WWTP Effluent Research Articles

Synthesis and characterization of bimetallic TiO2/CNT/Pd-Cu for efficient remediation of endocrine disruptors under solar light

Metal and bimetal doped TiO2 supported on CNT hybrids were successfully synthesized in supercritical CO2 medium and evaluated for their solar light photocatalytic efficiency to degrade the endocrine disruptors clothianidin (CLT), estrone (E1) and estradiol (E2). Metallic dopants analyzed were Pd and Cu at metal concentrations of 2% by weight. The morphological analysis of the hybrids showed metal-doped TiO2 nanoparticles of around 10 nm over CNT. All of them exhibited highly crystalline anatase phase and shifted the absorption edge through the visible region. Band gap reduction was more pronounced for bimetallic Pd, Cu codoped TiO2 (TiO2/CNT/Pd-Cu) than with monometal-doped samples (TiO2/CNT/Pd and TiO2/CNT/Cu). Bimetalic codoping also led to an enhancement in the charge transfer process (Rct=1.4 ohms and Rs=19.4 ohms for TiO2/CNT/Pd-Cu vs. Rct=13.0 ohms and Rs=38.5 ohms for TiO2/CNT) and photodegradation of target endocrine disruptors. At the vanishing times of these pollutants by treatment with TiO2/CNT/Pd-Cu, the removals achieved with the metal-doped catalyst least active (TiO2/CNT/Cu) were 80% (clothianidin), 84% (estrone) and 82% (estradiol), far higher than those observed with commercial P25 (53% for clothianidin, 56% for estrone and 54% for estradiol). The improved performance of bimetallic TiO2/CNT/Pd-Cu over its monometallic references was explained on the basis of a combination of factors mainly related to its band gap structure, easier availability of charge carriers and plasmonic effects. Furthermore, this catalyst showed a highly stable photocatalytic performance. Thus, neither background species present in a real WWTP effluent, nor four successive uses of the catalyst significantly affected to the removal efficiency of pollutants.

Occurrence of pharmaceuticals in the environmental waters: African and Asian perspectives

Environmental ubiquity of pharmaceuticals has stimulated a lot of societal and global concerns. The occurrence of pharmaceuticals in the environment differs from country to country depending on the extent of consumption and monitoring. Most studies reporting the occurrence of pharmaceuticals are conducted in coastal regions with numerous articles and reviews reported in developed countries. The current review reports the occurrence of pharmaceuticals in inland waters with major focus devoted to developing countries in Africa and Asia. The focus was further dedicated to sources and distribution mechanisms, which contribute greatly to their ubiquity in the environment. Antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) are the most reported pharmaceuticals in African waters. For example, an antibiotic (sulfamethoxazole) was detected in more than four African countries with highest concentrations reaching 53.8–56.6 μg L −1 detected in Kenya and Mozambique. Furthermore, highest concentrations of amoxicillin ranging from 0.087–272.2 μg L −1 were detected in Nigeria. Ibuprofen, which is NSAID was detected at highest concentrations reaching 67.9 and 58.7 μg L −1 in Durban city and Msunduzi River (KwaZulu-Natal, South Africa), respectively. However, highest concentration of antiretroviral drug (lamivudine) up to 167 μg L −1 was found in surface water samples collected from Nairobi and Kisumu city, Kenya. In Asian countries, antibiotics were detected at highest concentration reaching 365.05 μg L −1 in surface water samples. However, concentrations of other pharmaceuticals were comparably below the concentrations detected in African environmental waters. Health risks associated with their fate in the environment are critically reviewed. Sample preparation techniques and analytical instruments necessary for the occurrence studies were also reviewed. The concluding remarks were based on deliberating the possible future prospects within the research expertise. • WWTP effluents are the major source of pharmaceuticals in the river water systems. • Antibiotics and NSAIDs frequently detected in the environment matrices. • Variations in pharmaceutical levels in waters of developing countries observed. • Risk quotients showed that ibuprofen and other antibiotics are of greatest concern. • A risk assessment showed majority of pharmaceuticals pose no risk to aquatic life.

