there are several general methods to treat restaurant wastewater: physical method, chemical method, electrochemical method, biochemical method, membrane method, etc.

Physical treatment is generally to precipitate some organic matter in wastewater by adding coagulant. This method is simple and easy, but the removal of organic matter is not complete, and chemical sludge is produced, which requires supporting sludge treatment facilities.

Advanced oxidation method is generally used in chemical method, which can effectively remove organic matter from water, but the operating cost is too high.

electrochemical method also has the problem of high running cost, and the electrode plate needs to be replaced after being polluted;

The price of membrane module is too high, and the technologies of membrane cleaning and recovery need to be further solved. According to the characteristics of restaurant wastewater (BOD/COD >; ; 1.3), the most effective treatment method is to remove the grease from the wastewater first, and then adopt the biochemical treatment method.

The biochemical treatment method has the advantages of stable operation, low operating cost and convenient management. At present, the biochemical methods used for restaurant wastewater mainly include UASB (Upflow Anaerobic Sludge Reactor), HAF (High Efficiency Composite Anaerobic Reactor) and SBR (Continuous Batch Activated Sludge Process) aerobic treatment.

this paper mainly introduces HAF high-efficiency anaerobic reactor. HAF high-efficiency anaerobic reactor is an anaerobic reactor filled with fillers for microorganisms to attach. The fillers are submerged in water, and microorganisms attach to the fillers. Wastewater enters the reactor from the bottom. Through the fixed packed bed, the organic matter in wastewater is anaerobically decomposed under the action of anaerobic microorganisms.

compared with other anaerobic reactors, haf high-efficiency anaerobic reactor has the following advantages:

① the COD removal rate is high, and the cod removal rate of good biochemical wastewater can reach more than 81%;

② Start quickly and no excess sludge is generated;

③ running at normal temperature, with strong impact load resistance;

④ intermittent operation with low energy consumption;

⑤ strong anti-blocking ability;

⑥ No excess sludge is generated, and no special person is needed for management.

In addition, the HAF anaerobic reactor only needs one-time investment, and it runs stably and for a long time. During the operation, there is no need to replace any equipment (the equipment has only one lift pump, so the energy consumption is low) and the biogas generated by anaerobic fermentation can be recycled by catering enterprises.

Fourth, the treatment process of catering wastewater

Pretreatment and wastewater treatment process of catering wastewater First, the catering wastewater directly recovered by restaurants and restaurants is mechanically removed

. Then oil-water separation is carried out for the liquid part. For the oily part, the waste oil is obtained by acid precipitation and water washing, and the best amount of acid added in the acid precipitation process is to control the pH value between 2 and 3. After the water after oil-water separation is mixed with washing water, the water quality and quantity are adjusted by the regulating tank, and then lifted to the coagulation air flotation tank by the pump to remove most SS, oil and some organic matters, and then biochemical treatment is carried out. SBR—PACT method is used for biochemical treatment, powdered activated carbon is added into the biochemical tank, and the effluent from biochemical treatment reaches the standard and is discharged. Sludge is dewatered after entering the sludge concentration tank. The process flow is shown in Figure 2. In this process, the pretreatment system and the microbial liquid culture medium for biochemical treatment of kitchen waste are inoculated with bacterial molasses sugar.

Dining slop-centralized collection in grease trap or plastic bucket of restaurants and hotels-rotating mechanical grille-intelligent oil-water separation system-combined pool-acid precipitation-water washing-hogwash fat-comprehensive utilization sludge concentration pool-plate-and-frame filter press-a small amount of dry sludge is transported out

Pretreatment system: regulating pool and coagulation air flotation pool are mainly used to stabilize water quality and quantity. Because of the low pH value in the influent quality of wastewater, it belongs to acidic wastewater and the high oil content, the alkaline neutralization-coagulation flotation method is adopted here.

biochemical treatment system:

SBR tank, which is mainly used to remove dissolved organic substances in wastewater. In order to enhance the stability and impact resistance of biochemical treatment system, SBR (sequencing batch activated sludge process)-PAcT (feeding activated sludge process) was adopted. Adding powdered activated carbon into the aeration tank can remove some dissolved organic substances that cannot be removed by biochemical method, and improve the removal rate of COD and BOD. Sludge disposal adopts the method of sludge concentration-mechanical dehydration. The supernatant of the concentration tank is put into the regulating tank for further treatment, and the mud cake is operated outside for further proper disposal.

technical scheme of reclaimed water feed

The sanitary and fresh urban catering wastewater is collected in a centralized way, firstly, it is dehydrated and deoiled, then the solid components are dried and sterilized, and then the solid feed is produced through mechanical processing. Dehydration and deoiling: Catering wastewater is basically composed of solid and liquid components. In this process, natural precipitation or mechanical filtration is used for solid-liquid separation. The dehydration and deoiling of restaurant wastewater adopts a simple natural precipitation method, that is, the separation of solid and liquid is realized by using the self-weight and fluidity of liquid and using a filter screen. In order to improve the filtration efficiency, layered filtration can be considered, and the mesh of the filter screen is from large to small.

sorting: after dehydration and deoiling, there are still some inedible impurities in the catering wastewater, such as wooden chopsticks, plastic products, metals and paper, which must be removed before processing. The sorting system mainly uses the specific gravity, volume and magnetism of substances, and adopts continuous sorting such as repeated mechanization and magnetic separation (for special substances, magnetic separation, wind separation and manual sorting are supplemented appropriately) to separate impurities.

drying: microwave heating drying method is selected here. The advantage of this method is that it can achieve heating effect in a short time, heat evenly and kill bacteria at a lower temperature. And will not produce waste water, waste gas and waste.

The above answer is supported by Quanding Environmental Protection Technology. Please indicate it in the reprint. Thank you.