Ecotoxicological risk evaluation and regulatory compliance of endocrine disruptor phthalates in a sustainable wastewater treatment scheme

• Published in: Environmental science and pollution research international Vol. 27; no. 8; pp. 7785 - 7794
• Main Authors: Gani, Khalid Muzamil, Kazmi, Absar Ahmad
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-03-2020; Springer Nature B.V
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Biogas; Developing countries; Dibutyl phthalate; Diethyl phthalate; Dilution; Dioctyl phthalate; Earth and Environmental Science; Ecotoxicology; Effluent treatment; Effluents; Endocrine disruptors; Endocrine Disruptors - analysis; Environment; Environmental Chemistry; Environmental Health; Environmental Monitoring; Environmental science; Esters; LDCs; Phthalate esters; Phthalates; Phthalic acid; Phthalic Acids - analysis; Phthalic Acids - chemistry; Polishing; Ponds; Quotients; Raw wastewater; Research Article; Risk assessment; Sludge; Sludge disposal; Summer; Waste Disposal, Fluid; Waste Water - analysis; Waste Water Technology; Wastewater treatment; Wastewater treatment plants; Water Management; Water Pollution Control; Water treatment; Fate and removal; UASB/pond; Wastewater; Risk assessment; Emerging contaminants; Phthalates
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-019-07418-7

Due to their pervasive applications, phthalic acid esters or phthalates have ample presence in all environmental compartments. A principal source of their existence in freshwater is phthalate-laden wastewater treatment plant effluents. For its sustainable operation and biogas production, wastewater treatment scheme of up flow anaerobic sludge blanket (UASB) and polishing pond is more prevalent in developing countries. This yearlong study focused on evaluating the occurrence, fate and risk of four priority phthalates, diethyl phthalate (DEP), dibutyl phthalate (DBP), benzylbutyl phthalate (BBP), and diethylhexyl phthalate (DEHP) in a UASB+ polishing pond-based wastewater treatment plant. Concentration of the phthalates in raw wastewater ranged from nd to 17.36 μg/L (DEP), 0.92 to 18.26 μg/L (DBP), nd to 6.54 μg/L (BBP), and nd to 53.21 μg/L (DEHP). DEHP concentrations in UASB sludge were below 100 mg/kg, the recommended limit by the European Union for safe disposal of dewatered sludge. All four compounds were removed approximately 80% in the wastewater treatment plant, with larger removal in polishing pond than UASB. Sorption contributes a significant portion of BBP and DEHP removal (15–24%) in UASB than DEP and DBP (0–3%). Seasonally, larger removals of phthalates were observed during the summer season. Risk assessment showed that the treated effluents had low risk of DEP, DBP, and BBP. However, the hazard quotient (HQ) of DEHP was greater than 1. To comply with regulations, dilution requirement of effluents was investigated which showed that a dilution factor of 4.4 in summer and 2.1 in winter is required for effluents of UASB + Pond-based treatment plant.