DETERMINATION OF RECYCLE WATER TECHNOLOGY FOR WASTEWATER TREATMENT AT UNIVERSITAS PERTAMINA AREA WITH ANALYTICAL HIRACHY PROCESS (AHP)

<p><em>The wastewater treatment plant (</em><em>WWTP</em><em>) at the </em><em>Universitas Pertamina</em><em> </em><em>area </em><em>is one of the campus's efforts to reduce the environmental impact of wastewater production. The processed WWTP can be processed into ready-to-drink water as an effort to reduce plastic waste. This plastic waste is usually produced by the consumption of mineral water products. The availability of ready-to-drink water in the campus complex is expected to increase the interest of campus residents to use tumblers and reduce the generation of plastic waste as well as university proactive efforts. The purpose of this study was to analyze the units needed to process WWTP effluent into ready-to-drink water by looking at various alternatives. This study uses the analytical hierarchy process (AHP) in determining the best alternative. The units required for each alternative are equalization tub, slow sand filter, and disinfection. Meanwhile, for processing, there are three alternatives, namely microfiltration (MF), ultrafiltration (UF), and combined microfiltration – ultra-filtration (MF-UF). The selection of these alternatives was adjusted to the criteria of cost, required membrane area, flux recovery after backwashing, and the effectiveness of total coliform removal. MF filtration technology is the largest weight, which is 0.381. Where the use of MF in the </em><em>Universitas Pertamina</em><em> </em><em>area</em><em> is cheaper and requires better area than UF and MF-UF technology.</em></p>

Valorisation of drinking water treatment sludge as substrate in subsurface flow constructed wetlands for upgrading treated wastewater

Drinking water treatment sludge (DWTS) is the main waste produced in drinking water treatment plants (DWTPs). Its valorisation as substrate for constructed wetlands (CWs) aimed at upgrading treated urban wastewater is presented. Keeping a holistic approach in mind, this study looks for nutrient and organic matter removal but also contaminants of emerging concern (CECs) and pathogens. Three pilot subsurface flow CWs (1 m2) were installed under outdoor conditions in real WWTPs. Different operation modes (sequential: S-CW and continuous saturated flow: C-CW, CC-CW), different nutrient influent concentrations (S-CW and C-CW: 0.6 mg TP/l, 12.7 mg TN/l; CC-CW: 6.5 mg TP/l, 48 mg TN/l) and high hydraulic loading rates (HLRs, 0.9–5.1 m3/m2/d) were tested. C-CW presented higher removal efficiencies than S-CW for TP (C-CW: 56–86%; S-CW: 32–66%), total nitrogen (C-CW: 23–38%; S-CW: −3 to 6%) and E. coli (C-CW: 94%; S-CW: 84%), while S-CW performed better for ammonium (C-CW: 29–45%; S-CW: 72–86%) and CECs removal. Among fifteen CECs monitored, most pharmaceuticals, four were significantly reduced in C-CW and nine in S-CW, which had more aerobic conditions. CC-CW reduced nutrients and organic matter by 62% (TP), 8% (TN), 23% and 40% (chemical and biochemical oxygen demands, respectively). The potential release of aluminium was negligible. Novel values for the first-order reaction coefficient of P-k-C* model are provided for the TP removal process using DWTS (0.6–1.0 h−1). The main conclusion is that DWTS is a suitable substrate to significantly upgrade WWTP effluents, even at high HLRs. A hybrid system combining sequential and continuous flow modes could optimize the upgrading treatment. A proposal for the full valorisation of the sludge produced in one DWTP is presented.

Sources and Fate of the Antiandrogenic Fluorescent Dye 4-Methyl-7-Diethylaminocoumarin in Small River Systems.

