Experiments on ozone nano bubble coupling process for phenol-containing wastewater

This experiment was conducted to treat the production effluent of a chemical plant, which mainly contains organic pollutants such as epoxy resins, phenolic compounds, and propanetriol.

01Existing problems

Epoxy resins, phenolic compounds, propanetriol and other organic pollutants, COD concentration is high, are more than 10,000mg / L, and some of the sewage salt content is very high, is difficult to treat wastewater.

02Experiment purpose

This experiment is to treat organic pollutants in chemical wastewater by nano bubble coupled ozone process, and to verify the COD removal effect of ozone advanced oxidation in the pre-treatment process.

03Experimental equipment, reagents

Zhuhong® nano bubble generator (material 316 stainless steel), ozone generator (maximum output 60g/h, concentration 100-140mg/L), multi-parameter water quality meter 5B-3B (VII) (to measure the COD content), plexiglass reaction columns, dry pumps, connecting pipe fittings (PTFE) and so on. Phenol-containing wastewater 34.0 liters, a number of tap water, COD detection reagents.

04 Experimental program

Add the phenol-containing wastewater into the reaction column with a liquid level of 64cm and dilute it with tap water to a height of 120cm. Turn on the equipment to make the solution uniformly mixed, take the original water samples. Connect the inlet pipe of the nano bubble generator to the outlet of the ozone generator, start the ozone generator and the nano bubble generator, continuously add ozone to the water for 6 hours, take water samples regularly to test the COD parameters and record.

Start the Zhuhong® nano bubble generator to the water body through the ozone gas, the water body quickly filled with a large number of fine bubbles, the liquid level rose 10cm, the water body was brown. 4 minutes later, the water body color quickly became darker, and gradually turned from dark brown to gray-green. After 30 minutes of reaction, the water body gradually turned back to dark brown. Continuing to run for 5.5 hours, the color of the water sample gradually became lighter, from dark brown to light yellow.

In the experimental process to take the lower layer of waste water samples to detect the COD content of which the results are as follows.

After the phenol-containing wastewater was treated with ozone nano bubbles, the easily oxidizable pollutants in the wastewater reacted rapidly and led to the discoloration of the water body, the COD value decreased rapidly, and continued to pass the ozone super nano bubbles to decompose and oxidize the phenol cyclic organic matter, resulting in a rapid rise in COD value, and with the ozone super micro nano bubbles continue to be put into the COD continued to decrease.

In this experiment, the water volume was 58.8L, after 6 hours of reaction, the COD value was reduced from 12,190 mg/L to 10,480 mg/L, the COD removal rate was 14.03%, and a total of 100.55 g of COD was removed.The amount of ozone added was 140.4 g, and the O/C ratio was 1.396, which showed a high efficiency of ozone utilization.

05 Summary

Ozone oxidation is a kind of advanced oxidation process for treating difficult wastewater, which is widely regarded by the world for its fast reaction speed, strong oxidizing property and no secondary pollution. However, the ozone equipment investment is large, the operation cost is high, and the ozone utilization efficiency of the existing ozone application process is on the low side, thus leading to the economic benefits of ozone oxidation process relative to other advanced oxidation processes are not obvious. Zhuhong ® nano bubble generator can quickly enhance the gas content in the liquid, improve the utilization efficiency of the gas, and ozone oxidation process is very suitable for the needs of the device by improving the utilization efficiency of the ozone, reduce the loss of the operation of the way to achieve the ultimate goal of saving the project investment (including equipment and civil construction) and operating costs.

Zhuhong® nano bubble generator is highly integrated, and can be applied to various volumes of wastewater treatment projects by matching ozone generators with different outputs, and can be used in pre-treatment and deep-treatment processes, with obvious improvement in treatment effect.

It is believed that through continuous research, Zhuhong® ozone nano bubble coupling process can be widely used as a new type of advanced oxidation process for difficult wastewater treatment, contributing to the green mountains and green water of the motherland.