4.3 Waste and Wastewater Management Sector

Socio-scientific Issues in Waste and Wastewater Management

• Changes in lifestyle and socioculture, growth in infrastructure and the economy, and world population growth increase the discharge of solid waste and wastewater.
• Major issues and effects:
  • Sewage, chemical waste and rubbish discharged into rivers and seas disrupt river, marine and nearby ecosystems.
  • Generation, management and decomposition of solid waste increase greenhouse-gas emissions and contribute to global climate change.
  • Improperly disposed food waste causes environmental pollution.
  • About 268 million tonnes of paper are produced annually; producing 1 tonne of paper requires 2–4 tonnes of tree trunks. Paper is therefore a major contributor to solid waste.

Green Technology Applications

• Effective waste and wastewater management reduces the greenhouse effect efficiently and saves costs.

Prevention and reduction

• Minimise paper use by reusing used paper or using paper only when necessary.
• Prepare household food according to need to prevent food wastage.

Separation and recycling

• Separation of household waste, encouraged by the government since 2015, reduces the disposal of recyclable materials and the amount of solid waste at landfills.

Treatment and processing through biological processes

• Biological treatment converts solid waste into useful organic materials such as organic fertiliser.
• Processing solid waste can turn it into biomass, a renewable-energy resource that can replace fossil fuels as fuel.

5R concept

• The 5R concept replaces the former 3R concept: Refuse, Reduce, Reuse, Recycle and Recovery.
• Adding Refuse at the beginning and Recovery at the end supports the aim of achieving zero waste.

Issue-to-solution chain

Increased waste generation + improper disposal → ecosystem pollution and greenhouse-gas emissions.

Prevention and reduction + separation and recycling + biological treatment and processing + 5R → less landfill waste, useful organic products and renewable energy → lower greenhouse effect and cost savings.