Yunzi Hu

Valorisation of food waste via fungal hydrolysis and lactic acid fermentation with Lactobacillus casei Shirota

Food waste recycling via fungal hydrolysis and lactic acid (LA) fermentation has been investigated. Hydrolysates derived from mixed food waste and bakery waste were rich in glucose (80.0-100.2gL(-1)), fructose (7.6gL(-1)) and free amino nitrogen (947-1081mgL(-1)). In the fermentation with Lactobacillus casei Shirota, 94.0gL(-1) and 82.6gL(-1) of LA were produced with productivity of 2.61gL(-1)h(-1) and 2.50gL(-1)h(-1) for mixed food waste and bakery waste hydrolysate, respectively. The yield was 0.94gg(-1) for both hydrolysates. Similar results were obtained using food waste powder hydrolysate, in which 90.1gL(-1) of LA was produced with a yield and productivity of 0.92gg(-1) and 2.50gL(-1)h(-1). The results demonstrate the feasibility of an efficient bioconversion of food waste to LA and a decentralized approach of food waste recycling in urban area.

Newly Developed Techniques on Polycondensation, Ring-Opening Polymerization and Polymer Modification: Focus on Poly(Lactic Acid)

Polycondensation and ring-opening polymerization are two important polymer synthesis methods. Poly(lactic acid), the most typical biodegradable polymer, has been researched extensively from 1900s. It is of significant importance to have an up-to-date review on the recent improvement in techniques for biodegradable polymers. This review takes poly(lactic acid) as the example to present newly developed polymer synthesis techniques on polycondensation and ring-opening polymerization reported in the recent decade (2005–2015) on the basis of industrial technique modifications and advanced laboratory research. Different polymerization methods, including various solvents, heating programs, reaction apparatus and catalyst systems, are summarized and compared with the current industrial production situation. Newly developed modification techniques for polymer properties improvement are also discussed based on the case of poly(lactic acid).

Recent Trends in Sustainable Textile Waste Recycling Methods: Current Situation and Future Prospects

In recent years, there have been increasing concerns in the disposal of textile waste around the globe. The growth of textile markets not only depends on population growth but also depends on economic and fashion cycles. The fast fashion cycle in the textile industry has led to a high level of consumption and waste generation. This can cause a negative environmental impact since the textile and clothing industry is one of the most polluting industries. Textile manufacturing is a chemical-intensive process and requires a high volume of water throughout its operations. Wastewater and fiber wastes are the major wastes generated during the textile production process. On the other hand, the fiber waste was mainly created from unwanted clothes in the textile supply chain. This fiber waste includes natural fiber, synthetic fiber, and natural/synthetic blends. The natural fiber is mostly comprised of cellulosic material, which can be used as a resource for producing bio-based products. The main challenge for utilization of textile waste is finding the method that is able to recover sugars as monosaccharides. This review provides an overview of valorization of textile waste to value-added products, as well as an overview of different strategies for sugar recovery from cellulosic fiber and their hindrances.