Cooking up reuse
Industrial food processor recaptures energy, water, and nutrients
Michael E. Mecredy, Charles P. Gregory, Asher Benedict, and Jason W. Mullen
In 2014, a food manufacturing facility in the southeast U.S. began the process of replacing its existing wastewater treatment system. After nearly a decade of operation and production increases, the previous system was not capable of keeping up with the demands of current production. Thus, the facility began the process of planning to replace the existing wastewater treatment system with a new system to provide more capacity, reliability, and operational flexibility.
The facility also used this upgrade as an opportunity to implement a highly sustainable approach targeting beneficial reuse of multiple site generated waste streams and residuals. The design includes such features as harnessing biogas generated from anaerobic treatment, use of effluent water for routine site activities such as solids press wash water, water reuse and reduction via use of treated effluent for cooling tower makeup, and land irrigation with the balance of the treated effluent. The technologies and methods present at this facility are a case study and example for other industrial facilities seeking to maximize reuse and minimize environmental footprint.
Charging up 'behind the meter'
Wind, biogas, and solar projects boost water resource recovery facility energy efficiency and fossil fuel independence
James McCaughey, Thomas Uva, Barry Wenskowicz, and Kerri Houghton
In Rhode Island, 19 individual water resource recovery facilities (WRRFs) capable of receiving and treating up to 757 ML/d (200 mgd) wastewater collect and manage municipal wastewater. On average, these WRRFs combined consume more than 78,000,000 kWh of electricity annually at a cost of more than $9 million per year.
The Narragansett Bay Commission (NBC; Providence, R.I.) collects and treats both wastewater and stormwater from 10 Rhode Island cities and towns, servicing 40% of the state’s population. To help improve energy use performance and to help establish a sustainable energy management plan, NBC has successfully developed two 4.5-MW wind farms, a 644-kW biogas combined heat and power system, and 10 MW of solar energy for its renewable energy portfolio.
Seven keys to membrane bioreactor success
Designers and operators have discovered these keys based on 15 years of progressive MBR experience in the Pacific Northwest
The first generation of membrane bioreactors (MBRs) in the Pacific Northwest began around 2003. This new technology represents a considerable advancement over conventional wastewater treatment, particularly the ability to produce high-quality reclaimed water product within a small physical footprint. As with any new technology, the past 15 years has led to many lessons that can be applied to design and operation. Manufacturers are also continuing to refine membrane technology and develop new products.
During the past 15 years, seven topics have emerged as critical concerns to consider when working with MBRs. The guidance is intended toward modifying existing membrane bioreactors to improve performance and operability, as well as to provide guidance for design and operation of new membrane facilities. These topics are based on case studies, evaluations, and modifications at four MBR facilities.
Growing into a distributed model
Corralling 104 square miles and 85,000 individual lots into a manageable utility
Jennifer Desrosiers, Rick Newkirt, and Harold E. Schmidt Jr.
The City of North Port, Fla., consistently has been ranked as one of the top 20 fastest-growing cities in the U.S. and has a current population of approximately 66,300 people. Its buildout population has been estimated at 268,000 people — that’s more than four times the current population. Therefore, managing this utility’s growth continues to be a daily challenge.
These challenges include valuing the benefits and costs of a regional and decentralized approach to managing their utility system and growth. However, the city is rising to the challenge and is well-positioned for the future.
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