ABSTRACT
Occurrence of polychlorinated dibenzo-p-dioxins (PCDDs), especially 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (2,3,7,8-TCDD), as unwanted contaminants in the synthesis of several useful commercial products such as 2,4,5-trichlorophenol, 2,4,5-trichloro-phenoxyacetic acid (2,4,5-T), pentachlorophenol, and hexachlorobenzene has been well documented. Similarly, commercial polychlorinated biphenyl mixtures (PCBs) have been implicated in the presence of polychlorinated dibenzofurans (PCDFs) in industrial wastewater. Na-montmorillonite was swollen in water and treated twice with a commercially available solution of hydroxy aluminum. The total equivalents of aluminum used were about 30 times the cation exchange capacity of the clay. Fourier transform infrared difference spectra of humic acid bound to hydroxy aluminum-clay and of humic acid in solution have been recorded using a KBr pellet technique to help us understand the mode of binding of humic acid to hydroxy aluminum-clay. Similar Fourier transform infrared (FTIR) studies on hydroxy aluminum-clay alone reveal that the bulk of hydroxy-aluminum may be between clay lamellae.
