Potential of Constructed Wetlands for Removal of Antibiotics from Saline Aquaculture Effluents

Abstract

Abstract:This work aimed to evaluate the potential of constructed wetlands (CWs) for removal of antibiotics (enrofloxacin and oxytetracycline) and antibiotic resistant bacteria from saline aquaculture wastewaters. Removal of other contaminants (nutrients, organic matter and metals) and toxicity reduction and the influence of antibiotics with these processes were evaluated. Thus, nine CWs microcosms, divided into three treatments, were assembled and used to treat wastewater (doped or not with the selected antibiotics) between October and December of 2015. Each week treated wastewater was removed and new wastewater (doped or not) was introduced in CWs. Results showed >99% of each antibiotic was removed in CWs. After three weeks of adaptation, removal percentages >95% were also obtained for total bacteria and for antibiotic resistant bacteria. Nutrients, organic matter and metal removal percentages in CWs treated wastewater were identical in the absence and in the presence of each antibiotic. Toxicity in treated wastewaters was significantly lower than in initial wastewaters, independently of antibiotics presence. Results showed CWs have a high efficiency for removing enrofloxacin or oxytetracycline as well as antibiotic resistant bacteria from saline aquaculture wastewaters. CWs can also remove other contaminants independently of drug presence, making the aquaculture wastewater possible to be reutilized and/or recirculated.

Short-Term Effects of Salt Stress on the Amino Acids of Phragmites australis Root Exudates in Constructed Wetlands

“…For instance, physiological drought, nutrient deficiency, and cell structure damage can occur, and, especially, plant roots can be immediately injured by high salinity [3]. Phragmites australis, a representative wetland plant, is found in both freshwater and saline habitats [4] and even adapts to high-salinity regions. Many previous studies have shown that P. australis is easily propagated by seed dispersion and vegetatively propagated from vertical and horizontal rhizomes and stolons [5].…”

Constructed Wetlands for Water Treatment: New Developments

“…The systems were able to remove the antibiotics and antibiotic-resistant bacteria, and reduce wastewater toxicity. In addition, no impact of the antibiotic presence was observed on the removal of nutrients, organic matter, and metal, with percentages being similar between exposed and unexposed microcosms [18].…”

“…Bôto et al [18] used CW microcosms to evaluate CWs for the removal of antibiotics (enrofloxacin and oxytetracycline) and antibiotic-resistant bacteria from saline aquaculture wastewaters. The systems were able to remove the antibiotics and antibiotic-resistant bacteria, and reduce wastewater toxicity.…”

Treatment Processes for Microbial Resistance Mitigation: The Technological Contribution to Tackle the Problem of Antibiotic Resistance

“…CWs can be operated under different flow configurations, with different macrophytes and different solid supports, and it is thus possible to design specific configurations applicable to remove certain pollutants from effluents [107,108] (Figure 3). CWs can also represent an alternative strategy to reduce or remove antibiotics and ARB and ARGs in wastewater [109,110]. These systems exhibit a wide range of efficiencies (from 59 to almost CWs can also represent an alternative strategy to reduce or remove antibiotics and ARB and ARGs in wastewater [109,110].…”