标题: | 低浊含藻原水最适处理药剂及滤材之研究 Optimal Use of Chemicals and Filter Media for the Treatment of Low Turbidity Water with Problem Algae |
作者: | 黄志彬 Huang Chihpin 国立交通大学环境工程研究所 |
关键字: | 混凝;聚矽酸铁;藻类;聚合铁 |
公开日期: | 2012 |
摘要: | 低浊高藻原水常出现以水库为主要水源之水厂原水中,由于藻类密度太低而无法有效的藉 由混沉程序去除,加重净水场过滤单元之操作负荷,甚至阻塞无法出水。前氧化结合混沉程序 常被采用来去稳定且移除水中藻类,但原水之针状或条状藻是很难有效在净水场砂滤程序前被 去除,导致这些藻类阻塞于滤池中,阻碍滤池的操作而致反洗频率增加,再加上滤池中微生物 会以此藻类为食物,于滤池内增生,此会导致滤池内细菌量增加及生物膜的生长。为了避免这 些问题藻类流进滤池,传统混凝及过滤操作技术势必要有所改良。因此本计画首先以最近环保 署公告之净水用药聚矽酸铁(PSI),以提升藻类混凝效率为目的加以改良其成份比,接着研究 不同前氧化剂及加药量对问题藻类于混沉过滤程序移除之影响,最后并评估面临问题藻类出现 时之滤池使用传统滤料及抗生物滤料之操作差异。 首先,在不同季节下原水中各种问题藻类将在现地收集且藉由光学显微镜鉴定,并以实验 室制备之PSI 混凝剂,来评估聚铁型态物种对含藻原水混凝效率及混沉后上澄液过滤效能之影 响,并与Alum 作比较。此外,将评估前氧化结合PSI 及Alum 混沉程序对问题藻类去除之效 率。最终,抗生物滤料(锰砂)及传统滤料(即石英砂)之两种模厂管柱将同时过滤实场沈淀 出流水,并将进行两种滤料之过滤及反洗试验。本研究结果将作为自来水事业单位建立混凝及 过滤处理低浊高藻原水最适化操作策略之参考。 Low turbidity along with abundant algae is frequently found in raw water taken from reservoirs by water treatment plants (WTPs). Because the density of the algae is too low to be effectively removed from the water by coagulation-sedimentation, the burden on the operation of the filtration unit in the WTP is significantly increased. In addition, the algae may clog the filter and slow down or stop the filtration. While a hybrid pre-oxidation/coagulation-sedimentation process is commonly adopted to destabilize and remove the algae in raw water, it is difficult to effectively remove strip or needle algae before the sand filtration process in the WTP because the setting rate of these algae is rather poor. As a result, the filter is easily clogged with these algae, which significantly impedes its operation and causes an increased frequency of backwashing. Meanwhile, microbial hyperplasia may occur in the filter because microorganisms within the filter can feed on the algae cells, resulting in an increase in the quantity of bacteria and biofilms. To prevent the algae from flowing into the filter, the traditional coagulation and filtration technology needs to be improved. Therefore, this study aims to improve the coagulation of algae through preparing the polysilicate iron (PSI) coagulant, a new coagulant approved by the EPA. In addition, the effects of different pre-oxidants of various dosages on algae removal using the coagulation-sedimentation process will be investigated. Furthermore, the differences in the operation of filters equipped with anti-microbial and traditional filter media in the presence of algae will be evaluated. In this study, various problem algae in raw water during different seasons will be collected on-site and identified using a high-resolution optical microscope. The PSI coagulants will be prepared in the lab, which will be used to evaluate the effects of polyferric species and alum speciation on the coagulation of algae-rich raw water, and determine the filtration performance of the supernatants after coagulation-sedimentation. The removal efficiency of the algae by PSI and alum coagulation coupled with a pre-oxidation process will be determined by counting residual algae after coagulation. Then pilot-scale filtration columns equipped with anti-microbial filter media (i.e., manganese sand) and traditional filter media (i.e., quartz sand) will be simultaneously operated to filtrate the effluents of sedimentation unit of WTP, followed by filtration and backwashing experiments of both media. The results of this study will help water utilities to establish optimization strategies for coagulation and filtration operation to treat low turbidity water with abundant algae. |
官方说明文件#: | NSC100-2221-E009-009-MY3 |
URI: | http://hdl.handle.net/11536/96488 https://www.grb.gov.tw/search/planDetail?id=2379850&docId=377168 |
显示于类别: | Research Plans |