Dairy processing wastewater treatment (anaerobic aerobic treatment technology)

In the past, physical and chemical methods (air flotation, coagulation and sedimentation, adsorption, etc.) were generally used to treat dairy wastewater. The removal effect was not good, the operation cost was high, and the management was inconvenient. At the same time, a simple aerobic biological treatment method was used. Although the removal of organic matters was good, the operation cost was also high, and the economy was unreasonable. Based on the introduction of the treatment process of dairy wastewater in a factory, an anaerobic aerobic treatment technology is proposed in this paper, in which UASB technology with mature application is used for anaerobic treatment and trickling filter bed technology without power consumption is used for aerobic treatment. According to the operation for more than one year, the process has the advantages of high treatment efficiency, low operation cost, less investment, simple operation and management, and fast growth of granular sludge in UASB. The treated effluent can be used for recycling.

1 quality and quantity of wastewater

The main raw materials and resources of dairy production in a dairy factory are fresh milk, sugar, peanut, walnut, electricity, water, coal, etc. In the dairy production process, waste water such as tank washing water and bottle washing water will be produced, which will enter into the open drainage channel of the plant together with the ground washing water, toilet washing water and a small amount of domestic sewage, and will be discharged outside the workshop through the common discharge outlet. The wastewater mainly contains a large number of soluble organic matter (sugar, fatty acid, protein, starch, etc.), which has good biochemical property and does not contain toxic and harmful substances. It is milky white with COD concentration of about 800-1000mg / L, so it belongs to low and medium concentration organic wastewater. The wastewater discharge of the dairy processing plant is 300m3 / D, cod: 1000mg / L

2. Treatment process

Anaerobic (UASB) - aerobic (trickling bed)

3. conclusion

(1) UASB trickling bed technology is used to treat dairy processing wastewater, which is feasible in practical operation, high in treatment efficiency, stable in operation, low in operation cost and simple in operation;

(2) after UASB runs for a certain time, it can grow better granular sludge with a diameter of more than 1mm;

(3) the sludge output of the system is low, and the sludge is easy to be used or treated, so the sludge can not be discharged;

(4) the operation shows that the system has good anti shock load capacity, and the effluent is still stable under certain fluctuation;

(5) the membrane of trickling filter bed falls off several times a year, but the original removal rate can be restored in a short time;

(6) using the new packing of trickling filter bed can solve the problems of trickling filter bed;

(7) the system effluent can be directly used for circulating cooling, and can also be used for production water after advanced treatment.