How is hazardous waste treated?
There are several options for hazardous-waste management. The most ideal option is to decrease waste at its source, or to recycle the materials for another useful purpose.
Nonetheless, while reduction and recycling are desirable possibilities, they are not seen as the final solution to the hazardous-waste disposal problem. Some amount of hazardous waste will always need to be treated, stored, or disposed of.
Let us understand the treatment of hazardous waste.
Physical treatment of hazardous waste
These processes are extremely useful for separating hazardous materials from non-hazardous waste streams, in order for them to be treated in a more concentrated form, separating various hazardous components for different treatment processes, and preparing a waste stream for ultimate destruction in a biological or thermal treatment process.
Regardless, of the nature of the waste materials or the ultimate technology utilized for treatment or destruction, physical treatment processes are critical to most integrated waste treatment systems.
The following physical processes are widely utilized in waste treatment operations:
1: Screening is a method used to protect downstream pre-treatment systems, by eliminating particles from waste streams.
2: The process of removing suspended solid particles from a waste stream is known as sedimentation. Sedimentation is normally performed by allowing enough time and space, for settling in specific tanks or holding ponds. To encourage the settling of fine particles, chemical coagulating agents are frequently applied.
3: Filtration is the separation of liquids and solids using various porous materials. There are numerous filter types designed to achieve varying degrees of separation.
4: Reverse osmosis separates liquid stream components by exerting external pressure, to one side of a membrane, causing the solvent to flow in the opposite direction.
5: Ultrafiltration works in the same way as reverse osmosis, except the separation begins at higher molecular weights. As a result, dissolved components with low molecular weights will pass through the membrane with the bulk liquid, whereas higher-molecular-weight components will be concentrated due to solvent loss.
Chemical treatment of hazardous waste
Chemical treatment procedures change the chemical structure of waste elements, to produce a benign or less dangerous substance. Chemical processes are appealing because they produce low air pollutants, can often be carried out on the waste generator's premises, and some processes can be planned and built as mobile units.
The following are a few chemical treatment activities that are often employed in waste treatment:
1: Neutralisation is a procedure that uses acids and bases to create a neutral solution, to reduce the acidity or alkalinity of a waste stream. This has shown to be an effective waste management method.
2: Ion exchange is a technique for removing ions originating from inorganic compounds from solutions. The solution is poured through a resin bed, which exchanges ions for the removal of inorganic contaminants. When the bed's ability to remove the component deteriorates, it can be regenerated with a caustic solution.
3: De-chlorination is the removal of chlorine atoms from chlorinated substances, like polychlorinated biphenyls (PCBs). To break the chlorine bond, one of the techniques uses a metallic sodium reagent.
4: Oxidation-reduction is a toxic waste detoxification process in which chemical bonds are destroyed, by the transfer of electronics from one reactant to the next.
Biological treatment of hazardous waste
Biological waste treatment is a catch-all phrase for techniques that use microorganisms, to breakdown organic pollutants into water, carbon dioxide, and simple inorganic chemicals, or simpler organic molecules like aldehydes and acids.
The microorganisms employed in a biological process are typically present in the incoming waste. Microorganisms designed to target certain substances are sometimes put into waste streams.
A biological treatment system's objective is to control the environment for microorganisms, so that their development and activity are promoted, as well as to provide a mechanism of maintaining high concentrations of microorganisms in contact with wastes.
Conclusion
The emphasis on hazardous waste management stems from an endeavour, to address possible dangers to public health and the environment.
Hazardous waste management must include more than just dumping it on the ground. Industries are encouraged to produce less hazardous waste as part of the manufacturing process. Because, toxic wastes cannot be totally eliminated, the only option is to reduce, recycle, and treat waste.
As a result, actions should be done to employ current technologies without endangering the environment.
How can we assist?
Netsol Water has 10+ years of experience in water, wastewater and solid waste treatment. Call +91 9650608473 or send an email to enquiry@netsolwater.com to know more about hazardous waste management and its treatment systems.
