OPTIMIZATION OF NICKEL (II) AND CHROMIUM (III) REMOVAL FROM CONTAMINATED WATER USING SORGHUM BICOLOR

A central composite design (CCD) under the response surface methodology (RSM)was used to study the effect of three adsorption variables (pH, initial concentration, and adsorbent dosage) in order to determine the optimum process conditions for the adsorptions of Ni (II) and Cr (III) onto sulphuric acid modified sorghum bicolor activated carbon (SBAC).This study yielded removal efficiency of 98.89 % for Ni (II) and 94.27 % for Cr (III) ion under optimal conditions of pH (8), initial metal ion concentration (25 mg/L), adsorbent dosage (10 mg) and pH (7), initial metal ion concentration (5 mg/L), dosage (15 mg);respectively. Statistical analysis of variance results showed a good correlation existed between the experimental and predicted data with R2 values of 0.99 for Ni and 0.98 for Cr. The equilibrium data for Ni (II) adsorption was best described using Freundlich model while Langmuir model best fit Cr (III) adsorption. The mechanism of adsorption for both Ni and Cr adsorptions on SBAC followed Pseudo second order kinetic model.  http://dx.doi.org/10.4314/njt.v36i3.4

Restoring Fertility with Cryopreserved Prepubertal Testicular Tissue: Perspectives with Hydrogel Encapsulation, Nanotechnology, and Bioengineered Scaffolds

New and improved oncological therapies are now able to cure more than 80% of cancer-affected children in Europe. However, such treatments are gonadotoxic and result in fertility issues, especially in boys who are not able to provide a sperm sample before starting chemo/radiotherapy because of their prepubertal state. For these boys, cryopreservation of immature testicular tissue (ITT) is the only available option, aiming to preserve spermatogonial stem cells (SSCs). Both slow-freezing and vitrification have been investigated to this end and are now applied in a clinical setting for SSC cryopreservation. Research now has to focus on methods that will allow fertility restoration. This review discusses different studies that have been conducted on ITT transplantation, including those using growth factor supplementation like free molecules, or tissue encapsulation with or without nanoparticles, as well as the possibility of developing a bioartificial testis that can be used for in vitro gamete production or in vivo transplantation