Over the years, the persistent occurrence of superfluous endocrine-disrupting compounds (EDCs) (sub µg L−1) in water has led to serious health disorders in human and aquatic lives, as well as undermined the water quality. At present, there are no generally accepted regulatory discharge limits for the EDCs to avert their possible negative impacts. Moreover, the conventional treatment processes have reportedly failed to remove the persistent EDC pollutants, and this has led researchers to develop alternative treatment methods. Comprehensive information on the recent advances in the existing novel treatment processes and their peculiar limitations is still lacking. In this regard, the various treatment methods for the removal of EDCs are critically studied and reported in this entry.
Major Contaminants/Sources | Treatment Process | Treatment Factor | Brief Procedure | Major Findings | Limitations | References |
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TCS, NP2EO, IBF, DCF, TCS, BPA, KFN, NP, NP1EO, NPX/wastewater, and sewage sludge samples | Conventional treatment (mesophilic anaerobic sludge digestion) |
Major Contaminants/Source | Treatment Process | Treatment Factor | Brief Procedure | Major Findings | Limitations | References | |||
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EE2/ ultra-pure water and treated wastewater | (HRT: 9 h; SRT: 8 d), | (SRT: 17 d). (HRT: 23 h, SRT: 18 d). |
Photocatalytic degradation using ZnO under simulated solar radiation | EE2 conc: 100–500 µg/L, photon flux: 4.93 × 10−7–5.8 × 10−7Wastewater samples collection. Sewage sludge samples were homogenized extractions of wastewater samples. |
The removal efficiency of DCF and IBF ranged between 39% and 100%, IBF and NPX were ˃80%. | Einstein L−1 S−1; ZnO conc: 50–500 mg/L, treatment time: 2–10 min. | Spiking of water matrix was spiked with EE2, photocatalysis of the solution. Periodic sampling and centrifugation.Higher proportions of NP in digested sludge. |
Rapid EE2 degradation occurred via first-order kinetics.Detection of TCS and NP in treated wastewater. Too many modular units. |
Detection of EE2 in the effluent.[30] |
Retardation of EE2 degradation by organic and inorganic matter. | [ | 39 | ] | E1, E2, E3, EE2, BPA, and 4-NP/rural wastewater effluent |
Activated sludge. Micro-power biofilm reactor. Constructed wetland. Stabilization pond. |
Temp: 30 and 70 °C; HRT = 12–24; 24–120; 24–240; 10–16. |
Biological contact oxidation. Subsurface flow. Facultative pond. Anoxic oxidation. |
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BPA/municipal WWTP, bottled water, ultra-pure water |
Major Contaminants/Water | Treatment Process | Operating/Treatment Factor | Brief Procedure | Major Findings | Limitations | References | |||||||||||
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Major Contaminants/Sources | Treatment Process | Treatment Factor | Brief Procedure | Major Findings | Limitations | References | |||||||||||
E1, E2, progesterone, testosterone/purified water | UF membrane | MWCO: 1–100kDa Pressure: 0.5–5 bar Pure water flux (L/m2h) 20.8–359.2 Final flux:21.9–288.5 Time: 2–40 min pH: 8 |
Stirring feed solution at 200 rpm for 16 h. Filtering of purified membrane for 30 min. Measurement of pure water flux. Collection of permeate. |
Removal via solute–solute interactions for E1 correspond to higher proportion of organic matter at 25–50 mg/L for 10 kDa (48–52%); 100 kDa (33–38%) membranes. | Poor removals of E1 and hormone contaminants (52% and 38%). | [ | |||||||||||
EE2/water | Adsorption (polyamide adsorbent) | pH: 4.8–9.1; constant dosage of 0.2 g/L; contact time: 24 h; agitation rate: 250 rpm; temp.: 25 °C. | Dilution of EE2 working solutions from EE2 stock solutions. Addition of adsorbent into EE2 aqueous solutions. Agitation of mixed solutions. | Production of toxic by-products. | The high cost of ozone production. | 59] | [ | Maximum adsorption capacity = 25.4 mg g/L. Adsorption rates ranged between 5.3- and 22.4-fold.87] |
