Elimination In Wastewater Treatment Plants Research Articles

Degradation of the cytostatic drug bicalutamide by photo-assisted catalytic wet peroxide oxidation

The presence of cytostatic drugs, such as bicalutamide (BICA), in aquatic compartments reveals the necessity of developing efficient processes for their elimination in wastewater treatment plants (WWTP). This work explores for the first time the use of natural magnetite as a low-cost catalyst in the photo assisted — catalytic wet peroxide oxidation (UV-CWPO) of BICA. For this purpose, real WWTP secondary effluents were spiked with 100 μg/L BICA and subjected to UV-CWPO. Preliminary runs comparing UV photolysis, UV/H2O2, CWPO and UV-CWPO confirmed the synergistic effect of UV radiation and the CWPO process employing magnetite. Afterwards, a parametric study was performed evaluating the influence of the pH, catalyst load, H2O2 dosage, temperature and water matrix. Under optimum operating conditions (pH 0: 6, [magnetite]: 375 mg/L and [H2O2]: 75 mg/L), 99.7 % BICA degradation and 60.7 % mineralization were reached after 30 min in WWTP effluent. UV-CWPO also proved to be effective in hospital wastewater. Catalyst activity was studied in 5 consecutive runs, showing great stability for both BICA removal and TOC elimination. Finally, phytotoxicity tests revealed a lower toxicity in the UV-CWPO effluent compared to the untreated stream. Hence, UV-CWPO proved to be a feasible to eliminate risky cytostatic drugs in relevant environmental matrices.

Efficacy of point source legislation quantified for a 64-year river water quality trajectory of phosphorus loading

Changes in river water quality often follow typical trajectories characterized by sequential phases of degradation and recovery induced by management measures, typically achieved with combinations of legislative and technological interventions. However, the key question about the effectiveness of the different types of legal interventions – source control, use-related, and end-of-pipe – remains poorly understood. With the case of phosphorus (P), which is a valuable indicator of surface water quality and a widespread target of legislation at various governance levels in order to control eutrophication of water bodies, we quantified the relation between point source loading of P and resulting river water quality for a multidecadal trajectory of the river Ruhr (Germany). In particular, we analysed P-related legislation targeting point source pollution enforced at EU, national, state, and local level and linked their development with measured total phosphorus (TP) concentrations in the river Ruhr (Germany). To this end, we combined archival data with information in the literature and conducted interviews with contemporary witnesses to describe and quantify the efficacy of each legislative approach. Although not specifically targeted at P reduction, end-of-pipe measures (sewer systems and wastewater treatment plants (WWTP)) reduced TP inputs to surface waters already in the 1960s and 1970s, curbing TP inputs to the Ruhr by 38% in 1980. The first targeted source control legislation – the banning of phosphates in textile detergents in 1981 – effectively reduced TP concentrations in WWTP influents by 36% since 1990. In combination with stronger end-of-pipe legislation focusing on P elimination in WWTP since the 1990s, TP concentrations in WWTP effluents were reduced by 86% at the end of the 1990s and by 92% in 2021. Complete and successful source control for textile detergents made use-related legislation redundant. Our study demonstrates that source control measures should be prioritized, because they are the fastest way to curb emissions. These findings provide insights that can inform efficient decision-making regarding water quality in a trajectory perspective of hierarchical governance and technological needs, as well as effective policy-making and management for other pollutants requiring control from point sources.

Behavior of antibiotic resistance genes in a wastewater treatment plant with different upgrading processes

Wastewater treatment plants (WWTPs) in China have been upgraded or renovated with a variety of emerging processes, but a comprehensive understanding of the behavior of antibiotic resistance genes (ARGs) in these WWTPs is still lacking. Here, the distribution of ARGs and bacterial community were investigated in a wastewater treatment plant with upgrading processes (WWTP-UP). 238 unique ARGs were detected in all samples. During the study period, the average ARGs concentration decreased by 98.4% along the entire treatment process. The removal efficiency of A2/O-membrane bioreactor (MBR) process was significantly higher than that of A2/O-high efficiency flocculent settling/cloth media filter (HEFS/CMF) process (p < 0.05), which corresponded to 3.5 and 2.1 log values on average, respectively. Notably, 35 ARGs and 14 mobile genetic elements (MGEs) were persistent in all samples. Based on the co-occurrence pattern revealed by network analysis, persistent ARGs possibly spread through the transfer of persistent MGEs among persistent bacteria. Using multiple linear regression analysis, we obtained 3 to 5 possible indicators for major ARG types, which might be served to evaluate the general distribution of ARGs or even predict the abundance of different ARG types. Our findings provide new insights into the impacts of upgrading process on ARGs and highlight the need for better strategies to improve ARGs elimination in WWTPs.

