REMOVAL OF Cr (VI) FROM AQUEOUS SOLUTION BY ADSORPTION ON THE NATURAL AND ACTIVATED FLUORAPATITE

Abstract

The present paper to study the immobilization of chromium ions Cr(VI) in an aqueous solution by adsorption on a natural phosphate (PN) and activated (PA).The natural phosphate whose main component is fluorapatite Ca10(PO4)6F2. The study of the retention of chromium (VI) ions on natural and activated flourapatite is conditioned by several parameters namely the pH. The initial concentration of metals and the contact time. Results obtained showed that after 40 minutes of contact. The results obtained showed that after 40 minutes of contact, the elimination of chromium (VI) was maximum with a yield of 67.4% for the natural flouraptite and 75.9% for the activated phosphate. Increasing the adsorbent dose (0.5 to 1 g/l) makes it possible to improve the chromium removal efficiency with an initial concentration (10 mg/l) / l. The efficiency of removing chromium (VI) by each adsorbent decreases with the increases of the initial chromium content (2 to 10 mg / l). PH has a significant effect on the retention rate of chromium (VI). The efficiency of removing Cr (VI) is interesting for acid pH. Moreover, the adsorption of this compound we described by the kinetic models of Langmuir and Freundlich.

A Comparative Study on Hexavalent Chromium Adsorption onto Chitosan and Chitosan-Based Composites

“…Depending on the solution pH, the hexavalent chromium ions exist as oxyanions (HCrO 4 − , Cr 2 O 7 2− , and CrO 4 2− ). In pH range 2–6, HCrO 4 − and Cr 2 O 7 2− species predominantly exist in aqueous solution [ 34 , 35 ]. The Cs contains polar functional groups such as amino groups (-NH 2 ) in their molecular structure that can be involved in adsorption [ 36 ].…”

Study of Chromium Desorption From Polluted Soil Around Tannery Industry: Effect of Low Molecular Weight Organic Acid (Lmwoa)

“…The study was carried out at a temperature of 27 °C and a pressure of 1 atm. For pH and time variation were performed in the same way as concentration variation with the range of 3.5 to 8.5 for pH (adjusted by HCl and NaOH) 13 ; and 1-48 h for variation of…”

THE FEASIBILITY OF SAGO BARK (Metroxylon sagu) IN Cu(II) REMOVAL: BATCH AND FIXED BED COLUMN EVALUATION

“…4,5 The adsorption technique is preferred because it is easy operation, high efficiency, low-cost and regeneration ability. 6 The low-cost comes from the utilization of biomass or agricultural waste as adsorbent to remove heavy metals such as barley straw ash 7 , stem tree of soybean 8 , nypa fruticans merr shell 9 , activated carbon from oak leaves 10 and date palm dead leaflets, 11 curry tree carbon, 12 watermelon peel, 13 rice husk, 14 tree sawdust, natural and activated fluorapatite, 15 zeolite, 16 eggshell and sugarcane bagasse. 17 These adsorbents consist of lignocellulosic which has pores, carboxylic and hydroxyl functional group playing a role in metal ion removal.…”