Biosorbents have been highlighted as an alternative method for the removal of contaminants from spills or leaks of oil and its derivatives, since they are biodegradable, are highly available, low-cost, and have a good sorption capacity. This research investigated the sorption capacity of Calotropis procera fiber in natura (CP) and thermally treated (150 °C and 200 °C) for crude oil removal and recovery. The oil sorption tests were carried out in a dry and water (layer) static systems. The assays revealed that CP fiber has excellent hydrophobic-oil properties and good crude oil sorption capacity, about 75 times its own weight (76.32 g/g). The results of the treated fibers, CPT150 and CPT200, showed oil sorption capacities (in 24 h) higher than CP, between 94.31–103.37 g/g and 124.60–180.95 g/g, respectively. The results from sample CPT200 showed that it can be an excellent biosorbent for the removal of crude oil and other derivatives due to its high hydrophobicity, great reuse/resorption capacity, and ability to retain oil within the fiber lumens. Thus, it can be applied in the recovery, cleaning, and removal of petroleum products and its derivatives from spills and leaks in the future.

Aim of the present communication is to show experimental results, and related conclusions, on the electrochemical oxidation (EO) of tartaric acid (TA), which has been oxidized at Ti/PbO2, Ti/Pt, Pt and HBDD electrodes at different current densities in acidic media. TA complete mineralization has been achieved only at HBDD and Ti/PbO2, being higher the faradaic efficiency at the latter electrode. At Pt electrode, the electroxidation was found to be extremely slow, in acidic conditions. The experimental evidence has shown that the main factor is the interaction of the organic substrate and hydroxyl radicals with the electrode surface, during TA oxidation. In the case of the EO of oxalic acid (OA) in acidic media that was previously studied, better results were obtained at the Pt electrode, supporting the idea that the interaction of organic substrate with the electrode surface, was the main determining parameter and based on the results here reported, this idea was confirmed for TA, more complex compound than OA.