Achilleos P, Roberts K R, Williams I D
Thames Water, Kemble Court, 550 South Oak Way, Reading, RG2 6AD, UK.
School of Civil Engineering and Surveying, University of Portsmouth, 2.50 Portland Building, Portsmouth, Hampshire, PO1 3AH, UK.
Heliyon. 2022 Jul 3;8(7):e09862. doi: 10.1016/j.heliyon.2022.e09862. eCollection 2022 Jul.
Enhanced biological phosphorus removal at wastewater treatment plants that use anaerobic digesters for sludge treatment have historically encountered phosphate precipitation problems in the form of struvite. Literature on struvite is thin which is surprising given it can foul/block the sludge return lines and associated pumps and valves, causing significant operational problems. This study has evaluated if a typical large wastewater treatment plant can overcome this problem by adopting circular economy thinking. The struvite profile based on the supersaturation ratio of (Mg:NH:PO ), pH and temperature demonstrates the potential operational hotspots that can present uncontrolled struvite formation. Based on current struvite monitoring technologies and a cost-benefit analysis, the controlled struvite recovery via an Ostara crystallization reactor has been demonstrated to be economically viable with a pay-back period of less than a decade. An integrated evaluation illustrates the positive environmental impact arising from the utilisation of the recovered product. Economic viability and payback periods will vary according to circumstances, but we recommend that WWTP operators globally consider fitting a crystallisation reactor to appropriate plants, The outcomes and recommendation from this study are particularly timely given the global fertiliser shortage (2022) that is driving up food prices and reducing crop sizes.
在使用厌氧消化器处理污泥的污水处理厂中，强化生物除磷过程历来会遇到以鸟粪石形式出现的磷酸盐沉淀问题。鉴于鸟粪石会堵塞污泥回流管道及相关泵和阀门，引发重大运行问题，关于鸟粪石的文献却很少，这令人惊讶。本研究评估了一座典型的大型污水处理厂是否可以通过采用循环经济思维来克服这一问题。基于（镁：铵：磷）的过饱和比、pH值和温度得出的鸟粪石分布情况表明了可能出现不受控制的鸟粪石形成的潜在运行热点。基于当前的鸟粪石监测技术和成本效益分析，已证明通过奥斯特拉结晶反应器进行受控鸟粪石回收在经济上是可行的，投资回收期不到十年。综合评估表明了回收产品的利用所产生的积极环境影响。经济可行性和投资回收期会因情况而异，但我们建议全球的污水处理厂运营者考虑为合适的工厂安装结晶反应器。鉴于2022年全球肥料短缺导致食品价格上涨和作物种植面积减少，本研究的结果和建议尤为及时。
