Search

There is a nationwide need among policy and decision makers and drinking water supply engineers in India to obtain an initial assessment of water quality parameters for the selection and subsequent development of new riverbank filtration (RBF) sites. Consequently, a snapshot screening of organic and inorganic water quality parameters, including major ions, inorganic trace elements, dissolved organic carbon (DOC), and 49 mainly polar organic micropollutants (OMPs) was conducted at 21 different locations across India during the monsoon in June–July 2013 and the dry non-monsoon period in May–June 2014. At most existing RBF sites in Uttarakhand, Jammu, Jharkhand, Andhra Pradesh, and Bihar, surface and RBF water quality was generally good with respect to most inorganic parameters and organic parameters when compared to Indian and World Health Organization drinking water standards. Although the surface water quality of the Yamuna River in and downstream of Delhi was poor, removals of DOC and OMPs of 50% and 13%–99%, respectively, were observed by RBF, thereby rendering it a vital pre-treatment step for drinking water production. The data provided a forecast of the water quality for subsequent investigations, expected environmental and human health risks, and the planning of new RBF systems in India. [ABSTRACT FROM AUTHOR]

Dissolved organic carbon (DOC) is a sum parameter that is frequently used in water analytics. Highly resolved and accurate DOC data are necessary, for instance, for water quality monitoring and for the evaluation of the efficiency of treatment processes. The conventional DOC determination methods consist of on-site sampling and subsequent analysis in a stationary device in a laboratory. However, especially in regions where no or only poorly equipped laboratories are available, this method bears the risk of getting erroneous results. For this reason, the objective of the present study was to set up a reliable and portable DOC analyzer for on-site analysis. The presented DOC system is equipped with an electrolysis-based decomposition cell with boron-doped diamond electrodes (BDD) that oxidizes the organic compounds to carbon dioxide. Within this study, the influence of different electrode materials and the composition of the applied electrolytes on the DOC decomposition in an undivided electrolytic cell were systematically investigated. Furthermore, some technical aspects of the portable prototype are discussed. After a detailed validation, the prototype was used in an ongoing monitoring program in Northern India. The limit of detection is 0.1 mg L -1 C with a relative standard deviation of 2.3% in a linear range up to 1000 mg L C -1 . The key features of the portable DOC analyzer are: No need for ultra-pure gases, catalysts or burning technology, an analyzing time per sample below 5 min, and a reliable on-site DOC determination.