Recently, the potent antiandrogen 4-methyl-7-diethylaminocoumarin (C47) and its potential transformation products 4-methyl-7-ethylaminocoumarin (C47T1) and 4-methyl-7-aminocoumarin (C47T2) were identified as novel environmental contaminants. We assessed for the first time the sources, distribution, and fate of these compounds in aquatic systems using the Holtemme River (Saxony-Anhalt, Germany), which is a hotspot for these contaminants. To this end, wastewater-treatment plant (WWTP) influent and effluent samples, surface water samples over 3 years, and the longitudinal profiles in water, sediment, and gammarids were analyzed. From the longitudinal profile of the river stretch, the WWTP of Silstedt was identified as the sole point source for these compounds in the River Holtemme, and exposure concentrations in the low micrograms per liter range could be recorded continuously over 3 years. Analysis of WWTP influent and effluent showed a transformation of approximately half of the C47 into C47T1 and C47T2 but no complete removal. A further attenuation of the three coumarins after discharge into the river could be largely attributed to dilution, while transformation was only approximately 20%, thus suggesting a significant persistence in aquatic systems. Experimentally derived partitioning coefficients between water and sediment organic carbon exceeded those predicted using the OPERA quantitative structure-activity relationship tools and polyparameter linear free-energy relationships by up to 93-fold, suggesting cation binding as a significant factor for their sorption behavior. Near-equilibrium conditions between water and sediment were not observed close to the emitting WWTP but farther downstream in the river. Experimental and predicted bioaccumulation factors for gammarids were closely matching, and the concentrations in field-sampled gammarids were close to steady state with exposure concentrations in the water phase of the river. Environ Toxicol Chem 2021;40:3078-3091. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Riparian Land Use and Hydrological Connectivity Influence Nutrient Retention in Tropical Rivers Receiving Wastewater Treatment Plant Discharge

Riparian areas are recognized for their buffering capacity regarding phosphorus and nitrogen from agricultural and urban runoff. However, their role in attenuating nutrient loads of rivers receiving point source nutrient inputs (e.g., from wastewater treatment plants, WWTPs) is still little understood. Here, we investigated whether ammonium (NH4-N), nitrate (NO3-N), and soluble reactive phosphorus (SRP) retention were influenced by the riparian land use in three Brazilian rivers receiving WWTP effluents. We hypothesized that nutrient attenuation would be potentially influenced by the hydrological connectivity between the main channel and riparian areas with native vegetation. We estimated retention from longitudinal patterns of dilution-corrected nutrient concentrations below the WWTPs. We assessed nutrient retention during periods with high (i.e., the wet) and low connectivity (i.e., the dry season). Relationships between non-conservative (nutrients) and conservative (chloride) solutes in both seasons were used to identify potential changes in the river chemistry due to the hydrological connectivity with the riparian areas. We also evaluated the relationship between net uptake velocities (Vf-net) and the accumulated percent native vegetation cover in the 100-m buffer using linear regressions, comparing the response for each nutrient between seasons with Analysis of Covariance. Slopes of regressions between nutrients and chloride significantly differed between seasons for NO3-N and SRP but not for NH4-N. The relationships between Vf-net and accumulated native vegetation in the riparian buffer presented steeper slopes for SRP in the wet than in the dry season. No significant relationships between NO3-N Vf-net and native vegetation cover were observed in either season. In contrast, increases in Vf-net with increasing vegetation cover were observed for NH4-N in the dry season. In periods with expected higher connectivity, NO3-N and SRP concentrations tended to be lower relative to chloride concentrations, with a potential effect of native vegetation in the riparian area on SRP retention. Our results suggest that seasonal connectivity between nutrient-rich river water and riparian areas is likely to induce changes in the predominant nutrient transformation processes, thereby favoring either nutrient retention or export in such rivers.

Feasibility study of the application of treated wastewater for the irrigation of forest species in a Saharan area

Background: After suffering from an acute problem of excess water for a long time, the Oasis of Ouargla benefited from an aerated lagoon treatment plant, producing biologically treated domestic effluents. The aim of this study was to examine the feasibility of reusing this effluent for watering plants. The experiment was conducted in the Ouargla WWTP, which is located in the region of Said Otba (northeast of Ouargla), north of the national road NR 49. Methods: The study area was selected based on the originality of the study and availability of water. The plants used were Acacia farnesiana and Leucaena leucocephala. The selection of Leucaena was based on the following criteria: It is used as a windbreak, it is very tolerant to drought, and it is used as a fodder to maintain soil fertility. And, Acacia was selected because it is used as a fodder, protects the soil against erosion, and to fix nitrogen. The watering of these plants is done jointly by treated wastewater from the WWTP and well water (WW), of which the latter was used as a control. Sampling and analysis of the irrigation water were performed according to the experimental protocol. To show the growth rate of the two plants studied, biometric measurements were taken weekly for 25 weeks. Results: The physicochemical analyses show that the treated wastewater is of poor quality belonging to the last class of Riverside’s C5-S4, with an excessive salinity (EC) of 13.51 dS/m and an Sodium adsorption ratio (SAR) of 12.61 against EC of 2.49 dS/m and 2.13 for the WW. At the end of the experiment, it was found that irrigation with purified wastewater (PWW) gave less growth compared to that with WW. Statistical analyses of the biometric measurements confirmed that there is a highly significant difference at P<0.05. Conclusion: The reuse of WWTP effluent gives less interesting results but is still possible. It is recommended to choose Salt-tolerant crops, as well as the dilution of these waters by the addition of less salty waters.

