Pounsamy Maharaja, Karmegam Patchai Murugan, Ganesan Sekaran
Environmental Engineering Department, Council of Scientific & Industrial Research (CSIR)-Central Leather Research Institute (CLRI), Adyar, Chennai-600020, Tamil Nadu, India.
Environmental Science Lab, Council of Scientific & Industrial Research (CSIR)-Central Leather Research Institute (CLRI), Adyar, Chennai-600020, Tamil Nadu, India.
Environ Sci Pollut Res Int. 2023 Apr;30(16):47699-47711. doi: 10.1007/s11356-023-25702-5. Epub 2023 Feb 6.
This present study investigated the removal of COD and ammoniacal nitrogen (NH-N) from tannery deliming wastewater (TDLWW) through microbes immobilized carbon consisted a bioreactor (MICCR) and reactive struvite crystallization process. Initially, 90% of the organic content of TDLWW was removed using a MICCR reactor at 24 h retention time. Nanoporous carbon (NPC) was used as the carrier matrix for the MICCR reactor. SEM and AFM images of NPC used in the MICCR reactor identify different microorganisms on its surface. The microbial profile of NPC used in the MICCR was analyzed, and the relative abundance is phyla Firmicutes, 25.64%; Proteobacteria, 43.68%; Bacteroidetes, 6.58%; Cyanobacteria, 2.22%; Actinobacteria, 2.34% reason for organic removal. The removal of organics follows the pseudo-second-order rate kinetics with the rate constant of 1.75 × 10 L COD h. For the reactive struvite crystallization, MgO and NaHPO.2HO were taken as the precipitating agents. The optimum molar ratio for the maximum conversion of NH-N into struvite was obtained as 1:1.4:1.4 (NH-N:MgO:NaHPO.2HO). The volume of struvite precipitate was 48.5 mL/L of TDLWW, and the dry weight was 8.89 g/L. More than 93% of NH-N was converted as the struvite fertilizer. The conversion of NH-N into struvite follows the pseudo-first-order rate kinetics with the rate constant of 1.67 × 10 min. Despite the conversion of NH-N into struvite, COD removal was observed, which confirms the conversion of organic nitrogen into struvite. The struvite was evaluated using SEM, XRD, TGA, DSC, and FT-IR spectroscopic analysis. Hence, the integrated MICCR and the reactive struvite crystallization process can be applied to manage tannery deliming wastewater.
本研究通过由微生物固定化碳组成的生物反应器（MICCR）和反应性鸟粪石结晶过程，研究了制革脱毛废水（TDLWW）中化学需氧量（COD）和氨氮（NH₃-N）的去除情况。最初，在24小时的停留时间内，使用MICCR反应器去除了TDLWW中90%的有机成分。纳米多孔碳（NPC）用作MICCR反应器的载体基质。MICCR反应器中使用的NPC的扫描电子显微镜（SEM）和原子力显微镜（AFM）图像识别出其表面的不同微生物。分析了MICCR中使用的NPC的微生物概况，相对丰度为厚壁菌门25.64%；变形菌门43.68%；拟杆菌门6.58%；蓝细菌门2.22%；放线菌门2.34%，这是有机物去除的原因。有机物的去除遵循准二级速率动力学，速率常数为1.75×10⁻³L COD/(g·h)。对于反应性鸟粪石结晶，氧化镁（MgO）和磷酸二氢钠（NaH₂PO₄·2H₂O）用作沉淀剂。将NH₃-N最大程度转化为鸟粪石的最佳摩尔比为1:1.4:1.4（NH₃-N:MgO:NaH₂PO₄·2H₂O）。鸟粪石沉淀的体积为48.5 mL/L的TDLWW，干重为8.89 g/L。超过93%的NH₃-N转化为鸟粪石肥料。NH₃-N转化为鸟粪石遵循准一级速率动力学，速率常数为1.67×10⁻²min⁻¹。尽管NH₃-N转化为鸟粪石，但仍观察到COD的去除，这证实了有机氮转化为鸟粪石。使用SEM、X射线衍射（XRD）、热重分析（TGA）、差示扫描量热法（DSC）和傅里叶变换红外光谱（FT-IR）分析对鸟粪石进行了评估。因此，集成的MICCR和反应性鸟粪石结晶过程可应用于处理制革脱毛废水。