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A molecule-level investigation. | [ | 107 | ] | Solar photocatalytic degradation | BPA, E2, and EE2/wastewater | AOP (H2O2, O3, UV, UV/TiO2 | |||||||||||
BPA, NP BP3, TCS/aerobically treated greywater | , UV/H2O2 | pH: 6.1, catalyst: 81.3–339.2 mg, TiO | Percent removal of target EDCs > 70% in summer. | 2 loading: 0, 81.3, 101.8, 152.3, 339.2 mg, ZnO loading: 0.5–6.8 mg/cm | Unstable performance of decentralized processes. Pronounced impacts of effluent discharged on the quality of receiving water. Too many modular units. |
, and UV/O2, H2O2: (25–100 mg/L), BPA initial conc.: 50–200 µg/L, treatment time: 0–90 min. | The incident radiation intensity was measured econometrically. The water matrix was spiked with the organic substance with the addition of the ZnO /TiO2 | ||||||||||
BPA, CBZ, IBF, and SFZ/drinking water | UF membrane | 3)Operating speed: 50 psi. Flow rate: 0.65 L/min per cell. | catalytic plate. Periodic sampling and analysis. | [ | 31 | ] | |||||||||||
Increasing the number of immobilized catalysts enhances BPA conversion. | Partial inhibition of BPA degradation due to the presence of EE2. | Weak degradation in wastewater. | [ | 26 | ] | NAInitial partial removal of BPA. | NA | The removal rate of pharmaceutical EDCs ≥ 96% during UV/TiO2 process. | Poor removal of caffeine. |
Adsorption (PAC) | 29.0 g/70.6 mL bed volume; initial compound proportion: 100–1600 µg/L; dose: 1.25 g/L; contact time: 5 min. | NAGeneration of several oxidation by-products with high toxic potential. | TCS removal = 95%. BPA removal = 99%. NP removal = 84%.[88] |
BPA, E1, E2, E3, EE2, and DES/effluent from a wastewater treatment plant | WWTP activated sludge treatment processes. | ||
Poor BPA removal using modified PES membranes. | [ | 60 | ] | ||||||||||||||
The exorbitant cost of PAC. | [ | 108 | ] | [ | 78 | ] | E1, E2, EE2, E3, NP, BPA/artificial, and real wastewater Oxidation ditch reversed anaerobic and sequential batch reactor SBR. |
Enzymatic degradation using fungal laccasesHRT: 7.6–35.31 h SRT: 5.8–31.9 days |
pH: 1–1.5 Temperature: −20 °C Contact time: 2, 6, 24 h. |
Constant shaking as laccase uses molecular oxygen for oxidizing substrates. Acidification of enzymatic reaction at each time interval (2, 6, and 24 h). Complete inactivation of the laccase activity. Extraction via solid-phase extraction (SPE) for chemical analysis.73.7% of BPA was removed. |
E2, EE2, BPA/wastewater treatment plant effluent matrixHigh removal rates of EDCs (i.e., > 85%). | Degradation by UV light/chlorine | Chlorine conc.: 0.2–2 mg/L; reaction time: 30 min; initial EDC conc.: 100 µg/L; UVC irradiance: 14.79 mW cm−2; temp.: 25; pH: 7 | Spiking of EDCs in WWTP effluent and ultrapure water. UV/Cl process. Samples collection.Some concentrations of EDCs were found in the effluents and can pose potential risks to ecosystems and human health. |
Addition of sodium thiosulfate followed by filtration. Disinfection evaluations.Immobilized laccase removed EDCs (83% for T. Versicolor and 87% of M. thermophile), 99% removal after 24 h. Removal rates for estrogenic = 82% after 24 h. Longer HRT and SRT. |
The combination of UVC with chlorine significantly and rapidly degrades EDCs. An upsurge in chlorine concentration yields almost 99% EDCs removal.Formation of toxic by-products.[32] |
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[ | 40 | ] | 59 EDC contaminants/ wastewater effluents | Fluidized powdered activated carbon (PAC) pilot (WWTP configuration). | SRT: 5–7 days; bed depth: 1–3 m. hydraulic velocity: 6–12 m/h; contact time: 10–20 min. |
Pre-primary and biological treatments. Pre-treatment (screening). Biofiltration system, Micropollutant analyses. | Removal of parabens and pesticides ranged between 50% and 95%, paracetamol, IBF, sulfamethoxazole 60–80% | Artificial sweeteners (1000–10,000 ng/L), BPA and NP (100–1000 ng/L) were detected in the effluent. | [21] |
BPA/drinking water | ||||||||||||||||
