Compounds In Sewage Treatment Plants Research Articles

Multiresidue Determination of Endocrine Disrupting Compounds in Sewage Treatment Plants (SPE-HPLC-DAD)

This work focuses on the validation and application of solid phase extraction followed by high-performance liquid chromatography (SPE-HPLC) analysis of important endocrine disruptors compounds (EDC) from different classes in highly complex wastewater matrix. The endocrine disruptors investigated included three different categories: pharmaceuticals (sulfamethoxazole (SMZ), trimethoprim (TMP) and diclofenac (DCF)), hormones (estrone (E1), 17α-ethinylestradiol (EE2) and 17β-estradiol (E2)) and plastic materials (bisphenol A (BPA)). The method involves pre-concentration by SPE using Strata-X extraction cartridges followed by HPLC coupled with diode array detector (DAD). As the assumption of homoscedasticity was met for analytical data, ordinary linear regression procedure was applied to the data. The method was considered validated for 7 EDC after consistent evaluation of the key analytical parameters. Recoveries were ranged from 52.3 to 179.6%. Limits of quantification were in the range 6.0-0.4 µg L−1. The described method was applied to evaluate the occurrence and removal efficiency of EDC in two biological sewage treatment plants (STPs). The influent mean concentrations of E1, E2 and EE2 hormones were 79.54; 175.09 and 102.19 µg L−1, respectively, while for SMZ, TMP, DCF and BPA were 215.17; 187.01; 218.97 and 87.12 µg L−1 for STP A, respectively. The efficiencies for the removal of EDCs ranged from 0 to 79.4%.

Disentanglement of the chemical, physical, and biological processes aids the development of quantitative structure-biodegradation relationships for aerobic wastewater treatment

Attenuation of organic compounds in sewage treatment plants (STPs) is affected by a complex interplay between chemical (e.g. ionization, hydrolysis), physical (e.g. sorption, volatilization), and biological (e.g. biodegradation, microbial acclimation) processes. These effects should be accounted for individually, in order to develop predictive cheminformatics tools for STPs. Using measured data from 70 STPs in the Netherlands for 69 chemicals (pharmaceuticals, herbicides, etc.), we highlighted the influences of 1) chemical ionization, 2) sorption to sludge, and 3) acclimation of the microbial consortia on the primary removal of chemicals. We used semi-empirical corrections for each of these influences to deduce biodegradation rate constants upon which quantitative structure-biodegradation relationships (QSBRs) were developed. As shown by a global QSBR, biodegradation in STPs generally relates to structural complexity, size, energetics, and charge distribution. Statistics of the global QSBR were reasonable, being R2training=0.69 (training set of 51 compounds) and R2validation=0.50 (validation set of 18 compounds). Class-specific QSBRs utilized electronic properties potentially relating to rate-limiting enzymatic steps. For class-specific QSBRs, values of R2 of in between 0.7 and 0.8 were obtained. With caution, environmental risk assessment methodologies may apply these models to estimate biodegradation rates for ‘data-poor’ compounds. The approach also highlights ‘meta data’ on STP operational parameters needed to develop QSBRs of better predictability in the future.

Mass loading and removal of pharmaceuticals and personal care products, including psychoactive and illicit drugs and artificial sweeteners, in five sewage treatment plants in India

Despite the high consumption of pharmaceuticals, mass loading and removal of these compounds in sewage treatment plants (STPs) in India have not been investigated. In this study, 43 pharmaceuticals and personal care products as well as 13 of their metabolites were analyzed in five domestic STPs (wastewater influent, effluent, and sludge) and in raw domestic sewage collected in open sewerage channels in residential areas in India. The mean concentrations of amphetamine in two of the five STPs (mean: 4300ng/L and 4720ng/L) were the highest ever reported for wastewater influents, globally. Among artificial sweeteners, saccharin was the most abundant compound in influents (mean: 303,000ng/L, df: 100%), followed by cyclamate [3460ng/L, detection frequency (df): 75%] and sucralose (1460ng/L, df: 100%). Elevated mean concentrations of an antimicrobial (triclocarban=6180ng/L), analgesic (ibuprofen=2320ng/L), antihypertensive (atenolol=3180ng/L), illicit drug (amphetamine=984ng/L), and saccharin (419,000ng/L) were found in the Cooum River in Chennai. The median removal efficiencies of pharmaceuticals and personal care products (PPCPs) ranged from 5% (norcocaine) to 100% (triclosan) for the five STPs. On the basis of the concentrations measured in influents, the mass loadings of PPCPs were estimated to range from 0.1 (norquetiapine) to 77,800 (saccharin) mg/d/1000 people. An estimated 2.55kg of triclocarban, 3.24kg of carbamazepine, 6.93kg of amphetamine, and 252kg of saccharin were discharged from a typical STP with an average flow rate of 20.7 million liters per day (serving a population of 325,000) in India.

