Nonylphenol Polyethoxylates Research Articles

IMPACT OF 4-NONYLPHENOL ON TESTOSTERONE PRODUCTION IN MICE LEYDIG CELLS

Nonylphenol (NP) is an important environmental toxicant and potential endocrine disrupting chemical. It is also the primary final biodegradation product of nonylphenol polyethoxylate, a non-ionic surfactant that is frequently incorporated into detergent formulation. Several studies have reported adverse effects of NP on the male reproductive system, including hormonal changes and testicular abnormalities. However, its mechanisms are not clearly understood. In the present study, experiments were performed to examine the effects of 4-nonylphenol on the testosterone production in mice Leydig cells. Interstitial (Leydig) cells were cultured with addition of 0.04, 0.2, 1.0, 2.5 and 5 μg/mL of 4-nonylphenol and compared with control. Concentrations of testosterone in the media were determined using enzyme linked immunosorbent assay (ELISA). Hormone production significantly (P

The formulation makes the honey bee poison

Dr. Fumio Matsumura's legacy embraced a passion for exploring environmental impacts of agrochemicals on non-target species such as bees. Why most formulations are more toxic to bees than respective active ingredients and how pesticides interact to cause pollinator decline cannot be answered without understanding the prevailing environmental chemical background to which bees are exposed. Modern pesticide formulations and seed treatments, particularly when multiple active ingredients are blended, require proprietary adjuvants and inert ingredients to achieve high efficacy for targeted pests. Although we have found over 130 different pesticides and metabolites in beehive samples, no individual pesticide or amount correlates with recent bee declines. Recently we have shown that honey bees are sensitive to organosilicone surfactants, nonylphenol polyethoxylates and the solvent N-methyl-2-pyrrolidone (NMP), widespread co-formulants used in agrochemicals and frequent pollutants within the beehive. Effects include learning impairment for adult bees and chronic toxicity in larval feeding bioassays. Multi-billion pounds of formulation ingredients like NMP are used and released into US environments. These synthetic organic chemicals are generally recognized as safe, have no mandated tolerances, and residues remain largely unmonitored. In contrast to finding about 70% of the pesticide active ingredients searched for in our pesticide analysis of beehive samples, we have found 100% of the other formulation ingredients targeted for analysis. These ‘inerts’ overwhelm the chemical burden from active pesticide, drug and personal care ingredients with which they are formulated. Honey bees serve as an optimal terrestrial bioindicator to determine if ‘the formulation and not just the dose makes the poison’.

Hydrothermal Carbonization of Nonylphenol Ethoxylates Waste Liquid for Energy Source Generation

Nonylphenol polyethoxylates (NPEOs) are widely used as nonionic surfactants in many industry fields. High concentration NPEOs waste water is produced in some production processes. It is often treated to realize reduction by distillation. Therefore, NPEOs waste liquid with higher concentration is produced and it is difficult to be treated by traditional water treatment process. In this study, hydrothermal carbonization process was used to convert NPEOs waste liquid to carbonaceous product (hydrochar) with sulfuric acid as additive in 24 h at 200°C. The hydrochar was characterized by scanning electron microscope, Fourier-transform infrared spectrometer and thermogravimetric analysis. The element composition and the high heat value of the hydrochar were similar to lignite, showing that it could be used as an alternative fuel.

Wettability of paraffin surfaces by nonionic surfactants: Evaluation of surface roughness and nonylphenol ethoxylation degree

Abstract Wettability is a widely used property in many industrial applications. This study aimed at determining the wettability of long-chain paraffin surfaces by nonionic surfactants, nonylphenol polyethoxylates with different ethoxylation degrees. Interactions between solid and liquid phases were determined by apparent contact angle measurements. The morphology was obtained by atomic force microscopy. The results demonstrated that the molar mass of paraffin has a direct influence on the wettability of the surfaces by surfactant solutions. The rise in paraffin molar mass promoted a reduction of the contact angle between solid–liquid interfaces due to the formation of surfaces with less roughness. An increase in the ethoxylation degree of surfactants reduced the wettability, showing a tendency toward water behavior. It was observed that the melted paraffin crystallized more abruptly due to having a higher melting temperature, which impedes crystal formation and, consequently, decreases its roughness.