Removal of 17α-ethinylestradiol and caffeine from wastewater by UASB-Fenton coupled system

ABSTRACT In aquatic systems, some substances considered as endocrine disruptors have been detected, which can be due to their incomplete elimination in wastewater treatment plants (WWTPs) and inadequate disposal of pharmaceuticals. Among these contaminants are 17α-ethinylestradiol (EE2) and caffeine (CAF). Moreover, it has been reported that this kind of contaminants may provoke different adverse effects in many aquatic organisms. Because of that, in the present study, up-flow anaerobic sludge blanket reactors (UASB) coupled with the Fenton process was evaluated for EE2 and CAF removal spiked in wastewater samples. First, the best reaction conditions were established in each process. For UASB reactor, two hydraulic retention times (HRT 8 and 24 h) were evaluated, achieving the highest chemical organic demand (COD) removal (70 %) and drug elimination (84 %–86 %) with HRT 24 h. Subsequently, Fenton process was conducted at pH 3 with different levels of Fe2+ (0.05–0.5 mmol/L) and molar ratios Fe2+:H2O2 (1:1–1:10). Better results were obtained with 0.5 mmol Fe2+/L, and 1:10 ratio molar Fe2+:H2O2. Finally, UASB-Fenton coupled system allowed 80 % of COD decrease, almost complete removal of drugs and the toxicity of samples on Vibrio fischeri was reduced from 73 % to 30 %, demonstrating that this coupled system is a promising and efficient system for pharmaceutical compounds removal from wastewater.

Emerging organic contaminants in wastewater: Understanding electrochemical reactors for triclosan and its by-products degradation

Degradation technologies applied to emerging organic contaminants from human activities are one of the major water challenges in the contamination legacy. Triclosan is an emerging contaminant, commonly used as antibacterial agent in personal care products. Triclosan is stable, lipophilic and it is proved to have ecotoxicologic effects in organics. This induces great concern since its elimination in wastewater treatment plants is not efficient and its by-products (e.g. methyl-triclosan, 2,4-dichlorophenol or 2,4,6-trichlorophenol) are even more hazardous to several environmental compartments. This work provides understanding of two different electrochemical reactors for the degradation of triclosan and its derivative by-products in effluent. A batch reactor and a flow reactor (mimicking a secondary settling tank in a wastewater treatment plant) were tested with two different working anodes: Ti/MMO and Nb/BDD. The degradation efficiency and kinetics were evaluated to find the best combination of current density, electrodes and set-up design. For both reactors the best electrode combination was achieved with Ti/MMO as anode. The batch reactor at 7 mA/cm2 during 4 h attained degradation rates below the detection limit for triclosan and 2,4,6-trichlorophenol and, 94% and 43% for 2,4-dichlorophenol and methyl triclosan, respectively. The flow reactor obtained, in approximately 1 h, degradation efficiencies between 41% and 87% for the four contaminants. This study suggests an alternative technology for emerging organic contaminants degradation, since the combination of a low current density with the flow and matrix induced disturbance increases and speeds up the compounds’ elimination in a real environmental matrix.

