Shweta Tyagi

Arsenic speciation analysis and remediation techniques in drinking water

Abstract Arsenic is present in environment in trace amounts in rocks, soil, water and air but its toxicity effects are highly dependent on its chemical forms; inorganic and organic. There is a direct association between elevated arsenic exposure through drinking water and prevalence of different types of cancers. Present review describes the brief account of arsenic chemistry with reference to water and environment which is relevant to its toxicity arising out of different arsenic species and finally its remediation technologies. The quantification of arsenic species is difficult owing to the low concentration of arsenic in drinking water which is relatively lower than detection limits of modern analytical methods. New hyphenated techniques with more advanced tools have therefore, been discussed in the present paper which are being used in arsenic speciation analysis. The present review also highlights the importance to identify and quantify each chemical species of arsenic as more than 20 arsenic compoun...

Advanced and Hyphenated Techniques for Nano-Level Analysis of Iron in Water

The monitoring of iron in water sources has been and will be of immense importance because modern applications require accurate and reliable results of quantification of low levels of iron in water being used in specialized fields. Although iron in drinking water supplies is found to exist in four forms, Fe(II), Fe(III), iron bacteria, and organic iron, no single method is capable of nano-level analysis of all these forms of iron. Hence, various advanced and hyphenated techniques are being used for the determination of iron species in drinking water sources that give precise and reliable results and reduce human effort. The present article reviews the new generation of equipment and a variety of modified and hyphenated instrumental techniques for iron analysis. Additionally, this review describes detection limits of widely used hyphenated techniques for quantitative analysis of four forms of iron in water down to ultratrace levels.

Studies of River Water Quality Using River Bank Filtration in Uttarakhand, India

The poor water quality, bacterial contamination, seasonal variation, uncertainty in monsoon, lack of sustainability etc. are some major challenges of the water sector in the Himalayan region of India. To tackle the major problem of water quality, River Bank Filtration (RBF) has been applied in Uttarakhand as a domestic water pre-treatment technology. This technique is found to be effective for removal of turbidity and bacterial contamination present in surface water of four rivers of Uttarakhand, namely Alaknanda, Mandakini, East Nayar, and Pinder. The present paper reveals the improved water quality of rivers produced through RBF in a sustainable manner as compared to surface river water being supplied for drinking purpose. The classification of water quality using Pearson correlation followed by Piper trilinear and Chadha’s diagrams further provide support to the better water quality through RBF. Moreover, the results of Water Quality Index (WQI) also reflect the excellent water quality with ‘A-Grade’ of all river water samples obtained after RBF process in comparison to normal river water samples having good water quality with ‘B-Grade’ except the Srinagar site, where the river water sample was found to be unsuitable for drinking purpose with ‘E-Grade’. Alluvial deposits of RBF sites along the banks of the four rivers show the potential of replication of RBF at large scale in the hill state of Uttarakhand.

Evaluation of Water Quantity and Quality Status of Drinking Water Sector of Uttarakhand, India

Abstract The freshwater resources are under siege in Uttarakhand. More than 2 million people do not have consistent access to clean water and more than twice that number lack access to sanitation in hills as well as plan areas of the state. Surface drinking water sources are disappearing and level of ground sources is falling abruptly. Moreover, water quality in almost all the districts of Uttarakhand is in decline. The water sector in Uttarakhand is facing severe challenges with respect to drinking water supply of adequate quantity and good quality. The shortage of water is crucial in both Kumaun and Garhwal regions of state. The quality being supplied is in poor condition and in many areas getting contaminated due to various natural, human and industrial activities. The paper evaluates and describes the quantity and quality status of drinking water sector of Uttarakhand. The organizational as well as technical reforms are required along with proper engineering and infrastructural support suitable for hill conditions of state. However, current and future crises will not resolved only through new and technological advances, but changing the way we use and manage our water sources.