Biological treatment technique for coking waste water

Abstract

The invention discloses a technique of biological treatment for coking wastewater. The filter chamber is composed of a preprocessing part, a biological treatment part and a physical treatment part, wherein the biological treatment part is composed of an anaerobic ceramsite filter chamber, an anoxia ceramsite filter chamber and an aerobic ceramsite filter chamber which are connected in series, spherical ceramsite filtering materials or irregular-shape ceramsite filtering materials are all filled in the anaerobic ceramsite filter chamber, the anoxia ceramsite filter chamber and the aerobic ceramsite filter chamber as biofilm culturing filling and filtrating precoats, the anaerobic ceramsite filter chamber employs an internal reflux mode, a reversed flow mode is employed between the anoxia ceramsite filter chamber and the aerobic ceramsite filter chamber, the precoats in the filter chambers are respectively formed by ceramsite filtering materials with different thickness, the filter chambers employs backwash to exclude accumulated sludge and suspended substance in the filter chambers into flotation tanks of the preprocessing part, the anaerobic ceramsite filter chamber, an anoxia ceramsite filter chamber employs regular water scrubbing to drive macro-gas-bubble in the chambers. Compared with the prior art, the technique has the advantages of prolonging sluicing periodic time, stabilizing operational effect, improving treatment loading, thereby reducing retention time of waterpower, decreasing accommodation area and investment of pile plant.

Description

technical field [0001] The invention relates to a biological treatment process of coking wastewater, in particular to a biological treatment process in which different types of biological ceramsite filters are connected in series for the biological treatment of coking wastewater. Background technique [0002] The coking wastewater treatment process generally consists of three parts: pretreatment (such as adjustment, oil removal, flotation, etc.), biological treatment and physical and chemical treatment (such as coagulation, sedimentation, etc.), and the biological treatment is the core of the whole process. So far, the biological treatment part of most coking wastewater treatment processes at home and abroad has adopted two forms: the first is anaerobic-anoxic-aerobic (A 1 -A 2 -O) or anoxic-aerobic (A-O) series biologically activated sludge method, which uses activated sludge to remove pollutants as the main means of purifying wastewater; the second is anaerobic-anoxic-aer...

AI Technical Summary

Problems solved by technology

[0003] 1. Anaerobic-anoxic-aerobic (A 1 -A 2 -O) or anoxic-aerobic (A-O) serial biologically activated sludge method has the disadvantages of low treatment load (for example, the COD sludge load in the aerobic pool is only 0.4-0.7kgCOD / kg.mlvss.d, and the aerobic Pool COD volume load is only 0.7~1.2kgCOD / m 3 .d; A-A-O overall COD volume load is only 0.6~1.0kgCOD / m 3 .d), the hydraulic retention time is long (30-90h, depending on the quality of the wastewater), and a secondary sedimentation tank must be installed, resulting in a large area and high infrastructure investment

[0004] 2. Anaerobic-anoxic-aerobic (A 1 -A 2 -O) or anoxic-aerobic (A-O) biofilm reactors connected in series to form a biological treatment process, although the treatment load is increased and the hydraulic retention time is shortened compared with the activated sludge treatment process, however, the treatment load Still low (for example, the COD volume load of the aerobic pool is only 0.8-1.5kgCOD / m 3 .d; A-A-O overall COD volume load is only 1.0~1.8kgCOD / m 3 .d), the hydraulic retention time is still too long (25-60h, depending on the quality of the wastewater), and it is necessary to set up a secondary sedimentation tank, which leads to a relatively large area and a high infrastructure investment

[0005] 3. A with slag, medical stone, zeolite or pebble as biofilm carrier 1 (anaerobic), A 2 (Anoxic), O (aerobic) biofilm reactors often have clogging and filter material compaction, requiring frequent flushing or resulting in unstable operation; A with activated carbon as the biofilm carrier 1 (anaerobic), A 2 (Anoxic), O (aerobic) biofilm reactors, either the above phenomenon occurs, or the overall infrastructure investment is high due to the high price of activated carbon

[0006] 4. A with slag, medical stone, zeolite, pebble or activated carbon as biofilm carrier 1 (anaerobic), A 2 (Anoxic) biofilm reactor, because A 1 (anaerobic), A 2 (Hypoxia) produces a large number of microbubbles, but there is no practical way to drive them away, resulting in these microbubbles staying in A for a long time 1 (anaerobic), A 2 In the (anoxic) filter, the effective reaction space of the filter is occupied for a long time, which reduces the treatment efficiency

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