...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Water science & technology >The response of typical South African raw waters to enhanced coagulation
【24h】

The response of typical South African raw waters to enhanced coagulation

机译：典型的南非原水对增强混凝的反应

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Drinking water treatment plants in South Africa rely almost entirely on surface water sources, which are often compromised due to high return flows and indirect reuse. The typical treatment plants focus on the removal of physical and microbial contaminants which include turbidity, colour, chemical compounds and microorganisms. A relatively new concern to this list is natural organic matter (NOM) which has become a major concern in potable water treatment due to its recent regulation. In this study, eight different raw water samples from the various water types found in the country were seasonally collected and treated for the removal UV absorbance at a wavelength of 254 nm (UV_(254)) using enhanced coagulation (EC). The efficacy of EC, which can be employed as a practical technology in the removal of both turbidity and NOM, was evaluated in remaining UV_(254) from these raw water sources. Jar tests were conducted, with ferric chloride used as the coagulant (due to its extensive use as a coagulant in the water treatment industry in South Africa) and specific pH values (initial water pH, 7.0, 6.0, 5.5, 5.0 and 4.5) were chosen as target values guiding the six different coagulant dosages for the jar tests. The pH of the low-alkalinity (<60 mg/L CaCO_3) raw waters were adjusted and raised by the addition of sodium carbonate. The response parameters of the tests were turbidity (NTU), pH and UV_(254). Algorithms for finding the optimum coagulant dosage for UV_(254) removal were developed and consistently applied to all the results. Results showed large variations in the nature of NOM across the country from specific ultraviolet absorbance values. From the UV_(254) values, the concentrations of NOM also varied greatly geographically than temporally. The general trend observed in the EC results suggested that the pH should always be dropped to between 4.5 and 7.0 to lower the amounts of UV_(254) and turbidity to reasonable levels.
机译：南非的饮用水处理厂几乎完全依赖地表水源，由于高回流量和间接回用，这些水源经常受到损害。典型的处理厂集中于去除包括浊度，颜色，化学化合物和微生物在内的物理和微生物污染物。清单中相对较新的关注是天然有机物（NOM），由于其最近的法规，它已成为饮用水处理中的主要关注点。在这项研究中，从该国发现的不同类型的水中采集了八个不同的原水样品，并使用增强混凝（EC）处理了其在254 nm（UV_（254））波长下的紫外线吸收率。在这些原水中残留的UV_（254）中评估了EC的功效，可以将EC用作去除浑浊和NOM的实用技术。进行广口瓶测试，使用氯化铁作为凝结剂（由于在南非的水处理行业广泛用作凝结剂），并且特定的pH值（初始水的pH值为7.0、6.0、5.5、5.0和4.5）为选择的目标值指导广口瓶测试的六种不同混凝剂剂量。通过添加碳酸钠调节和提高低碱度（<60 mg / L CaCO_3）原水的pH。测试的响应参数为浊度（NTU），pH和UV_（254）。开发了寻找用于去除UV_（254）的最佳混凝剂剂量的算法，并将其始终应用于所有结果。结果表明，全国特定NOM吸收值与NOM的性质差异很大。从UV_（254）值来看，NOM的浓度在地理上也比时间上有很大变化。 EC结果中观察到的总体趋势表明，应将pH值始终降至4.5至7.0，以将UV_（254）和浊度降低至合理水平。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号