Reviews - WWTP Multi-Process - Septic System -Biological - Alternative - Single PPCP - Other


Review Papers on PPCP Removal
Citation Notes Abstract



WWTP Multi-process Removals of Multiple PPCPs
Citation Notes Abstract
Lubliner, B., Redding, M. and Ragsdale, D. (2010) Control of Toxic Chemicals in Puget Sound, Phase 3: PPCPs in Municipal WW and their Removal by Nutrient Treatment Technologies.
  In August 2008, the Washington State Department of Ecology (Ecology) and the U.S. Environmental Protection Agency (EPA) conducted a one-day screening study to characterize pharmaceuticals and personal care products (PPCPs) at five municipal wastewater treatment plants (WWTPs) in the Pacific Northwest. Wastewater influent, secondary effluent, tertiary effluent, and biosolids were sampled. Four of the five WWTPs discharge within the Puget Sound watershed. Two of the plants provide secondary treatment, and three employ advanced (tertiary) treatment for nitrogen and phosphorus removal. Two of the plants produce tertiary-treated reclaimed water. Target analytes included 172 organic compounds (PPCPs, hormones, steroids, semi-volatile organics). In addition, nutrients and total suspended solids were sampled. Newly approved EPA methods were used to measure PPCPs, hormones, and steroids at low concentrations. Removal efficiencies were evaluated for each analyte at the five WWTPs. In the study, PPCPs were found in all samples at concentrations comparable to those found in the literature. Secondary treatment alone achieved high removals for hormones and steroids. Approximately 21% of the 172 analytes were reduced to below reporting limits by conventional secondary treatment, whereas 53% were reduced to below reporting limits by at least one advanced nutrient-removal technology. Roughly 20% of the 172 analytes (mainly polycyclic aromatic hydrocarbons) were found only in the biosolids and not the wastewater samples. Some analytes were clearly concentrating in the biosolids. Three PPCPs (carbamazepine, fluoxetine, and thiabendazole) were relatively untreated by the surveyed WWTP technologies. These three PPCPs may serve well as human-influence tracer compounds in the environment. Overall, this screening study indicates that (1) there are differences in PPCP removal between the WWTP processes and (2) advanced nutrient reduction and tertiary filtration may provide additional PPCP removal.
Ying, G.G., Kookana, R.S. and Kolpin, D.W. (2009) Occurrence and removal of pharmaceutically active compounds in sewage treatment plants with different technologies. Journal of Environmental Monitoring 11(8), 1498-1505.   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.
Kasprzyk-Hordern, B., Dinsdale, R.M. and Guwy, A.J. (2009) The removal of pharmaceuticals, personal care products, endocrine disruptors and illicit drugs during wastewater treatment and its impact on the quality of receiving waters. Water Research 43(2), 363-380.   A 5-month monitoring program was undertaken in South Wales in the UK to determine the fate of SS pharmaceuticals, personal care products, endocrine disruptors and illicit drugs (PPCPs) in two contrasting wastewater plants utilising two different wastewater treatment technologies: activated sludge and trickling filter beds. The impact of treated wastewater effluent on the quality of receiving waters was also assessed. PPCPs were found to be present at high loads reaching 10 kg day(-1) in the raw sewage. Concentrations of PPCPs in raw sewage were found to correlate with their usage/consumption patterns in Wales and their metabolism. The efficiency of the removal of PPCPs was found to be strongly dependent on the technology implemented in the wastewater treatment plant (WWTP). In general, the WWTP utilising trickling filter beds resulted in, on average, less than 70% removal of all 55 PPCPs studied, while the WWTP utilising activated sludge treatment gave a much higher removal efficiency of over 85%. The monitoring programme revealed that treated wastewater effluents were the main contributors to PPCPs concentrations (up to 3 kg of PPCPs day(-1)) in the rivers studied. Bearing in mind that in the cases examined here the WWTP effluents were also major contributors to rivers' flows (dilution factor for the studied rivers did not exceed 23 times) the effect of WWTP effluent on the quality of river water is significant and cannot be underestimated.

