WE&T Magazine

WET_cover1_Nov13_90Water Environment & Technology (WE&T) is the premier magazine for the water quality field. WE&T provides information on what professionals demand: cutting-edge technologies, innovative solutions, operations and maintenance, regulatory and legislative impacts, and professional development.

 


November 2013, Vol. 25, No.11

Featured Articles

Spreading the wealth

Feature 3 Hake art Resource recovery programs at water resource recovery facilities (WRRFs) are greatly increasing biogas production and electricity generation for those facilities accepting high-strength organic wastes — such as fats, oils, grease, or food waste — in their digesters. In some cases, the increased generation may exceed the demand required to serve onsite load, resulting in surplus power that may be sold to buyers for a “green premium.” 

 

During the deluge

Feature 1 guis art When it rains, it pours into many places, including wastewater systems. Older systems in the East and Midwest may include combined sewer areas where stormwater runoff is captured intentionally. However, areas with separate sanitary sewers also feel the effects of heavy rain. 
One of the most important types of information for operators is the level of wastewater at various points in the collection and conveyance piping and structures. Several types of devices provide real-time level measurements in collection and conveyance systems, but the pulsed ultrasonic level meter probably is the most common. These are time-tested and reliable devices, but their behavior when the system is stressed heavily and the meters are underwater should be understood.

 

News

The incredible growing ‘fatberg’

news You might think that the headline-grabbing discovery of a foul-smelling, 13.6-Mg (15-ton) “fatberg” in a London sewer tunnel this past July might persuade locals to rethink where and how they dispose of their used cooking grease and nonflushable wet wipes. 
But just 6 weeks after an eight-member crew worked day and night to dislodge the bus-sized blob, tons of fresh fat were found oozing from the same sewer, according to a release from Thames Water (Reading, U.K.), the city’s water and wastewater utility.
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Coming in the next issue:
WET_cover1_December13_90

Rethinking residuals

Sometimes the key to moving forward is stepping back to look at a situation as a whole. A bit of perspective can help to reveal pathways to great efficiency and sustainability. This is especially true in the case of biosolids, where adherence to strict regulations can stifle a broader viewpoint. 

For example, something as simple as choosing the proper settling vessel for sludge volume index testing can affect the process by giving varying accuracies of solids settling performance. In “Better data for clarifiers,” the authors develop solids flux curves for a particular facility using 1-L graduated cylinders, 1-L beakers, 2-L settleometers, 2-L square beakers, and 4-L graduated cylinders. They then compare those curves with curves developed using empirical models to determine which models were better in predicting clarifier performance. Small changes lead to better data. 

Stepping back even further, Bowling Green, Ky., planned a complete overhaul of its biosolids handling practices in coordination with a treatment facility upgrade. Last summer the new sequencing batch reactor water resource recovery facility began operation, as did a new indirect thermal biosolids drying process. The new process generates a Class A that is being sold to local farmers. The switch from the old to the new process is saving the facility more than $22,000 per month. 

In an even more overarching switch, Dayton, Ohio, took action to bring its biosolids processing back under city control. The city conducted a benefit-cost evaluation to determine the 15-year life-cycle costs across a series of biosolids handling alternatives and used its best asset — its employees — to save costs. 

 

Also in this issue    

  • Operations Challenge 2013. Congrats to Terminal Velocity and Team HRSD from the Virginia Water Environment Association for earning top honors overall in Divisions 1 and 2, respectively.   
  • The WEFTEC® report. Highlights of WEFTEC 2013 in Chicago.   
  • Echo Park Lake revival. Stormwater rehabilitation gives Los Angeles lake fans reasons to rejoice.     
  • Stricter seafood. Moving bed bioreactor helps seafood manufacturer meet regulatory requirements.