Treated oil shale ash and its capacity to remove Cd and Pb from aqueous solutions

Abstract

Cadmium (Cd) is the most highly toxic heavy metal even at a trace level. In this study, the oil shale ash treated material was used as an adsorbent to remove cadmium and lead (Pb) metals/ions from aqueous solutions. The absorbent treated oil shale material was characterized prior to experimental work using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The effects of multiple factors on percent metal removal, including contact time, initial ions concentration and pH, are investigated. Results show that the adsorption capacities of Pb and Cd are 29.15 and 23.81 mgg -1 , whereas removal efficiencies are 56% and 48% in 10 minutes, respectively. Removal efficiency and time of equilibrium are affected by the metal atomic weight (Pb 207.2 u and Cd 112.4 u) and pH values. The equilibrium isotherms were analyzed using Freundlich and Langmuir isotherm models and described by the Freundlich isotherm model indicating a heterogeneous surface of the adsorbent. The calculated Langmuir adsorption constant and maximum adsorption capacity of adsorbent, K L and q max , are 1.313*10 -2 and 25.25, respectively. The Freundlich adsorption constant K F and the characteristic constant of the Freundlich isotherm n are 0.5234 and 1.39, respectively.

Pyrolysis of Domestic Sewage Sludge: Effect of Process Parameters on Biochar Calorific Value

“…On the other hand, more than 95% of the consumed energy in Jordan is being imported from outside the country [3][4][5][6]. The DSS is a heterogeneous biomass characterized by high organic matter content, these biosolids could be a source of clean bioenergy and biofertilizers if they converted thermochemically namely via pyrolysis [7][8][9].…”

“…The DSS is a heterogeneous biomass characterized by high organic matter content, these biosolids could be a source of clean bioenergy and biofertilizers if they converted thermochemically namely via pyrolysis [7][8][9]. Pyrolysis process involves thermochemical decomposition of organic compounds in the absence of oxygen, at a temperature range from 300 to 800 °C [4,10,11]. The main products of the pyrolysis process are recoverable volatile compounds mainly bio-oil, noncondensable gases and biochar (BC), these products are considered green energy sources [12][13][14].…”