The world is facing an acute shortage of clean and safe freshwater. What are the alternative technologies which can solve this crisis? Briefly discuss any three such technologies citing their key merits and demerits. (Answer in 250 words)

Introduction

Water stress requires demand management alongside technologies that expand reliable supply without shifting ecological costs elsewhere.

Three technologies

• Desalination: dependable coastal supply, but energy-intensive and creates brine-disposal risks.
• Wastewater recycling: enables industrial and potable reuse and reduces pollution; it requires advanced treatment, monitoring and public acceptance.
• Rainwater harvesting and managed aquifer recharge: low-energy, decentralised and useful for local resilience, but seasonal, land-intensive and dependent on groundwater quality.

Way forward

Use renewable energy, lifecycle assessment, basin-level planning, leakage reduction, water-efficient agriculture and equitable tariffs. Technology must complement conservation and protect vulnerable communities.

Keywords: desalination, reuse, MAR, circular water economy, brine, water efficiency.