Deposition patterns and transport mechanisms for the endocrine disruptor 4-nonylphenol across the Sierra Nevada Mountains, California

Dust and particulate distribution patterns are shifting as global climate change brings about longer drought periods. Particulates act as vehicles for long range transport of organic pollutants, depositing at locations far from their source. Nonylphenol, a biodegradation product of nonylphenol polyethoxylate, is a known endocrine disruptor. Nonylphenol polyethoxylate enters the environment as an inert ingredient in pesticide sprays, potentially traveling great distances from its application site. This is of concern when a highly agricultural region, California's Central Valley, lies adjacent to sensitive areas like the Eastern Sierra Nevada Mountains. The distribution and transport mechanisms for 4-nonylphenol were investigated in Eastern Sierra Nevada canyons. Regions close to canyon headwalls showed trace amounts of 4-nonylphenol in surface water, snow, and atmospheric deposition. Exposed areas had yearly average concentrations as high as 9 μg/L. Distribution patterns are consistent with particulate-bound transport. This suggests with increasing drought periods, higher levels of persistent organic pollutants are likely.

Biodegradation and utilization of 4-n-nonylphenol by Aspergillus versicolor as a sole carbon and energy source

4-n-Nonylphenol (4-n-NP) is an environmental pollutant with endocrine-disrupting activities that is formed during the degradation of nonylphenol polyethoxylates, which are widely used as surfactants. Utilization of 4-n-NP by the filamentous fungus Aspergillus versicolor as the sole carbon and energy source was investigated. By means of gas chromatography–mass spectrometry, we showed that in the absence of any carbon source other than 4-n-NP in the medium, A. versicolor completely removed the xenobiotic (100mgL−1) after 3 d of cultivation. Moreover, mass spectrometric analysis of intracellular extracts led to the identification of eight intermediates. The mineralization of the xenobiotic in cultures supplemented with 4-n-NP [ring-14C(U)] as a growth substrate was also assessed. After 3 d of incubation, approximately 50% of the initially applied radioactivity was recovered in the form of 14CO2, proving that this xenobiotic was completely metabolized and utilized by A. versicolor as a carbon source. Based on microscopic analysis, A. versicolor is capable of germinating spores under such conditions. To confirm these observations, a microcalorimetric method was used. The results show that even the highest amount of 4-n-NP initiates heat production in the fungal samples, proving that metabolic processes were affected by the use of 4-n-NP as an energetic substrate.

Distribution of anionic and nonionic surfactants in a sewage-impacted Mediterranean coastal lagoon: Inputs and seasonal variations

In this work we have monitored the seasonal inputs, occurrence and distribution of the world's most widely used surfactants (linear alkylbenzene sulfonates, LAS, nonylphenol polyethoxylates, NPEOs, and alcohol polyethoxylates, AEOs) in Mar Menor lagoon (SE Spain) and its main tributary (El Albujón) for the first time. Concentration of target compounds was determined in both surface waters and sediments after solid phase extraction and pressurized liquid extraction, respectively, followed by liquid chromatography–mass spectrometry (LC–MS). There were significant differences in surfactant fluxes from El Albujón towards Mar Menor depending on the season and the day of the week, with maximum estimated annual inputs being detected for LAS (406kg) and their metabolites, sulfophenyl carboxylic acids (482kg). Average concentrations of surfactants in the lagoon were between 44 and 1665μg/kg in sediment, and between 0.3 and 63μg/L in water. These levels were significantly higher for samples collected near the shore than for those measured inside the lagoon itself. Overall, the occurrence and distribution of surfactants in the system could be explained due to a combination of different sources (surface and groundwater inputs, treated and untreated wastewater effluents, towns, ports, etc.) and simultaneous in-situ physicochemical and biological processes, with an special emphasis on degradation during warmer months.

