Removal of diclofenac and sulfamethoxazole from synthetic municipal waste water in microcosm downflow constructed wetlands: Start-up results

Abstract

The objectives of this study were to investigate the start-up removal of pharmaceutical compounds diclofenac and sulfamethoxazole in microcosm downflow constructed wetlands and their effect on the performance of the studied constructed wetlands, and also to assess the effect of plants on the removal of these compounds. The experimental system that was used in this 86-day experiment consisted of 24 columns filled up to 70 cm with predominantly sandy material. Four types of columns were used (six replicates) depending on the presence of plants (Phalaris arundinacea L. var. picta L.) and the presence of pharmaceutical compounds in the influent. The influent was synthetic municipal waste water to which a mixture of 5 mg/L of diclofenac and 5 mg/L of sulfamethoxazole was added. The observed removal of diclofenac was moderate (approx. 50%) and the removal of sulfamethoxazole was relatively low (24-30%). It was found that the removal of diclofenac and sulfamethoxazole was not affected by the vegetation. The presence of diclofenac and sulfamethoxazole in the influent had significant effect on the effluent concentration of N-NO3 and the water loss in the columns, which in both cases were lower than in the control columns. The scope for further research was discussed.

Isolation of Bacterial Endophytes from Phalaris arundinacea and their Potential in Diclofenac and Sulfamethoxazole Degradation

“…DCF and SMX were added to the synthetic wastewater to a final concentration of 2 mg/l and were dosed to columns B1-3 and D1-3. A detailed description of the technical part of the experiment is provided in previous publication (Nowrotek et al 2016).…”

The treatment of wastewater containing pharmaceuticals in microcosm constructed wetlands: the occurrence of integrons (int1–2) and associated resistance genes (sul1–3, qacEΔ1)

“…The removal efficiency in conventional activated sludge wastewater treatment systems was reported to be in the range 4–89% (Luo et al 2014; Luczkiewicz et al 2013; Miksch et al 2016). The removal of SMX in constructed wetlands (CWs), which were the wastewater treatment systems used in the present study, depended on the type of the CW (Nowrotek et al 2016). The three main types of CWs can be distinguished based on the flow direction and water position (relative to substrate): surface flow CWs (SF-CWs) and subsurface flow CWs with either horizontal (HF-CWs) or vertical flow (VF-CWs) (Fonder and Headley 2013).…”

“…The three main types of CWs can be distinguished based on the flow direction and water position (relative to substrate): surface flow CWs (SF-CWs) and subsurface flow CWs with either horizontal (HF-CWs) or vertical flow (VF-CWs) (Fonder and Headley 2013). The most common type of VF-CWs are downflow (DF-CWs) intermittently fed systems with unsaturated bed (Nowrotek et al 2016). The important feature of unsaturated DF-CWs is that they promote aerobic conditions allowing nitrification, which is in contrast to SF-CWs and HF-CW, which provide mostly anoxic conditions (Nowrotek et al 2016).…”

“…The most common type of VF-CWs are downflow (DF-CWs) intermittently fed systems with unsaturated bed (Nowrotek et al 2016). The important feature of unsaturated DF-CWs is that they promote aerobic conditions allowing nitrification, which is in contrast to SF-CWs and HF-CW, which provide mostly anoxic conditions (Nowrotek et al 2016). The elimination of SMX in CWs was relatively high in the systems, in which typically anoxic conditions prevail, in HF-CWs 73–97% (Hijosa-Valsero et al 2011), in SF-CWs 59–92% (Hijosa-Valsero et al 2011; Xian et al 2010), and in DF-CWs with submerged (saturated) bed 63% in summer (but −74% in winter) (Rühmland et al 2015).…”

“…The elimination of SMX in CWs was relatively high in the systems, in which typically anoxic conditions prevail, in HF-CWs 73–97% (Hijosa-Valsero et al 2011), in SF-CWs 59–92% (Hijosa-Valsero et al 2011; Xian et al 2010), and in DF-CWs with submerged (saturated) bed 63% in summer (but −74% in winter) (Rühmland et al 2015). Low removal of SMX (24–31%) was observed in unsaturated DF-CWs (Nowrotek et al 2016). The co-existence of various biotic and abiotic processes and the presence of various microenvironments in the CWs allow to treat these systems as an interesting alternative to conventional treatment methods regarding the removal of standard wastewater pollutants but also organic micropollutants including pharmaceuticals (Ávila et al 2010; Li et al 2014; Zhang et al 2012; Matamoros et al 2007).…”