Effective removal of pharmaceutical contaminants ibuprofen and sulfamethoxazole from water by Corn starch nanoparticles: An ecotoxicological assessment.

Pharmaceutical pollutants, a vital type of emerging contaminants, have attracted researchers to study their removal from water. In this research, Corn starch nanoparticles (CSNP) have been synthesized and characterized using various analytical techniques. The synthesized CSNP was used for the biosorption of two pharmaceutical drugs, ibuprofen (IBU) and sulfamethoxazole (SUL). The influence of various experimental conditions was optimized through batch study with the removal efficiency of 86.33 % (IBU) and 85.80 % (SUL) at pH 2 and 3, initial concentration of 10 mg/L, 0.01 g of CSNP dosage. The biosorption of IBU follows Temkin, and SUL follows Langmuir isotherm models. The toxicological assessment was performed using the seeds of Vigna mungo (VM) and Vigna radiata (VR) and zebrafish to evaluate the toxic effects of pollutants on these organisms. The LC50 of IBU and SUL on zebrafish before the biosorption process was 209.50 mg/L and 338.84 mg/L. After biosorption, the LC50 values increase to 1435.82 mg/L for IBU and 1317.04 mg/L for SUL. Thus, CSNP is an efficient biosorbent for removing the pharmaceutical pollutants to protect ecological systems.

Valorization of sawdust by mineral acid assisted hydrothermal carbonization for the adsorptive removal of bisphenol A: A greener approach.

sawdust was valorized using acid-assisted hydrothermal carbonization and used in the removal of endocrine disruptor bisphenol A (BPA). The effect of acid addition on the hydrothermal carbonization of sawdust and removal of BPA was studied. Two different hydrochars were prepared using deionized water (HCD) and hydrochloric acid solution (HCAH) as feed water. The prepared hydrochars were characterized using FESEM, EDS, XRD, Raman spectroscopy, FTIR, TGA, and surface area analysis to study the structural and functional changes. Then they were compared in the removal of bisphenol A. Out of the two hydrochars prepared, acid-assisted hydrothermal carbonized hydrochar (HCAH) showed better removal efficiency. Hence, HCAH was used to study the influence of different parameters like pH, adsorbent dosage, and initial bisphenol A concentration by one variable at a time approach. Further, the study of interactive effects and optimization of adsorption of bisphenol A onto HCAH was carried out using RSM-CCD. The isotherm, kinetics, and thermodynamic studies revealed that the adsorption of bisphenol A could be explained by the Freundlich isotherm, pseudo-second-order kinetics fitted well in all the initial BPA concentrations, and the adsorption of bisphenol A onto HCAH was exothermic and spontaneous.

Toxicological assessment and adsorptive removal of lead (Pb) and Congo red (CR) from water by synthesized iron oxide/activated carbon (Fe3O4/AC) nanocomposite.

Heavy metals and dyes are the persistent pollutants causing harmful effects on living organisms in different ecosystems. In current study, removal of Lead (Pb) and Congo Red (CR) from water was performed using Iron oxide/Activated Carbon (Fe3O4/AC) nanocomposite. Ferromagnetic behavior of the nanocomposite is the crucial advantage in separation of nanocomposite after biosorption process. The biosorbent was thermally stable till 800 °C of temperature. The synthesized biosorbent was polycrystalline in nature comprising of elements like C, O, Fe. The influence of various experimental conditions was optimized through batch study with the biosorption capacity of 144.92 mg/g (Pb) and 122.22 mg/g (CR) at pH 5-6, Fe3O4/AC dosage (0.04 g) for 40 mg/L of Pb and CR. Toxicological assessment was performed using Danio rerio and seeds to evaluate the harmful effects of pollutants on these organisms. The phytotoxicity results revealed that growth inhibition of seeds lies between 85.64% and 55.92% (Pb) and 77.94%-51.85% (CR). The LC50 value of Pb on the Danio rerio was found to be 20.98 mg/L. In contrast, we observed significant increase in LC50 value about 86.82 mg/L after biosorption of Pb onto biosorbent.