Septic System Removals of Multiple PPCPs
(See also: Natural Systems-Groundwater)
Citation Notes Abstract
Wilcox, J.D., Bahr, J.M., Hedman, C.J., Hemming, J.D.C., Barman, M.A.E. and Bradbury, K.R. (2009) Removal of Organic Wastewater Contaminants in Septic Systems Using Advanced Treatment Technologies. Journal of Environmental Quality 38(1), 149-156.   The detection of pharmaceuticals and other organic wastewater contaminants (OWCs) in ground water and surface-water bodies has raised concerns about the possible ecological impacts of these compounds on nontarget organisms. On-site wastewater treatment systems represent a potentially significant route of entry for organic contaminants to the environment. In this study, effluent samples were collected and analyzed from conventional septic systems and from systems using advanced treatment technologies. Six of 13 target compounds were detected in effluent from at least one septic system. Caffeine, paraxanthine, and acetaminophen were the most frequently detected compounds, and estrogenic activity was detected in 14 of 15 systems. The OWC concentrations were significantly lower in effluent after sand filtration (p < 0.01) or aerobic treatment (p < 0.05) as compared with effluent that had not undergone advanced treatment. In general, concentrations in conventional systems were comparable to those measured in previous studies of municipal wastewater treatment plant (WWTP) influent, and concentrations in systems after advanced treatment were comparable to previously measured concentrations in WWTP effluent. These data indicate that septic Systems using advanced treatment can reduce OWCs in treated effluent to similar concentrations as municipal WWTPs.

Removals by Biological Treatment
(see also: Natural Systems - Sorption)
Citation Notes Abstract
Sui, Q., Huang, J., Deng, S.B., Chen, W.W. and Yu, G. (2011) Seasonal Variation in the Occurrence and Removal of Pharmaceuticals and Personal Care Products in Different Biological Wastewater Treatment Processes. Environmental Science & Technology 45(8), 3341-3348.
seasonal variability: see: 697z L#18 The occurrence of 12 pharmaceuticals and personal care products (PPCPs) in two wastewater treatment plants in Beijing was studied monthly over the course of one year. The removal of PPCPs by three biological treatment processes including conventional activated sludge (CAS), biological nutrient removal (BNR), and membrane bioreactor (MBR) was compared during different seasons. Seasonal variations of PPCPs in the wastewater influent were discrepant, while in the wastewater effluent, most PPCPs had lower concentrations in the summer than in the winter. For the easily biodegradable PPCPs, the performance of MBR was demonstrated to be more stable than CAS or BNR especially during winter months. Diclofenac, trimethoprim, metoprolol, and gemfibrozil could be moderately removed by MBR, while their removal by CAS and BNR was much lower or even negligible. Nevertheless, no removal was achieved regardless of the season or the treatment processes for the recalcitrant PPCPs. Studies on the contribution of each tank of the MBR process to the total removal of four biodegradable PPCPs indicated the oxic tank was the most important unit, whereas membrane filtration made a negligible contribution to their elimination.
Mascolo, G., Balest, L., Cassano, D., Laera, G., Lopez, A., Pollice, A. and Salerno, C. (2010) Biodegradability of pharmaceutical industrial wastewater and formation of recalcitrant organic compounds during aerobic biological treatment. Bioresource Technology 101(8), 2585-2591.   The biodegradability of different wastewater samples originated from the industrial production of three pharmaceuticals (naproxen, acyclovir, and nalidixic acid) was performed through the standard Zahn-Wellens test. Moreover, the wastewater composition before and during the test was evaluated in terms of parent compounds and main metabolites by LC/MS, and the biodegradability of the parent compounds was also assessed by performing extra Zahn-Wellens tests on synthetic solutions. The results, besides showing the relatively good biodegradability of acyclovir and naproxen, evidenced the masking role of the organic matrices, especially in the case of nalidixic acid. The latter compound showed to be recalcitrant and persistent, despite the apparently good performance of the Zahn-Wellens test. Deeper evaluation evidenced that the biodegradation of high concentrations of organic solvents and other biodegradable compound tended to "hide" the lack of removal of the target compound.
Khunjar, W., Mackintosh, S., Skotnicka-Pitak, J., Baik, S., Love, N. and Aga, D. (2010) Elucidating the Role of Ammonia Oxidizing Bacteria versus Heterotrophic Bacteria During the Biotransformation of 17a-Ethinylestradiol and Trimethoprim, IWA, Montreal.    
Skotnicka-Pitak, J., Khunjar, W.O., Love, N.G. and Aga, D.S. (2009) Characterization of Metabolites Formed During the Biotransformation of 17 alpha-Ethinylestradiol by Nitrosomonas europaea in Batch and Continuous Flow Bioreactors. Environmental Science & Technology 43(10), 3549-3555.   The biotransformation of 17 alpha-ethinylestradiol (EE2) by an ammonia oxidizing bacteria, Nitrosomonas europaea, grown in batch (ammonia-rich) and continuous flow (chemostat, ammonia-limited) reactors was investigated. Both C-14 labeled EE2 (10 mu g/L) and unlabeled EE2 (1 mg/L) were used to facilitate metabolite identification under environmentally relevant physiological conditions. Whole cell ammonia monooxygenase (AMO) activity was not inhibited at the EE2 concentrations used in this study. Characterization of the primary metabolite formed during batch cultivation by liquid chromatography/ion-trap mass spectrometry (LC-ITMS) and nuclear magnetic resonance (NMR) spectroscopy showed modification at the ethinyl group and addition of a carboxyl group. This metabolite (M386) (revealed by m/z 385 in negative mode electrospray LC/MS) was not formed in the abiotic control. In contrast, biotransformation of EE2 under continuous flow conditions showed formation of a monohydroxylated EE2 (revealed by m/z 311), but not M386. Furthermore, nitrated EE2 derivatives were formed in both batch and continuous flow cultures, as a result of abiotic transformation of EE2 in the presence of high concentrations of nitrite in the bioreactors. Results from this study underscore the importance of physiological state and growth conditions as critical variables that can dictate the metabolic pathway for EE2 biodegradation and the nature of byproducts formed.
Gaulke, L.S., Strand, S.E., Kalhorn, T.F. and Stensel, H.D. (2009) Estrogen Nitration Kinetics and Implications for Wastewater Treatment. Water Environment Research 81(8), 772-778.   Understanding estrogen-removal mechanisms in wastewater treatment is imperative, as estrogens have environmental effects at trace concentrations. Previous research investigating co-metabolic degradation of 17 alpha-ethinylestradiol (EE2) by ammonia-oxidizing bacteria (AOB) revealed that, in batch tests where high nitrite-nitrogen (NO2-N) concentrations occurred as a result of ammonia-nitrogen (NH4-N) oxidation by AOB, an abiotic estrogen nitration reaction actually was occurring-not co-metabolic degradation. This paper addresses nitration kinetics. A first-order abiotic nitration model was developed that predicts nitration of EE2, 17 beta-estradiol (E2), and estrone (E1) as a function of temperature, pH, estrogen (EE2, E2, and E1), and NO2-N concentration. A contact time of 3.6 to 4.1 days is required for 90% estrogen nitration at 500 mg/L NO2-N and pH 6.4. At 20 degrees C and pH 6.4, the threshold NO2-N concentration for nitration to occur is 9 mg/L; therefore, estrogen nitration is not likely in activated sludge treatment of domestic wastewater, but has potential for high-NH4-N-strength wastewaters.


