Almomani Fares A, Örmeci Banu
Department of Chemical Engineering, Qatar University, Doha, Qatar.
Department of Civil and Environmental Engineering, Carleton University, Ottawa, Canada.
Environ Monit Assess. 2018 Jan 20;190(2):90. doi: 10.1007/s10661-018-6468-y.
Monitoring of microalgae in water supplies and industrial applications are becoming increasingly important, yet there are few options available that are simple and accurate, and can provide real-time information. The present work illustrates a new method to determine the concentration of microalgae in water and wastewater using spectrophotometry and the first derivative of absorbance. Chlorella vulgaris was used as an indicator microalga, spiked in water samples representing a range of water qualities (distilled water, surface water, and wastewater), and correlations among C. vulgaris concentrations, absorbance, and the first derivative of absorbance measurements were investigated. In addition, detection limits were established and sensitivity analyses were carried out to determine the lowest C. vulgaris concentrations that can be confidently measured in different water matrices. Finally, the study compared the performance and detection limits of the spectrophotometry-based methods with the well-accepted chlorophyll extraction method. A strong linear relationship (R > 0.97) was found between C. vulgaris concentration and absorbance at 695 nm. Using the first derivative of absorbance improved C. vulgaris detection limits by reducing the effects of the background noise and interferences from other substances. The detection limits established using the first derivative method were 0.47, 0.56, and 1.96 mg TVS/L in distilled water, surface water, and wastewater, respectively. In comparison, the detection limits of the chlorophyll extraction method were found to be 19.6, 38.6, and 48.3 mg TVS/L in the same water matrices. These results indicate that first derivative of absorbance can be successfully used for monitoring of microalgae in surface waters and environmental samples as well as in bioreactors used for microalgae cultivation in industrial applications.
监测供水和工业应用中的微藻变得越来越重要，但目前几乎没有简单、准确且能提供实时信息的方法。本研究展示了一种利用分光光度法和吸光度一阶导数来测定水和废水中微藻浓度的新方法。以普通小球藻作为指示微藻，将其添加到代表一系列水质（蒸馏水、地表水和废水）的水样中，研究了普通小球藻浓度、吸光度和吸光度测量值的一阶导数之间的相关性。此外，确定了检测限并进行了灵敏度分析，以确定在不同水基质中能够可靠测量的最低普通小球藻浓度。最后，该研究将基于分光光度法的方法与广泛认可的叶绿素提取法的性能和检测限进行了比较。发现普通小球藻浓度与695nm处的吸光度之间存在很强的线性关系（R>0.97）。使用吸光度的一阶导数可减少背景噪声和其他物质干扰的影响，从而提高普通小球藻的检测限。采用一阶导数法确定的蒸馏水、地表水和废水中的检测限分别为0.47、0.56和1.96mg TVS/L。相比之下，叶绿素提取法在相同水基质中的检测限分别为19.6、38.6和48.3mg TVS/L。这些结果表明，吸光度的一阶导数可成功用于监测地表水和环境样品中的微藻，以及工业应用中用于微藻培养的生物反应器中的微藻。
