The photocatalytic degradation (PCD) of benzenesulfonic acid (BSA) using concentrated solar radiation in a batch as well as a continuous bubble column reactor has been studied. The photocatalytic reaction takes place on the surface of the catalyst material. Therefore, the adsorption behavior of benzenesulfonic acid on the catalyst has also been studied. The effects of presence of anions, which are commonly present in industrial wastewaters, are reported. The effect of pH on the photocatalytic degradation of benzenesulfonic acid was also studied. The photocatalytic degradation studies of benzenesulfonic acid in the novel slurry bubble column indicate that this type of reactor can be used commercially.