CN103693809B - Anaerobic biological treatment system for fruit juice wastewater - Google Patents

Abstract

A fruit juice wastewater anaerobic biological treatment system, comprising a juice wastewater regulating tank, the outlet of the juice wastewater regulating tank is filtered through a screen and connected to the water inlet of the anaerobic reactor, and the water outlet and the water inlet of the anaerobic reactor are connected to each other. Connected through the water return pipe, the outlet of the anaerobic reactor is connected to the water inlet of the PVA oxidation tank, the outlet of the PVA oxidation tank is connected to the water inlet of the activated sludge tank, the outlet of the activated sludge tank is connected to the inlet of the sedimentation tank Water port connection, the water outlet of the sedimentation tank is connected to the water inlet of the filter tank, the water at the water outlet of the filter tank is reused in the production workshop or discharged up to the standard, and the sludge outlet of the sedimentation tank passes through the sludge return pipe and the sludge inlet of the activated sludge tank Port connection, or direct sludge utilization, the invention realizes the standard discharge of fruit juice wastewater under the conditions of low cost, low sludge, and low energy consumption, and provides technical basis and reference for the design, commissioning, and operation management of related projects.

Description

An anaerobic biological treatment system for fruit juice wastewater

technical field

The invention relates to wastewater biological treatment technology in the technical fields of environmental engineering and water pollution control, in particular to an anaerobic biological treatment system for fruit juice wastewater.

Background technique

At present, the production of concentrated apple juice in China has accounted for 70% of the world's total trading volume, and the fruit juice industry brings tens of billions of yuan in income to the country every year.

While fruit juice production enterprises have made great contributions to the Chinese economy, the environmental problems they have brought about, especially wastewater pollution, are particularly prominent. Juice processing plants generally produce 3.8-10.5m ³ of waste water per ton of raw materials processed. Due to the high organic load and changes in acid-base concentration of juice production wastewater, the structure of the river ecosystem is damaged, which has a serious impact on the feeding and growth of fish and the yield and quality of surrounding crops.

The fruit juice processing industry has a relatively late development history, and its wastewater treatment research lags behind that of other high-concentration organic wastewater such as beer and alcohol wastewater. At present, the aerobic-based treatment process used in the wastewater treatment of fruit juice factories has problems such as high energy consumption, large amount of mud, and difficulty in meeting water quality standards. There is no relatively mature wastewater treatment process technology. The treatment of fruit juice wastewater generally adopts traditional physical and chemical + biochemical treatment methods, and most of the processes are designed according to other organic wastewater treatment processes, such as the use of lime milk neutralization precipitation-hydrolysis acidification-contact oxidation process, CAST process, inclined plate three-phase separator UASB- Biological contact oxidation tandem process and UASB-EIC technology. Due to the specific process of fruit juice production and the lack of consideration of the characteristics of juice wastewater, many problems have occurred during the operation process, and the treatment effect is generally unsatisfactory.

Contents of the invention

In order to overcome the shortcomings of the above-mentioned prior art, the object of the present invention is to provide a kind of fruit juice wastewater anaerobic biological treatment system, realize the discharge of fruit juice wastewater under the condition of low cost, low sludge, and low energy consumption, and provide a basis for the design and debugging of related projects and operation management to provide technical basis and reference.

In order to achieve the above object, the technical scheme that the present invention takes is:

A fruit juice wastewater anaerobic biological treatment system, comprising a juice wastewater regulating tank, the outlet of the juice wastewater regulating tank is filtered through a screen and connected to the water inlet of the anaerobic reactor, and the water outlet and the water inlet of the anaerobic reactor are connected to each other. Connected through the water return pipe, the outlet of the anaerobic reactor is connected to the water inlet of the PVA oxidation tank, the outlet of the PVA oxidation tank is connected to the water inlet of the activated sludge tank, the outlet of the activated sludge tank is connected to the inlet of the sedimentation tank Water port connection, the water outlet of the sedimentation tank is connected to the water inlet of the filter tank, the water at the water outlet of the filter tank is reused in the production workshop or discharged up to the standard, and the sludge outlet of the sedimentation tank passes through the sludge return pipe and the sludge inlet of the activated sludge tank Port connection, or direct sludge utilization.

The juice wastewater regulating pond, PVA oxidation pond and activated sludge pond are all connected with acid-base regulating devices.