UF-PS (PS) membrane. | Temp: 25 ± 0.5 °C. | pH: 7–13 BPA concentration: 100–500 μg/L. pH: (3.68–10) |
Measurement of pure water flux. | |||||||||||||
TCS, E1, E2, and EE2, clofibric acid, CBZ, clofibrate methyl ester, clofibrate/water, and treated wastewater | Batch adsorption using crosslinked polymer adsorbent and activated carbon | Filtration of BPA solution. | Higher removal at the initial stage of the filtration. | Lower removal efficiency (20%). Fouling. |
Polymer sorbent dosage: 0.2–1.2 g/L; AC: 0.05–0.2 g/L; retention time: 5.7–24.2 min, temp.: 21 ± 2 °C. | Removal of selected EDCs from ultrapure water. Introduction of polymer adsorbents in solutions of EDCs and agitation.Formation of chlorate by-product disinfection. [61] |
TCS = 92%, CBZ = 90.5%, E1 = 71.4%, EE2 = 71.3% removals.UV light penetration can be obstructed by turbidity. | BPA | Fungal laccases degradation using oxidative enzyme | |||||||
[ | 89 | ] | [ | Poor contaminants removal using AC when treated municipal wastewater was used. | 90 | ] | BPA/pure BPA solution | |||||||||
[ | 109 | ] | (1): 25 μM | E1, E2, EE2, DES, TCS, 17α- treubolone, 17 β- treubolone, 19- nortestosterone, AEDb testosterone, methyltestotesterone, 4-OHA, prednisone cortisol, cortison, 19- norethindrone, medroxyprogesterone, BPA, 4-tert-OP, 4- NP, triclocarban, ADD, 17β- boldenone, stanozolol, epi-andosterone, andosterone 5α-dihydrosteterone, preanisolone, dexamethasone, ethynyl testosterone, progesterone/secondary wastewater effluentUF membrane of each molecule, pH 5.0 (50 mM sodium citrate buffer), 1.5 U/mL laccase, (2): 100 μM BPA, pH 5.0 (50 mM sodium citrate buffer), 25 °C, and 1.5 U/mL laccase, reaction time: 1 h. |
pH: (3–13) MWCO: 100 Da TMP: 0.1 × 10 |
Fe (VI) treatment process6 | Temp. = 23 ± 2 °C micropollutants = 100 µg/L−1; Fe (VI) = 10 mgFeL−1; pH: 6.88–7.09; Fe (VI) dosage = 0, 2.5, 5, and 10 mgFe L−1; DOC. = 5.0 mgCl−.Addition of methanol and Tween to the solution. Incubation of each EDC. Addition of hydrochloric acid (HCl) to the reaction mixture and centrifugation at a specific time interval at room temperature. Analysis of supernatant and BPA degradation. |
Application of Fe (VI) to secondary effluent. Dosing of solid Fe (VI) in the effluent. Stirring of the solution. Addition of methanol and H2SO4.BPA was oxidized under all conditions tested. |
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BPA/DI water | Batch Adsorption (nano-magnetite) |
Adsorption time: 0–120 min; pH: 2–12; adsorbent dose: 0.04–0.22 g; BPA conc: 10–75 ppm; temperature: 30, 35, 40, 45, 50, 55, and 60 °C. | Fe (VI) treatment could achieve both oxidative eliminations of detected EDCs as a tertiary treatment technology. | Complex procedure. | [ | 41] | ||||||||||
–0.3 × 10 | 6 | Pa Temp: 20 ± 2 °C BPA conc.: 5 mg/L |
The UF membrane was installed and the solution was introduced into the UF cup and followed by magnetic stirring. | Both salt and acidic pH improve the transportation of BPA. | BPA rejection decreased significantly when the BPA molecule was ionized. | It failed to react with triclocarban, three androgens. Low ferrate (VI) production rate.[62 |
Introduction of 0.1 g of magnetite into different conc. of BPA. [91][90] |
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Solutions agitation for 45 min at 30 °C. | Measurement of residual BPA conc. | Synthetized magnetite offers great potential for the remediation of BPA-contaminated media. | Low adsorption capacity. | Longer treatment period. |
[110] | 2-chlorophenol and SMZ/municipal wastewater |
Laccase degradation | pH 7, initial SMX at 10 μM and ACE at 10 μM. Time (h): 0, 0.25,1, 24. |
NA | Excellent removal of SMZ in the absence of mediators in secondary effluent. | Poor removal of sulfamethoxazole in all buffered solutions. Not economically viable. |
[42] | ||||
] | ||||||||||||||||
DMP, DEP, DBP, DnOP, DEHP/water | NF membrane | pH: 4–9; pure water flux: 47.5 L/m2 h; temperature: 25–45 °C. | EE2/synthetic secondary effluent | Ozonation | Ozone conc.: 2, 4, 9 mg/L; NOM conc.: 0–80 mg/L; pH: 6–10 O3Preparation of a feed solution. Measurement of concentrations of PAEs in both the feed and permeate. |
