Study On Sorbic Acid Manufacturing Wastewater Treatment By Supercritical Water Oxidation

Sorbic acid, known as a kind of antiseptic agents with low toxic and high efficiency, has a broad-market prospect. However, during its producing, the amount of this wastewater is very huge and its quality is extraordinary bad. This wastewater need a galaxy of oxygen when they are treated by chemical and microorganism and it has very bad affect if discharged into the environment. Cause of its character of high concentration and bad degraded, it's very difficult to be degraded by chemical oxidation or biological method. Considering all of these situations, this paper proposes a new method to treat sorbic acid wastewater by supercritical water oxidation.Based on the character of supercritical water, supercritical water oxidation is a new method to treat some toxic and harmful pollutants. This paper introduce you the character of supercritical water , the research findings of the supercritical water oxidation and also do some research study on many aspects of the sorbic acid wastewater treatment by SCWO. The conclusions are as follows:(1) SCWO is very efficient at treating the wastewater of sorbic acid. Through the orthogonal test, it is concluded that the most important factor is reaction time; peroxidatio, temperature, and pressure are followed. The experimental data shows that the oxidation efficient of air is higher than the H₂O₂ with the same peroxidatio;(2) In the condition of pressure P=25MPa, temperature T=450℃, react time t=180s, it can be a liner relationship between the peroxidatio increasing amount and the removal rate of COD. The functions related coefficients can reach or be up to 0.9. But the influence of peroxidatio will be lower if it achieves a certain value.(3) This paper does some kinetic experiments based on power exponent model and concludes three kinetic equations. They have same peroxidatio (K=1.l) and pressure (P=25MPa) but different temperatures. when T= 450℃, 485℃and 500℃, their parameters are as follows: k=0.0202, a=0.995 (T=450℃); k=0.02232, a=0.996 (T=485℃);k=0.02294, a=0.997 (T=500℃).And this paper also obtains the action energy (E_n) and preexponential factor (k₀) of the treatment of sorbic acid manufacturing wastewater by SCWO: E_n=16815.07J·moI^-1;k₀=1.125;(4) Through the Comparison of the removal rate of the sorbic acid and COD after the treatment of SCWO under different temperatures, it turns out that sorbic acid transformed into a kind of intermediate product, and the intermediate product has higher activation energy so that its rapid oxidation need to be under the temperature of nearly 600℃;(5) This article analysis the calorific existed during the reaction of treating the wastewater by SCWO and calculates the calorific of sorbic acid wastewater: 896kJ/L;(6) This article uses SEM (scanning electron microscope) to examine corrosion rate of reaction system and obtains its corrosion rate: 0.25 mm/a;(7) This paper conducted the cost analysis of treating sorbic acid wastewater by SCWO and it costï¿¥577.3 per ton (without the exploition of SCF which is produced during the reaction).More over, this paper summarizes the problems that would be appeared in the engineering process of treating this wastewater by SCWO. It also proposes some solutions to solve them.