Abstract：
The enrichment of phosphorus (P) and nitrogen (N) in aquatic systems can cause eutrophication. Moreover, P rocks may become exhausted in the next 100 years. A slow-release fertilizer called struvite (MgNH4PO4.6H2O) can reduce surface runoff. However, the high cost of raw material or chemicals is a bottleneck in their economical production. Therefore, incinerated sewage sludge ash, food wastewater, and bittern were combined as the sources of P, N, and Mg, respectively. Sawdust biochar was used to enhance the adsorptive recovery of nutrients. First, recovery kinetics was studied by comparing bittern-impregnated biochar (BtB) with the Mg-impregnated biochar (MgB). Subsequently, the synergistic physical and chemical interactions were observed for P and N recovery. Almost complete PO43-P recoveries were achieved within 10 min for both biochars. However, NH4+-N recovery was stable after 2 h, with 26% recovery by MgB and 20% recovery by BtB. Biochars activated with steam (steam-activated biochar) and KOH (KOH-activated biochar) gave superior activities to those of unactivated biochars and activated carbon (AC) nutrient recovery and struvite purity. Moreover, the activated biochars showed a lower risk of surface runoff, similar to that of AC. Therefore, activated biochars can be used as an alternative to AC for economical struvite production from a combination of wastewater sources.
摘要：
水体系统中磷(P)和氮(N)的富集可引起水体富营养化。此外，在接下来的100年中，P岩石可能会耗尽。一种称为鸟粪石（MgNH4PO4.6H2O）的缓释肥料可以减少地表径流。然而,原材料或化学品的高成本是其经济生产的瓶颈。因此,焚烧污水污泥灰，食品废水,和卤水结合起来作为P的来源，N,Mg,分别。木屑生物炭用于增强养分的吸附回收。首先,通过比较卤水浸渍的生物炭（BtB）和镁浸渍的生物炭（MgB），研究了回收动力学。随后，观察到P和N回收的协同物理和化学相互作用。两种生物炭都在10分钟内实现了几乎完全的PO43-P回收。然而,NH4+-N回收率在2h后稳定，MgB回收率为26%，BtB回收率为20%。用蒸汽（蒸汽活化的生物炭）和KOH（KOH活化的生物炭）活化的生物炭具有比未活化的生物炭和活性炭（AC）养分回收和鸟粪石纯度更好的活性。此外，活性生物炭显示了较低的地表径流风险，类似于AC。因此,活性生物炭可以用作AC的替代品，用于从废水来源的组合中经济地生产鸟粪石。
