No abstract

No abstract

Human welfare is adversely affected by unwanted and undesirable plants, which convert the useable land into a wasteland. The present study was an attempt to utilize unwanted weeds as a resource with the objective to evaluate the removal efficiency of two low cost adsorbents named as Raw Parthenium hysterophorus (RPH) and Raw Saccharum munja (RSM) for adsorption of dyes like Congo red (CR), Methylene blue (MB) and Crystal violet (CV). The batch study was carried out to study the impacts of various parameters like pH, adsorbent dose, initial dye concentration, contact time and shaking speed. The maximum adsorption for CR was 86% by RPH, MB was 98% and CV was 97% by RSM at dose 1g/100ml, 150rpm, dye concentration 50ppm, time 120 minutes and temperature 25C but optimized pH was varied according to dyes and type of adsorbents, it was ranged from 4 to 10. Adsorption isotherms were applied on the experimental data and found to be Freundlich isotherm was well fitted for RSM and RPH during MB dyes adsorption (r 2 = 0.892 & 0.858) as compared to CR and CV dyes. Low-cost adsorbents have potential to adsorb dyes from wastewater and show applicability in wastewater treatment process.

No abstract

This study evaluated the adsorption of Cr6+ from aqueous solution using dead biomass of aquatic plants Salvinia molesta (Kariba weed) and Typha latifolia (broadleaf cattail). The batch experiments were carried out to study the effects of pH, adsorbent dose, initial metal concentration, contact time, agitation speed in rotation per minute (rpm), and temperature. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize the adsorbent and analyze the functional groups and morphology of the adsorbent, respectively. The hydroxyl and amine groups were the main functional groups involved in the adsorption. Both adsorbents showed good results at pH 1, metal concentration of 20 mg/L for Cr6+ removal, and adsorption equilibrium was attained within 60 min with 150 rpm at 25 °C. The adsorption rate obtained was above 95% for both the adsorbents at a dose of 0.150 g for S. molesta and 0.8 g for T. latifolia. Isotherm and kinetic models were applied on the adsorption data. The monolayer adsorption capacity (qm) was found to be 33.33 mg/g for S. molesta and 10.30 mg/g for T. latifolia. The Langmuir isotherm was better fitted to S. molesta, while the Freundlich isotherm was better fitted to T. latifolia. It was reported that the pseudo-second-order model (R2 = 0.999) was better fitted to the adsorption data for both the adsorbents. The thermodynamic study was also conducted and found the adsorption process was exothermic and spontaneous. Results revealed the good adsorption potential of S. molesta and T. latifolia, and they can be used for the removal of hexavalent chromium.

No abstract

No abstract

No abstract