Occurrence and spatial distribution of emerging contaminants in the unsaturated zone. Case study: Guadalete River basin (Cadiz, Spain)

Irrigation with reclaimed water is becoming a common practice in arid- and semi-arid regions as a consequence of structural water resource scarcity. This practice can lead to contamination of the vadose zone if sewage-derived contaminants are not removed properly. In the current work, we have characterized soils from the Guadalete River basin (SW Spain), which are often irrigated with reclaimed water from a nearby wastewater treatment plant and amended using sludge. Physico-chemical, mineralogical and hydraulic properties were measured in soil samples from this area (from surface up to 2m depth). Emerging contaminants (synthetic surfactants and pharmaceutically active compounds, or PhACs) were also determined. Synthetic surfactants, widely used in personal care products (PCPs), were found in a wide range of concentrations: 73–1300μgkg−1 for linear alkylbenzene sulfonates (LAS), 120–496μgkg−1 for alkyl ethoxysulfates (AES), 19–1090μgkg−1 for alcohol polyethoxylates (AEOs), and 155–280μgkg−1 for nonylphenol polyethoxylates (NPEOs). The presence of surfactant homologues with longer alkyl chains was predominant due to their sorption capacity. A positive correlation was found between LAS and AEOs and soil organic carbon and clay content, respectively. Out of 64PhACs analyzed, only 7 were detected occasionally (diclofenac, metoprolol, fenofibrate, carbamazepine, clarithromycin, famotidine and hydrochlorothiazide), always at very low concentrations (from 0.1 to 1.3μgkg−1).

Phosphorylation of Histone H2AX Generated by Linear Alkylbenzene Sulfonates and its Suppression by UVB Exposure

We previously demonstrated that the nonionic surfactants, nonylphenol polyethoxylates (NPEOs) induced the phosphorylation of histone H2AX (γ-H2AX), accompanied by DNA double-strand breaks (DSBs), and that exposure to ultraviolet (UV) degraded NPEOs, which sometimes enhanced their DNA-damaging ability. In this study, we showed that linear alkylbenzene sulfonates (LAS), general anion surfactants, also generated DSBs with γ-H2AX, and this ability was attenuated by UVB exposure. In the human breast adenocarcinoma cell line, MCF-7, γ-H2AX was generated in a dose-dependent manner immediately after cells were treated with LAS, and this was attributed to the formation of DSBs and was independent of cell cycle phases. The ability to generate γ-H2AX was markedly reduced in LAS exposed to UVB. HPLC analysis revealed that LAS were a mixture of various alkyl chain lengths, the peaks of which were detected at individual retention times. UVB evenly decreased all peaks of LAS, without migration of peaks to other retention times, which indicated that UVB may degrade the benzene ring of LAS, but did not shorten the alkyl chains. UVB is an important environmental factor in the degradation of LAS exhibiting the ability to induce DSBs, the most serious type of DNA damage.

The Bioconcentration and Degradation of Nonylphenol and Nonylphenol Polyethoxylates by Chlorella vulgaris

Nonylphenol polyethoxylates (NPnEOs), a major class of nonionic surfactants, can easily enter into aquatic environments through various pathways due to their wide applications, which leads to the extensive existence of their relative stable metabolites, namely nonylphenol (NP) and mono- to tri-ethoxylates. This study investigated the bioconcentration and degradation of NP and NPnEO oligomers (n = 1–12) by a green algae, Chlorella vulgaris. Experimental results showed that C. vulgaris can remove NP from water phase efficiently, and bioconcentration and degradation accounted for approximately half of its loss, respectively, with a 48 h BCF (bioconcentration factor) of 2.42 × 103. Moreover, C. vulgaris could concentrate and degrade NPnEOs, distribution profiles of the series homologues of the NPnEOs in algae and water phase were quite different from the initial homologue profile. The 48 h BCF of the NPnEO homologues increased with the length of the EO chain. Degradation extent of total NPnEOs by C. vulgaris was 95.7%, and only 1.1% remained in water phase, and the other 3.2% remained in the algal cells. The algae removed the NPnEOs mainly through degradation. Due to rapid degradation, concentrations of the long chain NPnEO homologous in both water (n ≥ 2) and the algal phase (n ≥ 5) was quite low at the end of a 48 h experiment.

