Problem:
Wastewater treatment plants have become very sophisticated in collecting data on the costs associated with maintenance, repair, replacement, and efficient operation. Plant staff are generally the first to identify persistent maintenance and repair expenses and trace them back to the source. That source for many repetitive maintenance and repair expenses can be found at the headworks of the plant.
Plant operators and maintenance staff have dealt with unreliable equipment that requires a high amount of maintenance and constant operator attention. In more recent years, these issues have been increased by the increase in detrimental materials such as flushable wipes, paper goods, and other solids that come down the sewer collection system.
Many plants recognize the need for a better system that allows higher capture rates of solids, which may improve the biological downstream process, reduce pumps from clogging, improve dewatering equipment efficiency and may reduce polymer consumption; all of which are due to the reduction of inert solids allowed to enter the downstream process. Plants also are trying to reduce the amount of maintenance and oversight required by operators and maintenance personnel, while still working within the constraints of the plant hydraulics and capacity.
Goals and Objectives:
To create an understanding of:
- An overview of how to properly size a headworks screen based on plant hydraulics and existing headworks layout.
- Various designs for headworks screens and how those designs impact solids capture.
- An overview of third-party independent testing of screen technology capture rates and how screen opening effects capture.
- The increased costs to plant operations and maintenance risks caused by solids entering the downstream processes.
Presentation of two case studies showing where utilization of high-performance screen technologies has helped alleviate operator and maintenance staff problems.
Conclusion:
Plant personnel are on the front line of plant operations. They should be knowledgeable in the design and capabilities of various types of screening equipment. More and more plant operations and maintenance personnel are part of the decision-making process when new headworks' screens are being purchased. Basing that decision on a clear understanding of the capabilities of each type of screen, will lead to better, more cost-effective screen selection.