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Editorial Calendar January ..........Wastewater Treatment February..........Water Supply; Alternative Sources March..............Energy Efficiency; Environmental Stewardship April ................Conservation and Reuse; Florida Water Resources Conference May ..................Operations and Utilities Management June ................Biosolids Management and Bioenergy Production July ................Stormwater Management; Emerging Technologies; FWRC Review August ............Disinfection; Water Quality September ......Emerging Issues; Water Resources Management October ..........New Facilities, Expansions, and Upgrades November........Water Treatment December........Distribution and Collection Technical articles are usually scheduled several months in advance and are due 60 days before the issue month (for example, January 1 for the March issue). The closing date for display ad and directory card reservations, notices, announcements, upcoming events, and everything else including classified ads, is 30 days before the issue month (for example, September 1 for the October issue). For further information on submittal requirements, guidelines for writers, advertising rates and conditions, and ad dimensions, as well as the most recent notices, announcements, and classified advertisements, go to www.fwrj.com or call 352-241-6006.
Acipio ........................................................................38 Blue Planet ................................................................67 Cascade Consulting ....................................................5 CEU Challenge............................................................21 CROM..........................................................................57 Data Flow ..................................................................35 FSAWWA Customer Service Seminar ..................41,53 FSAWWA Registration................................................24 FSAWWA Exhibit ........................................................25 FSAWWA Poker ..........................................................26 FSAWWA Golf ............................................................27 FSAWWA Competitions..............................................28 FSAWWA Water Award ..............................................29 FWPCOA State Short School......................................11 FWPCOA Training ......................................................55 FWRC Call for Papers ................................................59 Hudson Pump ............................................................15 Lakeside ......................................................................9 Stacon ..........................................................................2 Treeo ..........................................................................45 Water Science ............................................................20 Xylem ........................................................................68
Test Yourself Answer Key From page 31 1. C) preliminary treatment. Per Operation of Wastewater Treatment Plants (Volume 1, Chapter 4.1): “. . . an important part of a wastewater treatment plant is the equipment used to remove rocks, large debris, grit, and other materials as early as possible. These items of equipment . . . are called ‘pretreatment or preliminary treatment’ facilities.”
2. C) screening. Per Operation of Wastewater Treatment Plants (Volume 1, Chapter 4.1): “Screening is that part of the pretreatment or preliminary treatment facilities that removes the larger debris (rocks, cans, bottles, rags).
3. A) 3/8 to 2 in. Per Operation of Wastewater Treatment Plants (Volume 1, Chapter 4.2): “Parallel bars may be placed at an angle or set vertically in a channel in such a manner that the wastewater will flow through the bars, but large solids and debris will be caught on the bars. These bars are commonly called ‘racks’ when the spacing between them is 3 to 4 in. (7.6 to 10.2 cm) or more. When the spacing is about 3/8 to 2 in. (0.96 to 5.1 cm), they are called ‘bar screens.’”
4. A) detritus. Per Operation of Wastewater Treatment Plants (Volume 1, Chapter 4 Words): “Grit is the heavy material present in wastewater, such as sand, coffee grounds, eggshells, gravel, and cinders. It is also called detritus.
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5. D) comminutor. Per Operation of Wastewater Treatment Plants (Volume 1, Chapter 4.3): “Comminutors are devices that act both as a cutter and a screen. Their purpose is to shred (comminute) the solids and leave them in the wastewater.”
6. A) 1 ft per second Per Operation of Wastewater Treatment Plants (Volume 1, Chapter 4.40): “The simplest means of removing grit from the wastewater flow is to pass it through channels or tanks that allow the velocity of flow to be reduced to a range of 0.7 to 1.4 ft/second (0.2 to 0.4 m/second). The objective is to allow the grit to settle to the bottom, while keeping the lighter organic solids moving along to the next treatment unit. Experience has shown that a flow-through velocity of 1 ft per second is best.”
8. B) primary vortex. Per Operation of Wastewater Treatment Plants (Volume 1, Chapter 4.41): “The velocity of the slurry as it enters along the wall of the cyclone causes the slurry to spin or swirl around the inside of the cyclone. This is called the ‘primary vortex,’ which causes the heavy particles to move toward the wall of the cyclone and out the bottom.”
9. B) grit washer. Per Operation of Wastewater Treatment Plants (Volume 1, Chapter 4.42): “Organic matter may be separated from the grit by washing the detritus to resuspend the organic matter . . . Figure 4.21 shows a typical grit washer . . . grit settles to the bottom and is removed by a screw conveyor (or other device), while the velocity created by the impeller suspends the lighter organic materials so they flow over the outlet weir.”
7. B) lower specific gravity than water. Per Operation of Wastewater Treatment Plants (Volume 1, Chapter 4.40): “An aerated grit chamber is actually a tank with a sloping bottom and a hopper or trough in the lower end. Air is injected through diffusers located along the wall of the tank above the trough. The mixture of air and water has a lower specific gravity than water, so the grit settles out better. The rolling action of the water in the tank moves the grit along the bottom to the grit hopper.”
August 2017 • Florida Water Resources Journal
10. B) pre-aeration. Per Operation of Wastewater Treatment Plants (Volume 1, Chapter 4.45): “Pre-aeration is a wastewater treatment process used to improve grit removal efficiency, to freshen wastewater, to remove gases, to add oxygen, to promote flotation of grease, and to aid coagulation. The freshening of wastewater improves the effectiveness of downstream treatment processes. The pre-aeration process is usually located before primary sedimentation.”