Devarapalli Venkata Padma; Susarla Venkata Ananta Rama Sastry
Abstract
The aim of this work is to exploit low cost and efficient sorbent for removal of heavy metals from the aqueous solution using Mallet Flower Leaf Powder (MFLP). MFLP is processed into a fine powder and used as a bio-adsorbent. Experiments are conducted to find out the feasibility of metal recovery process ...
Read More
The aim of this work is to exploit low cost and efficient sorbent for removal of heavy metals from the aqueous solution using Mallet Flower Leaf Powder (MFLP). MFLP is processed into a fine powder and used as a bio-adsorbent. Experiments are conducted to find out the feasibility of metal recovery process to reclaim the metals. The adsorption rates of both Chromium and Copper are lowered by 3.4% and 48.4% respectively in contrast to those obtained when only one metal is present in the solution. The presence of Copper along with Chromium has not much affected the adsorption rates of Chromium. There is higher adsorption rate for Chromium than for Copper at different temperatures. In the binary system, the copper adsorption rate is found to be suppressed by the presence of Cr(VI). The uptake of Cr(VI) is higher in the binary system than the single system, while the uptake of Cu(II) is lower in the binary system than the single system. The effect of initial concentration on recovery of Cu(II) from loaded adsorbent decreases up to 60 mg/l where about 68% recovery was found. The maximum recovery for Cu(II) was found to be at an adsorbent dosage in the range 15-35 g. As the initial concentration of Cu(II) increases, the retention of metal on MFLP increases. The data collected are verified with the kinetic studies. The results suggested favorable removal efficiency of copper and chromium from waste water using MFLP.
Mohammad Taghi Kouhiyan Afzal; Ahmad Farrokhian Firouzi; Mehdi Taghavi
Abstract
Zero-valent iron particles at the nanoscale are proposed to be one of the important reductants of Cr(VI), transforming the same into nontoxic Cr(III). In this study zero valent iron nanoparticles(ZVINs) were synthesized and characterized for hexavalent chromium removal from aqueous solutions. Five different ...
Read More
Zero-valent iron particles at the nanoscale are proposed to be one of the important reductants of Cr(VI), transforming the same into nontoxic Cr(III). In this study zero valent iron nanoparticles(ZVINs) were synthesized and characterized for hexavalent chromium removal from aqueous solutions. Five different zero-valent iron nanoparticle types comprising of bare and stabilized ZVINs with poly acrylamide(PAM), polyvinyl pyrrolidone(PVP), polystyrene sulfonate(PSS) and guar gum(GG) were synthesized and employed in this study. The sizes of zero-valent iron nanoparticles were found to be 40, 14, 17, 29 and 34nm, using transmission electron microscopy (TEM), corresponding to bare zero valent iron nanoparticles(ZVINs), poly acrylamide(PAM), guar gum(GG), poly styrene solfunate(PSS) and polyvinyl pyrrolidone(PVP) stabilized zero valent iron nanoparticles (ZVINs) respectively. The trend in the sizes of ZVINs with various stabilizers in the decreasing order was found to be bare ZVIN > PVP-ZVIN >PSS-ZVIN> GG-ZVIN> PAM-ZVIN respectively. Results showed that by increasing hexavalent chromium concentrations from 20 to 100 mg/L, the Cr(VI) efficiency removal decreased significantly. When the ZVINs concentrations increased from 2 to 10 gr/L(0.1 to 0.5g per 50 mL), the Cr(VI) removal efficiency enhanced. The most effective treatments of ZVINs and Cr(VI) for hexavalent chromium removal from solutions were 10 gr/lit (0.5g per 50 mL) and 20 mg/L respectively, so the efficiency of bare and polymer stabilized-ZVINs on Cr(VI) removal from solutions was found to be in the following order: bare ZVINs < PVP-ZVINs <PSS-ZVINs< GG-ZVINs< PAM-ZVINs.