The Harlequin CAP18 is a compact sewage treatment plant designed specifically for domestic installations for up to 18 inhabitants. It is a Continuous Aeration Plant that operates using a unique bio-media system and delivers a pollutant removal level of 96.2% whilst also combating common problems associated with small packaged domestic plants.
Benefits:
Bio Media System - Similar to the MBBR system, there is no fixed media eliminating blockages that are commonly found in smaller treatment plants.
Durable & Stable Product - Made from tough durable polyethylene, it is easy to transport and has a wide base for stability.
Saves Money - With an easy installation due to the systems compact size and light weight, it also promotes low maintenance reducing costs.
Easy Maintenance - At full occupancy the system only need to be emptied every 12 months, with maintenance of the compressor easily carried out located in the neck of the tank.
Compact System - A perfect compact solution for homes of up to 6 inhabitants (4 bedrooms).
Low Noise - With a near silent air compressor housed beneath the flat lid, the operation of the system is virtually silent.
How it Works:
Chamber 1 | Primary Settlement:
Raw sewage flowing to the CAP unit is received in the primary settlement zone. Here, gross solids (primary sludge) settle to the bottom of the tank, where they remain until the tank is desludged. The settled sewage displaced from the primary zone then flows into the submerged filter zone, passing under a scum baffle.
Chamber 2 | Reactor Vessel
Flow circulation in the submerged filter zone is generated by the hydraulic effect of the outlet air diffuser. This causes settled sewage entering the filter zone at high level to be drawn down through the media, aerating the sewage in the process. The flow circulation ensures that the influent sewage receives several passes through the filter bed at low flow.
In the filter zone, as the sewage passes over the filter media it is purified by micro-organisms growing on the surface of the media. Growth of these micro-organisms results in an excess which is shed as solid particles known as humus solids. Humus solids settling at the bottom of the filter zones are recirculated with the flow of incoming sewage and are deposited on the top of the primary settlement zone.
Chamber 3 | Final Settlement
Sewage displaced from the submerged filter zone flows via a DIP pipe into the final settlement zone. Liquid displaced from the humus zone has now been fully treated and is known as final effluent. It is suitable for discharge to a watercourse or soakaway as defined in the consent to discharge issued by the Environment Agency.
Humus solids from the final settlement tank are recirculated to the primary tank via the recirculation pipework. This helps reduce the sludge build up in the humus tank and prevents stagnation during very low inflow.