H2O2/UV-C and Photo-Fenton treatment of a nonylphenol polyethoxylate in synthetic freshwater: Follow-up of degradation products, acute toxicity and genotoxicity

H2O2/UV-C and Photo-Fenton treatment of a nonylphenol polyethoxylate surfactant was investigated in synthetic freshwater. H2O2/UV-C treatment outperformed Photo-Fenton treatment in terms of mother pollutant abatement kinetics as well as overall organic carbon removal efficiencies. Short polyethoxy-chain nonylphenol polyethoxylates, polyethylene glycols, formic acid, acetic acid and formaldehyde were identified as the common degradation products of the nonionic surfactant. Monocarboxylated polyethylene glycols and oxalic acid were detected during H2O2/UV-C oxidation, whereas a degradation product resulting from the hydroxyl radical attack of the tertiary alkyl chain and the aromatic ring was detected during Photo-Fenton treatment. Based on the liquid chromatography–mass spectrometry results, it was suggested that the polyethoxy chain of the surfactant was more susceptible to degradation with the H2O2/UV-C treatment process, while the alkyl chain and aromatic ring were more prone to Photo-Fenton oxidation. Acute toxicity analysis employing the photobacteria Vibrio fischeri indicated that the inhibitory effect of the surfactant increased from 10% to 30% and 19% during the early stages of H2O2/UV-C and Photo-Fenton treatment, respectively. At the end of the treatment period, the inhibitory effect of the surfactant dropped back to less than 10%. According to the umu-genotoxicity test conducted with Salmonella typhimurium TA1535/pSK1002 strain, the genotoxic effect followed an increasing trend during the course of H2O2/UV-C treatment. A positive correlation was evident between the intensity of the nonylphenol monoethoxylate product ion and the genotoxic effect observed during H2O2/UV-C treatment. The genotoxic effect of Photo-Fenton-treated degradation products appeared to be relatively low as compared with those of H2O2/UV-C treatment.

Oxidation of nonylphenol ethoxylates in aqueous solution by UV-C photolysis, H2O2/UV-C, Fenton and photo-Fenton processes: are these processes toxicologically safe?

UV-C, H2O2/UV-C, Fenton and photo-Fenton treatment of a nonylphenol polyethoxylate (NP-10) were comparatively studied, primarily focusing on the acute toxicity of degradation products. Formic, acetic and oxalic acids were all identified as the degradation products of NP-10; however, the sole common carboxylic acid was found to be formic acid for the studied treatment processes. The percent relative inhibition towards Vibrio fischeri increased from 9% to 33% and 24% after 120 min-UV-C and H2O2/UV-C treatment, respectively. Complete NP-10 and 70% of its total organic carbon (TOC) content was removed by the photo-Fenton process, which ensured the fastest removal rates and lowest inhibitory effect (8% after 120 min treatment). The acute toxicity pattern being observed during H2O2/UV-C and photo-Fenton treatment positively correlated with temporal evolution of the identified carboxylic acids, whereas unidentified oxidation products were the most likely origin of the acute toxicity in UV-C photolysis.

Fate and degradation of nonylphenolic compounds during wastewater treatment process

In order to explore the biodegradation behavior of nonylphenolic compounds during wastewater treatment processing, two full-scale wastewater treatment plants were investigated and batch biodegradation experiments were conducted. The biodegradation pathways under the various operational conditions were identified from batch experiments: shortening of ethoxy-chains dominated under the anaerobic condition, whereas oxidizing of the terminal alcoholic group prevailed over the other routes under the aerobic condition. Results showed that the anoxic condition could accelerate the biodegradation rates of nonylphenolic compounds, but had no influence on the biodegradation pathway. The biodegradation rates of nonylphenol (NP) and short-chain nonylphenol polyethoxylates (NPnEOs, n: number of ethoxy units) increased from the anaerobic condition, then the anoxic, finally to the aerobic condition, while those of long-chain NPnEOs and nonylphenoxy carboxylates (NPECs) seemed similar under the various conditions. Under every operational condition, long-chain NPnEOs showed the highest biodegradation activity, followed by NPECs and short-chain NPnEOs, whereas NP showed relatively recalcitrant characteristics especially under the anaerobic condition. In addition, introducing sulfate and nitrate to the anaerobic condition could enhance the biodegradation of NP and short-chain NPnEOs by supplying more positive redox potentials.

Biodegradation of polyethoxylated nonylphenols.

Polyethoxylated nonylphenols, with different ethoxylation degrees (NPEOx), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native NPEOx and its derivatives. In this paper, the isolation of five bacterial strains, capable of using NPEO15, as unique carbon source, is described. The most efficient NPEO15 degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% NPEO15 medium. The NPEO15 degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the NPEO15 biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant (k) and half life time (τ) for this biotransformation were estimated to be 0.0072 h−1 and 96.3 h, respectively.