Activated Carbon and the Principal Mineral Constituents of a Natural Soil in the Presence of Carbamazepine

The presence of pharmaceutical residues in the different aquatic compartments is a major environmental issue. Carbamazepine (CBZ), a heterocyclic antiepileptic, which is neutral between pH 3 and 11, is known to resist biodegradation. Its elimination in wastewater treatment plants is below 20% regardless of the primary and/or secondary treatments currently implemented. Its presence in groundwater raises questions about soil permeability in relation to this molecule. In order to provide meaningful answers, the CBZ adsorption performances of the principal mineral constituents of a natural soil (alumina, quartz, goethite, haematite, kaolinite, montmorillonite, and a saponin stevensite) and of an industrial activated carbon were assessed. Prior to the batch adsorption tests, the texture, mineralogy, and zero point of charge of these products were determined. X-ray diffraction (XRD) and UV-visible spectrometry were used to characterize the CBZ used. With the exception of stevensite, these minerals did not adsorb CBZ. However, stevensite’s affinity for CBZ remained very low compared to that of activated carbon (235 mg/g, tap water), which proved to be the most appropriate product for eliminating CBZ. The π−π, CH−π, and hydrogen bonds are the basis for the interactions established between CBZ and activated carbon, and their combination increases the overall adsorption efficiency.

NO3 - removal efficiency in field denitrification beds: key controlling factors and main implications.

Nitrate pollution is a growing environmental threat that affects both ground- and surface-water. The typically used technique for nitrate elimination in wastewater treatment plants cannot be applied for all water streams as it necessitates a highly developed technical infrastructure. Field denitrification beds comprise one strategy to treat surface water containing high nitrate loads, which typically is due to the increasing agricultural land use. Here, the water passes through a basin containing a cheap carbon material as electron donor that provides the environmental niche for a complex microbial biocenosis. The microorganisms catalyse the hydrolysis of the polymeric organic carbon substrate and a variety of fermentative and respiratory pathways that are in the end supposed to lead to an efficient denitrification process. This review article integrates our current knowledge on environmental and operating parameters of and within denitrification beds including biotic and abiotic factors influencing the nitrate removal efficiency. Steering of these two factors can allow to minimise pollution swapping and the formation of greenhouse gases.

Performance of artificial sweetener sucralose mineralization via UV/O3 process: Kinetics, toxicity and intermediates

Sucralose (SUC) is ubiquitously present in aquatic ecosystems in many parts of the world, owing to its widespread usage and ineffective elimination in wastewater treatment plants. This study investigated the mineralization of SUC in aqueous solution via UV/O3 process and found that SUC can be mineralized efficiently. Effect of several operating parameters like solution pH, O3 concentration, gas flow rate and initial SUC concentration, on TOC removal were explored. Results indicated that the mineralization efficiency of SUC reached almost 90% in 120 min after UV/O3 treatment at neutral pH. The intensity of hydroxyl radicals generated in sole O3 and UV/O3 processes were compared using the fluorescence spectra analysis. Toxicity tests carried out using Daphnia Magna indicated that the UV/O3 process under the used experimental conditions was much more effective in the detoxification of the SUC solution than sole O3 process. The presence of inorganic anion like NO3− exhibited an enhancement on the mineralization rate, while Cl− showed some positive effect at low concentration (1 mM) but inhibited SUC mineralization at higher concentrations (10–200 mM). Finally, the intermediates produced in UV/O3 process were identified by LC-MS analysis and a possible transformation pathway was briefly discussed.

Pharmaceuticals released from senior residences: occurrence and risk evaluation.

One of the main pursuits, yet most difficult, in monitoring studies is to identify the sources of environmental pollution. In this study, we have identified health-care facilities from south European countries as an important source of pharmaceuticals in the environment. We have estimated that compounds consumed in by the elderly and released from effluents of senior residences can reach river waters at a concentration higher than 0.01μg/L, which is the European Medicines Agency (EMA) threshold for risk evaluation of pharmaceuticals in surface waters. This study has been based on five health institutions in Portugal, Spain, and France, with 52 to 130 beds. We have compiled the pharmaceuticals dispensed on a daily base and calculated the consumption rates. From 54.9 to 1801g of pharmaceuticals are consumed daily, with laxatives, analgesics, antiepileptics, antibiotics, and antidiabetic agents being the main drug families administered. According to excretion rates, dilution in the sewerage system, and elimination in wastewater treatment plants, macrogol, metformin, paracetamol, acetylcysteine, amoxicillin, and gabapentin, among others, are expected to reach river waters. Finally, we discuss the risk management actions related to the discharge of pharmaceuticals from senior residences to surface waters.

