Kinetics, equilibrium and thermodynamic study on removal of Cr (VI) from aqueous solutions using low-cost adsorbent Alligator weed

Hexavalent Chromium Removal by Citrus limonium Shell

“…Furthermore, we examined the ability of different solutions to desorb the metal biosorbed (250 mg/L) for the Citrus limonium biomass, obtaining high efficiency with 0.1 N NaOH and 0.5 N (83% and 62.86% respectively) (Figure 7), which are less than reported for desorption of Chromium(VI) with alkaline solutions (100%, pH = 9.5), 1.0 N NaOH (95%) and a hot solution of NaOH/Na 2 CO 3 (90%), respectively [42,43], and are higher than that reported (14.2%) using 0.2 M NaOH [44]. This indicates that binding of metal to biomass is not as strong and that it can be used up to 6-desorption cycles of removal, which further lowers the metal removal process of niches contaminated with it.…”

Stabilization of Cr(VI) from fine ferrochrome dust using exfoliated vermiculite

“…Cr(VI) adsorption drastically decreases with increasing pH. This is explained by the fact that in aqueous solution, the distribution of Cr(VI) species mainly depends on solution pH and Cr(VI) concentration according to the following equilibria [25] CrO -) and chromate ( 2 4 CrO -), while at high pH (basic conditions), the predominant forms of Cr(VI) are 2 27 CrO -and 2 4 CrO -. Better adsorption observed at low pH is attributed to the large number of H + ions in solution, which protonate the surface of the vermiculite as follows: …”

Adsorbsi Ion Cr (VI) Menggunakan Adsorben dari Limbah Padat Lumpur Aktif Industri Crumb Rubber

“…Walaupun banyak metoda untuk mengolah air limbah yang mengandung logam berat, seperti presipitasi, pertukaran ion, dan membrane filtration, namun adsorpsi merupakan salah satu metoda yang dinilai ekomomis dan ecofriendly untuk menghilangkan Cr dari dalam air limbah. Seperti penelitian adsorpsi Cr menggunakan biomassa dari limbah pertanian corn stalks (Chen et al, 2011), potato starch (Pillai et al, 2013), tumbuhan gulma Parthenium hysterophorus (Venugopal et al, 2011), tumbuhan gulma Alligator (Wang et al 2009), Biji Asam jawa (biji tamarind) dan Serbuk gergaji (Gupta & Babu, 2009adan 2009b, cornelian cherry dan kulit biji almond (Demirbas et al, 2004), daun casuarinas (Ranganathan, 2000). Begitu juga beberapa penelitian menggunakan adsorben dari limbah lumpur juga telah banyak dilakukan seperti penelitian pemanfaatan limbah lumpur sebagai penyerap logam Cr dalam larutan antara lain untuk ion Cr(III) (Liu et al, 2011;Iddou&Quali, 2008), dan Cr(VI) (Wu et al, 2010;Gorzin et al, 2013), serta beberapa penelitian menggunakan lumpur dari sumber yang berbeda seperti diantaranya clarifield sludge dari industri baja (Bhattacharya, 2008), limbah lumpur pengolahan air limbah kota (Wu et al, 2010;Yang et al, 2010), limbah lumpur pabrik tekstil (Hunsom et al, 2013), pabrik kosmetik (Monsalvo et al 2012), pabrik sawit (Zaini et al, 2013), dan pabrik susu (Iddou & Quali, 2008;Benaïssa & Elouchdi, 2011 (Salmariza, 2012;.…”