Impact of EfOM in the elimination of PPCPs by UV/chlorine: Radical chemistry and toxicity bioassays

The UV/chlorine process as a potential tertiary municipal wastewater treatment alternative for removing refractory PPCPs has been widely investigated. However, the role of effluent organic matter (EfOM) on the radical chemistry and toxicity alteration is unclear. The elimination of two model PPCPs, primidone (PRM) and caffeine (CAF), by the co-exposure of UV and free chlorine was investigated to elucidate the impact of EfOM. Experimental results indicated that both •OH and reactive chlorine species (RCS) were importantly involved in the decay of PRM at acidic condition, while ClO• played dominant role at alkaline pH. The decay of CAF was dominated by ClO• under all conditions. Chlorine dose, initial contaminant concentration, solution pH, and water matrix affect the process efficiency at varying degree resulting from their specific effect on the radical speciation in the system. Presence of EfOM isolate remarkably inhibited the decay of PRM and CAF by preferentially scavenging RCS and particularly ClO•. Good correlations (linear for PRM and exponential for CAF) between UV absorbance at 254 nm and the observed pseudo first-order rate constants (k'obs) for all EfOM solutions were obtained, demonstrating the importance of aromatic moieties in inhibiting the degradation of targeted contaminants by UV/chlorine process. Degradation of PRM/CAF in reconstituted effluent spiked with the major effluent constituents (i.e., EfOM isolates, Cl-, HCO3-, and NO3-) was comparable to the results obtained with the real WWTP effluent and fit well to the correlation between k'obs and UV absorbance at 254 nm, suggesting that EfOM isolates can be used to determine the efficiency of UV/chlorine process in real effluent. EfOM serves as the main precursor of adsorbable organic chlorine in the UV/chlorine treatment. Bioassays indicated that chlorine-containing compounds could induce oxidative stress, mitochondrial dysfunction, and increase the cell DNA damage. Among evaluated treatment conditions, the nature of EfOM, hydrophobic versus transphilic fraction, is likely the predominant factor affecting the cytotoxicity. Meanwhile the UV/chlorine treatment can significantly reduce the cytotoxicity of EfOM isolates. However, adding high level of selected contaminants (e.g., PRM and CAF) can inhibit this phenomenon due to the competition with reactive radicals.

Peroxymonosulfate activation by Fe3O4-MnO2/CNT nanohybrid electroactive filter towards ultrafast micropollutants decontamination: Performance and mechanism

Electrocatalytic peroxymonosulfate (PMS) activation is a promising advanced oxidation process for the degradation of micropollutants. Herein, we developed an electroactive carbon nanotube (CNT) filter functionalized with Fe3O4-MnO2 hybrid (Fe3O4-MnO2/CNT) to activate PMS towards ultrafast degradation of sulfamethoxazole (SMX). SMX was completely degraded via a single-pass through the nanohybrid filter (τ < 2 s). The ultrafast degradation kinetics were maintained across a wide pH range (from 3.0 to 8.0), in complicated matrices (e.g., tap water, lake water, WWTP effluent and pharmaceutical wastewater), and for the degradation of various persistent micropollutants. Compared with a conventional batch reactor, the flow-through operation provides an 9.2-fold higher SMX degradation kinetics by virtue of the convection-enhanced mass transport (1.47 vs. 0.16 min−1). The efficient redox cycle of Fe2+/Fe3+ and Mn2+/Mn4+ facilitate the PMS activation to generate SO4•– under electric field. Meanwhile, the ketonic groups on the CNT provide active sites for the generation of 1O2. Both experimental and theoretical results revealed the superior activity of nanohybrid filter associated with the synergistic effects among Fe, Mn, CNT and electric field. Therefore, the electrocatalytic filter based PMS activation system provides a green strategy for the remediation of micropollutants in a sustainable manner.

