Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, PR China.
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China.
Water Res. 2022 Aug 1;221:118678. doi: 10.1016/j.watres.2022.118678. Epub 2022 May 26.
Recovery of phosphorus from wastewater through struvite crystallization is one of the most attractive methods. However, the cost of chemical consumption makes this technology is unattractive to some extent. In this work, highly active serpentine was prepared by one-step mechanical activation and then used to recover phosphate as struvite from the black water containing 132.8 mg/L phosphorus and 3144 mg/L ammonia nitrogen. The results indicated that the prepared active serpentine can release magnesium ions and hydroxide ions simultaneously into an aqueous solution and is an ideal raw material for struvite crystallization. The factors for phosphorus recovery in this process mainly include mechanical activation intensity, serpentine dosage, and contact time. For the actual black water, a high recovery rate of phosphorus (>98%) is achieved by using active serpentine as the magnesium and alkali source for struvite precipitation. The recovery product was identified as struvite with a median particle size of 32.96 μm. It was confirmed that the mechanical activation damaged the crystal structure of the raw serpentine, improving the activity of Mg and OH. The undissolved Si-containing particles act as crystal seeds, accelerating the struvite crystallization process. Furthermore, a pilot-scale test was conducted with a rural public toilet in Xiong'an New District, Hebei Province. The results showed that an acceptable phosphorus recovery (98%) could be achieved using active serpentine. Additionally, it was demonstrated that the serpentine process to recover phosphate as struvite reduced the cost by 54.4% in compared with an ordinary chemical process. The active serpentine is a promising dual source of magnesium and alkali for the phosphorus recovery by the struvite method. It has a potential prospect for the large-scale application in phosphorus recovery and struvite fertilizer production.
从废水中通过鸟粪石结晶回收磷是最有吸引力的方法之一。然而，化学消耗的成本使得这项技术在某种程度上不具有吸引力。在这项工作中，通过一步机械活化制备了高活性蛇纹石，然后将其用于从含有 132.8mg/L 磷和 3144mg/L 氨氮的黑水回收磷酸盐作为鸟粪石。结果表明，所制备的活性蛇纹石可以同时将镁离子和氢氧根离子释放到水溶液中，是鸟粪石结晶的理想原料。该过程中磷回收的因素主要包括机械活化强度、蛇纹石用量和接触时间。对于实际的黑水，使用活性蛇纹石作为镁和碱源沉淀鸟粪石，可实现磷的高回收率（>98%）。回收产物被鉴定为鸟粪石，其中值粒径为 32.96μm。研究证实，机械活化破坏了原蛇纹石的晶体结构，提高了 Mg 和 OH 的活性。未溶解的含 Si 颗粒作为晶种，加速了鸟粪石结晶过程。此外，在河北省雄安新区的一个农村公共厕所进行了中试试验。结果表明，使用活性蛇纹石可以实现可接受的磷回收（98%）。此外，与普通化学法相比，用蛇纹石法回收磷酸盐作为鸟粪石可将成本降低 54.4%。活性蛇纹石是鸟粪石法回收磷的镁和碱的双源，在大规模磷回收和鸟粪石肥料生产中具有广阔的应用前景。
