The treatment of water and wastewater involves the use of various chemicals to purify water for drinking and domestic purposes and treat wastewater before discharging it back into the environment. These chemicals play a vital role in killing germs, removing impurities, and managing sludge.
Coagulants and Flocculants
One of the first steps in water treatment is the removal of dirt and other suspended solids from raw water sources like lakes and rivers. This is achieved through coagulation and flocculation using chemicals like alum (aluminum sulfate) and ferric chloride. Coagulants neutralize the electric charge of small suspended particles in water, allowing them to stick together. Flocculants like polymers then help form these particles into larger, heavier clumps or "flocs" that are easier to remove by sedimentation or filtration.
Around 200-300 mg/l of alum or ferric chloride is often used for coagulation. A small amount of polymers, usually 1-2 mg/l, acts as an aid to improve flocculation. Together, coagulants and flocculants are highly effective at removing turbidity, colour, and microorganisms from raw water. They play a key role in the primary treatment stage.
Disinfectants
Disinfection is essential to kill harmful pathogens and make water safe for human consumption through water and waste water treatment chemicals. Chlorine in the form of hypochlorites and chlorine gas is the most widely used disinfectant globally. It provides effective residual disinfection in distribution systems to prevent bacterial regrowth. Around 0.5-1 mg/l free chlorine residual is normally maintained in treated water.
Other disinfectants gaining popularity include chloramines (formed by reacting chlorine with ammonia), chlorine dioxide, ozone and ultraviolet light. While chlorine is cheaper and leaves residual protection, alternatives like ozone are growing in use due to formation of fewer disinfection by-products. Disinfectants ensure microbiological safety of drinking water.
Corrosion Inhibitors
Water passing through pipes can corrode them, releasing metals like lead into the water. Corrosion inhibitors form a protecting film on pipe surfaces to prevent this. Commonly used ones include orthophosphates, silicates, carbonates and zinc. Around 1-5 mg/l of these chemicals is sufficient. They help extend infrastructure life and protect public health by minimizing leaching of metals into drinking water.
pH Adjusters
The acidity or alkalinity of water needs to be properly controlled for its treatment and disinfection to work efficiently. This is achieved through pH adjustment using chemicals like lime, caustic soda (sodium hydroxide) and carbon dioxide. They raise or lower the pH to optimal levels - usually within the range of 6.5-8.5 - for processes like coagulation, corrosion control and disinfection. Around 10-100 mg/l of these chemicals ensure the treatment process proceeds smoothly.
Filtration Aids
Several filter aids are used to improve solid-liquid separation in processes like rapid sand filtration, cartridge filtration and membrane filtration. Diatomaceous earth (diatomite) and perlite are popular precoat filters added as a thin layer on filter media to enhance removal of fine solids. Polymers also aid in sludge dewatering by binding water during filtration. They lengthen filter run times and improve overall plant performance.
Sludge Conditioners
Chemical conditioning using polymers plays a key role in sludge thickening and dewatering, the final stage of wastewater treatment before safe disposal. Commercial polymer products like cationic and anionic polyacrylamides help consolidate sewage sludge by electrostatic attraction and Formation of bridges between suspended solids. This increases solids concentration for easier handling and reduces moisture content upto 70-80%. Around 1-5 mg/l of polymers significantly boost conditioning efficiency.
Neutralizing Agents
Neutralizing chemicals are essential for managing industrial wastewaters with extreme pH before discharging them. They bring pH to acceptable levels suitable for the environment and sewers. Common neutralizing agents include acids for high pH effluents and alkalies for acidic wastes. Sulfuric acid and caustic soda are frequently utilized for this purpose in addition to other specialized chemicals depending on the industry. Proper pH control is necessary to meet discharge compliance.
The safe treatment of water is unthinkable without usage of these treatment aids and process chemicals. They work behind the scenes to remove impurities, disinfect pathogens, inhibit corrosion, facilitate filtration and condition sludge efficiently. With growing populations putting higher demand on water resources, chemical suppliers will continue playing a vital supporting role in maintaining water quality and public health worldwide. Appropriate treatment ensures access to clean drinking water for all.
Explore Our More Blogs Here: https://www.ukwebwire.com/water-and-wastewater-treatment-chemicals-essential-for-ensuring-clean-drinking-water/
Explore more trending article on this topic: https://captionssky.com/isohexadecane-a-synthetic-emollient-for-wide-range-cosmetic-applications/
Global Water and wastewater treatment equipment market Information by Treatment Type (Membrane Separation, Disinfection, Sludge treatment and Others), By Application (Municipal and Industrial) And Region - Forecast To 2023
The demand for water and wastewater treatment equipment is growing significantly, over the years.
Various industries such as food & beverages, chemicals, pharmaceuticals, pulp & paper, power, metal & mining, semiconductors, textiles, and oil & gas, call for the usage of clean water and therefore drive the growth of the market during the forecast period.
The other factors contributing growth in the market are stringent government emission regulations and increasing urbanization.
The global water and wastewater treatment equipment market is expected to experience opportunities during the forecast period, owing to factors such as increasing scope for operations & maintenance, and growth in emerging economies.
The growing population, technological developments, rapid urbanization, and growth in infrastructure have augmented the growth of these equipment in the emerging markets.
