title: Influence of pyrolysis temperature on lead immobilization by chemically modified coconut fiber-derived biochars in aqueous environments.
abstract: Biochar has received widespread attention as an eco-friendly and efficient material for immobilization of toxic heavy metals in aqueous environments. In the present study, three types of coconut fiber-derived biochars were obtained by pyrolyzing at three temperatures, i.e., 300, 500, and 700 °C. In addition, nine types of biochars were prepared by chemical modification with ammonia, hydrogen peroxide, and nitric acid, respectively, which were used to investigate changes in physico-chemical properties by inter alia, Fourier transformation infrared spectrophotometry (FTIR), scanning electron microscope (SEM), and BET specific surface area analysis. Batch sorption experiments were carried out to determine the sorption capacity of the biochars for lead (Pb) in aqueous solutions. Results showed that the cation exchange capacity of biochar pyrolyzed at 300 °C and modified with nitric acid increased threefold compared to the control. Loosely corrugated carbon surface and uneven carbon surface of the biochar pyrolyzed at 300 °C were produced during ammonia and nitric acid modifications. Removal rate of Pb by the coconut biochar pyrolyzed at 300 °C and modified with ammonia was increased from 71.8 to 99.6 % compared to the untreated biochar in aqueous solutions containing 100 mg L-1Pb. However, chemical modification did not enhance adsorption of Pb of the biochars pyrolyzed at higher temperatures (e.g., 500 or 700 °C), indicating that resistance of biochars to chemical treatment increased with pyrolysis temperature.
authors: Ministry of Education Key Laboratory of Protection and Development Utilization of Tropical Crop Germplasm Resources, Hainan University, Haikou, 570228, China.|Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang A & F University, Lin'an, Hangzhou, 311300, China.
authors: Weidong
authors: W
authors: Wu
authors: Ministry of Education Key Laboratory of Protection and Development Utilization of Tropical Crop Germplasm Resources, Hainan University, Haikou, 570228, China.
authors: Jianhong
authors: J
authors: Li
authors: Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad, Faisalabad, 38040, Pakistan.|MARUM and Department of Geosciences, University of Bremen, Bremen, D-28359, Germany.
authors: Nabeel Khan
authors: NK
authors: Niazi
authors: The New Zealand Institute for Plant & Food Research Limited, Ruakura Research Centre, Private Bag 3123, Hamilton, 3240, New Zealand.
authors: Karin
authors: K
authors: Müller
authors: Ministry of Education Key Laboratory of Protection and Development Utilization of Tropical Crop Germplasm Resources, Hainan University, Haikou, 570228, China.
authors: Yingchao
authors: Y
authors: Chu
authors: Ministry of Education Key Laboratory of Protection and Development Utilization of Tropical Crop Germplasm Resources, Hainan University, Haikou, 570228, China.
authors: Lingling
authors: L
authors: Zhang
authors: School of Environmental and Chemical Engineering, Foshan University, Foshan, Guangdong, 528000, China.|Guangdong Dazhong Agriculture Science Co. Ltd., Hongmei Town, Dongguan City, Guangdong, 523169, China.
authors: Guodong
authors: G
authors: Yuan
authors: Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang A & F University, Lin'an, Hangzhou, 311300, China.
authors: Kouping
authors: K
authors: Lu
authors: Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang A & F University, Lin'an, Hangzhou, 311300, China.
authors: Zhaoliang
authors: Z
authors: Song
authors: Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Zhejiang A & F University, Lin'an, Hangzhou, 311300, China. nzhailongwang@gmail.com.|School of Environmental and Chemical Engineering, Foshan University, Foshan, Guangdong, 528000, China. nzhailongwang@gmail.com.|Guangdong Dazhong Agriculture Science Co. Ltd., Hongmei Town, Dongguan City, Guangdong, 523169, China. nzhailongwang@gmail.com.
authors: Hailong
authors: H
authors: Wang
mesh_terms: D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D003059:Cocos / Q000737:chemistry*; D006358:Hot Temperature; D007854:Lead / Q000032:analysis* / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D018508:Water Purification / Q000379:methods
chemical_list: D002606:Charcoal; D007854:Lead; D012996:Solutions; D062065:Wastewater; D014874:Water Pollutants, Chemical; C540010:biochar
keywords: Biochar; Coconut fibers; FTIR; Functional group; Modified biochar; SEM; Wastewater treatment