Removal of Antibiotics and Nutrients by Vetiver Grass (Chrysopogon zizanioides) from a Plug Flow Reactor Based Constructed Wetland Model

Abstract

Overuse of antibiotics has resulted in widespread contamination of the environment and triggered antibiotic resistance in pathogenic bacteria. Conventional wastewater treatment plants (WWTPs) are not equipped to remove antibiotics. Effluents from WWTPs are usually the primary source of antibiotics in aquatic environments. There is an urgent need for cost-effective, environment-friendly technologies to address this issue. Along with antibiotics, nutrients (nitrogen and phosphorus) are also present in conventional WWTP effluents at high concentrations, causing environmental problems like eutrophication. In this study, we tested vetiver grass in a plug flow reactor-based constructed wetland model in a greenhouse setup for removing antibiotics ciprofloxacin (CIP) and tetracycline (TTC), and nutrients, N and P, from secondary wastewater effluent. The constructed wetland was designed based on a previous batch reaction kinetics study and reached a steady-state in 7 days. The measured concentrations of antibiotics were generally consistent with the modeling predictions using first-order reaction kinetics. Vetiver grass significantly (p < 0.05) removed 93% and 97% of CIP and TTC (initial concentrations of 10 mg/L), simultaneously with 93% and 84% nitrogen and phosphorus, respectively. Results show that using vetiver grass in constructed wetlands could be a viable green technology for the removal of antibiotics and nutrients from wastewater.

Inactivation of antibiotic-resistant bacteria and antibiotic-resistance genes in wastewater streams: Current challenges and future perspectives

“…TET is a naturally sourced antibiotic that is obtained from Streptomyces sp. (e.g., chlortetracycline, tetracycline and oxytetracycline) and they are also semi-synthetic antibiotics (e.g., demeclocycline and doxycycline; Pazda et al, 2019 ; Panja et al, 2021 ). The naturally sourced TET are used in the treatment of aquaculture and livestock, and they are also as medicine for humans ( Pazda et al, 2019 ).…”

“…For humans, TET is used to treat diseases such as malaria, rosacea, chlamydia, etc. while for livestock, it is administered as a growth promoter in concentrated animal feeding operations ( Panja et al, 2021 ). TET is mostly found in WWTPs because it is released in human and animal faeces and urine, in its active form ( Bockelmann et al, 2009 ).…”

Effect of Plant Species on the Performance and Bacteria Density Profile in Vertical Flow Constructed Wetlands for Domestic Wastewater Treatment in a Tropical Climate

“…A. gayanus is also a common perennial forage grass of the tropical regions that forms tall and dense stands and has a high evapotranspiration capacity [40][41][42]. C. zizanioides is a high biomass perennial tropical grass that has been successfully used for soil and water conservation due to its robust root system and tolerance for adverse environmental conditions [43,44], and it is grown worldwide for perfumery, agriculture, and bioengineering [45,46]. E. pyramidalis produces a high shoots density and a dense mat of roots and rhizomes, allowing a high evapotranspiration rate, and has been successfully used for wastewater treatment and fecal sludge dewatering [47,48].…”

Integrated Methods for Household Greywater Treatment: Modified Biofiltration and Phytoremediation

“…In developing countries, particularly in urban and periurban areas, greywater is frequently discharged untreated into street drains or onto open ground, primarily ending up in rivers, resulting in oxygen depletion, eutrophication, and microbial and chemical contamination of soil and aquatic systems [ 2 , 9 , 10 ]. In the absence of treatment, this greywater contributes an excessive and frequently unwanted amount of chemicals and pathogenic microorganisms, endangering the environment, food safety, and human health [ 11 – 13 ].…”