The removing and discharge of the synthetic polycyclic musk compounds in sewage treatment plant

The removing and discharge of the synthetic polycyclic musk compounds in sewage treatment plant

Determination of bisphenol A, tetrabromobisphenol A and alkylphenols in water samples of sewage treatment plant using liquid chromatography-tandem mass spectrometry

Bisphenol A, tetrabromobisphenol A and alkylphenols have received much attention in recent years because of their endocrine disrupting effects to aquatic ecosystem. The fate of these compounds in sewage treatment plant which is important to deal with this kind of compounds has significance on the study of exposure levels of the target compounds in the environment, and the development of analytical method is the basis on the above study. An analytical method based on liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) with negative ionization mode has been developed for measuring bisphenol A, tetrabromobisphenol A and six alkylphenols in raw and treated sewage samples. The target compounds were separated on a ZORBAX Eclipse Plus C18 column (150 mm x 2.1 mm, 3.5 microm) with mobile phases of acetonitril and 0.02% (v/v) ammonia. Analyte confirmations were performed under multiple reaction monitoring (MRM) mode and the eight compounds were separated within 11 min. The calibration curves were linear in the range of 1 - 100 microg/L (R2 > or = 0.998). The quantification limits of the eight compounds were 2.0 - 20 ng/L. The recovery experiments were performed with samples spiked at the levels of 0.2, 2 and 20 microg/L, and the recoveries for the target compounds were in the range of 64.3%-118.0%, 65.9% - 100.5% and 70.3%-102.7% (RSD < 7.1%, n = 3), respectively. Based on the analytical method, the raw and treated sewage samples from an industrial park of Jiangsu Province were analyzed. Five compounds were detected in the water outlet in the range of 11.9-3 015.3 ng/L. It shows that the method is simple, selective, sensitive and can be used to analyze the water samples of sewage treatment plant containing alkylphenols.

Ozonation and activated carbon treatment of sewage effluents: Removal of endocrine activity and cytotoxicity

Concerns about endocrine disrupting compounds in sewage treatment plant (STP) effluents give rise to the implementation of advanced treatment steps for the elimination of trace organic contaminants. The present study investigated the effects of ozonation (O3) and activated carbon treatment (AC) on endocrine activities [estrogenicity, anti-estrogenicity, androgenicity, anti-androgenicity, aryl-hydrocarbon receptor (AhR) agonistic activity] with yeast-based bioassays. To evaluate the removal of non-specific toxicity, a cytotoxicity assay using a rat cell line was applied. Wastewater (WW) was sampled at two STPs after conventional activated sludge treatment following the secondary clarifier (SC) and after subsequent advanced treatments: O3, O3 + sand filtration (O3-SF), and AC. Conventional treatment reduced estrogenicity, androgenicity, and AhR agonistic activity by 78–99% compared to the untreated influent WW. Anti-androgenicity and anti-estrogenicity were not detectable in the influent but appeared in SC, possibly due to the more effective removal of respective agonists during conventional treatment. Endocrine activities after SC ranged from 2.0 to 2.8 ng/L estradiol equivalents (estrogenicity), from 4 to 22 μg/L 4-hydroxytamoxifen equivalents (anti-estrogenicity), from 1.9 to 2.0 ng/L testosterone equivalents (androgenicity), from 302 to 614 μg/L flutamide equivalents (anti-androgenicity), and from 387 to 741 ng/L β-naphthoflavone equivalents (AhR agonistic activity). In particular, estrogenicity and anti-androgenicity occurred in environmentally relevant concentrations. O3 and AC further reduced endocrine activities effectively (estrogenicity: 77–99%, anti-androgenicity: 63–96%, AhR agonistic activity: 79–82%). The cytotoxicity assay exhibited a 32% removal of non-specific toxicity after O3 compared to SC. O3 and sand filtration reduced cytotoxic effects by 49%, indicating that sand filtration contributes to the removal of toxicants. AC was the most effective technology for cytotoxicity removal (61%). Sample evaporation reduced cytotoxic effects by 52 (AC) to 73% (O3), demonstrating that volatile substances contribute considerably to toxic effects, particularly after O3. These results confirm an effective removal or transformation of toxicants with receptor-mediated mode of action and non-specific toxicants during O3 and AC. However, due to the limited extractability, polar ozonation by-products were neglected for toxicity analysis, and hence non-specific toxicity after O3 is underestimated.

Occurrence and removal of pharmaceutically active compounds in sewage treatment plants with different technologies

Occurrence of eight selected pharmaceutically active compounds (PhACs; caffeine, carbamazepine, triclosan, gemfibrozil, diclofenac, ibuprofen, ketoprofen and naproxen) were investigated in effluents from fifteen sewage treatment plants (STPs) across South Australia. In addition, a detailed investigation into the removal of these compounds was also carried out in four STPs with different technologies (Plant A: conventional activated sludge; plant B: two oxidation ditches; plant C: three bioreactors; and plant D: ten lagoons in series). The concentrations of these compounds in the effluents from the fifteen STPs showed substantial variations among the STPs, with their median concentrations ranging from 26 ng/L for caffeine to 710 ng/L for carbamazepine. Risk assessment based on the "worst case scenario" of the monitoring data from the present study suggested potential toxic risks to aquatic organisms posed by carbamazepine, triclosan and diclofenac associated with such effluent discharge. With the exception of carbamazepine and gemfibrozil, significant concentration decreases between influent and effluent were observed in the four STPs studied in more detail. Biodegradation was found to be the main mechanism for removing concentrations from the liquid waste stream for the PhACs within the four STPs, while adsorption onto sludge appeared to be a minor process for all target PhACs except for triclosan. Some compounds (e.g. gemfibrozil) exhibited variable removal efficiencies within the four STPs. Plant D (10 lagoons in series) was least efficient in the removal of the target PhACs; significant biodegradation of these compounds only occurred from the sixth or seventh lagoon.

