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Heavy metal contamination of water is a burning global issue, and enormous importance has been given on easily applicable watertreatment methods namely adsorption. However, search for an efficient and reusable adsorbent is ever-evolving. In this study, activated carbon from highly ligno-cellulosic jute stick (JS-AC), the agricultural by-product of jute (Corchorus olitorius), was evaluated as a new adsorbent for removing cadmium (Cd) from the aqueous medium. The direct and interaction effects of four independent adsorption factors namely, initial Cd(II) concentration (20–100 mg/L), adsorbent dose (0.5–1 g/L), solution pH (3–7), and time (30–180 min) were investigated by applying response surface methodology (RSM). A 24 Box-Behnken matrix model with 3 centre points indicated that the maximum % Cd(II) removal was achieved at the initial concentration, dose, pH and time of 60.87 mg/L, 0.5 g/L, 7, and 30 min, respectively. The adsorption equilibrium was investigated by applying Freundlich, Langmuir, Temkin, and Jovanoic isotherm models while Langmuir isotherm exhibited the best fit (R2 = 0.99). The maximum Cd(II) adsorption capacity value of JS-AC was 73.53 mg/g. Finally, JS-AC was regenerated with 0.1M HNO3 as the desorption medium and reused for five successive cycles. This study indicated that jute stick, the under-utilised agro-residue of a cash crop, could be converted into a valuable product like JS-AC which offers immense application potential as an efficient and reusable adsorbent to treat Cd(II) contaminated aqueous medium before releasing in the environment. [ABSTRACT FROM AUTHOR]

For the first time, jute activated carbon (JAC), a byproduct of the jute industry, was characterised and evaluated for its cleanup efficiency in a mixture of 181 multiclass pesticide residue testing using gas chromatography tandem mass spectrometry (GC-MS/MS). Four commercially-important food matrices including okra, spinach, pomegranate and tea were chosen. Various physico-chemical techniques were used to characterise the material. The cleanup method involved dispersive solid phase extraction (dSPE) using a combination of JAC (5 mg) with 25 mg of primary secondary amine per mL of the sample extract (in ethyl acetate). The findings demonstrated a lower matrix effect and higher signal-to-noise ratio were recorded for JAC. Overall, the method offered satisfactory recoveries for most of the pesticides in all the tested matrices. The cleanup effectiveness of JAC showed superiority over the commercially available, non-renewable dSPE sorbent viz. graphitised carbon black (GCB). With a production cost of only US Dollar ~10/kg, JAC is a low-cost alternative to commercial GCB (cost = US Dollar 11–12/g). The study valorises the potential of JAC and anticipates its large-scale application in food testing laboratories. • Jute activated carbon (JAC) as a cleanup agent in pesticide residue analysis. • JAC provided efficient cleanup in okra, spinach, pomegranate and tea. • The GC-MS/MS method performance was satisfactory for multiclass pesticides. • JAC is a cost-effective alternative of commercially available carbon sorbents. [ABSTRACT FROM AUTHOR]