Reusing wastewater with papermaking quality in mind
A paper mill studies the feasibility of effluent treatment with a membrane bioreactor/reverse-osmosis pilot system
Vetrivel Dhagumudi and Dongxu Yan
A paper mill in the Southwestern United States was considering expanding its production, which would double its freshwater requirements, as well as wastewater production. The mill had been treating its wastewater with a cloth disc filter to reduce the total suspended solids loading to the lift station of the local municipal water resource recovery facility. While considering several treatment options, the mill hired a consultant to look into reusing the wastewater to minimize discharge fees and the need for additional fresh water. The quality of the treated wastewater, however, had to meet the special requirements of paper manufacturing. Read full article (login required)
Bob Kimball and Mitch Baumann
A high-recovery treatment process for water from coal-bed methane production uses fewer chemicals, costs less to operate
Natural gas production from unconventional resources is one of the fastest-growing energy sources in the United States. Coal-bed methane, or natural gas produced from coal beds, accounts for about 7.5% of the total natural gas production in the United States, according to the U.S. Geological Survey. Coal-bed methane’s contribution to natural gas production is expected to grow as the need to decrease carbon dioxide emissions favors the increased use of natural gas as an alternative to coal, according to the agency.
While this energy source holds great potential, its production is limited by the potentially large amount of brackish water displaced when the gas is recovered. Coal beds contain many fractures and pores that can contain and transmit large volumes of water that must be treated and managed. Conventional treatment technologies are expensive, require large amounts of chemicals, and cannot remove trace-level contaminants. Read full article (login required)
Operations Forum Features
The right fit for granular medium filtration
Onder Caliskaner and George Tchobanoglous
Proper selection of granular medium filter properties is of crucial importance in meeting turbidity and disinfection requirements efficiently and cost-effectively. Optimized design of granular medium filtration systems results in significant capital and operational savings, while achieving the desired effluent quality. Filtration design criteria (e.g., granular medium depth, effective size, single or dual media, and filtration rate) are optimized utilizing a granular medium depth filtration model and results obtained from pilot studies or similar plants. Read full article (login required)
Optimizing granular medium filters to decrease capital, operational, and maintenance needs.
If you don’t sell your tunneling project to the public during planning, there’s no need to dig deeper
Jason Swartz, James McKelvey, Faruk Oksuz, Donald Benjamin, and Mark Cline
The surface expression of a tunneling project generally is limited to the shaft or portal locations. Thus, the driving factor for alignment selection, particularly in urban construction, typically comes down to available shaft locations. Construction activities may be concentrated at these locations for several years. Stakeholders adjacent to shafts consequently may experience increased traffic, potential traffic detours, light pollution from night work, noise, and vibrations. An early jump on determining an appropriate shaft location will enable tough discussions with adjacent stakeholders to begin. Read full article (login required)
A community-based approach to managing operations and related data
Corey Williams, Robert Irvin, and Tim Kruse
When it comes to data management systems, most wastewater facilities in the United States cannot legally operate without one, yet the wastewater industry has no standard system, much less an assigned proper acronym, to manage data. It isn’t a SCADA (supervisory control and data acquisition) system, it isn’t a LIMS (laboratory information management system), and it isn’t Microsoft Excel … so what is it?
There is no simple answer. But many utilities, including the City of Los Angeles Bureau of Sanitation, name it by its primary function: an “operations data management system” (ODMS). The bureau’s impetus for a new ODMS included efficiency improvements, greater accuracy in reported data, and increased functionality to support expanding needs. But the emphasis was not on direct return on investment. The existing ODMS was at the end of its software life cycle and could no longer support the demand for managed information. This need pushed the bureau to adopt a community-based approach to data organization, management, and use that can be helpful for other utilities looking at their data management systems. Read full article (login required)
Proactive sewer planning in Columbia
A plan to prioritize cleaning and inspection of the sewer system in the South American country’s second-largest city
Luis Roberto León, Carlos Eduardo Quijano Altamirano, Marta Lucía Londoño Toro, and Angélica María Orozco
Empresas Públicas de Medellín (EPM) is a decentralized public utility that serves the residents of the City of Medellín and other municipalities of the Aburrá Valley in Colombia. The Medellín sewer system has been in operation more than 50 years. Over time, the system, which is a combined system with mostly concrete (95%) pipes, has experienced problems due to lack of capacity in some areas and degradation of pipes due to corrosion, obstructions, deposits of materials, and tree roots. Recognizing that knowledge and understanding of the internal condition of its extensive sewer network are important for the sustainable and efficient operation and maintenance of its system, EPM developed a plan, with the help of CDM Smith (Cambridge, Mass.), to clean and inspect via closed-circuit television (CCTV) all 4390 km (2728 mi) of its sewer network in the Aburrá Valley. Read full article (login required)