Removal efficiencies of 95.4%, 95.1%, and 91.5% were recorded for DEHP, DnOP, and DBP. | : TOC: 0.2–1.0 | Spiking different conc. of ozone into the stock solution. Removal of residual ozone and radicals. Testing of blank controls.Lower adsorption rates. |
The initial concentration of ozone and natural organic substance adversely affect degradation efficiency. Effective degradation of EE2 by ozonation at pH 6 resulted in higher degradation of EE2.Low rejection of sulfamides. | Generation of toxic by-products. Production of solid by-products. High operating costs.[63] |
[92] | BPA, 2,4-dichlorophenol, 4-tert OP, pentachlorophenol, and NP/aquatic plants | Enzymatic degradation | Endogenous H2O2 concentration in aquatic plants (170–590 μmol/kg-FW) | EDCs were degraded by oxidative enzymes. | |
BPA/biologically treated wastewater | MF and NF | Suspended solids = 78 ± 12 mg BPA conc.: 0.3 ± 0.14–0.7 ± 0.27 | ||||||||||||||
BPA/aqueous solution | Jv(L/m2h) = 6.0–18.6 80 L/(m2h) for NF Temp = 21 °C TMP = 0.3 MPa (MF) |
Microwave-enhanced Mn-Fenton process 0.7 MPa (NF) |
Circulation of module with pure water. Determination of pure water infiltration. | Longer treatment period (>100 days). | Both techniques eliminate BPA. BPA removal efficiency: 61–75% with NF. Complex procedure. |
Fouling. | BPA initial concentration = 100.0 mg/L; reaction time = 6 min | Addition of BPA solution with Fenton reagents followed by heating. Determination of BPA conc. |
BPA removal = 99.7% and total organic carbon (TOC) (53.1%). | Generation of complicated secondary sludge. [43] |
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A decline in permeate flux in MF. | A narrow range of optimal pH (2.5–4.0). | [ | 64 | ] | [ | Atrazine (herbicide), phenyl phenol, BPA, and TCS/municipal wastewater | Biosorption and biodegradation. | Feed NaCl concentration (0–15 g/L). Initial MLSS = 16 g/L; HRT = 5 d; mixed liquor pH = 7 ± 0.1; temperature = 35 ± 1 °C. | Feeding the bioreactor, circulation of digested sludge. Mixing of the sludge. |
Trimethoprim, carazolol, hydroxyzine, amitriptyline, and linuron, removal rates ≤ 80%. | ||||||
93 | ] | BPA/model solution | NF and RO membranes | Temperature: 45–50 °C Max pressure: 31–83 bar, pH: 2–11 water permeability: 0.85–14.86 (L/m2h bar) Time: 30–360 min Phenyl phenol removal = 60%. |
Relatively low removal rates of phenyl phenol, BPA, and TCS. BPA was poorly removed, from 40% to 20%. Poor removal of atrazine (6.8%). |
[ | ≥98% BPA rejection was achieved with polyamide-based RO membranes.44] | |||||||||
High energy demand. | Too many modular units. | [ | 65 | ] | DEHP, fluoranthene, AMPA, and E1/ wastewater effluent | Filamentous fungi biodegradation. | ||||||||||
BPA, E2, E1, E3, EE2/synthetic wastewater | pH 5.5, incubation period: 96 h (AT96h), degradation period: | 10 days. |
Degradation test conducted in mineral medium incubated for 10 days with each fungus. | UF membrane | working pressures (25, 30, 50, 75 kPa); temp: 20 ± 2 °C; TOC = 7 mg/L; pH 7.6; conductivity = 1000Fungi degradation of DEHP = 100%, AMPA = 69% with F. solani and T. harzianum. | E1 not degraded by all fungal isolate trials. | [35] |
Soaking of fresh membrane for 24 h. | ||||||
Removal of impurities. | ||||||
Determination of flux. | ||||||
EDCs removal rates of (10–76%) were achieved via a fouled membrane. | ||||||
Poor removal of E3 (10–17%). | [ | 66 | ] | |||
BPA, DMP, DBP, NP, DOP/water | Nano-functionalized membrane using polypropylene (PP) non-woven fabric | Operating pressure: 0.02–0.5 Mpa; pH: 6.5; Temp: 25 °C | The target pollutants were dissolved in deionized water and quantified. The filtration experiment was conducted. |
˃80% BPA rejection was recorded after a period of 1.3 s. | Removal of contaminants was attained at higher operating pressure of 0.5 MPa. | [67] |
Oxybenzone and BPA/synthetic solution | Nanohybrid (CuSG) blended PES-HF membranes | Filtration time: 120 min; temp: 20 °C; pressure: 1 bar |