Improvement of wastewater and water quality via a full-scale ozonation plant? – A comprehensive analysis of the endocrine potential using effect-based methods

Micropollutants (MPs), especially endocrine disrupting compounds (EDCs), are mainly released from WWTPs into surface water bodies and can subsequently lead to adverse effects in biota. Treatment with ozone proved to be a suitable method for eliminating such MPs. This method was implemented at the WWTP Aachen-Soers by commissioning the largest full-scale ozonation plant in Europe at the moment. Recently, effect-based methods (EBMs) have been successfully proved for compliance monitoring, e.g. estrogenic compounds. Therefore, the impact of ozone treatment on endocrine potential (agonistic and antagonistic) of treated wastewater was investigated using the ERα- and AR CALUX assays. Additionally, the impact on the receiving stream and a potential preload of the water body was assessed. Therefore, the current study could deal as a case study for small rivers being highly impacted by WWTPs.The estrogenic potential was nearly fully eliminated after ozone treatment. Contrary, the antagonistic (anti-estrogenic and anti-androgenic) potential did not show a clear elimination pattern after ozone treatment independent of the applied ozone dosage and control system. Therefore, further investigations are required regarding the antagonistic potential. Additionally, preloading of the receiving stream was found during the study period. One significant impact is a rain overflow basin (ROB) located upstream of the WWTP effluent. The highest endocrine potential was found after a ROB overflow (2.7 ng EEQ/L, 2.4 μg TMX-EQ/L, 104 μg FLU-EQ/L), suggesting that such runoff events after a heavy rainfall may act as a driver of endocrine loading to the water body. This manuscript contributes significantly to the basic understanding of the efficiency of eliminating the endocrine potential of ozone treatment by, e.g., showing that there is a further need for improving the removal efficiency of antagonistic potential. Moreover, it highlights the need to include other point sources, such as ROBs, to assess polluted surface waters comprehensively.

BDD electrochemical oxidation of neonicotinoid pesticides in natural surface waters. Operational, kinetic and energetic aspects

Neonicotinoids pesticides were introduced to the market in the 1990s to control various pests. Its accumulation in the environment supposes a severe problem that can affect human health. This study investigates the electrochemical degradation of four common neonicotinoid pesticides; thiamethoxam (TMX), imidacloprid (ICP), acetamiprid (ACP) and thiacloprid (TCP), in different natural surface waters by a boron-doped diamond anode (BDD). The most influencing variable was the current density (j), and to a lesser extent, the supporting electrolyte concentration (Ce). In optimal conditions (j = 34.14 mA cm−2 and Ce = 10.00 mM, using Na2SO4 as electrolyte) pesticide removals for TMX, ICP, ACP and TCP were 97.2, 96.9, 87.8 and 98.2 %, respectively. The obtained results with different support electrolytes (Na2SO4, NaCl, NaNO3 and HK2PO4) suggest that sulphate electrolyte was the optimum for TMX, ICP and ACP. However, for TCP, a total removal was achieved in less than 10 min using NaCl. It was also verified that the initial pH of the solution did not significantly influence the process in the range 3–9. All these results were rationalized in this paper. Finally, to evaluate the matrix influence, some experiments were carried out in different natural surface water matrices (river, reservoir and two different WWTP effluents). The factors influencing the process were the conductivity of the solution and the organic matter content. It was noticeable that the specific energy consumption (SEC) reduced by approximately 15 % for river water and WWTP effluent. High mineralization rates were obtained for all water matrices, with TOC removals ranging between 60 and 80 %.

Influence of reclaimed water on water quality of urban rivers receiving WWTP effluent in Beijing

As a new type of water source, reclaimed water is used to replenish the landscape water bodies of urban river courses, which can alleviate the problem of insufficient water in river courses. However, due to the large amount of reclaimed water input, the water quality of the downstream river is obviously different from that of the upstream river. In this study, with the recharge of reclaimed water, the water conductivity increased gradually from upstream to downstream of the Wenyu River river, while the pH decreased gradually. In terms of nutrient concentration, TN, NO3-N and NO2-N of river water showed an obvious upward trend from upstream to downstream.

