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

The global scarcity of clean and safe freshwater, aggravated by climate change, pollution, and population growth, poses a significant threat to human survival and development. According to the United Nations World Water Development Report 2023, around 2 billion people worldwide lack access to safe drinking water, highlighting the urgency to explore alternative water technologies.

1. Desalination Technology

Desalination involves removing salt and impurities from seawater to make it potable.

Merits:
- Abundant Water Source: Provides access to a virtually limitless supply of seawater.
- Reliable: Independent of seasonal changes, ensuring consistent water supply.
Demerits:
- High Energy Consumption: Energy-intensive, contributing to greenhouse gas emissions.
- Waste Disposal: Generates brine waste, posing environmental concerns.

2. Rainwater Harvesting

Rainwater harvesting is the collection and storage of rainwater for reuse in domestic and agricultural applications.

Merits:
- Cost-Effective: Involves low infrastructure and maintenance costs.
- Reduces Groundwater Depletion: Helps recharge aquifers and reduce urban flooding.
Demerits:
- Seasonal Dependency: Efficiency is limited by rainfall patterns.
- Quality Issues: Collected water may require treatment to ensure safety.

3. Wastewater Recycling and Reuse

This technology treats wastewater for reuse in non-potable and potable applications.

Merits:
- Sustainable: Offers a circular water economy by reusing water.
- Reduces Pollution: Lowers wastewater discharge into water bodies.
Demerits:
- High Initial Cost: Requires significant investment in infrastructure.
- Public Perception: Social acceptance can be a barrier due to health concerns.

In conclusion, combining these technologies with sustainable water management practices is vital to mitigate the freshwater crisis and ensure a secure water future for all.