Foladori Paola, Petrini Serena, Andreottola Gianni
Department of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano 77, 38123, Trento, Italy.
Heliyon. 2019 Dec 28;6(1):e03088. doi: 10.1016/j.heliyon.2019.e03088. eCollection 2020 Jan.
The use of microalgae for the treatment of municipal wastewater makes possible to supply oxygen and save energy, but must be coupled with bacterial nitrification to obtain nitrogen removal efficiency above 90%. This paper explores how the concentration of Total Suspended Solids (TSS, from 0.2 to 3.9 g TSS/L) affects the nitrification kinetic in three microalgal-bacterial consortia treating real municipal wastewater. Two different behaviors were observed: (1) solid-limited kinetic at low TSS concentrations, (2) light-limited kinetic at higher concentrations. For each consortium, an optimal TSS concentration that produced the maximum volumetric ammonium removal rate (around 1.8-2.0 mg N L h), was found. The relationship between ammonium removal rate and TSS concentration was then modelled considering bacteria growth, microalgae growth and limitation by dissolved oxygen and light intensity. Assessment of the optimal TSS concentrations makes possible to concentrate the microbial biomass in a photobioreactor while ensuring high kinetics and a low footprint.
利用微藻处理城市污水能够供氧并节约能源，但必须与细菌硝化作用相结合，才能实现90%以上的脱氮效率。本文探讨了总悬浮固体（TSS，浓度范围为0.2至3.9克TSS/升）对三个处理实际城市污水的微藻-细菌联合体硝化动力学的影响。观察到两种不同的行为：（1）在低TSS浓度下为固体限制动力学，（2）在较高浓度下为光照限制动力学。对于每个联合体，都发现了一个能产生最大体积铵去除率（约1.8 - 2.0毫克氮/升·小时）的最佳TSS浓度。然后，考虑细菌生长、微藻生长以及溶解氧和光照强度的限制，对铵去除率与TSS浓度之间的关系进行了建模。评估最佳TSS浓度有助于在确保高动力学和小占地面积的同时，将微生物生物质浓缩在光生物反应器中。
