Dolores Camacho-Muñoz

Occurrence of pharmaceutical compounds in wastewater and sludge from wastewater treatment plants: Removal and ecotoxicological impact of wastewater discharges and sludge disposal

The occurrence of sixteen pharmaceutically active compounds in influent and effluent wastewater and in primary, secondary and digested sludge in one-year period has been evaluated. Solid-water partition coefficients (Kd) were calculated to evaluate the efficiency of removal of these compounds from wastewater by sorption onto sludge. The ecotoxicological risk to aquatic and terrestrial ecosystems, due to wastewater discharges to the receiving streams and to the application of digested sludge as fertilizer onto soils, was also evaluated. Twelve of the pharmaceuticals were detected in wastewater at mean concentrations from 0.1 to 32 μg/L. All the compounds found in wastewater were also found in sewage sludge, except diclofenac, at mean concentrations from 8.1 to 2206 μg/kg dm. Ibuprofen, salicylic acid, gemfibrozil and caffeine were the compounds at the highest concentrations. LogKd values were between 1.17 (naproxen) and 3.48 (carbamazepine). The highest ecotoxicological risk in effluent wastewater and digested sludge is due to ibuprofen (risk quotient (RQ): 3.2 and 4.4, respectively), 17α-ethinylestradiol (RQ: 12 and 22, respectively) and 17β-estradiol (RQ: 12 and 359, respectively). Ecotoxicological risk after wastewater discharge and sludge disposal is limited to the presence of 17β-estradiol in digested-sludge amended soil (RQ: 2.7).

Occurrence, temporal evolution and risk assessment of pharmaceutically active compounds in Donana Park (Spain)

Doñana National Park (Southern Spain) is one of the most emblematic protected areas in Europe and is included in UNESCOs World Heritage List. A 1-year monitoring study was carried out to investigate the presence of 16 pharmaceutical compounds belonging to seven therapeutic groups in wastewater discharges, rivers and streams affecting Doñana Park. Fourteen pharmaceuticals were detected in effluent wastewater at concentration levels up to 26.8 μg L(-1) and thirteen were detected in surface water at concentration levels up to 4.55 μg L(-1). Ibuprofen was the compound at the highest concentration levels. An increase of the concentration levels in surface water was observed in summer months due to the reduction of the flow rates of the rivers. Nevertheless, risk quotient values estimated in surface water were lower than one so no toxicological effect is suspected to occur. The highest average risk quotients were obtained for ibuprofen (risk quotient 0.67±0.28), gemfibrozil (risk quotient 0.52±0.33), propranolol (0.13±0.06) and naproxen (0.10±0.09). Nevertheless, in summer months, risk quotient values up to 9.3 and 10.7 were estimated for the estrogenic compounds 17α-ethinylestradiol and 17β-estradiol.

Simultaneous determination of a selected group of cytostatic drugs in water using high‐performance liquid chromatography–triple‐quadrupole mass spectrometry

In recent years, an increasing concern has risen about the presence of pharmaceuticals in the aquatic environment. Despite their toxicity, increasing consumption and release into the municipal sewage, only a few studies have been focused on cytostatic drugs, mainly due to the lack of methods for their simultaneous analysis. In this work, a method, based on solid-phase extraction prior to high-performance liquid chromatography-triple quadrupole mass spectrometry determination, was optimized and validated for the simultaneous determination of some (14) of the most widely used cytostatic drugs in river water, influent and effluent wastewater. Process efficiency was in the range between 41 and 99% in real samples, except for cytarabine (24%), docetaxel (17%) and methotrexate (30%), due to suppression effects; precision values were <11%, except for gemcitabine (up to 19%); and detection limits were in the range between 0.1 and 38 ng/L. Cytarabine, doxorubicin, etoposide, gemcitabine, iphosphamide and vinorelbine were found at concentration levels up to 14 ng/L in influent and effluent wastewater, showing an insignificant decrease during sewage treatment; cytarabine and gemcitabine were found in effluent wastewater and were also detected in river water associated with effluent discharges.

