Removal of Lead from Industrial Wastewater with Sodium Hydroxide Activated Melon Husk (Published)
Melon (Citrullus colocynthis) husk, a readily available agricultural waste products in Nigeria was used as a low-cost potential adsorbent to get rid of lead from industrial wastewater. Adsorption studies were carried out on NaOH activated melon husks at constant adsorbent mass and adsorbate concentration. The contact time was varied from 1 to 100 minutes at 10 minutes interval. Lead removal was found to be rapid from the first minute and equilibrium was attained within 10 minutes. Lead adsorption by NaOH activated melon husk was found to be less dependent on contact time. Adsorption isotherms correlated well with both Langmuir and Freundlich isotherm models and their R2 values are 1. Experimental data were also evaluated to seek out out kinetic characteristics of the adsorption process. Adsorption process for the heavy metal ion was found to follow pseudo-second order adsorption kinetics with the r2 value of 0.8697. Activated melon husk was found to be efficient as adsorbent in the uptake of Pb(II) ions in industrial wastewater, thus, predisposing it as a suitable alternative for the removal of heavy metals from wastewater.
Keywords: Adsorption, Heavy Metal, Lead, melon husks, wastewater
Distribution of Trace Metals in the Coastal Waters of Caspian Sea, Baku, Azerbaijan (Published)
In 2015, dissolved As, Cu and Pb levels were measured for the winter and summer seasons in the coastal waters of Caspian Sea in Azerbaijan. Ten stations were sampled around the vicinity areas of the Hovsan channel and Hovsan WWTP discharge outfall, while control samples were obtained 3 km away from the effluent. Levels of heavy metals were assessed using ICP-MS. Due to the rapid dilution, the concentrations of trace metals increased from coastal to seaward stations. High values of As and Pb were recorded in the Hovsan channel area and control zone in summer, while in winter it was constant high for both area. The hot spot area for Cu was observed in the Hovsan channel site in winter. Heavy metals and solids were generally considerably deleterious at discharge area. The high levels and behavior of the metals were assessed, and it is therefore, correlated to salinity, nitrites and ammonium. Moreover, As and Cu appear to co-vary more with Ammonium and Nitrite ions in the control area for the winter samples compared to the summer samples.
Keywords: Arsenic, Caspian Sea, Coastal Pollution, Copper, Lead, Trace Metals