Fabrication of sand-based novel adsorbents embedded with biochar or binding agents via calcite precipitation for sulfathiazole scavenging
Al-Wabel, Abdullah Almajed, Munir Ahmad, Adel RA Usman, Mohammad I . 2021
Fabrication of efficient and low-cost adsorbents through enzyme induced carbonate precipitation (EICP) of sand embedded with binding agents for sulfathiazole (STZ) removal is reported for the first time. Sand enriched with biochar (300 °C, 500 °C, and 700 °C), xanthan gum, guar gum, bentonite, or sodium alginate (1% w/w ratios) was cemented via EICP technique. Enrichment with binding agents decreased the unconfined compressive strength, improved the porosity, and induced functional groups. Biochar enrichment reduced the pH, and increased the calcite contents and electrical conductivity. Fixed-bed column adsorption trials revealed that biochars enrichment resulted in the highest STZ removal (64.7–87.9%) from water at initial STZ concentration of 50 mg L−1, than the adsorbents enriched with other binding agents. Yoon–Nelson and Thomas kinetic models were fitted well to the adsorption data (R2 = 0.91–0.98). The adsorbents embedded with 700 °C biochar (BC7) exhibited the highest Yoon–Nelson rate constants (0.087 L min−1), 50% breakthrough time (58.056 min), and Thomas model-predicted maximum adsorption capacity (4.925 mg g−1). Overall, BC7 removed 168% higher STZ from water than pristine cemented sand. Post-adsorption XRD and FTIR analyses suggested the binding of STZ onto the adsorbents. π–π electron-donor-acceptor interactions, aided-by electrostatic interactions and H-bonding were the main STZ adsorption mechanisms.
Elevated levels of doxycycline (DC) have been detected in the environment due to its extensive utilization as a veterinary antibiotic. Sorption–desorption behavior of DC in soil affects its…
Application of manure and compost can result in the accumulation of veterinary antibiotics in soil, subsequently posing ecological risks.
Healthy soils ensure food security through sustainable agricultural production and also support in mitigating the climate change hazardous like global warming and greenhouse gases emission.