LV11309B - Method and device for biochemical treatment of sewage - Google Patents

Abstract

This invention pertains to high-productivity equipment for anaerobic wastewater biological cleaning of organic contamination. It consists of (fig.1) a vertical cylindrical reservoir covered with a lid, in which there are several functional compartments: for sorption, degasification, sedimentation and filtration which are divided with cylindrical partitions. High cleaning efficiency is achieved by using movable bearers in the sorption compartment to immobilize biomass, thin-layer modules in the sedimentation compartment and immovable bearing material in the filtration compartment to immobilize biomass. The gas evolved in the reaction tank is brought with a compression pump to the lower part of the reservoir to ensure proper conditions at the surface layer in the sorption compartment, thus improving mass exchange.<IMAGE>

Description

Method and equipment for biochemical treatment of waste water

The plant and the process refer to wastewater treatment of various concentrations. The object of the invention is to intensify the treatment of wastewater, to reduce the area of the plant, to reduce the construction and operating costs.

In a known situation in technological solutions for biological treatment of wastewater

Various bioreactors, often containing tanks separated by vertical partitions, are widely used in biological treatment of wastewater. The use of multiple tanks is usually determined by internal recirculation, as well as the different concentrations required by the need for dissolved oxygen and biomass. In addition, maintain a greater diversity of activated sludge. Bioreactors often seek to maintain pseudorandom fluid bed conditions, whereby the movement of suspended particles in solution is achieved by gas bubbling to achieve intense mass exchange. In such cases, cylindrical reactors of several times their diameter are commonly used.

A prototype design was selected in U.S. Pat. No. 5,190,646, dated 02.03.03, in which a partition serves to maintain recirculation. In this case, a special composition ceramic biomass carrier is used, which, after intensive washing, ensures effective waste water treatment. The moving medium cannot be used at all in this case as it would be compacted by high recirculation volumes / 1 /. The disadvantage of such a system can be called the necessary large recirculation, which makes the process more expensive.

In the device described in the present invention, it is considered useful to use both types of biomass carriers: the moving one described is only reinforced and the stationary one. The mobile carrier allows for more efficient use of less intensive gas bubble mixing, while the fixed carrier usefully fills in a second recirculation zone through which the waste water returns.

Design and method description

The apparatus consists of a cylindrical reservoir fitted with pipes for the inlet and outlet of waste water, for the removal of sludge, for the removal of gas and for gas bubbling. Separation, degassing, settling and filtration zones separated by a cylindrical partition. The separation of suspended matter in the settling zone occurs in thin-film plastic modules. In order to ensure a high concentration of biomass in the sorption zone, the biomass is immobilized on floating granules of higher density than water. In addition, granules of various densities are used here to disperse them throughout the sorption area in an upstream stream. There is a rigid carrier in the filtration zone - modules made of corrugated plastic sheets to achieve biomass immobilization here. Biogas from the top of the reactor is fed into the bottom of the reactor by a compressor to provide internal waste water recirculation. During this initial phase, air is used in this closed loop of gas circulation.

The unit is additionally equipped with a degassing unit constructed in the form of a cylindrical partition with a conical extension at the bottom to concentrate the upward gas bubbles and the flow of liquid, thereby allowing them to burst more rapidly. Si node at the top of the cylindrical partition, releasing gas bubbles, and flowing downward again, creating internal circulation. Because of the narrowing of the cylindrical bulkhead at the top, the effluent stream gains more velocity, so when flowing downward, they are attracted by the addition of the previously carried upward suspended solids. Thus, the formation of a crust above the liquid level, which is often characteristic of anaerobic reactors, is neglected.

The plant is designed to treat wastewater with a high concentration of organic pollutants, which prevents it from being treated in a purely aerobic biological process. In order to reduce the operating costs of the plant, it is not intended to be heated or to store biogas.

Description of the drawing

FIG. 1 is a schematic representation of a bioreactor according to any one of claims 1 to 4.

The wastewater flows upwardly into the sorption area delimited by the cylindrical partition 8 through a slurry of suspended carrier pellets 11. The lower part of the cylindrical partition 8 is conical filtration zone 10. As the effluent rises above the sorption zone 11, a conical partition 6 mounted above it directs the effluent stream to the degassing tank, preventing the effluent flowing downstream of the reactor outer wall 9 from being mixed. In the degassing tank, the effluent rushes over the top of the tapering partition 6, releasing most of the bubbling gas to subsequently flow down between the partitions 3 and 14. The effluent then flows down through the biomass carrier modules 10 in the filtration zone, slides over the top wall of the gutter 2 and leaves the unit through the pipeline 16. The suspended solids separated in the thin-layer laminar separator 4 fall down and are carried away by the effluent stream downstream of the filtration zone 10.

Source of information [1] US Patent Publication No. 5,190,646

Claims (4)

Inventive formula for anaerobic cylindrical heated, partition degassing, 1. A plant for biological treatment of waste water, which is contained in a vertical heat insulating tank, which is not characterized in that it has four functional tanks: sorption, settling and filtration. 2. The apparatus according to claim 1, characterized in that its degassing unit is separated by a cylindrical partition with a conical extension at the bottom to concentrate the ascending gas bubbles and fluid flow, thereby giving them a higher velocity. 3. The process for biological anaerobic treatment of wastewater using the device according to claim 2, characterized in that plastic granules of different densities are used in the sorption vessel for immobilization, and corrugated plastic plate modules are used in the filtration vessel. 4. The process for biological anaerobic treatment of wastewater according to claim 3, characterized in that the biogas released in the reaction vessel is collected at the top of the reactor and fed back to the bottom of the reactor by means of a compressor, providing a fluid bed mode and mass exchange process.