Global freshwater resources account for only 2.5% of the Earth's total water supply. Due to pollution, overexploitation, and climate change, approximately 40% of the population faces water scarcity (UN data for 2024). Pollutants in industrial wastewater, domestic sewage, and agricultural runoff exacerbate this crisis. As a core component of wastewater treatment, water treatment chemicals play an irreplaceable role in purifying water and promoting water recycling.
1. Core Functions of Water Treatment Chemicals
· Coagulation and Flocculation:
Chemicals such as polyaluminum chloride (PAC) and polyacrylamide (PAM) neutralize the charge of colloidal particles, forming flocculent sediments, effectively removing suspended solids and colloidal pollutants (such as fiber particles in papermaking wastewater).
· Redox:
Oxidants such as sodium hypochlorite (NaClO) and ozone (O₃) degrade organic pollutants (such as benzene and pesticides) while simultaneously killing pathogenic microorganisms, ensuring the biological safety of the effluent.
· pH Adjustment:
Chemicals such as lime (Ca(OH)₂) and sulfuric acid (H₂SO₄) are used to neutralize acidic or alkaline wastewater, preventing equipment corrosion and meeting the requirements of subsequent treatment processes.
· Scale and Corrosion Inhibition:
Chemicals such as organophosphates and silicates inhibit scaling and corrosion in circulating water systems, extending the life of industrial equipment.
2. Industry Application Scenarios
· Municipal Wastewater Treatment:
Chemical phosphorus removal can reduce the risk of eutrophication and facilitate water reuse.
· Industrial Wastewater Treatment:
Heavy metals in electroplating wastewater can be converted to less toxic forms using reducing agents and then removed through precipitation.
· Seawater Desalination Pretreatment:
Inhibitors and biocides can delay reverse osmosis membrane fouling, reducing energy consumption and operating and maintenance costs.
3. Technological Innovation and Sustainability Challenges
· Green Chemical R&D:
Bio-based flocculants and catalytic oxidation technologies are gradually replacing traditional high-risk chemicals.
· Quantitative Chemical Dosage Control:
Sensors and AI algorithms enable precise dosing, minimizing the secondary impact of chemical residues on the environment.
Conclusion: The Future Role of Water Treatment Chemicals
As global water stress intensifies, water treatment chemicals will continue to evolve towards water conservation, reuse, and zero-discharge systems. As the world's largest producer of water treatment chemicals (holding a 35% market share), China's low-cost, high-efficiency solutions are driving wastewater management in developing countries. In the future, the synergy between technological innovation and environmental regulations will further enhance the value of chemicals in sustainable water resource management.