25 mg/L solution of oxybenzone and 5 mg/L BPA solution were filtrated via the HFM samples and the permeate was analyzed via a UV–visible spectrophotometer | Higher rejection of oxybenzone (98%) and BPA (95%) was recorded. Elevated pure water permeability (528.2 ± 44.6 Ml/m2/h/mmHg). |
Nil | [68] |
BPA/synthetic solution | UF(TFC) immobilized with TiO2 | Preparation of feed solution. Quantification of the feed and the permeate solution. |
[69] | |||
BPA/drinking water | Nanocomposite membrane electrospun PVDF-PVP-MnO2 | Working pressure: 0.5–2.5 bars; sampling period: 0, 5, 10, 20, and 30 min; temp: 27 °C. |
The membrane was fabricated using electrospinning technique and was applied in a filtration system to assess the removal efficiency of BPA. The concentrations of BPA were analyzed using HPLC. | Complete rejection of BPA (100%) was attained for NF2 and NF6 after 30 min. | Nil | [70] |
BPA/synthetic solution | Photocatalytic PSF/TiO2/Fe-doped composite UF membrane | BPA concentration: 10 mg/L; specific temperature: 140–220 °C, 6–24 h; pressure: 0.1–0.2 MPa. |
Preparation of Fe-doped TiO2 photocatalysts, synthesis of photocatalytic membranes; assessment of photocatalytic performance | BPA removal rate of 90.78% was recorded. | Nil | [71] |
BPA/water | PSF/GO nano-composite membranes | Input pressure: 1–5 bar, operating time: 10–50 min, pH: 3–11, initial BPA concentration: 1–9 mg/L. |
Synthesis of GO; preparation of GO/PSF nano-hybrid membranes; BPA concentration was analyzed using a UV–vis spectrophotometer |
BPA removal efficiency of 93% was attained. | [72] |
Major Contaminants/Sources | Treatment Process | Treatment Factor | Brief Procedure | Major Findings | Limitations | References |
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Diltiazen, progesterone, BBP, E1, CBZ, acetaminophen/biological sludge |
Pulse ozonation experiment | Operating pressure = 5 bar; gas flow rate = 10–140 L/h; MLSS = 2.3–4.2 g/L; ozone period: 6–150 min. Ozone dose (mgO3/L): 1.11–18.65; pH = 6.4–7.1 |
Ozonation of the sludge samples. Continuous aeration. Analysis of the residual EDCs conc. in the samples. |
˃99% removal of target EDCs contaminants were achieved after 4 days. |
BPA, E2, EE2/sediment | ||||||
Adsorption (aquatic colloids and sediment in a single and binary system). | ||||||
Equilibrium conc.: 0.40–2.00 mg/L; aquatic colloids: 42.0 mg/L, 103.5 mg/L; | initial concentration of EDCs: 0.5–2.5; pH: 8.24–8.37. | NA | Sediments enhance contaminants. sorption process by colloids in a binary system. | [111] | ||
BPA, EE2, CytR, 5-Fu, diazinon, cytrabine, caffeine, phenazone, atrazine, 4-NP/hospital wastewater | Adsorption (PAC) | Dosage: 8, 23, 43 (mg/L); PAC doses: 10, 20, and 40 mg/L; initial conc.: 20, 40, and 80 mg/L. Retention time = 2 days. |
The effluent of the PAC reactor was filtered via a flat sheet UF membrane. | Removal efficiencies of diclofenac and carbamazepine and propranolol were 99%, 100%, and ˃94%. | PAC could not remove antibiotic resistance and failed to deactivate pathogens. Energy-intensive. |
[106] |
Tonalide, BPA, TCS, metolachlor, ketoprofen, and E3/aqueous solutions | Adsorption using PVP-coated magnetite nanoparticles sorbent | pH: 7.5; contact time: 5–40 min; adsorbent dose: 0.75 to 2.5 mg/L; stirring speed: 150 rpm. | NPs were added to the solution followed by sonication. Vials were agitated at 150 rpm. Sample analysis. | The maximum adsorption capacities of BPA and ketoprofen were 90.91 and 83.33 µg/mg, respectively. | NA | [112] |
PFOA, PFOS, ACE, DIF, and CHL/eenvironmental water | Batch adsorption (magnetic nanoparticles-attached fluorographene-based sorbent) | Initial conc. of adsorbate: 180 µg/L; adsorbent dose: 400 mg/L; speed: 220 rpm; contact time: 10, 30 min |
Solution stirring with developed sorbents and PAC, followed by separation. Measurement of residual EDCs conc. |
DIF, ACE, and CHL (97–99%), PFOA removal ranged between 92% and 95%, PFOS (94–97%). | NA | [113] |