背景:塑料广泛用于包装,框架,作为覆盖物材料。它的过度消费和缓慢退化,由于其毒性作用,对生态系统构成威胁。虽然聚羟基链烷酸酯(PHA)提供了石油基塑料的可持续替代品,它们的生产成本对全球采用构成重大障碍。在另一边,许多家庭和工业活动会产生大量含有有机和无机污染物的废水。这不仅对生态系统构成威胁,而且还提供了从循环经济中受益的机会。生物塑料的生产可以通过使用废水中的营养物和矿物质作为微生物发酵的原料来改善。像饥荒文化这样的策略,混合财团文化,并且已经开发了用于从具有高有机负荷的高污染废水中生产PHA的集成工艺。各种工艺参数,如有机加载速率,有机物含量(挥发性脂肪酸),溶解氧,操作pH值,和温度在微生物生物质中的PHA积累中也具有关键作用。利用物理和化学(卤化溶剂,表面活性剂,绿色溶剂)方法。这篇综述重点介绍了将废水资源再循环为PHA的最新进展,涵盖各种生产战略,下游处理方法,和技术经济分析。
结论:废水中存在的有机碳和氮提供了有希望的,生产生物塑料的成本效益来源。以前的尝试集中在通过优化培养系统和生长条件来提高生产率。然而,尽管技术进步,重大挑战依然存在,如生产率低,复杂的下游处理,可扩展性问题,以及所得PHA的性质。
BACKGROUND: Plastic is widely utilized in packaging, frameworks, and as coverings material. Its overconsumption and slow degradation, pose threats to ecosystems due to its toxic effects. While
polyhydroxyalkanoates (PHA) offer a sustainable alternative to petroleum-based plastics, their production costs present significant obstacles to global adoption. On the other side, a multitude of household and industrial activities generate substantial volumes of wastewater containing both organic and inorganic contaminants. This not only poses a threat to ecosystems but also presents opportunities to get benefits from the circular economy. Production of bioplastics may be improved by using the nutrients and minerals in wastewater as a feedstock for microbial fermentation. Strategies like feast-famine culture, mixed-consortia culture, and integrated processes have been developed for PHA production from highly polluted wastewater with high organic loads. Various process parameters like organic loading rate, organic content (volatile fatty acids), dissolved oxygen, operating pH, and temperature also have critical roles in PHA accumulation in microbial biomass. Research advances are also going on in downstream and recovery of PHA utilizing a combination of physical and chemical (halogenated solvents, surfactants, green solvents) methods. This review highlights recent developments in upcycling wastewater resources into PHA, encompassing various production strategies, downstream processing methodologies, and techno-economic analyses.
CONCLUSIONS: Organic carbon and nitrogen present in wastewater offer a promising, cost-effective source for producing bioplastic. Previous attempts have focused on enhancing productivity through optimizing culture systems and growth conditions. However, despite technological progress, significant challenges persist, such as low productivity, intricate downstream processing, scalability issues, and the properties of resulting PHA.