Vertical distribution profiles and diagenetic fate of synthetic surfactants in marine and freshwater sediments

This manuscript deals with the presence and degradation of the most commonly-used surfactants, including anionic (linear alkylbenzene sulfonates, LAS, and alkyl ethoxysulfates, AES) and non-ionic (alcohol polyethoxylates, AEOs, and nonylphenol polyethoxylates, NPEOs) compounds, in sediments and pore water from several aquatic environments (Southwest, Spain). Different vertical distributions were observed according to the respective sources, uses, production volumes and physicochemical properties of each surfactant. Levels of nonionics (up to 10mgkg−1) were twice as high as anionics in industrial areas and harbors, whereas the opposite was found near urban wastewater discharge outlets. Sulfophenyl carboxylic acids (SPCs), LAS degradation products, were identified at anoxic depths at some sampling stations. Their presence was related to in situ anaerobic degradation of LAS in marine sediments, whereas the occurrence of these metabolites in freshwater sediments was attributed to the existence of wastewater sources nearby. No significant changes in the average length of AEO and NPEO ethoxylated chains were observed along the sediment cores, suggesting that their biodegradation was very limited in the sampling area. This may be directly related to their lower bioavailability, as their calculated sediment–pore water distribution coefficients (log Ksw), which showed that non-ionic surfactants examined in this study had greater sorption affinity than the anionic surfactants (e.g., 2.3±0.3 for NPEOs).

Degradation of surface-active compounds in a constructed wetland determined using high performance liquid chromatography and extraction spectrophotometry

Degradation of anionic and nonionic surfactants in a constructed wetland with horizontal subsurface flow was studied using high performance liquid chromatography and extraction spectrophotometry. The ratio of individual homologues of linear alkylbenzene sulfonates (LAS) and the efficiency of their removal were studied. Tridecyl-, dodecyl-, undecyl-, and decylbenzene sulfonates were removed with efficiencies of 92.9%, 84.3%, 64.7%, and 41.1%, respectively. These differences are due to sequential shortening of the alkyl chain in homologues during degradation (the higher homologue can provide the lower one). The formation of sulfophenyl carboxylic acids during ω-oxidation of the alkyl chain followed by successive α- and/or β-oxidation is also a possible mechanism for removal of LAS. Solid phase extraction using Chromabond® HR-P columns was used for preconcentration of the analytes prior to their determination by HPLC. Methylene blue active compounds were determined using extraction spectrophotometry. The average efficiency of their removal was 84.9% in this case. The efficiency of nonionic surfactant removal (98.2%) was significantly higher in comparison to that for anionic surfactants. The concentration of the endocrine disruptor nonylphenol (a product of nonylphenol polyethoxylate surfactant degradation) determined in the profile of the wetland was beneath the limit of detection (0.4 μg/L). The average outflow concentrations of anionic and nonionic surfactants determined by spectrophotometry were 0.54 and 0.021 mg/L, respectively. The average outflow concentrations of decyl- and tridecylbenzene sulfonates determined by HPLC were 0.195 and 0.015 mg/L. Efficiencies of 86.4% and 92.2% were obtained for removal of organic compounds as indicated by chemical and biochemical oxygen demand (CODCr and BOD5). These results demonstrate the suitability of the constructed wetland for degrading surface-active compounds.

Effects of Nonylphenol on immune function of female Sprague-Dawley rats

Nonylphenol (NP) is the final biodegradation product of nonylphenol polyethoxylates, which are widely used as surfactants in domestic and industrial products. NP was reported to exert estrogenic actions and shown to potentially adversely affect reproductive functions. However, NP influence on immune system function remains unclear. To address this issue, the effects of NP on spleen and thymus were examined in this study. Female Sprague-Dawley rats were treated with NP orally at doses of 0, 20, 80, or 200 mg/kg respectively. Data showed that NP increased the levels of natural killer (NK) cells and natural killer T (NKT) cells in peripheral blood and decreased the levels of interleukin-4 (IL-4) and interferon gamma (IFN-γ) in serum. These findings suggest that exposure to NP by oral route may induce adverse effects on the spleen and thymus and affect the immune function of female rats.

