The removal of illicit drugs and morphine in two waste water treatment plants (WWTPs) under tropical conditions

Abstract

The consumption of drugs of abuse has been recently investigated in Martinique using the back-calculation approach, also called the "sewage epidemiology" method. Results demonstrated a very high consumption considering the international data. Wastewater treatment plants (WWTPs) are located just behind the Martinique island shoreline, and effluents could impact the vulnerable corals and marine seagrass ecosystem. The present article aims to determine a WWTP's efficiency by comparing the influent and effluent of two WWTPs, with different residence times and biological treatments, located either outdoors or indoors. In parallel, a degradation study is conducted using spiked wastewater exposed to tropical and ambient temperatures. Results demonstrate the consistent efficiency of the two processes, especially for the outdoor WWTP which uses the activated sludge process. The positive effect of the tropical temperature is showed by the increase of cocaine degradation at 31 °C. Thus, low illicit drug residue concentrations in effluent would indicate that wastewater treatment is efficient and even enhanced under tropical context. This fact should be confirmed with others molecules. Furthermore, our results highlight the need for subsequent studies of sludge contamination because of their local recycling as compost.

Wastewater-Based Epidemiology of Cocaine in the Brazilian Federal District: Spatial Distribution, Weekly Variation and Sample Preservation Strategies

“…Mastroianni et al 59 carried out a five-year monitoring of illicit drugs in the region of Barcelona, Spain, and reveal an average cocaine use of 24 mg day -1 1000 inh 63 reported a cocaine daily consumption ranging from 619 ± 140 to 2420 ± 742 mg day -1 1000 inh -1 being among the highest reported in the literature, probably due to the fact that the region is part of the Caribbean hub of international illicit drug traffic. Cocaine consumption in the cities of Bogotá and Medellin, in Colombia, was investigated by Bijlsma et al, 64 which reported a weekly average of 742 and 3022 mg day -1 1000 inh -1 , respectively, using a correction factor of 3.59.…”

“…65 Since 29.2% of the consumed cocaine (molecular weight (MW) = 303 g mol -1 ) is excreted in urine as benzoylecgonine (MW = 209 g mol -1 ), a measured benzoylecgonine excretion rate of 100 mg day -1 1000 inh -1 corresponds to 100/0.292 × 303/289 = 359 mg of cocaine consumed. The work of Devault et al, 63 carried out in Martinique, explores excretion data considering the prevalence of crack consumption (smoked) as the authors assume a scenario formed by 75% of crack consumers and 25% of snorting users, leading to an excretion rate of 18.5% of benzoylecgonine.…”

“…However, the authors could notice a relatively high consumption in a northern region of the country during the weekend (2434 mg day -1 1000 inh -1 ), being almost 60% higher than the consumption estimated during the weekdays as a result of a special event occurred during sampling period, as pointed out elsewhere. 63 Bijlsma et al 64 investigated the presence of cocaine and benzoylecgonine in wastewater samples form the cities of Bogotá and Medellin, in Colombia, throughout a week and showed a slightly increase in benzoylecgonine loads in the weekend samples. According to the authors, Colombian consumers may use cocaine regularly and not more intensely during weekends.…”

“…65 Since 29.2% of the consumed cocaine (molecular weight (MW) = 303 g mol -1 ) is excreted in urine as benzoylecgonine (MW = 209 g mol -1 ), a measured benzoylecgonine excretion rate of 100 mg day -1 1000 inh -1 corresponds to 100/0.292 × 303/289 = 359 mg of cocaine consumed. The work of Devault et al, 63 carried out in Martinique, explores excretion data considering the prevalence of crack consumption (smoked) as the authors assume a scenario formed by 75% of crack consumers and 25% of snorting users, leading to an excretion rate of 18.5% of benzoylecgonine.In a previous work based on WBE approach, 15 we estimate that consumption of crack in Brazil may be higher in comparison with countries such as USA and Italy, but no back-calculating was proposed. Data from the National Institute of Science and Technology for Policies on Alcohol and other Drugs 66 show that 2.3 and 1.0 million adult Brazilians used intranasal and smoked cocaine, respectively.…”

Mesoporous activated carbon shows superior adsorption affinity for 11-nor-9-carboxy-Δ9-tetrahydrocannabinol in water

“…12 THC-COOH, a nonpsychoactive metabolite and biomarker for THC, has been found as a stable compound over a 3-day period in wastewater samples at neutral pH and at 20°C. [13][14][15] In addition, only 1.3% of THC-COOH adsorption was estimated to be on sewer borne solids at pH 7.5. 16 Since, wastewater treatment plants are only partially effective in removing this metabolite, 6,15,[17][18][19][20][21] THC-COOH is detected in concentrations up to 500 ng L −1 in raw fresh waters.…”