Adsorption of anionic azo dye from aqueous solution using Strychnos potatorum Linn seeds: isotherm and kinetic studies

Abstract

Dyes from several industry effluents are major concern of environmental pollution. In this study, the efficiency of a cost-effective natural adsorbent Strychnos potatorum Linn (Fam: Loganiaceae) seeds on removing reactive orange-M2R dye from aqueous solution was investigated using batch adsorption isotherms at 30 ± 1°C and 120 rpm. The efficacy of the adsorbent system was also studied at various parameters viz. contact time, pH, adsorbent dosage and initial dye concentration. Maximum adsorption (q e = 9 mg/g) was observed at pH 2.0, equilibrium time 6 h, initial dye concentration of 100 mg/L and adsorbent dosage of 0.2 g/100 mL. The unit adsorption of dye, q e (mg/g) increased with increase in contact time and initial dye concentration, while it decreased with increase in adsorbent dosage. The adsorption kinetic studies revealed that it follows pseudo-second-order reaction model. Equilibrium adsorption data followed both Langmuir and Freundlich isotherms with good agreement. These investigations suggest that Strychnos potatorum Linn seeds (SPS) could be used as a low-cost adsorbent in treating textile effluents for dye removal applications. The adsorbent (SPS) was also characterized using Fourier transform infrared spectroscopy, powder X-ray diffraction, and scanning electron microscopic technique.

Rapid, Highly-Efficient and Selective Removal of Anionic and Cationic Dyes from Wastewater Using Hollow Polyelectrolyte Microcapsules

“…Figure 11 b compares the adsorption capacity of P2P and P2 microcapsules with other dye adsorbents reported previously [ 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 ]. Clearly, both P2P and P2 microcapsules display the highest adsorption capacities for ROKG, DY5G, RhB and MB.…”

“… ( a ) Dye removal rate after three cycles of adsorption and desorption, ( b ) Comparison of some recently reported adsorbents with high maximum adsorption capacities to reactive orange, direct yellow, RhB and MB [ 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 ]. ( c , d ) SEM images of the P2P–ROKG micro-particles after three cycles of adsorption and desorption, ( e , f ) SEM images of the P2–MB micro-particles after three cycles of adsorption and desorption.…”

Investigation on the removal of contaminants from washing machine discharge using Strychnos potatorum (clearing nut) – A potential purifying agent

“…Seeds are globose in shape and used for treatment of bronchitis, burning sensation, conjunctivitis, chronic diarrhoea, dipsia, dysentery, diabetes, eye troubles, gonorrhoea, leucorrhoea, hepatopathy, gastropathy, nephropathy, scleritis, renal and vesical calculi [ 22 ]. In accordance with examining the literature, the removal of dye in industries using SP seeds has been studied [ 23 , 24 ]. Mathota Arachchige et al (2022) investigated research on Polyacrylamide-SP seed derived activated carbon composite for removal of hardness in drinking water [ 25 ].…”