Abstract: In order to solve the problem of regeneration of transformer waste oil, a composite adsorbent was prepared from chitosan (CS) and bentonite (BT) as raw materials. The results showed that when the mass ratio of CS to BT was 5% and the calcination temperature was 300 ℃, the decolorization and impurity removal performance of C5/BT-300 composite adsorbent was the best. The optimum process conditions for the treatment of transformer waste oil by using the composite adsorbent C5/BT-300 were as follows: the mass fraction of the adsorbent was 4%, the adsorption temperature was 50 ℃, and the adsorption time was 90 min. After the treatment of C5/BT-300 composite, the light transmittance of transformer waste oil increased to 99.5%, the color number decreased to No. 1, and the breakdown voltage increased by 60.2%; the dielectric loss factor, water concentration and acid value were reduced by 80.7%, 68.7% and 74.1%，respectively. Compared with common adsorbents such as bentonite and activated carbon, C5/BT-300 composite showed better adsorption and regeneration performance. In addition, a convenient, efficient, intelligent and green regeneration device for transformer waste oil was developed, and the regeneration process of transformer waste oil and the regeneration process of adsorbent after treatment were optimized.

Key words: transformer oil, chitosan, adsorbent, regeneration, breakdown voltage