Research On Synergetic Degradation Of Multi-energy Fields To Phenolic Contaminants In Water

With the rapid development of chemical industries such as petroleum chemical engineering, plastics, synthetic fabric, coking and so on, more and more phenolic compounds wastewater was discharged to our environment. Because phenolic contaminants take on great toxicity which could cause cancer, abnormality and sudden change, many environmental researchers attach importance to them. Eliminating or degrading phenolic contaminants in water was involved not only with the bioplastic and propagation of hydrophily biology but also with drinking safety of mankind and terraneous animals. So the research of a kind of high efficient treatment technology to treat phenol wastewater is of great importance to protect our environment.To a large deal of phenolic compounds wastewater, it's difficult to meet synthetical discharging standard of wastewater. The subject intends to research a kind of disposal method which is specially good effect on this kind of contaminant. What's more, AOPs, including photochemical oxidation, ultrasound, and so on, are of great advantages that they could oxidate and degrade organic contaminants thoroughly and don't have secondary pollution. So it's of great theoretical and practical values to study them to dispose phenol wastewater.In the paper, the feasibility and it's regulation were studied to degrade phenolic compounds wastewater by combinational technologies of ultrasound, UV catalytics and electro-chemical energy fields. And I choosed phenol as the research object because it is of the most toxicity in all phenolic compounds and stable in the environment, and it's difficult to degrade by normal wastewater treatment technologies. Through treating simulated wastewater of phenol, the synergetic effect of each energy field and H₂O₂ were probed systematically. Then, the general regulations were summed up preliminarily that combinational systems were used to treat wastewater which were US/UV, US/electro-chemical, UV/electro-chemical, US/UV/electro-chemical, and so on. At last, I got the most combinational conditions to degrade simulated wastewater by orthogonal experiments.The results of the experiments showed that the degradation ratio was very low only by individual energy field. When H₂O₂ was added , the degradation ratio was raised with different degrees. The removal effect of phenol was good in acid condition, but poor in alkaline condition. Under the same reaction condition, the degradation ratio of phenol has some increase in the double- energy field systems which were made up of each single energy field. For 20mg/L phenol solution, the degradation ratio was 77.48% after 120 minutes reaction time in US/UV system, 51.78% in UV/electro-chemical system, and 54.32% in US/electro-chemical system. Having the similar result, the degradation ratio was raised with different degrees when H₂O₂ was added into each double-energy field. Degrading phenol solution in UV/US/electro-chemical system, the effect was not good when fixed catalyst was used, but the degradation ratio was increased greatly when H₂O₂ was added to the system and the degradation ratio was nearly 100% when the concentration was 3ml/LH₂O₂. Using suspended photocatalyst, the degradation effect of phenol solution was good in the ternary-energy field. Designing a orthogonal experiment, the rule was studied that phenol solution was degraded by UV/US/electro-chemical system. The results showed that the reaction time was the first factor affecting degradation effect, the second factor was the amount of H₂O₂, followed by initial concentration and the last was the amount of TiO₂. Through the orthogonal experiments, under the preconditions of 40KHz and 0.1W/crn3, output voltage of electric field, 365nm wavelength and 160W high voltage light, we could ascertain that the best condition to degrade phenol solution in the ternary-energy field was lg TiO₂, 3ml H₂O₂, 20mg/L initial concentration and 120 minutes reaction time. And under this reaction condition, the degradation ratio of phenol solution was 94.19%, which was prefect.