The United Nations Sustainable Development Goals (SDGs) are a collection of 17 global goals designed to be a "blueprint to achieve a better and more sustainable future for all." Chemistry plays a crucial role in achieving many of these goals:

● SDG 6: Clean Water and Sanitation:
○ Chemistry is vital for water purification (e.g., chlorination to kill bacteria, chemical coagulation/flocculation to remove suspended particles, advanced membrane technologies for desalination and removal of microscopic pollutants).
○ It's also involved in wastewater treatment, breaking down pollutants before water is returned to the environment.
○ Understanding the chemistry of pollutants (like heavy metals, organic compounds) is essential for detecting and removing them.

● SDG 7: Affordable and Clean Energy:
○ Chemistry is central to developing renewable energy technologies:
■ Solar Cells: Chemical processes are used to manufacture silicon and other materials for photovoltaic cells that convert sunlight into electricity.
■ Batteries: Advanced battery chemistry (e.g., lithium-ion, solid-state batteries) is crucial for storing intermittent renewable energy (solar, wind) and powering electric vehicles.
■ Hydrogen Fuel Cells: Chemical reactions between hydrogen and oxygen in fuel cells produce electricity with water as the only by-product.
■ Biofuels: Chemical conversion of biomass (plants, algae) into liquid or gaseous fuels.

● SDG 12: Responsible Consumption and Production:
○ This is where Green Chemistry directly contributes, aiming to design chemical processes that:
■ Minimize waste generation.
■ Use safer chemicals and solvents.
■ Increase efficiency and use renewable resources.
○ Chemistry is also involved in developing recycling technologies for plastics and other materials, promoting a circular economy.
○ Development of biodegradable plastics and sustainable packaging materials.

● Other SDGs:
○ SDG 2: Zero Hunger: Chemical fertilizers, pesticides, and food preservatives (though with ethical considerations, as discussed earlier).
○ SDG 3: Good Health and Well-being: Development of new medicines, vaccines, and diagnostic tools.
○ SDG 9: Industry, Innovation, and Infrastructure: Development of new materials (e.g., lighter, stronger alloys, smart materials) for construction and manufacturing.
○ SDG 13: Climate Action: Developing technologies for carbon capture and storage, and reducing greenhouse gas emissions from industrial processes.

● Air Pollution Control:
○ Catalytic Converters: In cars, catalysts convert harmful nitrogen oxides and carbon monoxide into less harmful nitrogen, carbon dioxide, and water vapor.
○ Scrubbers: In industrial plants, chemical "scrubbers" remove sulfur dioxide and other acidic gases from exhaust fumes before they are released into the atmosphere. This often involves reacting acidic gases with basic solutions.

● Water Purification: (As mentioned under SDG 6)
○ Coagulation/Flocculation: Chemicals are added to make tiny suspended particles clump together, making them easier to filter out.
○ Chlorination: Chlorine gas or hypochlorite solutions are added to kill bacteria and other microorganisms.
○ Activated Carbon Filtration: Carbon filters adsorb (trap on their surface) dissolved organic pollutants and remove unpleasant tastes/odors.
○ Membrane Technologies: Reverse osmosis and nanofiltration use membranes to physically remove dissolved salts, heavy metals, and microorganisms.

● Biofuel Production: Chemical processes (like fermentation and transesterification) are used to convert biomass (e.g., corn, sugarcane, algae) into biofuels like ethanol (for gasoline blends) and biodiesel (for diesel engines).

● Hydrogen Fuel Cells: These devices chemically combine hydrogen and oxygen to produce electricity, with water as the only by-product. The chemical reactions occur on catalytic surfaces. Developing efficient and durable catalysts is a key chemical challenge.

● Advanced Battery Development: Chemists are constantly researching and developing new battery chemistries that offer higher energy density (store more energy), faster charging, longer lifespan, and improved safety, which are critical for electric vehicles and large-scale grid energy storage.

● Role of Chemistry: As discussed earlier, fertilizers and pesticides, products of chemical innovation, have been instrumental in increasing agricultural output and protecting crops from pests and diseases, thus contributing significantly to global food security.

● Sustainable Agriculture Practices: However, the long-term sustainability of relying heavily on synthetic chemicals is a concern. Chemistry also plays a role in developing more sustainable practices:
○ Smart Fertilizers: Developing fertilizers that release nutrients slowly, minimizing runoff and pollution.
○ Biopesticides: Developing naturally derived or biologically produced pesticides that are less harmful to the environment and non-target species.
○ Soil Chemistry: Understanding soil chemistry to optimize nutrient availability and reduce the need for excessive chemical inputs.
○ Food Preservation: Chemical methods help reduce food waste, making more food available globally.