Industrial Utility Efficiency

# Wastewater

A small site located within a floodplain, prone to erosion, and currently occupied by an existing in-service wastewater treatment facility is not at the top of any engineer’s list for a desirable site to expand a wastewater treatment plant or reclamation facility. However, these challenges created opportunity for specialized solutions during the design of the facility expansion; in particular, in designing the aeration and digester blower system.

## Progress Continues on ASME PTC 13, Blowers

In 2010, the American Society of Mechanical Engineers (ASME) established the PTC 13 Committee to establish a power test code for all blower technologies. Blower & Vacuum Best Practices Magazine interviewed Committee Chair Jacque Shultz, HRO-Turbo Product Technical Leader, Howden North America, Inc., for an update on the new code.

## The Basics of Aeration Control Valves - Part 1

Sizing, selection, and adjusting control valves often causes confusion for process and control system designers. Improper valve application can cause operating problems for plant staff and waste blower power. Basing the airflow control system design on fundamental principles will improve valve and control system performance.

## Pay Close Attention to Turndown to Achieve Blower System Optimization

Turndown designates the operating range of an aeration blower or a blower system – and it can often be the most important factor in determining the ability of a system to match process demand. It is also critical to the system’s energy optimization. Unfortunately, in designing blower systems and controls turndown is not always given the attention that its importance merits. Here’s a look at the critical nature of turndown in wastewater treatment plants and recommendations for ensuring adequate turndown when utilizing Positive Displacement (PD) and centrifugal blowers.

## Three Blower Technologies Help Pennsylvania Wastewater Plant Meet Wide Range of Operating Conditions

Originally built in 1958, the CMA wastewater treatment plant serves 14,000 residents, as well as businesses, in Clearfield Borough and surrounding portions of Lawrence Township, Clearfield County, PA. From the start, the plant consistently met water quality and effluent parameters as specified in its National Pollutant Discharge Elimination System (NPDES) permit throughout. However, new mandates in 2010 and the need for ongoing improvements drove the need for plant upgrades.

## Proper Blower System Design for Variable Wastewater Depth Processes

Most blower applications for wastewater treatment are for conventional activated sludge aeration. The water level is typically constant, and pressure variations are usually less than one psi. There are other applications, however, that undergo significant variations in water level. These processes present challenges, but they can be accommodated with proper blower system design.

## Blower Requirements with DO Control

The capacity and pressure requirements of blowers in a Water Resource Recovery Facility (WRRF) are determined by the aeration system. When systems are manually controlled blowers often operate at constant flow and pressure day in, day out. When the aeration system is automatically controlled to maintain a set dissolved oxygen (DO), however, the blower’s flow and system pressure vary constantly. Understanding these variations will help designers and suppliers optimize blower performance.

## Busch Provides Reliable Oxygen Supply to Aeration Tanks

The Wastewater Association of Rheinfelden-Schwörstadt operates the wastewater treatment facilities in Schwoerstadt and Rheinfelden-Herten, Germany, as well as several rainwater overflow basins. This wastewater treatment facility now satisfies the highest requirements, and with a population of about 47,000, has reached a size that also guarantees sufficient disposal capacity for future generations.

## Aeration Blower Turndown

Blower efficiency is a justifiable concern during the design and selection of aeration equipment. However, efficiency may not be the most important consideration in aeration blower applications. In many cases the blower with the highest efficiency will not provide the lowest energy consumption! Blower turndown is a parameter that is generally more important than efficiency in optimizing energy use.

## Black & Veatch Specifications from Diffusers to Blowers - Part 1: The Demand Side - Diffusers and DO Control

Blower & Vacuum Best Practices Magazine interviewed Julia Gass, P.E and Patrick Dunlap, P.E. at the Black & Veatch offices in Kansas City during the summer of 2016. Ms. Gass is responsible for aeration blower specifications while Mr. Dunlap is a wastewater process engineer. We held a general discussion covering technologies impacting aeration blowers in wastewater treatment plants.