An affordable method for the simultaneous determination of the most studied pharmaceutical compounds as wastewater and surface water pollutants

There is still an increasing need of knowledge about the presence of pharmaceuticals in the environment in many countries. To contribute to the improvement of this knowledge it should be useful to get not only more reliable methods, but also analytical methods that do not require expensive equipment and, consequently, could be used even in the less developed areas. In the present work, a novel analytical method for the simultaneous determination of several priority pharmaceuticals, as aquatic media pollutants, in wastewater and surface water is reported. The method involves sample treatment by SPE, followed by LC with diode array and fluorescence detection. Parameters that affect the efficiency of the SPE step such as elution solvents, sample pH and cartridge sorbents were evaluated and optimized. The best results were obtained using acetone as elution solvent, acidifying samples to pH 2 and employing Oasis HLB as SPE sorbent. Recoveries of the pharmaceuticals from influent and effluent wastewater and surface water samples were in the range from 61.4 to 123%. LODs were in the range of 0.001-0.323 microg/L and LOQs were between 0.020 and 1.078 microg/L.

Effectiveness of Conventional and Low-Cost Wastewater Treatments in the Removal of Pharmaceutically Active Compounds

In the present work, the effectiveness of conventional wastewater treatments (activated sludge and oxidation ditches) and low-cost wastewater treatments (trickling filter beds, anaerobic lagooning and constructed wetlands) in the removal of pharmaceutically active compounds has been studied. To evaluate the efficiency of removal, 16 pharmaceutically active compounds belonging to seven therapeutic groups (anti-inflammatory drugs, antibiotics, antiepileptic drugs, β-blockers, nervous stimulants, estrogens and lipid regulators) have been monitored during 1-year period in influent and effluent wastewater from 11 wastewater treatment plants of Spain. Mean removal rates of pharmaceutically active compounds achieved in conventional wastewater treatments were slightly higher than those achieved in low-cost treatments, being 64% and 55%, respectively. Ibuprofen, naproxen, salicylic acid and caffeine were the pharmaceutical compounds most efficiently removed, regardless the wastewater treatment applied, with removal rates up to 99%. Anaerobic lagooning was the less effective treatment for the removal of the most persistent compounds: carbamazepine and propranolol.

Occurrence of surfactants in wastewater: hourly and seasonal variations in urban and industrial wastewaters from Seville (Southern Spain).

Surfactants are daily discharged to the environment from urban and industrial activities. The assessment of the risk derived from the presence of these compounds in the environment requires a deep knowledge about their sources and their distribution in wastewater treatment plants (WWTPs). However, in spite of several studies reporting their presence in WWTPs, only a small number is focused on their different sources. In this work, the distribution of anionic (linear alkylbenzene sulfonates) and non-ionic (nonylphenol ethoxylates) surfactants in WWTPs and in urban and industrial wastewater collection systems has been investigated. Seasonal and daily variability was also assessed. Concentrations of linear alkylbenzene sulfonates in influent and effluent wastewaters ranged from 1155 to 9200 μg L(-1), and from below limit of detection to 770 μg L(-1), respectively, whereas the concentrations of nonylphenol ethoxylates were significantly lower. Linear alkylbenzene sulfonates were efficiently removed (>96%), while mean removal rates of nonylphenol ethoxylates were significantly lower (<20%). Studies carried out in different seasons revealed seasonal discharge patterns from both urban and industrial activities. The analysis of wastewater collection systems showed a major contribution of linear alkylbenzene sulfonates from urban areas while, in the case of nonylphenol ethoxylates, their major contribution came from industrial activities. In all cases the discharge patterns of surfactants were related with the water consumption.

Concentration evolution of pharmaceutically active compounds in raw urban and industrial wastewater

The distribution of pharmaceutically active compounds in the environment has been reported in several works in which wastewater treatment plants have been identified as the main source of these compounds to the environment. The concentrations of these compounds in influent wastewater can vary widely not only during the day but also along the year, because of the seasonal-consumption patterns of some pharmaceuticals. However, only few studies have attempted to assess the hourly variability of the concentrations of pharmaceutically active compounds in wastewater. In this work, the distribution and seasonal and hourly variability of twenty-one pharmaceuticals, belonging to seven therapeutic groups, have been investigated in urban and industrial wastewater. The highest concentrations of pharmaceutically active compounds, except salicylic acid, were found in urban wastewater, especially in the case of anti-inflammatory drugs and caffeine. The highest concentrations of salicylic acid were measured in industrial wastewater, reaching concentration levels up to 3295μgL(-)(1). The studied pharmaceutically active compounds showed different distribution patterns during winter and summer periods. Temporal variability of pharmaceutically active compounds during a 24-h period showed a distribution in concordance with their consumption and excretion patterns, in the case of urban wastewater, and with the schedule of industrial activities, in the case of industrial wastewater.

