Full Answer
What is a trickling filter effluent?
The biological growth is attached to the media. Trickling filter effluent always passes through a secondary clarifier or sand filter to allow for capture of solids generated as a result of treating the wastewater.
What calculations are used in trickling filter operation?
Calculations Several calculations are useful in the operation of trickling filters: these include hydraulic loading, organic loading, and biochemical oxygen demand (BOD) and suspended solids (SS) removal. Each type of trickling filter is designed to operate with specific loading levels.
Why should trickling filter recirculation be done during low-inflow periods?
Remove the packing grease from the filter bearings and replace with the proper grease 1, 3, 4, 5 *Why should trickling filter recirculation be done during low-inflow periods of the day and night? 1. To avoid clarifier problems from hydraulic overloading 2. To encourage the development of snail populations on the media 3.
Which items are guidelines for maintaining trickling filters to prevent odor problems?
*Which items are guidelines for maintaining trickling filters to prevent odor problems? 1. Check the ventilation in the trickling filter 2. Do everything possible to maintain aerobic conditions in the sewer collection system and in the primary treatment units 3.
What is the process by which the Earth's water cleanses itself through solar evaporation, precipitation,
evapotranspiration. The process by which the earth's water cleanses itself through solar evaporation, precipitation, and infiltration is called. hydrologic cycle.
What causes saltwater intrusion?
Saltwater intrusion occurs when. groundwater pumped from wells along the coastline causes saline groundwater to move inland. Worldwide, there is a relationship between the price of water and the amount consumed as the price. increases and water use decreases. Worldwide, the top use of water is for. agriculture.
What is the upper surface of shallow groundwater called?
groundwater. The upper surface of shallow groundwater is called a (n) water table. The porous layer where water accumulates in the ground is called a (n) aquifer. The major consumptive use of water in most parts of the world is for. agricultural use.
What is a trickling filter?
Trickling filters (TFs) are used to remove organicmatter from wastewater. The TF is an aerobictreatment system that utilizes microorganismsattached to a medium to remove organic matterfrom wastewater. This type of system is commonto a number of technologies such as rotatingbiological contactors and packed bed reactors (bio-towers). These systems are known asattached-growth processes. In contrast, systems inwhich microorganisms are sustained in a liquid areknown as suspended-growth processes.
What is TF in wastewater?
TF consists of permeable medium made of a bedof rock, slag, or plastic over which wastewater isdistributed to trickle through, as shown in Figure 1.Rock or slag beds can be up to 60.96 meters (200feet) in diameter and 0.9-2.4 meters (3 to 8 feet)deep with rock size varying from 2.5-10.2 cm (1 to4 inches). Most rock media provide approximately149 m2/m3 (15 sq ft/cu ft) of surface area and lessthan 40 percent void space. Packed plastic filters(bio-towers), on the other hand, are smaller indiameter (6 to 12 meters (20 to 40 feet)) and rangein depth from 4.3 to 12.2 meters (14 to 40 feet).These filters look more like towers, with the mediain various configurations (e.g., vertical flow, crossflow, or various random packings). Research hasshown that cross-flow media may offer better flowdistribution than other media, especially at loworganic loads. When comparing vertical mediawith the 60 degree cross-flow media, the verticalmedia provide a nearly equal distribution ofwastewater minimizing potential plugging at higherorganic loads better than cross flow media. Theplastic medium also required additional provisions,including ultraviolet protective additives on the toplayer of the plastic medium filter, and increasedplastic wall thickness for medium packs that areinstalled in the lower section of the filter whereloads increase.
What is a low rate filter?
Low-rate filters are commonly used for loadings ofless than 40 kilograms five day biochemical oxygendemand (BOD5)/100 meters cubed per day (25 lbBOD5/1000cu ft/day). These systems have fewerproblems than other filters with regards to filterflies, odors, and medium plugging because of thelower loading rate. Low-rate filters with a rockmedium range in depth from 0.9 to 2.4 meters (3-8 ft.). Most low-rate filters are circular with rotarydistributors, but some filters currently in use arerectangular. Both of these configurations areequipped with dosing syphons or periodic pumps toprovide a high wetting rate for short intervalsbetween rest periods. A minimum wetting rate of
What is the most common system to distribute wastewater?
Distribution systems evenly spread wastewater over the entire media surface. Rotary distributor s, which move above the media surface and spray the surface with wastewater, are the most common systems. Rotary systems are driven by the force of the water leaving the distributor arm orifices.
What happens to the slime layer of a filter?
As the biological film continues to grow, the microorganisms next to the surface lose their ability to cling to the media, and a portion of the slime layer falls off the filter.
What is a zoogleal slime?
These wastes either become part of the slime or return to the wastewater flowing over the media. Zoogleal slime comprises mostly bacteria, but may also contain algae, protozoa, worms, snails, fungi, and insect larvae. As the slime accumulates, it builds up and occasionally sloughs off the media materials.
What is a fixed nozzle system?
In fixed nozzle systems (frequently used with deep bed synthetic media filters), the nozzles remain in place above the media and are designed to spray effluent over a fixed portion of the media.
What is a secondary clarifier?
Secondary clarifier (or final clarifier as it is sometimes called) construction is similar in most respects to the primary clarifier, although differences occur in operation that can include detention time, surface settling rate, hydraulic loading, sludge pumping, overflow rate, weir loading, and other details.
What factors affect nitrification?
The extent of nitrification in trickling filters depend on a variety of factors; including temperature, dissolved oxygen, pH, presence of inhibitors, filter depth and media type, loading rate, and wastewater BOD. Low-rate trickling filters allowed the development of a high-nitrifying population.