Abstract

Wastewater reuse has been widely discussed as an essential strategy to minimize the consumption of drinking water for less noble purposes. During biological wastewater treatment, organic matter is converted into a complex matrix containing a variety of soluble organic compounds. The objective of the present study was to evaluate the removal efficiency of the residual organic load in the final effluent from wastewater treatment plant with a conventional activated sludge process by different coagulants and parameters of coagulation-flocculation process, using dissolved organic carbon (DOC) concentration, molecular weight (MW) size distribution by size exclusion chromatography (SEC) coupled to mass spectrometry (MS), and zeta potential (ZP) analyses. The results showed a DOC removal efficiency up to 45% with iron chloride, and of 38% for aluminum sulfate and 31% for PAC coagulants. ZP was also measured during the procedures and authors conclude that the ZP also does not have a determining role in these removals. SEC and MS assessment was able to detect changes on secondary effluent molecular weight distribution profile after effluent coagulation-flocculation, this technique might be a promising tool to understand the composition of effluent organic matter and be helpful to estimate and optimize the performance of wastewater effluents treatment processes.

摘要

废水回用已被广泛讨论为减少用于次要目的的饮用水消耗量的基本策略。在生物废水处理过程中，有机物被转化为含有多种可溶性有机化合物的复杂基质。本研究的目的是使用溶解的有机碳（DOC）浓度，通过不同的混凝剂和混凝-絮凝过程的参数，评估采用常规活性污泥工艺的废水处理厂最终废水中残留有机物的去除效率。 ，通过体积排阻色谱（SEC）结合质谱（MS）的分子量（MW）大小分布以及zeta电位（ZP）分析。结果表明，氯化铁对DOC的去除率高达45％，硫酸铝为38％，PAC凝结剂为31％。在程序中还对ZP进行了测量，作者得出结论，ZP在这些清除中也没有决定性作用。SEC和MS评估能够检测出废水混凝后二级废水分子量分布的变化，该技术可能是了解废水有机物组成的有前途的工具，有助于估计和优化废水处理性能流程。