Plasma technology in waste disposal
There are four fundamental states of matter, solid, liquid, gas and Plasma. A matter in plasma state has properties that are unlike properties in other states of that matter. Plasma consists of a mixture of mainly positively charged ions, electrons, and neutral particles. It is found in the stars, including our Sun, in the tails of comets, in flashes of lightning, and in the Northern Lights too. More than %90 of known universe is made up plasma.
It can be created by heating a gas or subjecting it to a strong electromagnetic field applied with a laser or microwave generator. This addition of energy causes the atoms to lose their electrons, leaving both the charged nuclei (ions) of the atom and its electrons in a plasma state. This ionized gas is both kinetically and electrically charged. Plasma state is the only form of matter that can carry energy but remain at cool temperature. This quality allows the use of plasma’s reactive characteristics without the dangerous aspect of large amounts of heat energy.
Two types of plasma application are used, vacuum and atmospheric. Vacuum technology introduces a gas with high frequency electrical discharge under low pressure to treat the various shaped products.
It is created through the addition of energy to a chosen gas. This energy is usually induced through electric fields with either direct or alternative currents. The known usable gases for this process are Oxygen, Hydrogen, Argon, Fluor, Nitrogen containing gases and their mixtures. Although through research and developments, more gases are introduced for using in plasma technology.
Plasma technology has a wide range of applications in the most diverse branches of manufacturing.
■ Electronics
■ Packaging
■ Surface treatment
■ Waste disposal
Electronics: Plasma pretreatment is a key asset for achieving cost-effectiveness and process reliability. It is used for transparent, scratch-proof coating of displays, it significantly reduces the reject rate and ensures a flawless appearance. Prior plasma activation, microfine cleaning and electrostatic discharge ensure that the coating of electrically conductive printing on printed circuit boards will adhere securely. In chip packaging microfine cleaning eliminates the need for vacuum chamber.
Packaging: Plasma technology is used to sterilize packaging. In packaging industry it involves three unique abilities. 1. It removes all unwanted organic contaminants, 2. Treats surfaces or activates a material to gain an increased wettability quality, and 3. It is used to deposit substrates onto a material in order to add desired new qualities.
Surface treatment: This application involves increasing wettability of materials such as fabrics, better printing, and bonding unlike materials during dual-injection molding.
Municipal waste, hazardous waste, medical waste and ash, are very harmful material for natural environment. Specially, hazardous and medical wastes are more dangerous for our natural environment since they can pollute soil and penetrate into underground water resources and contaminate water and therefore our food chain.
A large amount of municipal and medical wastes are generated daily in our cities. Lack of safe storage and processing wastes, cause threats to our health, extra cost to our health system and irreversible damage to our planet.
Conventional waste utilization methods such as burning and burying do more harm since the harmful residues, ash, dust, gases produced by burning or gases generated due to decomposing waste materials in landfill and leachate are byproducts of this method of waste treatment. These materials cannot be filtered even with the usage of most advanced technologies.
The most advanced solution to this problem is plasma utilization for incineration of all kinds of trash.