Removal in Alternative or Advanced Treatment Systems
Citation Notes Abstract
Nelson, E.D., Do, H., Lewis, R.S. and Carr, S.A. (2010) Diurnal Variability of Pharmaceutical, Personal Care Product, Estrogen and Alkylphenol Concentrations in Effluent from a Tertiary Wastewater Treatment Facility. Environmental Science & Technology 45(4), 1228-1234.
good diurnal variability data: see 697z L#18 Hourly samples of tertiary wastewater effluent were analyzed for 30 pharmaceuticals, personal care products, estrogenic steroids, and alkylphenols in order to better understand the rate at which these compounds enter the environment. Several distinct patterns of daily cycling were observed, and were characterized as three separate categories. The concentrations of compounds such as trimethoprim, sulfamethoxazole, naproxen, estrone, and triclosan varied greatly during a daily cycle, with relative standard deviations exceeding 100% of their daily mean. Less extreme daily cycles were seen for other compounds such as azithromycin, atenolol, tert-octylphenol, iopromide and gemfibrozil. Peak concentrations for most compounds occurred in the early evening (5-8 pm). However, some compounds including carbamazepine, primidone, fluoxetine, and triclocarban exhibited little or no variability.
Marfil-Vega, R., Suidan, M.T. and Mills, M.A. (2010) Abiotic transformation of estrogens in synthetic municipal wastewater: An alternative for treatment? Environmental Pollution 158(11), 3372-3377.
  The abiotic transformation of estrogens, including estrone (E1), estradiol (E2), estriol (E3) and ethinylestradiol (EE2), in the presence of model vegetable matter was confirmed in this study. Batch experiments were performed to model the catalytic conversion of E1, E2, E3 and EE2 in synthetic wastewater Greater than 80% reduction in the parent compounds was achieved for each target chemical after 72 h with the remaining concentration distributed between aqueous and solid phases as follows. 13% and 7% for E1, 10% and 2% for E2, 6% and 2% for E3, and 8% and 3% for EE2, respectively Testosterone, androstenedione and progesterone were also monitored in this study, and their concentrations were found to be in agreement with initially spiked amount. Data collected under laboratory conditions provided the basis for implementing new abiotic wastewater treatment technologies that use inexpensive materials
Le-Minh, N., Khan, S.J., Drewes, J.E. and Stuetz, R.M. (2010) Fate of antibiotics during municipal water recycling treatment processes. Water Research 44(15), 4295-4323.   Municipal water recycling processes are potential human and environmental exposure routes for low concentrations of persistent antibiotics. While the implications of such exposure scenarios are unknown, concerns have been raised regarding the possibility that continuous discharge of antibiotics to the environment may facilitate the development or proliferation of resistant strains of bacteria. As potable and non-potable water recycling schemes are continuously developed, it is imperative to improve our understanding of the fate of antibiotics during conventional and advanced wastewater treatment processes leading to high-quality water reclamation. This review collates existing knowledge with the aim of providing new insight to the influence of a wide range of treatment processes to the ultimate fate of antibiotics during conventional and advanced wastewater treatment. Although conventional biological wastewater treatment processes are effective for the removal of some antibiotics, many have been reported to occur at 10-1000 ng L-1 concentrations in secondary treated effluents. These include beta-lactams, sulfonamides, trimethoprim, macrolides, fluoroquinolones, and tetracyclines. Tertiary and advanced treatment processes may be required to fully manage environmental and human exposure to these contaminants in water recycling schemes. The effectiveness of a range of processes including tertiary media filtration, ozonation, chlorination, UV irradiation, activated carbon adsorption, and NF/RO filtration has been reviewed and, where possible, semi-quantitative estimations of antibiotics removals have been provided.
Hollender, J., Zimmermann, S.G., Koepke, S., Krauss, M., McArdell, C.S., Ort, C., Singer, H., von Gunten, U. and Siegrist, H. (2009) Elimination of Organic Micropollutants in a Municipal Wastewater Treatment Plant Upgraded with a Full-Scale Post-Ozonation Followed by Sand Filtration. Environmental Science & Technology 43(20), 7862-7869.   The removal efficiency for 220 micropollutants was studied at the scale of a municipal wastewater treatment plant (WWTP) upgraded with post-ozonation followed by sand filtration. During post-ozonation, compounds with activated aromatic moieties, amino functions, or double bonds such as sulfamethoxazole, diclofenac, or carbamazepine with second-order rate constants for the reaction with ozone >10(4) M-1 s(-1) at pH 7 (fastreacting) were eliminated to concentrations below the detection limit for an ozone dose of 0.47 g O-3 g(-1) dissolved organic carbon (DOC). Compounds more resistant to oxidation by ozone such as atenolol and benzotriazole were increasingly eliminated with increasing ozone doses, resulting in >85% removal for a medium ozone dose (similar to 0.6 g O-3 g(-1) DOC). Only a few micropollutants such as some X-ray contrast media and triazine herbicides with second-order rate constants <10(2) M-1 s(-1) (slowly reacting) persisted to a large extent. With a medium ozone dose, only 11 micropollutants of 55 detected in the secondary effluent were found at > 100 ng L-1. The combination of reaction kinetics and reactor hydraulics, based on laboratory and full-scale date, enabled a quantification of the results by model calculations. This conceptual approach allows a direct upscaling from laboratory- to full-scale systems and can be applied to other similar systems. The carcinogenic by-products N-nitrosodimethylamine (NOMA),(<= 14 ng L-1) and bromate (<10 mu g L-1) were produced during ozonation, however their concentrations were below or in the range of the drinking water standards. Furthermore, it could be demonstrated that biological sand filtration is an efficient additional barrier for the elimination of biodegradable compounds formed during ozonation such as NOMA. The energy requirement for the additional post-ozonation step is about 0.035 kWh m(-3), which corresponds to 12% of a typical medium-sized nutrient removal plant (5 g DOC m(-3)).