Adsorption of micropollutants onto realistic microplastics: Role of microplastic nature, size, age, and NOM fouling

This work aims at evaluating the role of nature, size, age, and natural organic matter (NOM) fouling of realistic microplastics (MPs) on the adsorption of two persistent micropollutants (diclofenac (DCF) and metronidazole (MNZ)). For such goal, four representative polymer types (polystyrene (PS), polyethylene terephthalate (PET), polypropylene (PP) and high-density polyethylene (HDPE)) were tested. MPs were obtained by cryogenic milling of different commercial materials (disposable bottles, containers, and trays), and fully characterized (optical microscopic and SEM images, FTIR, elemental analysis, water contact angle and pHslurry). The micropollutants hydrophobicity determined to a high extent their removal yield from water. Regardless of the MP's nature, the adsorption capacity for DCF was considerably higher than the achieved for MNZ, which can be related to its stronger hydrophobic properties and aromatic character. In fact, aromatic MPs (PS and PET) showed the highest adsorption capacity values with DCF (~100 μg g−1). The MP size also played a key role on its adsorption capacity, which was found to increase with decreasing the particle size (20–1000 μm). MPs aging (simulated by Fenton oxidation) led also to substantial changes on their sorption behavior. Oxidized MPs exhibited acidic surface properties which led to a strong decrease on the adsorption of the hydrophobic micropollutant (DCF) but to an increase with the hydrophilic one (MNZ). NOM fouling (WWTP effluent, river water, humic acid solution) led to a dramatic decrease on the MPs sorption capacity due to sorption sites blocking. Finally, the increase of pH or salinity of the aqueous medium increased the micropollutants desorption.

Application of Continuous Column Adsorption of Organochlorine Pesticides from Contaminated Water onto Date Stones Activated Carbon

The innovation of this study was to assess which types of AC derived from three selected date stones (Species: Phoenix dactylifera; types: Ajwa, Anbari, Khudri) showed better performance for the adsorption of organochlorine pesticides from contaminated water (outflow water from WWTP and agricultural effluent). In the bed column, the first experiments demonstrated that AC prepared from Ajwa date stones has a high efficiency to eliminate OCPs from an aqueous solution that 10 g of adsorbent was treated with 12 L of contaminated water. Therefore, the effects of the adsorbent mass of the material prepared from Ajwa date stones and flow rate of organochlorine pesticides onto prepared activated carbon were studied; the optimum adsorption capacity for all studied organochlorine pesticides from the water having a natural pH has reached 70–100%, using a 50 g of adsorbent in the particle size range of 0.75–100 mm, a flow rate of 2.5 mL/min, and an inlet concentration 57 µg/L. Finally, this AC proved its effectiveness to control water pollution by OCPs for agricultural and WWTPs effluents.

Legacy and emerging per- and polyfluorinated alkyl substances (PFASs) in sediment and edible fish from the Eastern Red Sea.

POLY: and perfluorinated alkyl substances (PFASs) are ubiquitously detected all around the world. Herein, for the first time, concentrations of 16 selected legacy and emerging PFASs are reported for sediment and edible fish collected from the Saudi Arabian Red Sea. Mean concentrations varied from 0.57 to 2.6μgkg-1 dry weight (dw) in sediment, 3.89-7.63μgkg-1 dw in fish muscle, and 17.9-58.5μgkg-1 dw in fish liver. Wastewater treatment plant effluents represented the main source of these compounds and contributed to the exposure of PFAS to biota. Perfluorooctane sulfonate (PFOS) was the most abundant compound in sediment and fish tissues analysed, comprising between 42 and 99% of the ∑16PFAS. The short chain perfluorobutanoate (PFBA) was the second most dominant compound in sediment and was detected at a maximum concentration of 0.64μgkg-1 dw. PFAS levels and patterns differed between tissues of investigated fish species. Across all fish species, ∑16PFAS concentrations in liver were significantly higher than in muscle by a factor ranging from 3 to 7 depending on fish species and size. The PFOS replacements fluorotelomer sulfonate (6:2 FTS) and perfluorobutane sulfonate (PFBS) exhibited a bioaccumulation potential in several fish species and 6:2 FTS, was detected at a maximum concentration of 7.1±3.3μgkg-1 dw in a doublespotted queenfish (Scomberoides lysan) liver. PFBS was detected at a maximum concentration of 2.65μgkg-1 dw in strong spine silver-biddy (Gerres longirostris) liver. The calculated dietary intake of PFOS, perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and perfluorohexane sulfonic acid (PFHxS) exceeded the safety threshold established by the European Food Safety Authority (EFSA) in 2020 in doublespotted queenfish muscle, indicating a potential health risk to humans consuming this fish in Jeddah, Saudi Arabia.

