Search

This study investigates the effect of reactor design parameters on cadmium removal from industrial wastewater discharged by the Tunisian Chemical Group (TCG) to improve as much as possible efficiency and cost of electrocoagulation (EC) process. Based on an examination of the design parameters one by one, the best cadmium removal was achieved for an inter-electrode distance (die) of 0.5 cm, monopolar connection mode, stirring speed of 300 rev min−1, surface-area-to-volume ratio (S/V) of 13.6 m−1, and an initial temperature of 50 °C. These operating conditions are allowed to achieve efficient removal in a relatively short operating time with the lowest energy consumption and cost possible. The present study proved that the parameters that have an effect on the operating cost are the electrode configuration, inter-electrode distance and S/V ratio. The energy consumption, the pH evolution, and the treatment cost were studied. The investigation of the effect of all the selected optimum EC design parameters together on the removal of cadmium from the TCG wastewater proved that the treatment was highly efficient; 100% of cadmium removal was reached in 5 min, with a very low power consumption (1.6 kW h m−3) and very low cost (0.116 TND m−3). Moreover, EC was found to be capable of removing cadmium as well as other pollutants at the same time from the case-study industrial wastewater. The investigation carried out in this work explores and proposes a very cost-effective treatment method to remove heavy metals from industrial wastewater if compared to results reported about cost of this treatment process through other widely used technologies such as coagulation (4.36 Tunisian National Dinar (TND) m−3) and precipitation (9.96 TND m−3) employed in previous studies. Keywords: Wastewater treatment, Electrocoagulation, Treatment cost, Investigation of reactor design parameters, Cadmium removal, Energy consumption

Letter to the editor

Aromatic and medicinal plants are sources of natural antioxidants thanks to their secondary metabolites. Administration of Pinus halepensis L. (Pinaceae family) in previous studies was found to alleviate deleterious effects of aspirin-induced damage on liver and kidney. The present study, carried out on female rats, evaluates the effects of P. halepensis L. essential oil (EOP) on aspirin (A)-induced damage to liver and kidney. The animals used in this study were rats (n=28) divided into 4 groups of 7 each: (1) a control group (C); (2) a group given NaCl for 56 days then treated with (A) (600 mg/kg) for 4 days (A); (3) a group fed with (EOP) for 56 days then (A) for 4 days; and a group fed with only (EOP) for 56 days and given NaCl for 4 days. Estimations of biochemical parameters in blood were determined using kit methods (Spinreact). Lipid peroxidation levels (TBARS), superoxide dismutase (SOD) and catalase (CAT), glutathione peroxidase (GPx) activities were determined. Histopathological study was done by immersing pieces of both organs in a fixative solution followed by paraffin embeddeding and hematoxylin-eosin staining. Under our experimental conditions, Aspirin at dose 600 mg/kg body weight induced an increase of serum biochemical parameters as well as an oxidative stress in both organs. An increase occurred in TBARS by 108% and 55%, a decrease in SOD by 78% and 53%, CAT by 53% and 78%, and GPx by 78% and 51% in liver and kidney, respectively, compared to control. Administration of EOP given to rats enabled correction in these parameters. It could be concluded that the treatment with P. halepensis L. essential oil inhibited aspirin-induced liver and kidney damage.

Objective: Currently, medicinal plants are found to have biological and pharmacological activities and are used in various domains. This study, carried out on Wistar rats, evaluates the beneficial effects of Artemisia arborscens extract on oestroprogestative-induced damages in kidney., Materials and Methods: Thirty-six 3-month-old Wistar rats were divided into 4 batches of nine each: a control group, a group of rats receiving oestroprogestative treatment, a group undergoing oestroprogestative treatment after receiving Artemisia arborescens extract in drinking water, and a group that received only Artemisia arborescens., Results: Artemisia arborescens extract was found to optimize many parameters which were shifted to pathological values as a consequence of oestroprogestative toxicity: plasma creatinine and urea levels were decreased, uric acid and proteins were restored to normal values. The alteration of renal architecture was also suppressed. In addition, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) activities that had been reduced in kidney of the treated group were restored by Aretmisia arborscens-based treatments and, therefore, the lipid peroxidation level was reduced in the renal tissue compared to the control group., Conclusion: The obtained results confirmed that the Artemisia-based treatment allowed efficient protection against oestroprogestative-induced nephrotoxicity by restoring the activities of kidney. The protective effect of Artemisia arborescens was mainly attributed to antioxidant properties as well as the presence of phenolic acids and flavonoids detected by means of HPLC., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)