Nonylphenol polyethoxylate coated body-center-cubic iron nanocrystals for ferrofluids with technical applications

An approach to the design of a suitable system for technological applications, such as magneto-rheological fluids with controllable performance, showing high saturation magnetization and low coercivity and remanence, is presented. This approach is based on the synthesis of stable iron nanoparticles with a relatively thick polymeric coating—the non-ionic surfactant nonylphenol polyethoxylate—by a microemulsion method with NaBH4 as a reducing agent. X-ray diffractometry, Mössbauer spectroscopy, and high resolution electron microscopy reveal a body-center-cubic structure in the iron cores. The resulting nanoparticles are predominantly spherical, having an average core size of 7 nm and a constant shell thickness of 3 nm. Magnetic measurements reveal a higher saturation magnetization (127.4 Am2 kg−1 at 300 K and 153.2 Am2 kg−1 at 5 K) than in other approaches and a small coercive field of 12 mT. X-ray diffractometry results account for the presence of iron borate traces as a secondary phase, formed at the initial stages of the synthesis during the reduction process of precursors. Preliminary studies under oxidant conditions show a reduction in saturation magnetization lower than 9% over a six months period.

Removal of nonionic surfactant from electroplating wastewater by fluidized zerovalent iron with two oxidants (H2O2/Na2S2O8)

Removal of nonylphenol polyethoxylate with 9 mol of ethoxylate (NP9EO), a nonionic surfactant, from electroplating wastewater by fluidized zerovalent iron (ZVI) with two oxidants (ZVI/H2O2 and ZVI/S2O82-) was studied. There are several benefits of using the proposed system: (1) the free radicals that result from the processes can reduce the organic contents and the occurrence of nonylphenol, an endocrine disruptor, (2) the ferric ion, dissoluted from the reaction for ZVI, can act as a coagulant to assist in the following precipitation process and (3) a higher ZVI utilization for the fluidized process due to abrasive motion of the ZVI. For the ZVI/H2O2 system, under optimum operating conditions, when the pH is 4.0, and Hydraulic Detention Time (HDT) 1.5 min and H2O2 concentration 23.6 mM, NP9EO and TOC removal efficiencies were 99 and 54%, respectively. The removal efficiency were increased with increased H2O2 dosage, but became reduced when H2O2 dosage was in excess of 23.6 mM. For the ZVI/S2O82- system, when the optimum operating conditions for pH value and HDT were 4.5 and 0.75 min, the removal efficiencies increased with an increase in S2O82- dosage. The removal efficiency of the ZVI/H2O2 was better than that of ZVI/S2O82- at the same pH value, HDT and oxidant dosage, but less acidity was required to maintain the constant pH for the ZVI/S2O82- system. In addition, ferrous ion, which was able to be measured quickly, can be used as an indicator for the removal of both TOC and NP9EO.

Coagulation enhancement of nonylphenol ethoxylate by partial oxidation using zero-valent iron/hydrogen peroxide

Coagulation enhancement of nonionic surfactant nonylphenol polyethoxylate with 9 mol of ethoxylate (NP9EO), was conducted by partial oxidation using zero-valent iron (ZVI)/hydrogen peroxide (H2O2) since coagulation is a typical process in many small-scale wastewater treatment plants but it is difficult to remove NP9EO due to micelle formation, and partial oxidation as pretreatment using the proposed process might be adequate and economically feasible. In this study, effects of pH, ZVI dosage, and H2O2 concentration were all investigated. The results show, highest NP9EO removal was observed at pH 2 instead of pH 1.5, since the presence of extra ferrous ion in the lower pH consumed the hydroxyl radicals, resulting in low removal efficiency. In addition, ferrous ion was converted to ferric ion for pH higher than 2 which reduced the efficiency of Fenton reaction. NP9EO removal efficiency by coagulation with ZVI/H2O2 pretreatment was as high as 99%, which is 40% higher than that without ZVI/H2O2 pre-treatment. The optimum dosages for ZVI/H2O2 oxidation were about 125 mg/L of H2O2 and 3 g/L of ZVI with NP9EO removal higher than 85%. But considering the following coagulation, the optimum dosages were about 125 mg/L of H2O2 and 2.5 g/L of ZVI with NP9EO removal efficiency of 95%. Besides, the dissolution of ferric ion from ZVI/H2O2 was able to reduce/replace the requirement of the traditional ferric chloride.