Rotating Biological Contractor Systems
These systems have rotating plastic discs on a horizontal shaft that are submerged about half way within the effluent. This allows the aerobic bacteria on the discs to be exposed to air and wastewater to help improve the effluent.
Suspended Growth Method
In this system, the effluent is circulated rapidly and agitated within an anaerobic chamber to encourage the digestion of the biodegradable substances. Changes in flow or the solids affect the system. This may result in the incomplete settling of the solids.
Activated Sludge Technology
This is a variation of these suspended growth systems which combines aerobic and anaerobic processing in a single unit. They operate in alternate sequences.
Membrane Bioreactor Method
This method improves the performance of the suspended growth method by using membranes as super clarifiers filtering the microscopic solids and even some bacteria.
The membranes can be damaged by air or stringy or abrasive materials which have a fine diameter. The membrane filtration works faster in clarifying the effluent than the settling process. This should leave salt and relatively less sludge for disposal. The membranes must be cleaned regularly to prevent problems that could cause loss of permeability.
Best Practices in the Use of Other Advanced Treatment Systems
- • Determine flow to the watertight septic tank, risers, and pipe connections, condition of baffles and outlets screens from the tank, wastewater level, and sludge and scum levels in the septic tanks to make sure they will not affect the rest of the process.
- • Check the control panel and controls to ensure that all pumps, floats, valves, electrical controls, and alarms are working properly as well as the dosing volume being accurately calculated and set. (See endnote 20.)
- • Inspect the surface of the filters for ponding of the effluent. Ponding is the accumulation of water on top of a trickling filter because the organisms which form a slime to utilize the incoming wastewater have sloughed off and have filled the gaps between the rocks in the filter, not allowing the wastewater to penetrate and be treated biologically.
- • Determine if there are unusual odors or insect infestations.
- • Take samples of the filter effluent to determine the level of clarity and odor as well as the amount of dissolved oxygen and BOD.
- • Protect the systems against freezing.
- • Provide electrical backup where needed in the event of electrical failure.
- • Establish frequent maintenance checks by trained individuals to avoid future breakdowns.
- • Have local or state health department or EPA personnel frequently monitor the systems to determine if they are working appropriately.