High-rate algal pond for removal of pharmaceutical compounds from urban domestic wastewater under tropical conditions. Case study: Santiago de Cali, Colombia

Abstract

This study evaluated the capacity of a pilot-scale high-rate algal pond (HRAP) to remove pharmaceutical compounds (PCs) from domestic wastewater in the city of Santiago de Cali, Colombia. The compounds analyzed included antiepileptics, hypolipidemic drugs, tranquilizers and analgesics, and anti-inflammatory drugs. The HRAP operated under a continuous water flow of 0.2 m3d−1 and a 3-day hydraulic retention time (HRT). Removal efficiencies were high (>70%) for fenofibric acid, ibuprofen, and paracetamol; medium (30–70%) for gabapentin, lamotrigine, fenofibrate, gemfibrozil, diclofenac, ketoprofen, naproxen, and pentoxifylline; and low (<30%) for carbamazepine and its metabolite 10,11-Dihidro-10,11-dihidroxicarbamazepine (CBZ-Diol). The findings herein are similar to other studies, but were obtained with a shorter HRT. These results show that tropical environmental conditions favor photodegradation and contribute to the development of microalgae and the biodegradation process. Twenty microalgae species were identified, with the Phylum Chlorophyta as the most abundant, particularly due to its natural introduction. The removal of the PCs also reflected a percentage reduction (>50%) in the ecological hazard posed by most of the compounds, although it is important to note that the hazard from gemfibrozil and ibuprofen remained high even after treatment, indicating the need for complementary treatment.

Removal of Pharmaceutical Micropollutants with Integrated Biochar and Marine Microalgae

“…According to preliminary experiments, hydraulic retention time was set at 2.8 days. This setup is in line with the findings of Jiménez-Bambague et al [16].…”

“…Langmuir isotherm was reached by plotting 1/(x/m) against (1/C e ) and using Equation (16). Based on the Langmuir isotherm (Table 6), the maximum adsorption capacities (q m , mg g −1 ) were 16.6 (CBZ), 13.9 (SMT) and 9.7 (TRA), and the R 2 values were 0.918, 0.904 and 0.902, respectively.…”

“…x m = abC e (1 + bC e ) (16) where x/m is the adsorbed the mass of the adsorbate (mg g −1 ), a and b are empirical constants and C e denotes the adsorbate concentration after the adsorption process (mg L −1 ). Freundlich isotherm factors were obtained by plotting log (x/m) against log (C e ).…”

“…Robledo-Padilla et al [ 15 ] expressed that several marine or freshwater microalgae can be used for the removal of organic pollutants. Jiménez-Bambague et al [ 16 ] removed 30–70% of PPCPs from domestic wastewater under tropical conditions by using green microalgae. Meanwhile, the capability of the marine diatom Chaetoceros muelleri to remove PPCPs has not been thoroughly explored in previous studies.…”

The Potential of Chaetoceros muelleri in Bioremediation of Antibiotics: Performance and Optimization

“…The photobioreactor was a tank (width (7 cm), length (20 cm), and height (44 cm)) that had a working value of 6 L. The aeration was done from the bottom. Hydraulic retention time (day) and aeration rates were set at 2.8 and 0.4 based on our preliminary experiments, which were in line with Jiménez-Bambague et al [31] and Sun et al [32], respectively. Synthetic aqueous solution was produced by dissolving both antibiotics and artificial seawater.…”