Commercial & Residential Installs
Ashco's commercial version of a recirculating sand filter, is a very adaptive product with great treatment results. A favorite of developers for the ease of "phase" development due to modular components in industrial or commercial-sized projects.
How the system works:
Wastewater flows by gravity to a septic tank from a waste-producing source. The heavy solids known as sludge settle to the bottom of the tank and largely decompose into liquids and gases; the lighter material known as scum floats to the top of the liquid contents and meets a similar fate.
Relatively clear effluent from the mid-level of the septic tank flows through an effluent filter and, by gravity, into a Recirculation tank. Pumps in the Recirculation tank pump effluent onto a sand filter. Pumps operate intermittently and sequentially 24 hours per day, seven days per week.
Every time the sand filter is dosed by the pumps in the Recirculation tank, the effluent trickles through the media where it is treated by naturally-occurring micro-organisms populating the filter. After passing through the filter media, the treated effluent is collected in a 4-inch diameter pipe at the bottom of the filter through which it is conveyed to a Recirculation valve which automatically returns effluent back to the Recirculation tank and a portion to the Disinfection unit.
Key Benefits
-Provides tertiary and better treatment capability.
-Easy to maintain with less required hours than a package plant.
-Modular Units allow for easy expansion
Wastewater flows by gravity from the home to the septic tank. Inside the septic tank, which is situated as close to the waste producing source as possible, the settable solids fall to the bottom of the tank where they decompose anaerobically to form a sludge layer. The lighter less dense material mainly composed of fats, oils, and greases floats to the top of the water and creates a scum layer. Effluent from the relatively clear zone of the septic tank, between the scum and the sludge layers, enters the effluent filter through inlet holes. Effluent then enters the annular space between the housing and the filter tubes. Particles larger than 1/8” are detained in the annular space, where decomposition of the organic material occurs.
The filtered septic tank effluent then flows by gravity to the recirculation tank bottom zone. The recirculation pump in the bottom zone pumps the effluent via a spray grid onto a sand filter. The effluent trickles down the filtrate media where it is treated by naturally occurring micro-organisms populating the sand filter. After passing through the biological filter media, the treated effluent is stored in the bottom zone where it is mixed with incoming septic tank effluent. The mixing of septic tank effluent with biologically filtered effluent creates a dilute waste to be recirculated through the sand filter. The treated effluent is discharged either by gravity or a small discharge pump to disinfection and/or discharge.
Key Benefits
-Environmentally friendly results.
-Efficient and easy to install.
-Esthetically appealing.
Residential Use. Ashco's single cell recirculating sand filter can be attached directly to existing aerobic treatment units to provide higher levels of treatment
This system should be used with other types of treatment as a means of additional treatment. The treated Home Aeration Unit effluent flows by gravity to the recirculation tank bottom zone. The recirculation pump in the bottom zone pumps the effluent via a spray grid onto a sand filter. The effluent trickles down the filtrate media where it is treated by naturally occurring micro-organisms populating the sand filter. After passing through the biological filter media, the treated effluent is stored in the bottom zone where it is mixed with incoming septic tank effluent. The mixing of septic tank effluent with biologically filtered effluent creates a dilute waste to be recirculated through the sand filter. The treated effluent is discharged either by gravity or a small discharge pump to disinfection and/or discharge.
Key Benefits
-Meets criteria for some levels of additional treatment.
-Can be retrofitted to existing treatment technologies.
-Cost effective means of providing superior treatment.
