Patent EP-2766313-A2 (EP)
Inventor: SCHUSTER PÉTER
IPC: C02F11/121
Filed: 2012-09-07
Abstract: The subject of the invention is a small installation for biological wastewater treatment with improved efficiency, which ensures an uninterrupted working for 3-50 people with a low sludge load, which also allows the easy and simple separation and removal of the dry material content of the stable sludge after passing the stable sludge through a sludge bag located in the appropriate part of the small installation, or it allows the removal of the stable sludge easily from a given space of the small installation. The small installation according to the invention comprising of an anaerobic space, an anoxic space, and aerobic space which is provided with micro-bubble air blower, a post settling space, a sludge thickener space, where passages, outlets, airlift pumps, lower and upper overflow weirs are located among these spaces. It is characterised by that, the wastewater to be purified arrives at the anaerobic space (2) of the small installation (1) in a gravitational way with upper inflow, and while the wastewater passes through the filter cage (12) located in the upper part of the anaerobic space (2) the granular parts of the wastewater are disintegrated with the help of the air provided by the airlift pump (15), which solid parts settle to the bottom of the anaerobic space (2), the wastewater flows from the anoxic space (3) to the bottom of the aerobic space (4) through symmetrically located passage pipes (20) having upper inlet and lower outlet, where the wastewater moves upward in the section of the space which is saturated with the micro-bubbles produced by the micro-bubble air blower (13), and flows through the two inlet openings (31) located symmetrically in the inclined walls (9) and through the passage pipe (21) having upper inlet and lower outlet,- and having a triangular cross section as fitted to the two inclined walls (9) of the post settling space (5), to the bottom of the post settling space (5), and in this post settling space (5) the sludge with higher density settles, and the water fraction is situated above the sludge fraction, and the sludge is sucked out from the post settling space (5), so that the T fitting (30) having a throttle (32) on the outlet pipe (14) that reaches into the post settling space (5), reduces the flow rate of the outlet water, (to about-3- litre/min), as. a result of which the- height of the water column in the post settling space (5) increases, and because of the increased pressure of the water column, the airlift pump (16) delivers the water to the anaerobic space (2) only in case of low quantity of water after branching in two directions on the surface, while in case of a larger quantity of water, sludgy water flows into the sludge thickener space (6) after flowing over the sludge suction elbow (29) which has an adjustable level and provides a higher overflow, and from the sludge thickener space (6) it is carried to the sludge precipitation space (70) with the help of the airlift pump (17) working with maximum capacity (by changing over the air baffle) for about 15 minutes a day, provided that sufficient quantity of liquid sludge has accumulated, where the liquid part of the sludge is filtered through the permeable sludge bag (71) and flows into the anaerobic space (2) through the drip tray (73) and the connected drip separator (27), and the dry content of the sludge is collected in sludge bag (71), where it starts to desiccate.