Arun Kumar is currently working as an Assistant Professor at Dev Bhoomi Uttarakhand University, Dehradun, in the field of forest restoration, bioremediation, and sustainable environment. He has published various research and review papers in reputed journals such as Frontiers in Microbiology, Frontiers in Biosciences, and Environment and Sustainability Indicators in the areas of microalgal bioremediation, biofuels, and bioproducts production from microalgae. He is the author of Microalgae in Waste Water Remediation and Solar Powered Wastewater Recycling, both are published by CRC Press, Taylor & Francis Group. He earned his doctoral degree in Environmental Microbiology from Babasaheb Bhimrao Ambedkar University, Lucknow, India. In his doctoral work, he successfully metabolized a widely used and hazardous insecticide, Chlorpyrifos, by the cyanobacterial strain Oscillatoria sp. CYA8 CPF isolated from paddy fields.

Sandhya Prajapati is currently working at DIT University, Dehradun, in the field of solar photovoltaic applications. She has published research and review papers in several leading journals like Energy Sources, Part A: Recovery, Utilization, and Environmental Effects. She is the co-author of Solar Powered Wastewater Recycling, published by CRC Press, Taylor & Francis Group. She earned her doctoral degree in Electrical Engineering from the Indian Institute of Technology, Roorkee, India. In her doctoral work, she successfully studied the utilization of solar energy in various fields, especially in greywater recycling.