Abrasives Environment The waste generated is a mixture of abrasive media and the soil being removed. Abrasive blasting is used in marineyards to remove paint from ships and boats. One unusual problem encountered here is that the waste stream will contain toxic biocides used in hull paints to reduce fouling. These biocides are often heavy metals or organometallic compounds. Laboratory testing is required to determine if the waste is hazardous. Marineyards must often meet regulations on release of waste to the ocean. Most blasting systems are closed, in that they allow reuse of the abrasive media. If disposal is required, the use of materials such as wheat starch and bicarbonate of soda may be easier to handle. These abrasive media can be more easily separated from the soil. Abrasive blasting eliminates or reduces the need for solvent disposal. Wheat starch media is biodegradable and is disposed of in a four-step process: An alpha-amylase enzyme is used to liquify the starch media Paint solids are removed via filtration Metal extraction is conducted via ion exchange Aerobic starch is digested to produce carbon dioxide and water. The water is subsequently reused. Parameters affecting the bioremediation process include temperature, pH, and solids/water concentration. State Information | Glossary | Conversion Checklist | Comments Home | Process Advisor | Alternatives | Links | Search All SAGE material, Copyright© 1992, Research Triangle Institute Last Update: 10 March 1995 sage@rti.org http://clean.rti.org/alt.cfm?id=ab&cat=en