Green synthesis of - nanoparticles using leaf extracts of and their application for the photocatalytic degradation of a model toxic dye, Congo red.

In the present work nanoparticles were synthesised for the first time using phytochemical extracts from leaves and applied in the photocatalytic degradation of Congo Red in the presence of Light Emitting Diode warm white light. The photocatalytic degradation was optimized with respect to nanoparticle dosage, initial Congo Red concentration, and degradation time. The optimum conditions for nanoparticle synthesis was pH 9, leaves extracts of dosage 4 g 100 mL, Zirconia, Cerium and Zinc metal ion concentration 0.

Characterization and reusability suggestions of the sludge generated from a synthetic acid mine drainage treatment using sodium ferrate (VI).

Mining activities are the main cause of generation of the voluminous sludge waste, loaded with metals precipitated from the treatment of acid mine drainage (AMD) and this is always disposed to the landfill. This study aimed at characterizing and suggesting the reusability potential of AMD sludge to reduce the environmental problem caused by its accumulation so that it could become a valuable material. The sludge was obtained after treating a synthetic AMD with a green oxidant sodium ferrate (VI) (NaFeO) that was prepared by a wet oxidation method.

Determination of DDT and metabolites in surface water and sediment using LLE, SPE, ACE and SE.

Surface water and sediment samples collected from Jukskei River in South Africa, were subjected to different extraction techniques, liquid-liquid (LLE), solid-phase extraction (SPE), activated carbon extraction (ACE) and soxhlet extraction (SE) for sediment. The samples were extracted with dichloromethane, cleaned in a silica gel column and the extracts quantified using a Varian 3800 GC-ECD. The percentage recovery test for 2,4'DDT, DDE and DDD and 4,4'DDT, DDE and DDD in water ranged from 80%-96% and 76%-95% (LLE); 56%-76% and 56%-70% (SPE) and 75%-84% (ACE), respectively; while that recoveries for sediment samples varied from 65%-95% for 2,4'DDT, DDE and DDD and 80%-91% for 4,4'DDT, DDE and DDD.

Application of maize tassel for the removal of Pb, Se, Sr, U and V from borehole water contaminated with mine wastewater in the presence of alkaline metals.

In this study, the removal of Pb(II) from aqueous solutions by tassel powder was studied and optimised. Batch experiments were conducted on simulated solutions using tassel powder adsorbent and the effects of contact time, pH and concentration on the extent of Pb (II) removal was studied. Equilibrium and kinetic models for Pb(II) sorption were developed by considering the effect of contact time and concentration at optimum pH 4 and fixed temperature(25 degrees C).

Improved derivatisation methods for the determination of free cyanide and cyanate in mine effluent.

Generally, the level of cyanide in waste effluents is too high to be discharged into the environment. Consequently, treatment regimes are necessary in order to protect the environment. However, the cost of most of the treatment methods is expensive and not sensitive enough and, therefore, cannot always be justified.