Premium
Nitrate removal from aqueous solutions by adsorption onto hydrogel‐rice husk biochar composite
Author(s) -
Sadeghi Afjeh Mahsa,
Bagheri Marandi Gholam,
ZohuriaanMehr Mohammad Jalal
Publication year - 2020
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.1002/wer.1288
Subject(s) - biochar , adsorption , aqueous solution , composite number , chemistry , husk , nitrate , nuclear chemistry , fourier transform infrared spectroscopy , endothermic process , chemical engineering , materials science , composite material , organic chemistry , pyrolysis , botany , engineering , biology
In the present study, we investigated the performance of hydrogel‐rice husk biochar composites, as low‐cost, alternative, and biocompatible adsorbents for separating nitrate ions from aqueous solutions. Hydrogel‐biochar composite was synthesized at dosages of 2.5%, 3.6%, 4.8%, and 9.6% weight ratios of biochar. The composite was characterized by several common methods including FTIR, SEM, TEM, TGA, and DSC. In addition, the effect of contact time, initial concentration of nitrate ions, and solution pH were considered. The maximum removal of nitrate was about 34.3% at acidic pH (pH = 3) using 0.02 g of adsorbent in 25 ml of nitrate solution with the initial concentration (20 mg/L) and temperature of 25°C for 60 min. Based on the findings, 5% biochar in the composite was the optimal dosage. Adsorption kinetic study revealed that this process followed the first‐order kinetic model. The experimental equilibrium adsorption data were tested by the Temkin isotherm model with R 2 > 0.97. Based on the thermodynamic studies, the adsorption process was endothermic and spontaneous. Overall, the results suggested that the obtained composite can be specifically employed for removal of contaminations from aqueous solutions. Practitioner points Hydrogel‐biochar composite provides a biocompatible and cost‐effective adsorbent. Hydrogel‐biochar composite was applied to eliminate nitrate from aqueous solutions. Nitrate removal increased in the synthesized composite upon elevation of the weight ratio of biochar to 0.2 g.