with an extensive effort to minimize the organic shock loadings to the plant. This paper discusses the approach, effluent quality improvement, chemical savings, load reductions and the minimal costs related to the project.