Removal of Cr(VI) by surfactant modified Auricularia auricula spent substrate: biosorption condition and mechanism

• Published in: Environmental science and pollution research international Vol. 24; no. 21; pp. 17626 - 17641
• Main Authors: Dong, Liying, Jin, Yu, Song, Tao, Liang, Jinsong, Bai, Xin, Yu, Sumei, Teng, Chunying, Wang, Xin, Qu, Juanjuan, Huang, Xiaomei
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2017; Springer Nature B.V
• Subjects: Adsorbents; Adsorption; Aquatic Pollution; Aqueous solutions; Atmospheric Protection/Air Quality Control/Air Pollution; Auricularia; Auricularia auricula; Basidiomycota; Biomedical materials; Biosorption; Chromium; Chromium - chemistry; Complex formation; Crystal structure; Drinking water; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Experiments; Fourier transforms; Hydrogen-Ion Concentration; Hydrophobicity; Interfaces; Kinetics; Particle size; pH effects; Phosphates; Regeneration; Research Article; Response surface methodology; Surface-Active Agents; Surfactants; Waste Water Technology; Water Management; Water Pollutants, Chemical - chemistry; Water Pollution Control; Water Purification; X ray photoelectron spectroscopy; Biosorption mechanism; Biosorption condition; Cr(VI); Didodecyldimethylammonium bromide(DDAB) modification; spent substrate (AASS); Auricularia auricula spent substrate (AASS)
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-017-9326-5

Auricularia auricula spent substrate (AASS) modified by didodecyldimethylammonium bromide(DDAB) was used as adsorbent to remove Cr(VI) from aqueous solution. Based on a single-factor experiment and response surface methodology, the optimal conditions were adsorbent dosage of 1.5 g/L, pH value of 4.0, initial Cr(VI) concentration of 19 mg/L, temperature of 25 °C, biosorption time of 120 min, rotational speed of 150 r/min, respectively, under which biosorption capacity could reach 12.16 mg/g compared with unmodified AASS (6.058 mg/g). DDAB modification could enlarge the specific surface area and porous diameter of the adsorbents, and supply hydrophilic and hydrophobic groups capable of adsorbing at the interfaces. In addition, DDAB increased ionic exchange and complex formation demonstrated by variations of elemental contents, shifts of carboxyl, amine groups, hydroxyl, alkyl chains, and phosphate groups as well as the crystal structure of the Cr-O compounds. Variations of peaks and energy in XPS analysis also testified the reduction of Cr(VI) to Cr(III).The biosorption behavior of modified AASS was in line with Langmuir and Freundlich isotherm equation. The final regeneration efficiency was 62.33% after three biosorption-desorption cycles. Apparently, DDBA is a eximious modifier and DDBA-modified AASS was very efficient for Cr(VI) removal.−