蓝色水工厂:框架与技术

Blue Water Factories(BWFs):Framework and Technologies

在目前的环境压力下,循环经济得到快速发展,而强调纳入生态循环的蓝色发展则突显人类回归自然的属性。传统污水处理虽然是人类排泄物的“清道夫”,但自身高能耗、高物耗且不回收其中的价值资源,使其处于一种“不得不前行,而又很难可持续”的尴尬境地。在蓝色发展指引下,污水处理完全可以藉理念与技术转变为蓝色水工厂。蓝色水工厂强调营养物、生物材料、热/电和水回用等循环,主要针对潜在环境压力涉及的两大问题——温室气体(需碳中和)和磷危机(要磷回收)。蓝色水工厂以被誉为下一代污水处理技术的好氧颗粒污泥为核心工艺,干化焚烧被用作剩余污泥处理/处置方式,强调回收各种价值资源/能源,如前端纤维素、颗粒污泥高值类藻酸盐(ALE)、污泥焚烧电/热、焚烧灰分磷与金属等,特别重视出水余温热能利用。蓝色水工厂在独特智慧控制模式下最终对环境可以实现“净零(Net-zero)”影响,同时获得可观的经济效益。为此,详述了蓝色水工厂之框架及相关技术。

Increased environmental pressures have forced us to develop the circular economy.The blue development focusing on ecological cycles highlights the attribute of human beings going back to nature.Wastewater treatment is a kind of“scavenger”for our feces.However,high consumption of energy and chemical usage and little in valuable resources recovery makes it be in an embarrassing situation:“having to go ahead but being unsustainable”.Based on the blue development principles,appropriate ideas and technologies are required for the transformation of conventional activated sludge treatment process into“blue water factories(BWFs)”.BWFs emphasize four sustainable cycles as nutrients,biomaterials,heat/power and water,focusing on alleviating two potential environmental stresses:greenhouse gases(carbon neutrality needed)and phosphorus crisis(phosphorus recovery required).BWFs take the next generation of wastewater treatment:aerobic granular sludge(AGS)as a key technology,and sludge drying and incineration are applied as the ultimate disposal for excess sludge.Valuable resource and energy is mainly recovered,such as celluloses from influent,highly valuable alginate-like extracellular(ALE)from AGS,heat and power from sludge incineration,phosphate&metals from incineration ash,and especially potential thermal energy from effluent.BWFs can not only realize the“Net-zero”impact on the total environment but also obtain a considerable economic benefit under the control of special smart system.The article introduced the framework and the key technologies associated with BWFs.