Wast Water Treatment Process System

An aerated biological filtration system for treating waste water, the system comprising:

• a treatment vessel through which waste water to be treated will pass, said treatment vessel having an inlet and an outlet;
• a circulating filter bed located in said treatment vessel between the inlet and the outlet, said circulating filter bed being arranged to trap solids from the waste water within said bed and comprising of a particulate filter material, individual particles having a surface or pore structure selected or adapted to facilitate the attachment of micro-organisms on said particles;
• and
• aeration means adapted to diffuse air through said filter bed either continuously or intermittently whilst waste water is being treated in said filter bed;
• wherein the structure and the operating characteristics of the treatment vessel, the circulating filter bed and the aeration means are selected such that the particles are able to move relative to each other within the circulating filter bed;
• and
• operation of the filtration system will cause a substantial portion of the particulate material to circulate within the circulating filter bed over time to promote distribution of the trapped solids within said bed.

An aerated biological filtration system for treating waste water, the system comprising:

• a treatment vessel through which waste water to be treated will pass, said treatment vessel having an inlet and an outlet;
• a filter bed located in said treatment vessel between the inlet and the outlet, the filter bed being arranged to trap solids from within said bed comprising a particulate filter material, the particles of the particulate filter material having a specific gravity in the range of 1.2 to 1.4 and an effective size of 0.6 mm to 1.5 mm;
• and
• aeration means adapted to diffuse air through the filter bed either continuously or intermittently whilst waste water is being treated in said filter bed.

An aerated biological filtration system for treating waste water, the system comprising:

• a treatment vessel through which waste water to be treated will pass, said treatment vessel having an inlet and an outlet;
• a circulating filter bed located in said treatment vessel between the inlet and the outlet;
• a static filter bed located in said treatment vessel downstream of said circulating filter bed, the static filter bed comprising a particulate material having a specific gravity of greater than 1;
• both the circulating filter bed and the static bed being arranged to trap solids from the waste water in said beds and
• aeration means adapted to diffuse air through the circulating filter bed either continuously or intermittently whilst waste water is being treated in said circulating filter bed.

A method for treating waste water, the method comprising the steps of:

• providing an aerated biological filtration system, said aerated biological filter comprising a treatment vessel having an inlet and an outlet, a filter bed located in said treatment vessel arranged to trap solids from said waste water in said bed, said filter bed comprising a particulate filter material, individual particles having a surface or pore structure selected or adapted to facilitate attachment of micro-organisms on said particles, and aeration means;
• passing waste water through said treatment vessel via said inlet and said outlet;
• diffusing air from said aeration means through said filter bed;
• and
• circulating the filter bed such that the particulate material particles move relative to each other in the filter bed, and such that a substantial portion of the particulate material circulates within the filter bed over time so as to promote distribution of said trapped solids in said filter bed.