Filter Media-Packed Bed Reactor Fortification with Biochar to Enhance Wastewater Quality

Applied Sciences

Agnieszka Renman¹  Gunno Renman²  Ezekiel Kholoma³ 

[1] Environmental Engineering, Botswana International University of Science &Technology, Private Bag 16, Palapye, Botswana;;Department of Civil &

关键词: wastewater treatment;    biochar;    packed bed reactor;    fortification;    phosphorus;    dissolved organic carbon;   

DOI  :  10.3390/app10030790

来源: DOAJ

【 摘 要 】

Contamination of water sources by inappropriately disposed poorly treated wastewater from countryside establishments is a worldwide challenge. This study tested the effectiveness of retrofitting sand (Sa)- and gas−concrete (GC)-packed reactors with biochar (C) in removing turbidity, dissolved organic carbon (DOC), phosphate (PO₄³⁻), and total phosphorus (P_tot) from wastewater. The down-flow reactors were each intermittently loaded with 0.063 L/d for 399 days. In general, all reactors achieved <3 NTU (Nephelometric Turbidity Units) effluent turbidity (99% efficiency). GC reactors dominated in inlet PO₄³⁻ (6.1 mg/L) and DOC (25.3 mg/L) reduction, trapping >95% and >60%, respectively. Compared to Sa (PO₄³⁻: 35%, DOC: 52%), the fortified sand (SaC) filter attenuated more PO₄³⁻ (>42%) and DOC (>58%). Student t-tests revealed that C significantly improved the Sa PO₄³⁻ (p = 0.022) and DOC (p = 0.034) removal efficacy. From regression analysis, 53%, 81%, and 85% PO₄³⁻ sorption variation in Sa, C, and SaC, respectively, were explained by variation in their effluent pH measures. Similarly, a strong linear correlation occurred between PO₄³⁻ sorption efficiency and pH of fortified (r > 0.7) and reference (r = 0.6) GC filters thus suggesting chemisorption mechanisms. Therefore, whereby only sand may be available for treating septic tank effluents, fortifying it with biochar may be a possible measure to improve its efficacy.

【 授权许可】

Unknown