Earth is a natural environmental ecosystem where self-remediation continues for ages, but the new trends in resource extraction lead to the depletion of natural resources, highlighting the threats to the ecosystem. Among the various waste materials, e-waste and discarded plastics pose a serious environmental concern due to their short life cycle, which may have lasting effects on the climate, ecosystems, and levels of biodiversity. According to the report of the United Nations Institute for Training and Research, a global record of 62 million tonnes (Mt) of e-waste was produced in 2022, which is more than 82% since 2010 and continues to rise by another 32% by 2030. The mismanagement of e-waste and discarded plastics results in many environmental problems, contaminating soil and water. E-waste also releases several toxic heavy metals to the natural ecosystem, which enter the ecosystem food chains through various sources. Improper management of e-waste and discarded plastics also leads to the loss of many precious and critical metals like lithium, cobalt, and nickel. These global environmental challenges demand more eco-friendly technology, thus integrating waste management with sustainability and business enhancement. Developing countries must urgently prioritize circular economic strategies to attain their sustainable development goals and create innovative methods for recovering materials from waste resources. This chapter highlights the increasing use of modern technologies and approaches for environmental sustainability and circularity.