Gadolinium-uptake by aquatic and terrestrial organisms-distribution determined by laser ablation inductively coupled plasma mass spectrometry.

Gadolinium (Gd) based contrast agents (CA) are used to enhance magnetic resonance imaging. As a consequence of excretion by patients and insufficient elimination in wastewater treatment plants they are detected in high concentrations in surface water. At present, little is known about the uptake of these species by living organisms in aquatic systems. Therefore the uptake of gadolinium containing chelates by plants and animals grown in exposed water or on soil irrigated with exposed water was investigated. For this purpose two types of plants were treated with two different contrast agents. The uptake of the Gd contrast agents was studied by monitoring the elemental distribution with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). This technique allows the multi-elemental analysis of solid samples with high resolution and little sample preparation. The analysis of L. minor showed that the uptake of Gd correlated with the concentration of gadodiamide in the water. The higher the concentration in the exposed water, the larger the Gd signal in the LA-ICP-MS acquired image. Exposure time experiments showed saturation within one day. The L. minor had contact with the CAs through roots and fronds, whereas the L. sativum only showed uptake through the roots. These results show that an external absorption of the CA through the leaves of L. sativum was impossible. All the analyzed parts of the plant showed Gd signal from the CA; the highest being at the main vein of the leaf. It is shown that the CAs can be taken up from plants. Furthermore, the uptake and distribution of Gd in Daphnia magna were shown. The exposure via cultivation medium is followed by Gd signals on the skin and in the area of the intestine, while the uptake via exposed nutrition algae causes the significantly highest Gd intensities in the area of the intestine. Because there are hints of negative effects for human organism these findings are important as they show that Gd based CAs may reach the human food chain via plants and animals growing in contaminated water or plants growing in fields which are irrigated with surface water.

Prioritizing Unknown Transformation Products from Biologically-Treated Wastewater Using High-Resolution Mass Spectrometry, Multivariate Statistics, and Metabolic Logic.

Incomplete micropollutant elimination in wastewater treatment plants (WWTPs) results in transformation products (TPs) that are released into the environment. Improvements in analytical technologies have allowed researchers to identify several TPs from specific micropollutants but an overall picture of nontarget TPs is missing. In this study, we addressed this challenge by applying multivariate statistics to data collected with liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) and subsequent tandem HRMS (MS/MS) in order to characterize peaks detected in the influent and effluent of a WWTP. Known biotransformation reactions were used to link potential parent compounds and TPs, while the structural similarity of these pairs hypothesized by MS/MS similarity was used for further prioritization. The methodology was validated with a set of spiked compounds, which included 25 parent/TP pairs for which analytical standards were available. This procedure was then applied to nontarget data, and 20 potential parent and TP pairs were selected for identification. In summary, primarily a surfactant homologue series, with associated TPs, was detected. Some obstacles still remain, including spectral interferences from coeluting compounds and identification of TPs, whose structures are less likely to be present in compound databases. The workflow was developed using openly accessible tools and, after parameter adjustment, could be applied to any data set with before and after information about various biological or chemical processes.

From consumption to harvest: Environmental fate prediction of excreted ionizable trace organic chemicals

