Resource recovery from municipal wastewater with forward osmosis membrane-based process

为了在循环经济的背景下实现可持续的废水处理，人们研究了各种技术来利用废水中的资源，如厌氧消化的能量回收，鸟粪石结晶的营养物质回收和反膜的水回收，以减少废水处理对环境的影响。然而，城市污水的高度稀释性质使得这些技术不可行或过于昂贵。由渗透压驱动的正向渗透（FO）膜过滤技术由于具有污水预浓缩的潜力，可以直接利用上述技术同时进行水净化和资源回收，近年来引起了人们的广泛关注。因此，正渗透过滤作为设计下一代污水处理厂的关键单元，其占地面积更小，操作更灵活，膜污染倾向更低，如果选择合适的提取液和工艺设计得当，能耗更低，具有广阔的前景。然而，大多数研究都集中在单一或几种模型化学物质上来研究FO膜过滤。由于缺乏对废水的研究，以及废水化学性质与抽提液之间的相互作用关系，以及它们对通量、膜污染和清洗、污染物截留等方面的影响，使得FO膜在废水处理中的实际应用具有挑战性。本博士项目致力于解决这一问题，最终目标是从城市污水中回收能源、营养物质和水，使其具有成本效益和可持续性。

To achieve sustainable wastewater treatment in the context of circular economy, various technologies have been studied to harness resources in wastewater such as anaerobic digestion for energy recovery, struvite crystallisation for nutrient recovery and reverse membrane for water recovery to reduce environment impact of wastewater treatment. The highly diluted nature of municipal wastewater, however, makes these technologies unfeasible or too costly. Forward osmosis (FO) membrane filtration driven by osmotic pressure has attracted intense attention recently because of its potential for wastewater preconcentration to allow direct use of the above-mentioned technologies for simultaneous water purification and resource recovery. Thus, a promising prospect of forward osmosis filtration as a key unit to design next-generation wastewater treatment plants can be expected due to its smaller footprint, more flexible operation, lower membrane fouling propensity and lower energy consumption if the draw solution is well selected and the process is well designed. Most studies, however, focus on a single or a few model chemicals to investigate FO membrane filtration. Studies on wastewater, and interactive relationships between the chemistry of wastewater and the draw solution, and their effects on flux, membrane fouling and cleaning, pollutant rejection etc, are lacking, which makes the real-world application of FO membrane for wastewater treatment challenging. This PhD project is dedicated to this issue, with the ultimate goal to allow energy, nutrient and water recovery from municipal wastewater cost-effective and sustainable.