The anaerobic reactor adopts a tower-type high-load anaerobic bioreactor, and a large amount of effluent flows back to the wastewater inlet of the reactor. The demand for alkalinity of the reactor is reduced by diluting the influent concentration, and the reflux ratio is controlled to be 3:1.

The PVA oxidation pond is a biological oxidation pond filled with PVA spherical particles, wherein the diameter of the PVA spherical particles is 4mm, and it is a porous medium with internal pores of 20-40 microns, and the inside and outside of it are attached and grown and filled with microbial bacteria.

Advantages of the present invention:

(1) Set up an acid-base adjustment device and a juice wastewater adjustment pool to solve the problem of pH in the juice wastewater treatment caused by cleaning and disinfecting production facilities and storage tanks with nitric acid, hydrochloric acid, caustic soda, and bleach several times a day during the juice production process Large fluctuations, containing the risk of strong alkali and strong acid shock.

(2) A large amount of effluent from the tower-type high-load anaerobic bioreactor returns to the wastewater inlet of the reactor, and the demand for alkalinity of the reactor is reduced by diluting the influent concentration, and the reflux ratio is controlled to be 3:1, so that the anaerobic reactor is at a low Treat fruit juice wastewater under alkalinity conditions and run stably at high load.

(3) Utilize the advantages of low operating cost, energy saving, and easy sludge disposal of wastewater anaerobic treatment technology, and adopt high-efficiency anaerobic biological softening technology to prevent the accumulation of calcium in wastewater and decompose stickies, thereby solving the problem of high COD value in juice wastewater Treatment of technical issues, effective treatment of organic matter in wastewater.

(4) The PVA oxidation tank is filled with Φ4mm special high specific surface area PVA spherical particles. According to the high adsorption characteristics of PVA porous media (internal pores 20-40 microns), the inside and outside of it are attached and grown and filled with microbial bacteria. Fruit juice wastewater is rich in high-concentration microorganisms. When the PVA reaction tank is used, the efficiency of wastewater treatment is greatly improved.

(5) The results of continuous operation of the whole system show that the volume load of the fruit juice wastewater treatment process system can reach 6.0kgCOD·m ^-3 ·d ^-1 , and the COD removal rate is above 90%.

Description of drawings

Accompanying drawing is the structural representation of the present invention.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing.

With reference to accompanying drawing, a kind of fruit juice wastewater anaerobic biological treatment system comprises fruit juice wastewater regulating tank, the water outlet of fruit juice wastewater regulating tank is connected with the water inlet of anaerobic reactor after being filtered through screen mesh, the water outlet of anaerobic reactor and The water inlets are connected by a water return pipe, the water outlet of the anaerobic reactor is connected with the water inlet of the PVA oxidation tank, the water outlet of the PVA oxidation tank is connected with the water inlet of the activated sludge tank, and the outlet of the activated sludge volume reduction tank is connected. The water outlet is connected to the water inlet of the sedimentation tank, the water outlet of the sedimentation tank is connected to the water inlet of the filter tank, the water at the outlet of the filter tank is reused in the production workshop or discharged up to the standard, and the sludge outlet of the sedimentation tank passes through the sludge return pipe and the active The sludge inlet of the sludge tank is connected, or the sludge is used directly.

The juice wastewater regulating pond, PVA oxidation pond and activated sludge pond are all connected with the acid-base regulating device.

The anaerobic reactor adopts a tower-type high-load anaerobic bioreactor, and a large amount of effluent flows back to the wastewater inlet of the reactor. The demand for alkalinity of the reactor is reduced by diluting the influent concentration, and the reflux ratio is controlled to be 3:1.

The PVA oxidation pond is a biological oxidation pond filled with PVA spherical particles, wherein the diameter of the PVA spherical particles is 4mm, which is a porous medium with internal pores of 20-40 microns, has high adsorption properties, and is attached to grow inside and outside and is full of microbial bacteria.