Degradation and environmental risk of surfactants after the application of compost sludge to the soil

In this work, the degradation of anionic and non-ionic surfactants in agricultural soil amended with sewage sludge is reported. The compounds analysed were: linear alkylbenzene sulphonates (LAS) with a 10-13 carbon alkylic chain, and nonylphenolic compounds (NPE), including nonylphenol (NP) and nonylphenol ethoxylates with one and two ethoxy groups (NP1EO and NP2EO). The degradation studies were carried out under winter (12.7°C) and summer (22.4°C) conditions in Andalusia region. The concentration of LAS was reduced to 2% of the initial concentration 100 day after sludge-application to the soil. The half-life time measured for LAS homologues were ranged between 4 and 14days at 12.7°C and between 4 and 7 days at 22.4°C. With regard to NPE compounds, after 8 and 4days from the beginning of the experiment at 12.7 and 22.4°C, respectively, their concentration levels were increased to 6.5 and 13.5mg/kgdm (dry matter) as consequence of the degradation of nonylphenol polyethoxylates. These concentration levels were reduced to 5% after 63 and 70 days for 12.7°C and 22.4°C, respectively. The half-life times measured for NPEs were from 8 to 16 days at 12.7°C and from 8 to 18 days at 22.4°C. Environmental risk assessment revealed that for LAS homologues no environment risk could be expected after 7 and 8 days of sludge application to the soil for 22.4 and 12.7°C, respectively; however, potential toxic effects could be observed for the nonylphenolic compounds during the first 56 days after sludge application to the soil.

Determination of priority pollutants in aqueous samples by dispersive liquid–liquid microextraction

A dispersive liquid-liquid microextraction (DLLME) method followed by high-performance liquid chromatography-triple quadrupole mass spectrometry has been developed for the simultaneous determination of linear alkylbenzene sulfonates (LAS C10, C11, C12, and C13), nonylphenol (NP), nonylphenol mono- and diethoxylates (NP1EO and NP2EO), and di-(2-ethylhexyl)phthalate (DEHP). The applicability of the method has been tested by the determination of the above mentioned organic pollutants in tap water and wastewater. Several parameters affecting DLLME, such as, the type and volume of the extraction and disperser solvents, sample pH, ionic strength and number of extractions, have been evaluated. Methanol (1.5 mL) was selected among the six disperser solvent tested. Dichlorobenzene (50 μL) was selected among the four extraction solvent tested. Enrichment factor achieved was 80. Linear ranges in samples were 0.01-3.42 μg L(-1) for LAS C10-13 and NP2EO, 0.09-5.17 μg L(-1) for NP1EO, 0.17-9.19 μg L(-1) for NP and 0.40-17.9 μg L(-1) for DEHP. Coefficients of correlation were higher than 0.997. Limits of quantitation in tap water and wastewater were in the ranges 0.009-0.019 μg L(-1) for LAS, 0.009-0.091 μg L(-1) for NP, NP1EO and NP2EO and 0.201-0.224 μg L(-1) for DEHP. Extraction recoveries were in the range from 57 to 80%, except for LAS C10 (30-36%). The method was successfully applied to the determination of these pollutants in tap water and effluent wastewater from Seville (South of Spain). The DLLME method developed is fast, easy to perform, requires low solvent volumes and allows the determination of the priority hazardous substances NP and DEHP (Directive 2008/105/EC).

Monitoring of emerging pollutants in Guadiamar River basin (South of Spain): analytical method, spatial distribution and environmental risk assessment

Guadiamar River is located in the southwest of the Iberian Peninsula and connects two protected areas in the South of Spain: Sierra Morena and Doñana National Park. It is sited in an area affected by urban, industrial and agriculture sewage pollution and with tradition on intensive mining activities. Most of the studies performed in this area have been mainly focused on the presence of heavy metals and, until now, little is known about the occurrence of other contaminants such as emerging organic pollutants (EOPs). In this work, an analytical method has been optimized and validated for monitoring of forty-seven EOPs in surface water. The analytical method has been applied to study the distribution and environmental risk of these pollutants in Guadiamar River basin. The analytical method was based on solid-phase extraction and determination by liquid chromatography-triple quadrupole–tandem mass spectrometry. The 60 % of the target compounds were found in the analyzed samples. The highest concentrations were found for two plasticizers (bisphenol A and di(2-ethyhexyl)phthalate, mean concentration up to 930 ng/L) and two pharmaceutical compounds (caffeine (up to 623 ng/L) and salicylic acid (up to 318 ng/L)). This study allowed to evaluate the potential sources (industrial or urban) of the studied compounds and the spatial distribution of their concentrations along the river. Environmental risk assessment showed a major risk on the south of the river, mainly due to discharges of wastewater effluents.