Excreted trace organic chemicals, e.g., pharmaceuticals and biocides, typically undergo incomplete elimination in municipal wastewater treatment plants (WWTPs) and are released to surface water via treated effluents and to agricultural soils through sludge amendment and/or irrigation with freshwater or reclaimed wastewater. Recent research has shown the tendency for these substances to accumulate in food crops. In this study, we developed and applied a simulation tool to predict the fate of three ionizable trace chemicals (triclosan—TCS, furosemide—FUR, ciprofloxacin—CIP) from human consumption/excretion up to the accumulation in soil and plant, following field amendment with sewage sludge or irrigation with river water (assuming dilution of WWTP effluent). The simulation tool combines the SimpleTreat model modified for fate prediction of ionizable chemicals in a generic WWTP and a recently developed dynamic soil-plant uptake model. The simulation tool was tested using country-specific (e.g., consumption/emission rates, precipitation and temperature) input data. A Monte Carlo-based approach was adopted to account for the uncertainty associated to physico-chemical and biokinetic model parameters.Results obtained in this study suggest significant accumulation of TCS and CIP in sewage sludge (1.4–2.8 mg kgDW−1) as compared to FUR (0.02–0.11 mg kgDW−1). For the latter substance, more than half of the influent load (60.1%–72.5%) was estimated to be discharged via WWTP effluent. Specific emission rates (g ha−1 a−1) of FUR to soil via either sludge application or irrigation were up to 300 times lower than for TCS and CIP. Nevertheless, high translocation potential to wheat was predicted for FUR, reaching concentrations up to 4.3 μg kgDW−1 in grain. Irrigation was found to enhance the relative translocation of FUR to plant (45.3%–48.9% of emission to soil), as compared to sludge application (21.9%–27.6%).A comparison with peer-reviewed literature showed that model predictions were close to experimental data for elimination in WWTP, concentrations in sewage and sludge and bioconcentration factors (BCFs) in plant tissues, which showed however a large variability. The simulation tool presented here can thus be useful for priority setting and for the estimation of human exposure to trace chemicals via intake of food crops.

Pharmaceuticals in hospital wastewater: Their ecotoxicity and contribution to the environmental hazard of the effluent

Nowadays, pharmaceuticals are found in every compartment of the environment. Hospitals are one of the main sources of these pollutant emissions sent to wastewater treatment plants (WWTP) that are poorly equipped to treat these types of compounds efficiently. In this work, for each pharmaceutical compound found in hospital wastewater (HWW), we have calculated a hazard quotient (HQ) corresponding to the highest concentration measured in HWW divided by its predicted no effect concentration (PNEC). Thus we have assessed the contribution of each compound to the ecotoxicological threat of HWW taken as a whole. Fifteen compounds are identified as particularly hazardous in HWW. In future more attention should be given to their analysis and replacement in hospitals, and to their elimination in WWTPs. This work also highlights the lack of knowledge of the ecotoxicity of certain pharmaceutical compounds found in HWW at high concentrations (mgL−1). In order to extend this study, it is now necessary to investigate ecotoxic risks linked to various emission scenarios, focusing in particular on dilution in the aquatic environment and the production of metabolites, especially during transit inside WWTPs.

The challenge of analyzing beta-blocker drugs in sludge and wastewater

In this study, different approaches were used to assess and overcome the severe effects of interference from the sample matrix from different types of sludges and wastewater on the analysis of nine beta-blockers and the beta sympathomimetic clenbuterol. The partitioning of the target compounds into sludge was investigated in wastewater treatment plants (WWTPs) in both Canada and Germany to evaluate whether this is an important mechanism for removal from sewage. Due to ion suppression in the electro spray interface, absolute recoveries were for certain compounds even lower than 20%. By using surrogate standards, acceptable relative recoveries of >75% were achieved for WWTP influents and effluents and for sludges. These matrix effects underline the need to use appropriate surrogate standards to aid in analyte quantitation. Using the developed methods, beta-blockers were detected at concentrations up to 2 microg/L in WWTP effluents, with metoprolol, sotalol, and atenolol present as the dominant compounds. Removal rates within WWTPs were highly inconsistent and ranged from 1-69%. Propranolol showed the greatest degree of partitioning into sludge with solid/water partition coefficients of one order of magnitude higher than those for all other compounds. However, even for propranolol, sorption did not contribute significantly to the overall elimination in WWTPs. It is likely that the removal of beta-blockers during waste water treatment can be attributed primarily to microbial biodegradation.

Fate of the Antibiotic Sulfamethoxazole and Its Two Major Human Metabolites in a Water Sediment Test