Single PPCP Studies in VariousTreatment Scenarios
Citation Notes Abstract
Gonzalez, O., Esplugas, M., Sans, C., Torres, A. and Esplugas, S. (2009) Performance of a Sequencing Batch Biofilm Reactor for the treatment of pre-oxidized Sulfamethoxazole solutions. Water Research 43(8), 2149-2158.
  A combined strategy of a photo-Fenton pretreatment followed by a Sequencing Batch Biofilm Reactor (SBBR) was evaluated for total C and N removal from a synthetic wastewater containing exclusively 200 mg L-1 of the antibiotic Sulfamethoxazole (SMX). Photo-Fenton reaction was optimized at the minimum reagent doses in order to improve the biocompatibility of effluents with the subsequent biological reactor. Consequently, the pretreatment was performed with two different initial H2O2 concentrations (300 and 400 mg L-1) and 10 mg L-1 of Fe2+. The pre-treated effluents with the antibiotic intermediates as sole carbon source were used as feed for the biological reactor. The SBBR was operated under aerobic conditions to mineralize the organic carbon, and the Hydraulic Retention Time (HRT) was optimized down to 8 h reaching a removal of 75.7% of the initial Total Organic Carbon (TOC). The total denitrification of the NO3- generated along the chemical-biological treatment was achieved by means of the inclusion of a 24-h anoxic stage in the SBBR strategy. In addition, the Activated Sludge Model No. 1 (ASM1) was successfully used to complete the N balance determining the N fate in the SBBR. The characterization and the good performance of the SBBR allow presenting the assessed combination as an efficient way for the treatment of wastewaters contaminated with biorecalcitrant pharmaceuticals as the SMX


