Chemical Engineering Department, Jadavpur University, Kolkata, 30033, India.
National Centre for Cell Science, Pune, 411007, India.
J Environ Manage. 2020 May 1;261:110241. doi: 10.1016/j.jenvman.2020.110241. Epub 2020 Mar 2.
A novel Anoxic-Aerobic Process (AnAP) that eliminated the anaerobic process was optimized and operated for the simultaneous remediation of phosphate, nitrate, and chemical oxygen demand (COD) from industrial effluents. Two sequential batch reactors (SBR) with AnAP were established for the treatment of effluent from two industries; phosphate fertilizer (AnASBR_PPL) and dairy industry (AnASBR_DW). The adaptability of the bacterial consortium in the SBRs, dominated by denitrifying phosphate accumulating organisms (DNPAOs), facilitates the stable performance of AnAP for simultaneous nutrient and COD removal. Up to 90% and ~80% of COD removal were achieved in AnASBR_PPL and AnASBR_DW, respectively. Nearly complete denitrification was observed along with phosphate removal accounted for ~90% in both the reactors. Granulation of sludge has been widely reported in aerobic reactors; however, interestingly, in this study, partial granulation of the sludge was observed in both the AnASBRs which facilitated the microorganisms to uptake a minimal amount of phosphate and nitrate even under the aerobic condition. The underlying mechanism of DNPAOs and other associated microbes in the consortium were investigated for microbial diversity by 16S rDNA based targeted amplicon sequencing using the Illumina platform and imputed metagenomic analysis. The dominance of Betaproteobacteria, Alphaproteobacteria, Gammaproteobacteria, and Bacteroidia was observed in AnASBRs. At steady-state operation, the identity of the core community members remained largly stable, but their relative abundances changed considerably in both the reactors as a function of varying industrial effluent. However, population of few strains such as Lactobacteriales, Enterobacteriales changed drastically with respect to the influent, as these strains were predominat in AnASBR_DW but not present in AnASBR_PPL. The dominant strains were the vital contributor to the gene pool encoding for denitrification, dephosphatation, TCA cycle, glycolysis, EPS production, and polyhydroxyalkanoate (PHA) storage, etc. Few less abundant but persistent species were also detected as contributors to these functional groups. It unveiled the TCA cycle remains preferable over conventional glycolysis in both the SBR irrespective of carbon source. The new AnASBR was proved to be an efficient alternative system that is energy efficient with higher ease of operation for the treatment of different industrial effluents without fail.
一种新型的缺氧-好氧工艺（AnAP）被优化并应用于同时修复来自工业废水的磷酸盐、硝酸盐和化学需氧量（COD）。为了处理来自两个行业的废水，建立了两个带有 AnAP 的序批式反应器（SBR）；一个是磷酸盐肥料厂（AnASBR_PPL），另一个是乳制品厂（AnASBR_DW）。SBR 中的细菌菌群（以反硝化除磷菌（DNPAOs）为主导）具有很强的适应性，使得 AnAP 能够稳定地同时去除营养物质和 COD。在 AnASBR_PPL 和 AnASBR_DW 中，COD 的去除率分别达到了 90%和 80%左右。在两个反应器中，硝酸盐的去除率几乎达到了完全去除，同时磷酸盐的去除率也达到了 90%左右。在好氧反应器中，污泥的颗粒化已经得到了广泛的报道；然而，在本研究中，有趣的是，在两个 AnASBR 中，污泥部分颗粒化，即使在好氧条件下，微生物也能够摄取少量的磷酸盐和硝酸盐。通过基于 Illumina 平台的 16S rDNA 靶向扩增子测序和推测的宏基因组分析，研究了 DNPAOs 和群落中其他相关微生物的潜在机制，以研究微生物多样性。在 AnASBR 中观察到β变形菌门、α变形菌门、γ变形菌门和拟杆菌门的优势。在稳定运行时，核心群落成员的身份基本保持稳定，但在两个反应器中，由于工业废水的变化，它们的相对丰度发生了很大的变化。然而，一些菌株的种群（如乳杆菌目和肠杆菌目）与进水相比变化很大，因为这些菌株在 AnASBR_DW 中占优势，但在 AnASBR_PPL 中不存在。优势菌株是编码反硝化、去磷酸化、三羧酸循环、糖酵解、EPS 产生和聚羟基烷酸（PHA）储存等功能的基因库的重要贡献者。还检测到一些较少但持续存在的物种，它们也是这些功能群的贡献者。这表明，无论碳源如何，三羧酸循环在两个 SBR 中仍然比传统的糖酵解更具优势。新型 AnASBR 被证明是一种高效的替代系统，具有节能、操作简便等优点，可用于处理不同的工业废水，而不会出现故障。