Water Reuse Study from Urban WWTPs via c-Ultrafiltration and Ozonation Technologies: Basis for Resilient Cities and Agriculture

The water–development nexus is essential for the advancement and progress of cities in the face of problems such as climate change, water security and increasing environmental stress in the agricultural sector. Aiming for a circular economy and, at the same time, improving the resilience of water supply alternatives and achieving a goal of zero waste, this work presents a technical–economic study of a novel continuous ultrafiltration (c-UF) system with self-cleaning capacity coupled to an ozonation process, for the treatment of urban WWTP effluent. The removal efficiencies achieved were analysed both through macroscopic parameters (suspended solids, turbidity) and for the most frequently occurring contaminants of emerging concern (CECs). Consequently, an effluent suitable for irrigation was obtained, with a total recovery factor of 97.92%, a concentration of suspended solids (SS) below 1 mg L−1, 0.06 NTU turbidity and toxicity free, complying with the new European Regulation on Water Reuse (EU 2020/741). A comparative analysis of the proposed process with regard to conventional tertiary treatment revealed that the proposed process was 39.1% more economic, with a cost of 0.0325 € m−3. This alternative treatment will be of great interest because of its favourable technical–economic characteristics, being postulated as a basic process for implementation in modern water reuse plants.

Graphite as catalyst for UV-A LED assisted catalytic wet peroxide oxidation of ibuprofen and diclofenac

Ibuprofen (IBU) and Diclofenac (DCF) are two of the most common non-steroidal anti-inflammatory drugs used worldwide. Their occurrence in natural streams, as contaminants of emerging concern, evidences the inefficiency of conventional wastewater treatment plants for their removal. The photocatalytic methods developed so far usually demand either highly energetic light sources working in the UV-C range, or exclusive tailor-made catalysts, which compromise the economy of the process. In this work, IBU and DCF degradation are addressed in a UV-A LED (395 nm) assisted Catalytic Wet Peroxide Oxidation process using graphite as catalyst. Total IBU and DCF removal is achieved in t < 60 min working at [IBU or DCF]0: 20 µM, [H2O2]0: 800 µM, [Graphite]: 1 g · L−1 and pH0:3.0, with a 53% TOC removal and ECTOC: 31.0 kWh gTOC−1. Results show a high influence of the interaction between the graphite's surface and H2O2, which enables pollutant adsorption as first step in the oxidation reaction. Further redox reactions on the graphite surface lead to the cleavage of the reaction intermediates, making active sites available again. Nonetheless, in absence of an external energy source this process is very slow. UV-A radiation promotes these reactions as well as H2O2 decomposition into hydroxyl and hydroperoxyl radicals, enhancing the contaminant removal rate. The UV-A assisted CWPO process is also effective in surface water and WWTP effluent. Furthermore, graphite shows a great stability in IBU removal from WWTP effluent upon five consecutive cycles.

