Research of technologies of leather production wastewater treatment by filtration-percolation method with baobab fruit shell powder

Wastewater from the leather industry is heterogeneous in nature, containing various organic and inorganic impurities. The presence of heavy metals and sulfides makes these wastewater streams more toxic. Therefore, it is necessary to treat them before discharging into the environment. Traditional methods commonly used for treating wastewater from leather factories are not capable of removing all types of substances present in the discharges in one go. Hence, it is crucially important to search for and develop innovative technologies that can be economically and environmentally effective. Natural mixed wastewater from a leather factory was treated using the filtration-percolation method with the use of waste from the agroforestry complex (baobab fruit shells). The study was conducted under laboratory conditions with 200 grams of adsorbent placed in a Pyrex glass column measuring 100 cm in length and 4 cm in diameter, through which 200 ml of a sample of complex leather factory effluent was passed. The untreated wastewater had initial concentrations of 2630 mg/l for BOD5, 7000 mg/l for COD, 1650 mg/l for suspended solids, 2 mg/l for sulfides, and 10 mg/l for chromium. Filtration-percolation on baobab fruit shell powder achieved a reduction of 86.70% for BOD5, 93.0% for COD, 94.47% for suspended solids, and 100% for sulfides and chromium. The retention of pollutants on the filter matrix (powder from raw baobab fruit shells) is promising and offers an alternative to the use of some extremely expensive filtering materials.