Nouri Amir, Zinatizadeh Ali Akbar
Environment Research Center, Department of Applied Chemistry, Faculty of Chemistry, Razi University, Kermanshah, Iran E-mail:
Water Sci Technol. 2018 Mar;77(5-6):1524-1536. doi: 10.2166/wst.2018.028.
Simultaneous removal of carbon and nutrients (CNP) in a single laboratory-scale bioreactor is advantageous in terms of reactor volume and energy consumption. In this study, an innovative up-flow anaerobic/anoxic/aerobic (A2O) single bioreactor with continuous feed and intermittent discharge (CFID) regime equipped with a movable aerator in the reactor height for simultaneous removal of CNP from soft drinks wastewater was successfully designed, fabricated and operated. The effects of four independent variables, i.e. hydraulic retention time (HRT), aerator height, biomass concentration and nitrogen/soluble chemical oxygen demand (N/sCOD) ratio at three levels in the range of 4-8 h, 37-55.5 cm, 4,000-6,000, and 0.05-0.2, respectively, on eight process responses were investigated. The central composite design (CCD) and response surface methodology (RSM) were applied to design the experimental conditions, model the obtained data, and optimize the process. The bioreactor provides three conditions with different dissolved oxygen (DO) (anaerobic, anoxic and aerobic) in a single bioreactor by placing the aerator in the middle of the reactor. As a result, the maximum sCOD, total nitrogen (TN) and total phosphorus (TP) removal were about 100, 92 and 41%, respectively. The optimum region obtained was an HRT of 5-11 h, a mixed liquor suspended solids (MLSS) concentration of 4,000-4,700 mgL, and an aerator height of 46.25 cm, at the N/sCOD ratio of 0.1.
在单个实验室规模的生物反应器中同时去除碳和营养物质（CNP），在反应器体积和能源消耗方面具有优势。在本研究中，成功设计、制造并运行了一种创新的上流式厌氧/缺氧/好氧（A2O）单生物反应器，采用连续进料和间歇出料（CFID）方式，并在反应器高度处配备可移动曝气器，用于同时去除软饮料废水中的CNP。研究了四个自变量，即水力停留时间（HRT）、曝气器高度、生物量浓度和氮/可溶性化学需氧量（N/sCOD）比，分别在4 - 8小时、37 - 55.5厘米、4000 - 6000和0.05 - 0.2的三个水平下，对八个过程响应的影响。应用中心复合设计（CCD）和响应面方法（RSM）来设计实验条件、对获得的数据进行建模并优化工艺。通过将曝气器放置在反应器中部，该生物反应器在单个生物反应器中提供了三种不同溶解氧（DO）的条件（厌氧、缺氧和好氧）。结果，sCOD、总氮（TN）和总磷（TP）的最大去除率分别约为100%、92%和41%。得到的最佳区域为：在N/sCOD比为0.1时，HRT为5 - 11小时，混合液悬浮固体（MLSS）浓度为4000 - 4700 mg/L，曝气器高度为46.25厘米。