Large PPCP Studies with some Treatment Data
Citation Notes Abstract
Anderson, P., Denslow, N., Drewes, J.E., Olivieri, A., Schlenk, D., Scott, G.I. and Snyder, S. (2012) Monitoring Strategies for Chemicals of Emerging Concern (CECs) in California's Aquatic Ecosystem, Costa Mesa, CA.

Diamond, J., Thornton, K., Munkittrick, K., Kidd, K., Bartell, S. and Kapo, K. (2011) Diagnostic Tools to Evaluate Impacts of Trace Organic Compounds, Water Environment Research Foundation, Alexandria, VA.

  With the recent advent of improved analytical and biomarker detection capabilities, a variety of organic chemicals have been found in trace amounts (Trace Organic Chemicals, TOrCs) in surface waters and fish tissue. TOrCs include pharmaceuticals, personal care products, surfactants, pesticides, flame retardants, and other organic chemicals, some with unknown modes of action or effects. Identifying or predicting ecological effects of TOrCs in typical aquatic multi-stressor situations is challenging, requiring a variety of epidemiological tools that together, can diagnose effects at multiple scales of ecological organization. The goal of this research is to provide information on TOrCs to help the water quality community make scientifically defensible and cost effective decisions that are appropriately protective of aquatic populations and communities. Five objectives were addressed in this research: 1) develop and apply a procedure to prioritize which TOrCs are of most concern; 2) develop and test a conceptual site screening framework to determine if sites are or could be affected by TOrCs; 3) evaluate and test diagnostic approaches to identify potential risks due to TOrCs using various case studies; 4) develop a relational database and user interface with which the water resource community can enter, store, and search TOrC exposure and occurrence data in the U.S.; and 5) foster partnerships and transfer knowledge gained in this research to the water quality community. TOrC fate, effects, and occurrence data were compiled in a database for over 500 organic chemicals based on over 100 published studies representing more than 50 organizations and 700 sites. Alternative risk-based prioritization processes and draft lists of high priority TOrCs were developed. A preliminary site screening and diagnostic framework was developed and evaluated using seven different case study sites. EPA’s causal analysis (stressor identification) procedures, Canada’s Environmental Effects Monitoring (EEM) procedure, the ecosystem model CASM (Comprehensive Aquatic System Model), and several other specialized diagnostic tools were used and evaluated. A relational database based on Tetra Tech’s EDAS2 was developed using the Microsoft platform. The modified version of EDAS2, built on the EPA WQX data model, provides web-based data queries using a combination of tabular data for downloads and a visual map interface that allows the user to view, query, and select sites from the map having chemical or biological data. This final report summarizes all approaches used and results obtained in this research; discusses critical data gaps and other important uncertainties, and provides testable hypotheses and recommendations for Phase 2 testing and analyses.
Snyder, S.A., Vanderford, B.J., Drewes, J.E., Dickenson, E., Snyder, E.M., Bruce, G.M. and Pleus, R.C. (2008) State of Knowledge of Endocrine Disruptors and Pharmaceuticals in Drinking Water, AWWA Research Foundation, Denver, CO.