The effect of caffeine, metronidazole, and ibuprofen on continuous flow activated sludge process

Abstract

BACKGROUND The aim of this work was to study the biological treatment of a synthetic wastewater containing emerging contaminants. The 95‐day experiment was conducted in an 81 L continuous flow conventional activated sludge apparatus consisting of anoxic and aerobic reactors with internal recycling, and a clarifier with activated sludge recycling. Real activated sludge from the municipal wastewater treatment plant in the Nur‐Sultan city was used. The degradation efficiencies of caffeine, metronidazole, and ibuprofen in the synthetic wastewater were studied either separately or in combination. RESULTS When treated separately at the concentration of 30 mg/L, the degradation of caffeine and ibuprofen was up to 100%, while the degradation of metronidazole was in the range of 12–27%. Caffeine and ibuprofen inhibited the nitrification process, while the presence of metronidazole in the system suppressed the activity of denitrifying microorganisms. The biological treatment of the synthetic wastewater containing all three compounds (at the concentration of 10 mg/L each) resulted in degradation of caffeine and ibuprofen up to 100%, and 56% in the case of metronidazole. As both nitrification and denitrification processes were affected, the total nitrogen removal was significantly reduced from 53% to 22%. CONCLUSION Complete degradation of caffeine and ibuprofen, and partial degradation of metronidazole were observed in a synthetic wastewater using the activated sludge process. As the presence of emerging pollutants in a wastewater affects the general efficiency of the wastewater treatment plants, other physical or chemical pre‐treatment should be utilized to minimize the harmful effect of contaminants on the biological processes. © 2021 Society of Chemical Industry

Extraction of antibiotics identified in the EU Watch List 2020 from hospital wastewater using hydrophobic eutectic solvents and terpenoids

“…Over the last few years, several techniques have been studied for the removal of pharmaceuticals from wastewater, such as activated sludge treatment [24][25][26][27], membrane bioreactor [28][29][30][31][32], constructed wetland [33][34][35][36][37], adsorption [3,[38][39][40], membrane filtration (ultrafiltration, nanofiltration and reverse osmosis) [41][42][43][44][45][46], and advanced oxidation processes (wet air oxidation; electrochemical oxidation; photolysis; ultrasound irradiation; heterogeneous photocatalysis; ozone and ozone/hydrogen peroxide treatment; and Fenton oxidation) [15,18,[47][48][49][50][51].…”

Photocatalytic treatment of metronidazole-containing wastewater

“…EPs are comprised of pharmaceuticals, pesticides, endocrine disrupting chemicals, and other recalcitrant organic compounds [4]. Due to the stable structure of these compounds, some of them escape WWTPs based on the activated sludge process and are released into the aquatic environment [5]. MNZ is a commonly IOP Publishing doi:10.1088/1755-1315/1123/1/012078 2 used water-soluble antibiotic with a stable imidazole ring [5].…”

“…Due to the stable structure of these compounds, some of them escape WWTPs based on the activated sludge process and are released into the aquatic environment [5]. MNZ is a commonly IOP Publishing doi:10.1088/1755-1315/1123/1/012078 2 used water-soluble antibiotic with a stable imidazole ring [5]. According to the previous reports, the activated sludge process is not highly efficient in terms of MNZ removal [5][6][7][8].…”

Photo-Fenton-Like Treatment of Municipal Wastewater

“…The following organic compounds are present in MWW: carbohydrates, synthetic detergents, fats, proteins, lignin, soaps and their decomposition products, various natural and synthetic organic chemicals from the process industries [2]. Some of these compounds pose serious problems in biological treatment systems due to their resistance to biodegradation and/or toxic effects on microbial processes [4,5]. Municipal wastewater also comprises different inorganic substances from domestic and industrial sources, including several potentially toxic elements such as arsenic, cadmium, lead, mercury, etc.…”

“…Moreover, Equation (5) demonstrates that more hydroxyl radicals can be produced from sulfate radicals at alkaline conditions [10]. Unlike hydrogen peroxide (H 2 O 2 ), persulfate can also oxidize some organic substances directly, without the participation of radical species [20].…”