State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
Water Res. 2016 Jan 1;88:524-537. doi: 10.1016/j.watres.2015.09.046. Epub 2015 Oct 1.
Among the existing in-situ sludge reduction processes, the oxic-settling-anaerobic (OSA) process is of particular interest because it has shown significant sludge reduction with several advantages. However, an ideal process for practical application must simultaneously incorporate effluent quality with sludge reduction. In this study, an improved OSA system, the stage-aerated anaerobic, anoxic, micro-aerobic, and oxic system combining a micro-aerobic starvation tank (abbreviated as A(2)MO-M system) was developed. Compared with OSA3# (hydraulic retention time (HRT) of 12 h), the A(2)MO-M2# system with optimized HRT of 9 h yielded almost 16.3% less sludge. The average total nitrogen (87.3%) and total phosphorus (91.9%) removal efficiencies in A(2)MO-M2# were 20.6 and 42.2% higher than those in OSA3#. Investigation of the mechanisms of sludge reduction revealed that, except for the main factors of energy uncoupling metabolism (16.7%) and sludge decay (21.2%), enrichment of slow-growing bacteria and lysis-cryptic growth metabolism analyzed by high-throughput 454 pyrosequencing were shown to contribute to sludge reduction in the A(2)MO-M system. On the basis of effluent organic matters (EfOM) measurements, soluble microbial products (SMP) were the major components in EfOM; and different reduction-oxidation (redox) potentials controlled in the OSA and A(2)MO-M systems led to different SMP formation mechanisms. To explore the mechanism and kinetics of SMP formation under different redox potentials, three new components (SUAP, SBAP, and XEPS) were integrated in an extended ASM2d model. Experimental and modeling results revealed that biomass-associated products (BAP) supported a substantial population of SMP that were quite sensitive to different redox potentials. The extended ASM2d model further illustrated that more BAP produced in the alternating anaerobic and aerobic conditions in the OSA system adversely affected its effluent quality.
在现有的原位污泥减量工艺中，好氧-沉淀-厌氧（OSA）工艺因其具有显著的污泥减量效果和多种优点而备受关注。然而，一个理想的实际应用工艺必须同时兼顾出水质量和污泥减量。在本研究中，开发了一种改良的 OSA 系统，即分段曝气厌氧-缺氧-微好氧-好氧系统结合微好氧饥饿池（简称 A(2)MO-M 系统）。与 OSA3#（水力停留时间（HRT）为 12 h）相比，优化 HRT 为 9 h 的 A(2)MO-M2#系统产生的污泥减少了约 16.3%。A(2)MO-M2#中平均总氮（87.3%）和总磷（91.9%）去除效率分别比 OSA3#高出 20.6%和 42.2%。对污泥减量机制的研究表明，除了能量解偶代谢（16.7%）和污泥衰减（21.2%）等主要因素外，通过高通量 454 焦磷酸测序分析发现，慢生长菌的富集和裂解-隐匿生长代谢也有助于 A(2)MO-M 系统中的污泥减量。基于出水有机物（EfOM）的测量，可溶微生物产物（SMP）是 EfOM 的主要成分；而在 OSA 和 A(2)MO-M 系统中控制的不同氧化还原（redox）电位导致了不同的 SMP 形成机制。为了探索不同氧化还原电位下 SMP 形成的机制和动力学，在扩展的 ASM2d 模型中引入了三个新的组分（SUAP、SBAP 和 XEPS）。实验和建模结果表明，与生物质相关的产物（BAP）支持了相当一部分对不同氧化还原电位敏感的 SMP。扩展的 ASM2d 模型进一步表明，在 OSA 系统中交替的厌氧和好氧条件下产生的更多 BAP 会对其出水质量产生不利影响。
