Li Zhiqiang's scientific contributions
Publications (4)
The leather industry is facing a serious problem with water pollution. To eliminate pollution by tanneries' wastewater, carbon dioxide supercritical fluid (SCF-CO2) was put forward to substitute for water as leather making medium. The results showed that chrome tanning in SCF-CO2 medium is an effective new clean method for leather making. In order...
Alkali and neutral salt treatment, especially in liming is a key procedure in orderto achieve a good quality of leather. However, liming creates sludge and wastewater which are difficult to process. To find a clean replacement for lime we need to know the properties of skin after alkali and neutral salt treatment. Collagen fibre and cattle hide are...
Global environmental regulations are changing the leather industry. Conventional unhairing contributes most of the pollution in the industry, such as hydrogen sulfide and lime. Ever-increasing attention to the environmental impact of the leather industry has necessitated the development of enzymatic unhairing as a potent alternative to polluting ch...
Bacillus Subtilis is a saprophytic bacteria which has a widespread distribution in nature and can be easily isolated from soil microbes. Bacillus Subtilis AS1.398 is a major strain of Bacillus Subtilis used extensively in light industry and the pharmaceutical industry and is commonly used in the leather industry in China for depilation and bating....
Citations
... Later, it was found to be produced by the aerobic bacterium Achromobacter iophagus and other microorganisms including fungi (Godfrey, 1996). Different authors reported various strains among Bacillus and Aspergillus genera as collagenase-producing: B. subtilis (Okamoto, 2001;Tran and Nagano, 2002;Rui et al., 2009), B. licheniformis (Baehaki et al., 2012), A. fumigatus (Reichard et al., 1990). ...
... Furthermore, the FTIR spectra of collagen hydrolysate and the solid waste obtained after treating the leather with an alkali solution for 48 h showed that the non-dissolved collagen fibre kept its natural triple-helical structure, while the hydrolysate denatured lost this helical conformation [16]. ...
... High pressure technology in tanning process increases the mass transfer, enables the reactions to take place rapidly resulting in higher uptake rates. From an environmental point of view, process times are reduced, which in turn ensures chemical savings by increasing exhaustion and reduced waste loads [1,2,28,32,33]. ...
... A major part of hair-saving unhairing process investigations is devoted to enzymatic unhairing [4,5]. Despite the fact that the enzymatic process has a serious advantage from an environmental point of view, i.e. wastewaters after the process are free from sulphides and hair degradation products, pure enzymatic unhairing is not widely used in the industry. ...
