Comparison of Pine Bark, Biochar and Zeolite as Sorbents for NH4+-N Removal from Water

• Published in: Clean : soil, air, water Vol. 43; no. 1; pp. 86 - 91
• Main Authors: Hina, Kiran, Hedley, Mike, Camps-Arbestain, Marta, Hanly, James
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 01.01.2015; Wiley Subscription Services, Inc
• Subjects: Ammonium sorption; Biomass; Clinoptilolite; Sorbents; Wastewater treatment; Zeolites
• ISSN: 1863-0650; 1863-0669
• DOI: 10.1002/clen.201300682

To assist the adoption of biochar production as a greenhouse gas mitigation technology, evidence is required that biochar can provide additional economic benefits covering its current cost of manufacture. Biochar has the potential to be used as sorbent for NH4+‐N removal from wastewaters. Two batch studies were conducted to compare (i) sorption of NH4+‐N on pine biochars with different particle sizes and (ii) sorption of NH4+‐N on pine biochar in comparison to alternative sorbents, zeolite (clinoptilolite) and pine bark. Decreasing the particle size of the feedstock (pine chip), or the biochar by crushing after pyrolysis, did not affect its NH4+‐N sorption properties. Sorption of NH4+‐N on comparative sorbents, when added at a dose of 39 mg NH4+‐N L−1, followed the order zeolite > biochar > bark. Zeolite proved to be the most efficient sorbent for NH4+‐N g−1 removal followed by biochar and bark. Biochar has the potential to be used as a cost effective commercial sorbent for removing NH4+‐N from waste streams. Pine biochar with a cation exchange capacity (CEC) of 17 cmolc kg−1, intermediate between pine bark (CEC 6.4 cmolc kg−1) and zeolite (clinoptilolite, CEC (27.5 cmolc kg−1) were capable removing NH4+ from NH4+‐rich water. Sorption of NH4+‐N from a solution of 39 mg NH4+‐N L−1 followed the same order as CEC: zeolite > biochar > bark. Biochar has potential to be used as an NH4+‐N adsorbent in wastewater treatment.