Algerian researchers explored the use of orange peel in the removal of acidic dyes from industrial effluent from manufacturers of dyes, paper printers, textile dyers, color photography and petroleum products.
The research demonstrates that absorption time depends on the initial concentration of the dyes as well as the chemical structures of the particular dyes being tested, but absorption can occur at just 25 Celsius rather than elevated temperatures. However, strong dyes including Nylosane Blue, Erionyl Yellow, Nylomine Red, and Erionyl Red were absorbed at between 40 and 70 milligrams per gram of orange peel from the samples.

"In laboratory-scale studies, the data show that orange peel has a considerable potential for the removal of dyes from aqueous solutions over a wide range of concentrations," Benaïssa says. "Orange peel may be used as a low-cost, natural and abundant source for the removal of dyes, and it may be an alternative to more costly materials. It may also be effective in removing other harmful or undesirable species present in the waste effluents."
Their findings have been published in the International Journal of Environment and Pollution.