Acacia Tortilis Seeds as a Green Chemistry Adsorbent to Clean up the Water Media from Cadmium Cations

Abstract

Abstract-The potential use of Acacia tortilies seeds as a new green chemistry adsorbent to reduce cadmium cations from water was evaluated through batch experiments. The Acacia tortilies seeds were characterized by determination of solubility in water and determination of surface area and pore volume as well as determination of cellulose content. The important parameters which affect the adsorption process, such as initial pH, contact time and contact temperatures were studied. The maximum adsorption capacity occurs at pH 3.4 after 2 hours. Two isotherm models include Langmuir and Freundlich were investigated. The maximum adsorption capacity obtained were 706, 807and 1004 mg/g at 293, 303 and 323 K, respectively. Experimental data were also performed to the first-order, pseudo-second order and intra-particle diffusion kinetic models. The results indicated that the adsorption of cadmium cations onto Acacia tortilies seeds followed well second-order kinetics. Thermodynamic parameters,  Gº ,  Hº and  Sº indicated the cadmium cations sorption to be endothermic and spontaneous with increase randomness at solid-solution interface. The adsorption mechanism of cadmium cations onto Acacia tortilies seeds was interpreted. A comparison between adsorption capacity of Acacia tortilies seeds and adsorption capacities of other low cost adsorbents were presented. It was found that, the adsorption capacity of Acacia tortilies seeds was higher than the adsorption capacities of all other low cost adsorbents indicated in this research.

Treatment of Water Contaminated by Ship Oil: Study of Adsorption in a Fixed-Bed Column

“…Both biomasses showed positive and low enthalpy values (less than 40 kJ mol −1 ), showing that the adsorption process is physical and endothermic [42]. The entropy energy of the system was reduced and negative, signaling a minimal change in the system, which demonstrates that the adsorption with oil emulsion may not be fully reversible for the biomasses of this study [43]. The Gibbs energy obtained was positive for the three temperatures with the two biomasses, as described in Table 7, proving that the adsorption process is not spontaneous.…”

Removal of Cupric Ions in Aqueous Solution by Adsorption on Barks of Dacryodes Edulis and Mangifera Indica.

“…. was used to know if adsorption is favorable or unfavorable (Ackacha and Meftah, 2014). This curve shows that in each case, the speed is fast at the beginning and decrease with time.…”

“…The effect of the pH was studied in the interval from 2 to 6 for a contact time of two hours ; the maximum value of the pH equal to 6 was retained to avoid the precipitation of the cupric ions which would be likely to cause an interaction between the phenomena of adsorption and precipitation of Cu(OH) 2 (Ackacha and Meftah, 2014).…”