Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
J Environ Manage. 2019 Nov 15;250:109401. doi: 10.1016/j.jenvman.2019.109401. Epub 2019 Aug 28.
This study evaluated a novel shortcut nitrogen removal method using a mixed consortium of microalgae, enriched ammonia oxidizing bacteria (AOB) and methanol utilizing denitrifier (MUD) in a photo-sequencing batch reactor (PSBR) for treating ammonium rich wastewater (ARWW). Alternating light and dark periods were followed to obtain complete biological nitrogen removal (BNR) without any external aeration and with the addition of methanol as the sole carbon source, respectively. The results showed that influent NH was oxidized to NO by AOB during the light periods at a rate of 8.09 mg NH-N Lh. Subsequently, NO was completely reduced during the dark period due to the action of MUD in presence of methanol. The high activities of ammonia monooxygenase (AMO) and nitrite reductase (NIR) enzymes revealed the strong role of AOB and MUD for achieving shortcut nitrogen removal from the wastewater. The reduced activities of nitrate reductase (NR) and nitrite oxidoreductase (NOR) at a high concentration of DO, NH and NOin the system further confirmed the nitrogen removal pathway involved in the process. The biomass produced from these experiments showed good settling properties with a maximum sedimentation rate of 0.7-1.8 m h, a maximum sludge volume index (SVI) of 193 ml g- 256 ml gand floc size of 0.2-1.2 mm. In order to describe the growth and interaction among the algae, AOB and MUD for nitrogen removal in the system, the experimental results were fitted to four metabolic models, which revealed best fit of the experimental data due to the models based on algae-AOB and algae-AOB-MUD activities than with the other two models.
本研究评估了一种新型的短程氮去除方法，即在光序批式反应器（PSBR）中使用微藻、富集氨氧化菌（AOB）和甲醇利用反硝化菌（MUD）的混合菌丛处理富铵废水（ARWW）。分别采用交替光照和黑暗周期，在无需外部曝气的情况下，并添加甲醇作为唯一碳源，以获得完全的生物脱氮（BNR）。结果表明，在光照期，AOB 将进水 NH 氧化为 NO 的速率为 8.09mg NH-N Lh。随后，由于黑暗期甲醇存在，MUD 的作用使 NO 完全还原。高氨单加氧酶（AMO）和亚硝酸盐还原酶（NIR）酶的高活性表明 AOB 和 MUD 对实现废水短程脱氮具有重要作用。在系统中高 DO、NH 和 NO 浓度下，硝酸盐还原酶（NR）和亚硝酸盐氧化还原酶（NOR）的活性降低，进一步证实了该过程中涉及的氮去除途径。这些实验产生的生物量具有良好的沉降性能，最大沉降速率为 0.7-1.8m h，最大污泥体积指数（SVI）为 193ml g-256ml g，絮体大小为 0.2-1.2mm。为了描述藻类、AOB 和 MUD 在系统中去除氮的生长和相互作用，将实验结果拟合到四个代谢模型中，结果表明，由于基于藻类-AOB 和藻类-AOB-MUD 活性的模型比其他两个模型更能拟合实验数据，因此这些模型拟合效果最佳。