Toxicity identification fractionation of environmental estrogens in waste water and sludge using gas and liquid chromatography coupled to mass spectrometry and recombinant yeast assay

We developed a toxicity identification fractionation (TIF) procedure to determine estrogenic compounds in wastewaters and sludge. The procedure consisted in fractionation of samples through a C(18) solid-phase extraction cartridge, in which Fraction I contained nonylphenol (NP) and its mono (NPEO(1)) and diethoxylate (NPEO(2)) and the markers of faecal exposure, Fraction II contained bisphenol A (BPA) and synthetic and natural hormones, and Fraction III contained the hormone conjugates. These three fractions were analyzed in parallel using gas or liquid chromatography coupled to mass spectrometry and recombinant yeast assay (RYA). Water samples collected daily throughout a whole week contained from 0.45 to 7.22 microg L(-1) of NP > NPEO(1) > NPEO(2) and were responsible for the estrogenicity of these samples. Fractions II and III were not estrogenic and that was due to the low ng L(-1) level of hormones and hormone conjugates found, respectively. The biological treatment sewage treatment plant (STP) was capable to eliminate from 52 to 100% of the compounds, with bisphenol A being the least removed. Only alkylphenols were accumulated in sludge with concentrations from 8.69 to 26.3 mg kg(-1) dw of NPEO(1) > NPEO(2) > NP. The integrated procedure herein proposed can be used as a screening method to evaluate estrogenic compounds in STPs and to survey faecal elimination.

Fate of dissolved odorous compounds in sewage treatment plants

The concentration of selected malodorous compounds dissolved in water in different unit processes of actual treatment plant, and in different location of small scale treatment plants (Jokasos) were identified in order to provide sufficient information to undertake proper action to solve the problems of malodor compounds in water environment and in wastewater reuse. Analytic methods to measure as low as mg/l level of 16 odorous compounds were developed. In total, four sewerage treatment plants, three sludge treatment plants and six Jokasos were surveyed. Treatment plants were chosen in a way so that most types of unit processes could be covered. Being exposed to anaerobic condition is the primary reason of production of odorous compounds. As far as the secondary treatment is operated properly, odorous compounds concentration in the effluent can be maintained below odor threshold concentration. Odorous compounds were produced during sludge treatment process while the sludge is sedimented, thickened and dewatered, or anaerobically digested. A new way to express the odor concentration is proposed to obtain quick and comprehensive visualization of odor intensity.

Fate of dissolved odorous compounds in sewage treatment plants

The concentration of selected malodorous compounds dissolved in water in different unit processes of actual treatment plant, and in different location of small scale treatment plants (Jokasos) were identified in order to provide sufficient information to undertake proper action to solve the problems of malodor compounds in water environment and in wastewater reuse. Analytic methods to measure as low as mg/l level of 16 odorous compounds were developed. In total, four sewerage treatment plants, three sludge treatment plants and six Jokasos were surveyed. Treatment plants were chosen in a way so that most types of unit processes could be covered. Being exposed to anaerobic condition is the primary reason of production of odorous compounds. As far as the secondary treatment is operated properly, odorous compounds concentration in the effluent can be maintained below odor threshold concentration. Odorous compounds were produced during sludge treatment process while the sludge is sedimented, thickened and dewatered, or anaerobically digested. A new way to express the odor concentration is proposed to obtain quick and comprehensive visualization of odor intensity.

Behaviour of alkylphenol polyethoxylate surfactants in the aquatic environment—I. Occurrence and transformation in sewage treatment

Specific analytical techniques were used to study the behaviour of alkylphenol polyethoxylate surfactants (AP nEO) in several full-scale mechanical-biological sewage treatment plants in the Glatt Valley, Switzerland. Both parent compounds and the major metabolic products were quantified. Untreated sewage and primary effluents contained considerable amounts of surfactant-derived nonylphenolic compounds (3.0–9.6% of the dissolved organic carbon). Parent nonylphenol polyethoxylates ( nEO = 3–20) were efficiently eliminated during biological treatment. However, the overall rate of biodegradation was limited due to the formation of biorefractory metabolites, including nonylphenol (NP), nonylphenol mono- and diethoxylate (NP1EO, NP2EO) and nonylphenoxy carboxylic acids (NPEC). The abundance of a particular metabolite was very dependent on the treatment conditions. Studies of the mass flows of nonylphenolic compounds in sewage treatment plants indicated that their fate was determined not only by microbial transformation, but also by physicochemical processes.