Martí N, Barat R, Seco A, Pastor L, Bouzas A
Dpto. de Ingeniería Química, Universitat de València, Avinguda de la Universitat s/n, 46100, Burjassot, Valencia, Spain.
Instituto de Ingeniería del Agua y Medio Ambiente, IIAMA, Universitat Politècnica de València, Camí de Vera, s/n, 46022, Valencia, Spain.
J Environ Manage. 2017 Jul 1;196:340-346. doi: 10.1016/j.jenvman.2016.12.074. Epub 2017 Mar 16.
Interest in phosphorus (P) recovery and reuse has increased in recent years as supplies of P are declining. After use, most of the P remains in wastewater, making Wastewater Treatment Plants (WWTPs) a vital part of P recycling. In this work, a new sludge management operation was studied by modeling in order to recover P in the form of struvite and minimize operating problems due to uncontrolled P precipitation in WWTPs. During the study, intensive analytical campaigns were carried out on the water and sludge lines. The results identified the anaerobic digester as a "hot spot" of uncontrolled P precipitation (9.5 gP/kg sludge) and highlighted possible operating problems due to the accumulation of precipitates. A new sludge line management strategy was simulated therefore using DESASS software, consisting of the elutriation of the mixed sludge in the mixing chamber, to reduce uncontrolled P precipitation and to obtain a P-rich stream (primary thickener supernatant) to be used in a crystallization process. The key operating parameters were found to be: the elutriation flow from the mixing chamber to the primary thickener, the digestion flow and the sludge blanket height of the primary thickener, with optimized values between 70 and 80 m/d, 90-100 m/d and 1.4-1.5 m, respectively. Under these operating conditions, the preliminary results showed that P concentration in the primary thickener overflow significantly increased (from 38 to 100 mg PO-P/L), which shows that this stream is suitable for use in a subsequent crystallization reactor to recover P in the form of struvite.
近年来，随着磷供应的减少，人们对磷回收和再利用的兴趣日益增加。使用后，大部分磷仍留在废水中，这使得污水处理厂成为磷回收利用的重要环节。在这项工作中，通过建模研究了一种新的污泥管理操作，以便以鸟粪石的形式回收磷，并尽量减少污水处理厂中因磷不受控制的沉淀而产生的运行问题。在研究过程中，对水和污泥管线进行了密集的分析活动。结果确定厌氧消化池是磷不受控制沉淀的“热点”（9.5克磷/千克污泥），并突出了由于沉淀物积累可能产生的运行问题。因此，使用DESASS软件模拟了一种新的污泥管线管理策略，该策略包括在混合室中对混合污泥进行淘洗，以减少磷的不受控制沉淀，并获得富含磷的水流（初沉池上清液）用于结晶过程。发现关键运行参数为：从混合室到初沉池的淘洗流量、消化流量和初沉池的污泥层高度，优化值分别为70至80米/天、90 - 100米/天和1.4 - 1.5米。在这些运行条件下，初步结果表明初沉池溢流中的磷浓度显著增加（从38毫克磷 - 磷/升增至100毫克磷 - 磷/升），这表明该水流适用于后续的结晶反应器以鸟粪石形式回收磷。