New insights on the removal of diclofenac and ibuprofen by CWPO using a magnetite-based catalyst in an up-flow fixed-bed reactor

This research has been focused on the removal of two anti-inflammatory drugs, diclofenac (DCF) and ibuprofen (IBU), by a continuous catalytic wet peroxide oxidation (CWPO) process using a lab-synthesized nanomagnetic catalyst (Fe3O4/MWCNTs). The central composite rotatable design (CCRD) method was used to study the effect of DCF and IBU concentration (expressed as theoretical oxygen demand (ThOD) between 0 and 52.5 mg L−1) and of the feed stream pH (from 3 to 7) on the removal of total organic carbon (TOC) and the concentration of aromatic compounds (Arm) and total phenolic compounds (TP) by CWPO. It could be observed that DCF was preferably removed from the DCF-IBU aqueous mixture at pH values ranging from 3 to 5. In addition, feed stream pH had a significant effect on the pollutants removal, as well as on TOC, TP and aromatic compounds removal, observing an increasing in the pollutants degradation when feed stream pH decreased from 7 to 3. Quadratic models predicted for response variable, such as TOC, TP and aromatic compounds removal, and their maximum model-predicted removal values were of 90.0, 80.2 and 90.0%, respectively. Finally, as a proof of concept, three environmentally-relevant aqueous matrices, spiked with DCF-IBU mixture, were treated. In this case, relatively high TOC degradation values were found after 20 h reaction time (ca. 57.7, 73.9 and 54.5% in surface water, WWTP effluent and hospital wastewater, respectively). This work deals the first study about DCF-IBU removal in aqueous solution by CWPO, as well as a continuous study using real wastewater that allow to extend the experimental results to a real scenario.

Assessment of the impact of Imzouren city’s WWTP on the quality of the surrounding groundwater, at the Rif Central (Northern Morocco)

The groundwater of the Ghis-Nekor aquifer (Central Rif of Morocco) is the main water resource used by the inhabitants for agricultural and domestic purposes. However, its low quality may affect the health of the consumer and weaken agricultural production. The existence of the WWTP at the level of this plain, makes it a probable source of pollution for these groundwater and requires urgent water managers’ intervention. Groundwater pollution in this area may be related to natural, anthropogenic and undefined sources (agricultural and industrial activities). To assess the impact of WWTP effluent on this aquifer, ten well water samples were collected upstream and downstream of this WWTP in 2018, and then analysed for physicochemical quality. Multivariate and principal Component Analysis (PCA) of the results obtained revealed two main components, in which the largest source of total variation being F1 presented at 54.75%. The PCA has visualized two groups that distinguish slightly mineralized well waters upstream to moderately from other wells downstream of the WTTP that are highly mineralized. Generally, the groundwater in the study area is characterized by high levels of salinization. The results of this study may be useful for monitoring and managing groundwater pollution in the study area.

Evidence that watershed nutrient management practices effectively reduce estrogens in environmental waters

We evaluate the impacts of different nutrient management strategies on the potential for co-managing estrogens and nutrients in environmental waters of the Potomac watershed of the Chesapeake Bay. These potential co-management approaches represent agricultural and urban runoff, wastewater treatment plant effluent, and combined sewer overflow replacements. Twelve estrogenic compounds and their metabolites were analysed by gas chromatography–mass spectrometry. Estrogenic activity (E2Eq) was measured by in vitro bioassay. We detected estrone E1 (0.05–6.97 ng L−1) and estriol E3 (below detection-8.13 ng L−1) and one conjugated estrogen (estrone-3-sulfate E1-3S; below detection-8.13 ng L−1). E1 was widely distributed and positively correlated with E2Eq, water temperature, and dissolved organic carbon (DOC). Among nonpoint sources, E2Eq, and concentrations of E1, soluble reactive phosphorus (SRP) and total dissolved nitrogen (TDN) decreased by 51–61%, 77–82%, 62–64%, 4–16% in restored urban and agricultural streams with best management practices (BMPs) relative to unrestored streams without BMPs. In a wastewater treatment plant (Blue Plains WWTP), >94% of E1, E1-3S, E3, E2Eq and TDN were removed while SRP increased by 305% during nitrification/denitrification as a part of advanced wastewater treatment. Consequently, E1 and TDN concentrations in WWTP effluents were comparable or even lower than those observed in the receiving stream or river waters, and the effects of wastewater discharges on downstream E1 and TDN concentrations were minor. Highest E2Eq value and concentrations of E1, E3, and TDN were detected in combined sewer overflow (CSO). This study suggests that WWTP upgrades with biological nutrient removal, CSO management, and certain agricultural and urban BMPs for nutrient controls have the potential to remove estrogens from point and nonpoint sources along with other contaminants in streams and rivers.