Neural network for modeling the capture of lead and cadmium ions from wastewater using date palm stones

Abstract

The current theoretical and experimental study was to thoroughly examine the capability of date stones for scavenging cadmium and lead ions from simulated wastewater. Three layers-artificial neural network (ANN) with 115 batch tests proved that the best conditions achieved the highest sorption efficiency (>63% for Cd(II) and > 91% for Pb(II)) where time 1 h, pH 5–6, dosage 5 g/100 mL, speed 100 rpm and temperature 25 °C. A satisfactory matching between the measurements and the ANN outputs was recognized with coefficient of determination greater than 99%. The ANN has also revealed throughout the sensitivity analysis that the initial pH and contact time with importance of 25 and 39% for cadmium and lead ions respectively were considered to be the most influential parameters in the removal process. Among Langmuir, Freundlich, and ANN models, the latter one was well fitted the sorption data. This model was substituted in solute transport equation to describe the spatial and temporal distribution of metal ions through the packed column. From the breakthrough curves, the well agreement between the theoretical and measurements (Willmott’s index almost greater less than 0.97), the date stones sorbent have had greater tendency to sorb lead ions than that of cadmium ones.

Оценка возможности использования отходов железо-магниевого производства для очистки сточных вод от тяжелых металлов (Cd2+, Zn2+, Co2+, Cu2+)

“…Discussion of results. To substantiate the possibility of using iron-magnesium production waste as a material for removing metals from wastewater solution, the following factors influencing the interactions were studied: initial concentration; contact time; waste dosage; pH of aqueous medium [18][19][20].…”

“…Thus, the results showing a linear dependence at the initial stage can be explained by the presence of available active centres, i.e., areas on the surface of iron-magnesium production waste that can interact with the studied metal ions or compete for a certain number in their initial concentration. Further, the number of active centres decreases, therefore, an increase in the concentration of metal ions in the solution over 1,000 mg/l will lead to saturation of waste areas and will not increase the treatment efficiency [9,18,19]. This necessitates research to assess the possibility of selective removal of the studied elements in terms of forming a cascade of biological ponds, taking into account the material composition of the bed and the composition of the filtration dam sensitive to each chemical element.…”

“…The efficiency of initial removal for copper, zinc and cadmium can be associated with the occurrence of a large number of free areas available on the waste surface. As the contact time increases, the number of active centres decreases, and further increase does not lead to significant changes in the treatment process [18,19] (see Table 2).…”