Current Technologies
Typical public water and sewage treatment plants are not designed for, nor capable of, treating wastewater contaminated with hydrocarbons and/or heavy metals and their salts beyond a very low level of contamination. In fact, federal, state and local laws require stringent testing of wastewater prior to discharge into the storm water or sewage system. Generators of wastewater are required to file lengthy periodic reports with the various government agencies monitoring such discharges and often find that their wastewater is too contaminated to meet the discharge requirements and must be disposed via a commercial TSD (treatment, storage, and disposal) facility. This can be quite-to-extremely expensive depending upon the particular contaminants, and their levels of concentration, in the wastewater.
Except for biological processes, which are very limited in the specific types of contaminants they can accommodate, all treatment processes now in use for treating mixed wastewater produce a large quantity of hazardous contaminated sludge which requires further management for its containment/disposal; and, the costs associated with such containment/disposal are very high. The only technology the EPA approves for such disposal is solidification/stabilization. This disposal is expensive and wastes valuable resources that DTIC's process can recover for reuse.
DTIC Solution
DTIC's present plant design allows only about 0.1 ppm DL* (1200-1500 times better than current "free oil" processes' effluent) which assures long-term compliance with EPA regulations without redesign. On-going internal R&D and enhancements to the basic system will assure that DTIC maintains its technological lead and marketplace advantage. (* DL refers to "discharge level" of the amount of contaminant in the water discharged.)
The image on the right shows before and after examples of the oily wastewater treatment process. The beaker on the left contains a mixture of free oils (on the surface) emulsified oils (suspended in the center) and solids on the bottom. The tube in the center contains the same wastewater, as shown in the left beaker, after it has been centrifuged for 30 minutes. The beaker on the right contains the treated water. The pink tint of the processed water results from a red food coloring, added for the initial plant and process testing purposes, and would not normally be seen in the effluent.
Heavy Metals
This is not a pancake you would want to eat! This is dry sludge after treatment of mixed electroplating wastewater. Metal-bearing sludge is only 1 to 2 pounds per ton of wastewater treated, a very significant reduction over current treatment methods in use.
