Chen Zhaobo, Hu Dongxue, Zhang Zhenpeng, Ren Nanqi, Zhu Haibo
State Key Laboratory of Urban Water Resource and Environment, Research Center of Environmental Biotechnology #2614, School of Municipal and Environmental Engineering, Harbin Institute of Technology, 202 Haihe Road, Harbin, China.
Bioresour Technol. 2009 Oct;100(20):4623-31. doi: 10.1016/j.biortech.2009.04.066. Epub 2009 May 23.
The aim of the study was to implement a mathematical model to simulate two-phase anaerobic digestion (TPAD) process which consisted of an anaerobic continuous stirred tank reactor (CSTR) and an upflow anaerobic sludge blanket (UASB) reactor in series treating traditional Chinese medicine (TCM) wastewater. A model was built on the basis of Anaerobic Digestion Model No. 1 (ADM1) while considering complete mixing model for the CSTR, and axial direction discrete model and mixed series connection model for the UASB. The mathematical model was implemented with the simulation software package MATLABTM/Simulinks. System performance, in terms of COD removal, volatile fatty acids (VFA) accumulation and pH fluctuation, was simulated and compared with the measured values. The simulation results indicated that the model built was able to well predict the COD removal rate (-4.8-5.0%) and pH variation (-2.9-1.4%) of the UASB reactor, while failed to simulate the CSTR performance. Comparing to the measured results, the simulated acetic acid concentration of the CSTR effluent was underpredicted with a deviation ratios of 13.8-23.2%, resulting in an underprediction of total VFA and COD concentrations despite good estimation of propionic acid, butyric acid and valeric acid. It is presumed that ethanol present in the raw wastewater was converted into acetic acid during the acidification process, which was not considered by the model. Additionally, due to the underprediction of acetic acid the pH of CSTR effluent was overestimated.
本研究的目的是建立一个数学模型，以模拟两相厌氧消化（TPAD）过程，该过程由串联的厌氧连续搅拌釜式反应器（CSTR）和上流式厌氧污泥床（UASB）反应器组成，用于处理中药废水。基于1号厌氧消化模型（ADM1）建立了一个模型，同时考虑了CSTR的全混流模型以及UASB的轴向离散模型和混合串联连接模型。使用模拟软件包MATLABTM/Simulinks实现了该数学模型。模拟了系统在化学需氧量（COD）去除、挥发性脂肪酸（VFA）积累和pH值波动方面的性能，并与测量值进行了比较。模拟结果表明，所建立的模型能够较好地预测UASB反应器的COD去除率（-4.8-5.0%）和pH值变化（-2.9-1.4%），但未能模拟CSTR的性能。与测量结果相比，CSTR出水模拟的乙酸浓度预测偏低，偏差率为13.8-23.2%，尽管对丙酸、丁酸和戊酸的估计较好，但导致总VFA和COD浓度预测偏低。推测原废水中存在的乙醇在酸化过程中转化为乙酸，而该模型未考虑这一点。此外，由于乙酸预测偏低，CSTR出水的pH值被高估。