Working principle of the present invention is:

The juice wastewater flows into the juice wastewater regulating tank (according to the water quality and pH value, the pH value is automatically adjusted and the nutrients required by microorganisms are added reasonably), and the juice regulating tank wastewater is filtered by the screen, and then pumped into the tower-type high-load anaerobic reaction 70% of COD is removed by biodegradation in the anaerobic reactor, and 75% of the wastewater treated by the anaerobic reactor is sent back to the reactor wastewater inlet to dilute the original juice wastewater, prevent the impact of the change of juice wastewater water quality on microorganisms, and effectively improve the stability of biological treatment. Other wastewater at the outlet of the anaerobic reactor flows into the PVA oxidation tank for further microbial softening treatment, and then flows into the activated sludge tank for aerobic biological treatment. The aerobic treated water flows into the sedimentation tank for mud-water separation, and most of the lower sludge is sent back In the activated sludge tank, a small part of the remaining sludge is used for other purposes, and the upper part of the clear water is filtered by the filter tank and then discharged up to the standard or reused according to the actual situation.

In order to avoid excessive impurities in the juice wastewater and reduce the COD removal rate of the wastewater treated by the bioreactor, the juice wastewater is selected to pass through the screen filter unit and then flow into the anaerobic bioreactor. In order to prevent the impact of juice wastewater load and pH value fluctuations on the adaptability and activity of microorganisms, a juice wastewater adjustment tank is set up, and the pH value of wastewater is automatically detected and adjusted at the same time. With the progress of wastewater treatment, the pH value of the PVA oxidation tank and activated sludge tank will fluctuate. The system sets the acid-base adjustment tank to automatically detect the pH value and adjust it.

Effect of the present invention:

Fruit juice wastewater, as low-alkalinity acidic organic wastewater, needs to add alkaline agents to adjust the pH of the influent before treatment. The reflux reduces the demand for alkalinity of the reactor by diluting the concentration of the influent, and controls the reflux ratio to 3:1 to make the anaerobic reactor Treat fruit juice wastewater under low alkalinity conditions and run stably at high load.

Using hydrolysis acidification to treat fruit juice wastewater, with the gradual increase of volume load, the removal trend of COD, BOD ₅ , TN, TP, TOC in juice wastewater is that when the load is increased, the removal rate will decrease, but with the operation of the reactor , the removal rate gradually increased. The removal effect on BOD ₅ , COD and TN is better.

The volume load of the fruit juice wastewater treatment system can reach 6.0kgCOD·m ^-3 ·d ^-1 , and the COD removal rate is over 90%.

Using this system to treat concentrated fruit juice wastewater, in the stable operation stage (influent COD, BOD ₅ , SS are 5968mg·L ^-1 , 2130mg·L ^-1 , 1020mg·L ^-1 , effluent are 131mg·L ^-1 , 10.8 mg·L ^-1 , 50.2mg·L ^-1 ) COD, BOD ₅ , and SS removal rates were 96%, 99.5% and 95.1%, respectively. The waste water treated by the waste water treatment system can be stably discharged up to the standard, while reducing the power consumption by 70-80%, and the discharge of residual biological sludge is reduced from 220 kg per ton of fruit juice (75% moisture content) to less than 80 kg.

Claims (1)

1. an Anaerobic biological treatment system for fruit juice wastewater, comprise fruit juice wastewater equalizing tank, it is characterized in that: the water outlet of fruit juice wastewater equalizing tank is connected with the water inlet of anaerobic reactor by after screen filtration, connected by water return line between the water outlet of anaerobic reactor and water inlet, the water outlet of anaerobic reactor is connected with the water inlet of PVA oxidation pond, the water outlet of PVA oxidation pond is connected with the water inlet of activated sludge tank, the water outlet of activated sludge tank is connected with the water inlet of settling tank, the water outlet of settling tank is connected with the water inlet of filtering basin, the Water circulation production plant of the water outlet of filtering basin or qualified discharge, the mud mouth of settling tank is connected with the mud inlet of activated sludge tank by mud return line, or directly carry out mud utilization,

Described fruit juice wastewater equalizing tank, PVA oxidation pond, activated sludge tank are all connected with acid-alkali accommodation device;

Described anaerobic reactor adopts tower high-load anaerobic bio-reactor, and water outlet is back to reactor waterwater entrance in a large number, and reduce reactor to the demand of basicity by dilution influent concentration, control reflux ratio is 3:1;

Described PVA oxidation pond is the bio-oxidation pond of filling PVA spheroidal particle, and wherein PVA spherical particle diameters 4mm, be the porous medium of internal gutter 20 ~ 40 microns, apposition growth inside and outside it is also full of microbial bacterial.