Sulfonamide antibiotics are widely used in human and veterinary medicine. After their application, they are excreted in unchanged as well as in metabolized form. Due to incomplete elimination in wastewater treatment plants, they can be emitted into surface water. The environmental fate of both parent compounds and metabolites is currently unknown. The aim of this study was to determine the biodegradation potential of river sediment for the sulfonamide sulfamethoxazole (SMX) and its two major human metabolites N4-acetyl-SMX and SMX-N1-glucuronide using a water sediment test system. Each compound was tested in a separate series together with sterile and "water only" controls. All three compounds were efficiently removed from the test system by biodegradation in the sediment. Only for SMX-N1-glucuronide, a substantial removal in the absence of sediment was determined. Dissipation times from the aqueous phase (DT50) between 8.5 and 17.2 days were measured. Sorption to sediment was of minor importance due to the slightly basic pH of the test system. By the application of a mathematical model, biodegradation half-lives in sediment between 3.3 and 25.6 h were calculated for SMX and its metabolites. The results of this study highlight the capability of native river sediment for degrading sulfonamide antibiotics, but also the potential of human metabolites to retransform into parent SMX under environmental conditions. Based on this study, it is unlikely that SMX or its metabolites will persist or accumulate in river sediments under pH conditions where sorption is of minor importance.

Methods for Detection and Quantification of Polyphosphate and Polyphosphate Accumulating Microorganisms in Aquatic Sediments

AbstractIt has been speculated that the microbial P pool is highly variable in the uppermost layer of various aquatic sediments, especially when an excessive P accumulation in form of polyphosphate (Poly‐P) occurs. Poly‐P storage is a universal feature of many different organisms and has been technically optimised in wastewater treatment plants (WWTP) with enhanced biological phosphorus removal (EBPR). In the recent past, new insights into mechanisms of P elimination in WWTP almost exclusively depended on the development and application of novel methods like 31P‐NMR spectroscopy and molecular methods for identifying Poly‐P accumulating microorganisms (PAO). The aim of the present review is to compile current methods potentially available for detection and quantification of Poly‐P in sediments and to complement it with yet unpublished results to validate their application in natural sediments. The most powerful tool for reliable Poly‐P quantification in sediments is the liquid 31P‐NMR technique which has been successfully used for Poly‐P measurements in a variety of aquatic sediments. But the microorganisms as well as mechanisms involved in Poly‐P storage and cycling are largely unknown. Therefore, we also intend to stimulate future studies focusing on these encouraging topics in sediment research via the implementation of novel methods. (© 2008 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Polyphosphate-accumulating microorganisms in aquatic sediments

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 47:299-311 (2007) - doi:10.3354/ame047299 Polyphosphate-accumulating microorganisms in aquatic sediments Michael Hupfer, Stefanie Gloess, Hans-Peter Grossart* Leibniz Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12561 Berlin, Germany *Corresponding author.Email: hgrossart@igb-berlin.de ABSTRACT: The direct contribution of microorganisms to the mobilisation and immobilisation of phosphorus (P) in aquatic sediments has been controversially discussed for more than a decade. Some authors have speculated that the microbial P pool is highly variable in the uppermost sediment layer, especially when excessive P accumulation in the form of polyphosphate (Poly-P) occurs. Poly-P storage is a widespread ability of many different organisms in nature. The phenomenon of Poly-P storage has been technically optimised in wastewater treatment plants (WWTP) providing conditions for enhanced biological phosphorus removal. New insights into the functioning of P elimination in WWTP were strongly linked to the development of novel methods, like 31P nuclear magnetic resonance, for the detection of Poly-P and molecular biological methods for the identification of the specific microorganisms responsible for biological P elimination. Our review summarises current literature on Poly-P in aquatic systems and discusses different potential habitats and mechanisms for Poly-P storage in sediments that are more diverse than in WWTP. Poly-P in sediments may originate from benthic or pelagic hetero- and autotrophic organisms. Poly-P-accumulating organisms in sediments may be of high ecological importance, since they insert phosphorus into the benthic food chain and affect the permanent P mineral deposition in sediments by physiologically inducing rapid P release. Although several studies indicate that Poly-P substantially contributes to total P in the uppermost sediment layer (up to 10%), its origin and the microorganisms and mechanisms involved in Poly-P storage and cycling are largely unknown. Therefore, we also aim to stimulate future studies focusing on these important areas of sediment research. KEY WORDS: Polyphosphate · Polyphosphate-accumulating organisms · Microbial diversity · Sediments · Phosphorus cycle · Diagenesis · Waste water treatment plant Full text in pdf format PreviousExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 47, No. 3. Online publication date: May 30, 2007 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2007 Inter-Research.