Utlization of wastewater sludge for the production of value added products

污水处理厂每年产生大量污泥。如今，污泥处理及其安全处置是世界范围内一个昂贵且环境敏感的问题。为了促进可持续的污泥管理流程，迫切需要通过从废水污泥中创造增值产品来开发可行的资源管理方案。在这种背景下，我们研究的长期目标是利用污泥作为混合微生物群落的来源来生产增值产品，同时产生三种产品，即细胞外多糖（EPS或生物絮凝剂）、生物塑料（聚羟基链烷酸酯或PHA）和脂质（用于生产生物柴油）。最近，我们的研究表明，废水污泥中含有大量可以同时合成这些产物的微生物。因此，本研究的主要目标是开发一种创新且经济可行的工艺，使用活性污泥作为微生物来源来生产这些产品。本研究项目的具体目标包括：污泥微生物群落分析；优化工艺参数，提高产品良率；使用不同的碳源并研究它们对产品的组成和分子量的影响；并开发一种合适的方法来回收增值产品。该研究将由五名博士生和一名研究员进行。该研究的成功完成将有助于开发一种经济且生产生物塑料、生物絮凝剂和脂质的新工艺，并最终促进环境友好和可持续的污泥管理。新工艺将不再需要昂贵的发酵罐及其复杂且昂贵的操作，并最大限度地降低生产成本。此外，这项研究非常及时，将帮助加拿大工业开发环保且商业上可行的生物塑料、生物絮凝剂和脂质，从而加强加拿大的环境政策。

Wastewater treatment plants produce huge quantities of sludge annually. Today, sludge treatment and its safe disposal is an expensive and environmentally sensitive problem world-wide. To promote sustainable sludge management processes, there is urgent need to develop viable options for resource management through the creation of value-added products from wastewater sludge. In this context, the long term goal of our research is to produce value-added products using sludge as a source of mixed microbial community to generate simultaneously three products – namely - extracellular polysaccharides (EPS or bioflocculants), bioplastics (Polyhydorxy alkanoates or PHA) and lipids (to produce biodiesel). Recently, our study demonstrated that wastewater sludge contains numerous microorganisms that can simultaneously synthesise these products. Therefore, the principal objective of the proposed research is to develop an innovative and economically viable process for the production of these products using activated sludge as a source of microorganisms. The specific objectives of the present research project includes: analysis of the microbial sludge community; optimization of the process parameters to increase the yield of the products; use of different carbon sources and study of their impact on the composition and molecular weight of the products; and development of a suitable method for recovery of the value-added products. The research shall be conducted by five PhD students and a research associate. The successful completion of the research will allow to develop a novel process of economical and production of bioplastics, bioflocculants and lipids concomitantly and it will eventually promote environment-friendly and sustainable sludge management. The new process will obviate the need of expensive fermentors, their sophisticated and expensive operation, and minimize the production cost. Further, this research is very timely and will aid Canadian industry to develop eco-friendly and commercially viable bioplastics, bioflocculant and lipids and thus strengthening Canada`s environmental policy.