The kinetics of uptake and recovery of lanthanum using freshwater algae as biosorbents: Comparative analysis

Abstract

In this study, the adsorption and desorption kinetics of lanthanum (La) on micro algal cells was investigated. The internal transcribed spacer (ITS) and 18S ribosomal RNA gene (rRNA) were used for molecular identification of the species. The algal species were found to have 95-98 % identities to Desmodesmus multivariabilis, Scenedesmus acuminutus, Chloroidium saccharophilum and Stichococcus bacillaris. The species were cultured and tested independently. Desmodesmus multivariabilis was found to be the most efficient at adsorbing lanthanum with a maximum sorption capacity (q max ) of 100 mg/g and a high affinity (b) of 4.55 L/g. Desorption of La was also highest in Desmodesmus multivariabilis with recovery up to 99.63% at initial concentration as high as 100 mg/L. Desorption data fitted best to the modified pseudo second-order with a better correlation coefficient (R 2 ) of ≤ 0.98 than first order model. The results showed feasibility of lanthanum recovery using algal sorbents, a cost effective method.

Metal sorption by algal biomass: From batch to continuous system

“…(14) and (15) are helpful in indentifying the role of intra-particle and external mass transfer processes, respectively, in biosorption. However, these equations fail to explain which one of these two processes has a greater influence on the rate of metal sorption.…”

“…Freshwater green microalgae, such as, species of Chlorella, Scenedesmus and Chlamydomonas, also possess excellent metal sorption ability as evidenced by their high q max (the parameter reflecting maximum metal sorption capacity). Birungi and Chirwa [15] have reported biosorption of La(III) by freshwater algal materials. Zhou et al [141] reported almost complete removal of Zn and Cu by Chlorella pyrenoidosa and Scenedesmus obliquus.…”

Uso De Biomassa De Microalga Para Biossorção De Lantanídeos

“…A microalga verde de água doce Chlamydomonas reinharditii, por exemplo, foi descrita por biossorver 1,03 mmol La/g em 5h (Birungi & Chirwa, 2014). O mesmo pode ser observado para neodímio (Nd), onde estudos demonstraram que as microalgas verdes de água doce Acanthorhodeus gracilis e Monoraphidium sp.…”

“…Oliveira et al (2011), por sua vez, observaram valores de q máx de 0,65 e 0,71 mmol/g para a biossorção de samário (Sm) e praseodímio (Pr), respectivamente, pela mesma espécie de alga marrom. O q máx de 1,03 mmol/g foi observado para a biossorção de La pela alga verde Chlamydomonas reinhardtii (Birungi & Chirwa, 2014). Por outro lado, valores elevados de q máx foram obtidos para a biossorção de Nd pela C. vulgaris, de 123,82 mg/g em pH 4,0 e 157,21 mg/g em pH 5,0 (Kücüker, Nadal e Kuchta, 2016).…”

“…A microalga Desmodesmus multivariabilis foi a espécie que apresentou maior q máx (100 mg La/g) e maior afinidade pelo La (K L = 4,55 L/g) (Birungi & Chirwa, 2014).…”