Heavy metals are very common contaminants in industrial waste treatment streams. Due to the fact that many metals are very toxic, they are removed before the waste water is discharged from the facility. The list of most common heavy metal contaminants include lead, copper, chromium, nickel, silver, zinc, mercury, cadmium, and arsenic. The most common way to effectively remove these metals from the waste stream is by precipitating the metal in an insoluble form, such as hydroxides or sulfides. Precipitation by hydroxide formation is the most common method. Many heavy metals are amphoteric, … [Read more...]