An elementary introduction to treatment technologies
Posted on Tue, Mar 16, 2010 @ 12:35 PM
By Amanda Mendonza,Technical Services Representative
In a world of chemical waste there is a diverse support system for helping to manage and treat the waste. Simply treating chemical waste to meet RCRA LDR regulations is no longer the accepted norm. As landfills are filling up and buzz words like "green" and "sustainable" are redesigning the industry, it is important to become familiar with the treatment technologies available. When deciding which treatment technology to utilize, first and foremost, you need to make sure the technology meets the LDR treatment standard for the chemical (40 CFR 268). Below is a brief description of four treatment technologies: incineration, fuel blending, solvent distillation and metals reclamation.
Incineration
Usually achieved in a high temperature rotary kiln, the main result of incineration is the combustion of organics. If there are no organics, the waste can still potentially be incinerated at an increased cost. However, if the material contains RCRA metals and has no organics then incineration is not an appropriate technology.
Fuel Blending
As it namesake states, this technology is meant for mostly clean fuels (usually organic solvents) with high BTU values to be combined to generate a product sold to customers such as cement kilns as fuel. Although this is not a recycling process, per say, several states recognize this as a stewardship approach to waste management as opposed to incineration and will recognize this technology as such when considering tax breaks.
Solvent Distillation of Solvents from Solid Debris
An alternative to simply combusting solids soaked with or containing high BTU organic solvents is a process known as solvent distillation. Solids, for example rags or wipers, contaminated with solvents are sent into a several-story high distillation unit where high temperatures evaporate off the solvents. These solvent vapors are recondensed and processed as clean fuels. This method reduces the amount of unusable solid waste (ie, rags) and is sometimes considered for state waste minimization tax breaks.
Metals Reclamation
The heavy metals usually get a bad reputation because they don't burn easily and metals stabilization prior to landfill can be a costly management disposal method. However, there is always the possibility of metals reclamation. Of course this option is very dependent on the quantity of recoverable metals present, the current industry monetary value of the metal and the complexity of the waste from which the metals are to be reclaimed. Lead pigs and bricks as well as silver fixers and SRU columns are good candidates for this option. Inorganic and elemental mercury, for example, only have the treatment standard of reclamation. Virtually every time you need to dispose of mercury as a hazardous waste, it will be reclaimed save for a few instances where very low levels of mercury are present in an organic medium. In this case incineration would be a viable option.