Sustainable algal wastewater treatment in the Canadian context with energy and phosphorus recovery

加拿大背景下的可持续藻类废水处理与能源和磷回收

• 批准号: RGPIN-2014-05510
• 负责人: Yuan, Qiuyan
• 金额: $ 1.82万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=708286
• 关键词: Sustainable; algal; wastewater; treatment; Canadian

Conventional wastewater treatment is an energy intensive process. In North America, approximately 320 kWh of electricity are utilized to treat 1000 cubic metres of wastewater (Menendez, 2010). For a city the size of Winnipeg, it costs wastewater treatment plants about $7,900 per day for electricity alone (Smyrski, 2013). In addition, there are a number of environmental concerns that are associated with wastewater treatment. First, a key component of wastewater treatment is the conversion of organic carbon into CO2 (a potent greenhouse gas). Second, there has been a steady increase in the quantity of dissolved nutrients (like nitrogen and phosphorus) that need to be removed from wastewater. These nutrients are disrupting the natural ecology of our lakes and rivers. Therefore, there is an urgent need for the development of sustainable and cost-effective technologies that reduce the energy requirements and greenhouse gas emissions associated with water treatment, while continuing to meet, or surpass, the stringent regulations that ensure the safety of the treated wastewater that is discharged back into our public waterways. Algae hold great promise in this regard. Algae use sunlight as an energy source and remove CO2 from the air, producing oxygen in return. Algae also have a demonstrated capacity for the removal of nutrients from wastewater. Therefore, the use of algae for the treatment of wastewater has the potential to provide great environmental and practical sustainability. However, there are a number of hurdles that must be overcome before algae can be made truly economically feasible. First, they must be adapted to grow in relatively cold temperatures, which is particularly relevant in northern regions like Canada. Second, there needs to be a cost effective way to provide sufficient light for algae growth. Finally, methods must be developed for efficient harvesting of the algae, which can subsequently be digested to produce fuel. Our research aims to develop sustainable algal wastewater treatment processes that remove nutrients at low temperatures, recover energy through the production of biogas (by digesting harvested algae), and recover the phosphorus from harvested algae so that it can be recycled as a natural fertilizer. This technology will lead to reduced cost, reduced carbon footprint and greenhouse gas emissions, and will therefore provide direct economic and environmental benefits for all of Canada. In addition, this technology can be exported to other cold climate areas throughout the world to raise the international recognition of our research in this important field of study.

传统的废水处理是一个能源密集型的过程。在北美，处理1 000立方米废水大约需要320千瓦时的电力（Menendez，2010年）。对于像温尼伯这样规模的城市来说，光是电费一项，废水处理厂每天的成本就约为7 900美元（Smyrski，2013年）。此外，还有许多与废水处理相关的环境问题。首先，废水处理的一个关键组成部分是将有机碳转化为二氧化碳（一种强效温室气体）。其次，需要从废水中去除的溶解营养物（如氮和磷）的数量稳步增加。这些营养物质正在破坏我们湖泊和河流的自然生态。因此，迫切需要开发可持续和具有成本效益的技术，以减少与水处理相关的能源需求和温室气体排放，同时继续满足或超过严格的法规，以确保排放回公共水道的处理后废水的安全性。 藻类在这方面有很大的希望。藻类利用阳光作为能源并去除空气中的二氧化碳，并产生氧气作为回报。藻类还具有从废水中去除营养物质的能力。因此，使用藻类处理废水具有提供巨大的环境和实际可持续性的潜力。然而，在使藻类真正经济可行之前，必须克服许多障碍。首先，它们必须适应在相对寒冷的温度下生长，这在加拿大等北方地区尤其重要。其次，需要有一种成本有效的方式来为藻类生长提供足够的光。最后，必须开发有效收获藻类的方法，随后可以消化藻类以生产燃料。我们的研究旨在开发可持续的藻类废水处理工艺，在低温下去除营养物质，通过生产沼气（通过消化收获的藻类）回收能量，并从收获的藻类中回收磷，以便它可以作为天然肥料回收。这项技术将降低成本，减少碳足迹和温室气体排放，因此将为加拿大提供直接的经济和环境效益。此外，这项技术可以出口到世界各地的其他寒冷气候地区，以提高我们在这一重要研究领域的研究的国际认可度。