不浸酸无铬鞣剂TWT的环保性能研究

考察了无铬鞣剂TWT的环保性能。研究结果表明,无铬鞣剂TWT属于低毒、可生物降解性物质,对家兔眼睛和皮肤均无刺激性,对豚鼠皮肤致敏性较弱。基于TWT的不浸酸鞣制工艺明显减轻了中性盐对环境的污染。TWT鞣制的白湿皮毒性较低（LD50〉5000 mg/kg）,片皮、削匀所产生的废皮屑可回收利用。与常规植鞣法相比,半植鞣法可节约栲胶50%左右,且废液中的栲胶含量较低。在铬复鞣逆转工艺中,当铬粉用量为削匀革5%时,皮坯收缩温度可达到110℃,与常规铬鞣法相当,但铬粉用量可节约50%以上,废液中的三氧化二铬含量也仅为240 mg/L。铬复鞣逆转工艺不产生含铬固体废弃物,仅最后一道工序产生低铬废水。以上研究结果表明,无铬鞣剂TWT环保性能优良。

Study on Environmental Performance of Non-Pickling Chrome- Free Tanning Agent TWT

The environmental performance of chrome-free tanning agent TWT was investigated. It was found that chrome-free TWT is low toxic and biodegradable, has no irritability for eye and dermal of rab- bits, and has little sensitivity for dermal of guineas. The non-pickling tannage based on TWT can reduce neutral salts pollution significantly, the wet white tanned by TWT is low toxic （LD50〉5000 mg/kg）, and the shavings derived from it can be reused. In comparison with traditional vegetable tannage, semi-vegetable tannage based on wet white can reduce the offer of vegetable tannins by 50%, and the vegetable tannin content in liquor is very low. It was also found that the shrinkage temperature of leather was up to 110 ~C when chrome powder offer was only 5% based on shaved pelts in reversed rechroming tannage. In compar- ison with traditional chrome tannage, the offer of chrome powder can be reduced by 50%, and Cr203 con- tent in effluent was only 240 mg/L. Moreover, no chrome containing solid wastes were produced and chrome contained effluent is only concentrated in the last process step in reversed rechroming tannage. The research results show that chrome-free tanning agent TWT possesses excellent environmental performance.