MilliporeSigma
  • Pharmaceutically active compounds in sludge stabilization treatments: anaerobic and aerobic digestion, wastewater stabilization ponds and composting.

Pharmaceutically active compounds in sludge stabilization treatments: anaerobic and aerobic digestion, wastewater stabilization ponds and composting.

The Science of the total environment (2014-06-10)
Julia Martín, Juan Luis Santos, Irene Aparicio, Esteban Alonso
ABSTRACT

Sewage sludge disposal onto lands has been stabilized previously but still many pollutants are not efficiently removed. Special interest has been focused on pharmaceutical compounds due to their potential ecotoxicological effects. Nowadays, there is scarce information about their occurrence in different sludge stabilization treatments. In this work, the occurrence of twenty-two pharmaceutically active compounds has been studied in sludge from four sludge stabilization treatments: anaerobic digestion, aerobic digestion, composting and lagooning. The types of sludge evaluated were primary, secondary, anaerobically-digested and dehydrated, composted, mixed, aerobically-digested and dehydrated and lagoon sludge. Nineteen of the twenty-two pharmaceutically active compounds monitored were detected in sewage sludge. The most contaminated samples were primary sludge, secondary sludge and mixed sludge (the average concentrations of studied compounds in these sludges were 179, 310 and 142 μg/kg dm, respectively) while the mean concentrations found in the other types of sewage sludge were 70 μg/kg dm (aerobically-digested sludge), 63 μg/kg dm (lagoon sludge), 12 μg/kg dm (composted sludge) and 8 μg/kg dm (anaerobically-digested sludge). The antibiotics ciprofloxacin and norfloxacin were found at the highest concentration levels in most of the analyzed sludge samples (up to 2660 and 4328 μg/kg dm, respectively). Anaerobic-digestion treatment reduced more considerably the concentration of most of the studied compounds than aerobic-digestion (especially in the case of bezafibrate and fluoroquinolones) and more than anaerobic stabilization ponds (in the case of acetaminophen, atenolol, bezafibrate, carbamazepine, 17α-ethinylestradiol, naproxen and salicylic acid). Ecotoxicological risk assessment, of sludge application onto soils, has also been evaluated. Risk quotients, expressed as the ratio between the predicted environmental concentration and the predicted non-effect concentration, were lower than 1 for all the pharmaceutically active compounds so no significant risks are expected to occur due to the application of sewage sludge onto soils, except for 17α-ethinylestradiol when chronic toxicity was considered.

MATERIALS
Product Number
Brand
Product Description

USP
Ibuprofen, United States Pharmacopeia (USP) Reference Standard
USP
Acetaminophen, United States Pharmacopeia (USP) Reference Standard
USP
Carbamazepine, United States Pharmacopeia (USP) Reference Standard
Norfloxacin for system suitability, European Pharmacopoeia (EP) Reference Standard
Supelco
Carbamazepine, analytical standard
Trimethoprim, European Pharmacopoeia (EP) Reference Standard
USP
Atenolol, United States Pharmacopeia (USP) Reference Standard
Bezafibrate, European Pharmacopoeia (EP) Reference Standard
Atenolol, European Pharmacopoeia (EP) Reference Standard
Carbamazepine, European Pharmacopoeia (EP) Reference Standard
Supelco
Estrone, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Carbamazepine, powder
Sigma-Aldrich
Salicylic acid, BioXtra, ≥99.0%
Sigma-Aldrich
Atenolol, ≥98% (TLC), powder
Sigma-Aldrich
Salicylic acid, meets analytical specification of Ph. Eur., BP, USP, 99.5-100.5% (calc. to the dried substance)
Supelco
Trimethoprim, VETRANAL®, analytical standard
Sigma-Aldrich
Acetaminophen, analytical standard
Sigma-Aldrich
Bezafibrate, ≥98%, solid
Sigma-Aldrich
Trimethoprim, ≥98.5%
Sigma-Aldrich
Estrone, ≥99%
Sigma-Aldrich
Carbamazepine, meets USP testing specifications
Sigma-Aldrich
Salicylic acid, suitable for plant cell culture
Sigma-Aldrich
Salicylic acid, ReagentPlus®, ≥99%
Sigma-Aldrich
Salicylic acid, puriss. p.a., ≥99.0% (T)
Sigma-Aldrich
2-(p-Chlorophenoxy)-2-methylpropionic acid, 97%
Sigma-Aldrich
Trimethoprim, ≥99.0% (HPLC)
Sigma-Aldrich
(±)-Propranolol hydrochloride, ≥99% (TLC), powder
Supelco
Carbamazepine, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Ibuprofen, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
Trimethoprim, Pharmaceutical Secondary Standard; Certified Reference Material