A comparative biosorption study of sulfide (S-2) by using Lagenaria siceraria fruit based raw biosorbent

Abstract

In batch mode, the adsorption characteristics of S 2¯i ons on Lagenaria siceraria mesocarp, pedicle and peel as raw materials have been studied in comparison to remove sulfide ions from tanneries waste water, under various parameters such as adsorbent dosage, contact time, agitation speed and pH. Maximum removal efficiency (70.96%) was observed on L. Siceraria peel followed by pedicle (51.58%) and mesocarp (29.57%) for adsorbent dosage of 0.10 g/L peel for 50 ml solution of sulfide (20 mg/L). The adsorption process was rapid, and it reached equilibrium in early 20-35 min for all adsorbents. Freundlich and Langmuir adsorption isotherms were employed for mathematical description of the adsorption equilibrium and to explain mechanism of adsorption.The maximum amounts of sulfide ions adsorbed, as evaluated by Langmuir isotherm, was 1.0436 mg/g of LS pedicle, 0.886 mg/g of peel and 0.843 mg/g of pedicle. The adsorption process conforms well to a pseudo second order kinetic model with best adsorption results at pH 8.

Removal of dissolved sulfides from synthetic and industrial solutions by activated carbon derived from Tunisian olive stone

“…The Langmuir model confirms its high efficiency to describe the experimental data, and the adsorption is better by monolayer than multilayer with maximum adsorption capacities equal to 20.833 and 22.72 mg/g for CAP and CAC. The results are consistent with previous works, where the Langmuir model predictions agree with the experimental data of the uptake of sulfides 13,16 . Table 6 presents a comparison of the performance of various adsorbents used for the removal of dissolved sulfides.…”

“…It can be deduced that the adsorption of sulfides by the three ACs is described by the pseudo‐second order kinetic model. Similar results have been noted in previous works where the pseudo‐second order model was found suitable to describe the kinetic of sulfides removal by many adsorbents with different characterizations and from diverse precursors 13,14,16 …”

“…This solid waste was valorized for the preparation of AC, which has been used in many applications, namely adsorption of heavy metals from aqueous solutions 9,10 and pollutant (NO 2 ) from gas effluent 11 . The removal of dissolved sulfides by adsorption was the object of many works by solutions from different origins: synthetic solutions produced in the laboratory (from sodium sulfide 5 ) and industrial solutions rejected from refinery 12 or tanneries wastewater, 13 with concentrations from 140 μg/l 14 to 1000 mg/l 12 . Various adsorbents have been used for the uptake of sulfides, such as granular ferric hydroxide, 15 porous graphitic carbon/manganese dioxyde, 16 bio‐sorbents, 13 and AC 5,12 .…”

“…The removal of dissolved sulfides by adsorption was the object of many works by solutions from different origins: synthetic solutions produced in the laboratory (from sodium sulfide 5 ) and industrial solutions rejected from refinery 12 or tanneries wastewater, 13 with concentrations from 140 μg/l 14 to 1000 mg/l 12 . Various adsorbents have been used for the uptake of sulfides, such as granular ferric hydroxide, 15 porous graphitic carbon/manganese dioxyde, 16 bio‐sorbents, 13 and AC 5,12 . The adsorbents proved efficient removal capacity of sulfides from 29.1 mg/g for granular ferric hydroxide 15 to 500.1 mg/g for graphitic carbon 16 …”

Impact of Sustainable Leadership on Sustainable Performance with Mediating Role of Structural Empowerment: A Study in SMEs [manufacturing (textile) sector] of Pakistan

“…SMEs play a substantial role through their significant contribution towards GDP worldwide (Ayyagari et al, 2007;Heinicke, 2018); in the case of Pakistan, it is 40% w ( Dar et al, 2017). However, it also causes harmful effects on the environment, as most SMEs do not incorporate environmentally friendly practices in their strategies or processes, which are complicated and expensive (Rita et al, 2018).…”