Environmentally Friendly Leather Chemicals Are Available In Size.

An activated sludge process

The project was jointly completed by Sichuan University, Shaanxi University of Science and Technology, China leather and footwear industry research institute and other units.

Professor Wang Xuechuan said that the project is part of the national science and technology support project in 11th Five-Year. The systematic study and evaluation system of the biodegradability of leather chemicals will provide a basis for screening and using environment-friendly leather chemicals for tanning and fur enterprises. More importantly, due to a clearer understanding of the biodegradability of various tannery chemicals and their structure-activity relationship, they can guide the molecular design and industrial production of new leather chemicals in turn, which is of guiding significance for the development of environment-friendly leather chemicals.

At present, the project team has studied the biodegradability of leather tanning agents, acrylic tanning agents, aldehyde tanning agents, vegetable tanning agents and dyestuffs.

The leader of the project, the chairman of the Federation of International Leather Chemists and Chemists Association, and Shi Bi, member of the Chinese Academy of engineering, said that China's leather industry uses 500 thousand to 800 thousand tons of leather chemicals every year, and about 30% of them are discharged from the wastewater. The biodegradability of leather chemicals in the waste water is the key factor determining the environmental friendliness of the leather industry.

The activated sludge from tannery wastewater was treated by precipitation and air exposure. The oxygen consumption was measured by a breathing apparatus, and then the curve of oxygen consumption varying with time was determined. By comparing the two curves before and after the pollutant, the biodegradability of the chemical product can be determined qualitatively or semiquantitatively.

This method directly uses activated sludge from tannery wastewater treatment plant as a degrading microorganism, and its research results can objectively reflect the actual biodegradability of chemicals.

Shi BIE added that because of the great difference of activated sludge in different tannery enterprises, in order to achieve comparability of different enterprise evaluation results, twelve Sodium Alkylbenzene Sulfonate with good biodegradability was selected as the reference material, and its degradability was 100%.

It is understood that there has been no evaluation system for the biodegradability of leather chemicals.

Activated sludge process is a traditional process of wastewater treatment. It has been widely used in the management and operation of sewage treatment plants in Europe and America.