Biodegradation of nonylphenol in mangrove sediment

This study investigated the biodegradation of nonylphenol (NP) in mangrove sediments collected at five sites along the Tanshui River in northern Taiwan. NP biodegradation rate constants (k₁) and half-lives (t_1/2) ranged from 0.039 to 0.139 day⁻¹ and 5.0 to 17.8 days, respectively. The biodegradation of NP was enhanced by the addition of yeast extract, hydrogen peroxide, brij 35, sodium chloride, or cellulose. However, NP biodegradation was inhibited by the addition of humic acid, heavy metals, or phthalic acid esters (PAEs). Of the microorganism strains isolated from the mangrove sediment, we found that strains A9, A10 and A13 (all identified as Bacillus sp.) expressed the best biodegrading ability. NP biodegradation rate constants (k₁) and half-lives (t_1/2) by the three strains ranged from 0.291 to 0.630 day⁻¹ and 1.1 to 2.4 days, respectively. The highest NP biodegradation rate was found in the sediment with the inoculation containing strains A9, A10 and A13, whereas the sediment without any inoculation had the lowest biodegradation rate.     

Degradation of 4-<Emphasis Type="Italic">n</Emphasis>-nonylphenol under nitrate reducing conditions

Nonylphenol (NP) is an endocrine disruptor present as a pollutant in river sediment. Biodegradation of NP can reduce its toxicological risk. As sediments are mainly anaerobic, degradation of linear (4-n-NP) and branched nonylphenol (tNP) was studied under methanogenic, sulphate reducing and denitrifying conditions in NP polluted river sediment. Anaerobic bioconversion was observed only for linear NP under denitrifying conditions. The microbial population involved herein was further studied by enrichment and molecular characterization. The largest change in diversity was observed between the enrichments of the third and fourth generation, and further enrichment did not affect the diversity. This implies that different microorganisms are involved in the degradation of 4-n-NP in the sediment. The major degrading bacteria were most closely related to denitrifying hexadecane degraders and linear alkyl benzene sulphonate (LAS) degraders. The molecular structures of alkanes and LAS are similar to the linear chain of 4-n-NP, this might indicate that the biodegradation of linear NP under denitrifying conditions starts at the nonyl chain. Initiation of anaerobic NP degradation was further tested using phenol as a structure analogue. Phenol was chosen instead of an aliphatic analogue, because phenol is the common structure present in all NP isomers while the structure of the aliphatic chain differs per isomer. Phenol was degraded in all cases, but did not affect the linear NP degradation under denitrifying conditions and did not initiate the degradation of tNP and linear NP under the other tested conditions.     

Biodegradation of phenolic compounds by sulfate-reducing bacteria from contaminated sediments

The biodegradation of phenolic compounds under sulfate-reducing conditions was studied in sediments from northern Indiana. Phenol, p-cresol and 4-chlorophenol were selected as test substrates and added to sediment suspensions from four sites at an initial concentration of 10 mg/liter. Degradative abilities of the sediment microorganisms from the four sites could be related to previous exposure to phenolic pollution. Time to onset of biodegradation of p-cresol and phenol in sediment suspensions from a nonindustrialized site was approximately 70 and 100 days, respectively, in unacclimated cultures. In sediment slurries from three sites with a history of wastewater discharges containing phenolics, time to onset of biodegradation was 50–70 days for p-cresol and 50–70 days for phenol in unacclimated cultures. In acclimated cultures from all four sites, the length of the lag phase was reduced to 14–35 days for p-cresol and 25–60 days for phenol. Length of the biodegradative phase varied from 25 to 40 days for phenol and 10 to 50 days for p-cresol and was not markedly affected by acclimation. Substrate mineralization by sulfate-reducing bacteria was confirmed with radiotracer techniques using an acclimated sediment culture from one site. Addition of molybdate, a specific inhibitor of sulfate reduction, and bacterial cell inactivation inhibited sulfate reduction and substrate utilization. None of the sites exhibited the ability to degrade 4-chlorophenol, nor were acclimated phenol and p-cresol degrading cultures from a particular site able to cometabolize 4-chlorophenol.Correspondence to: D. Dean-Ross     

The rapid degradation of bisphenol A induced by the response of indigenous bacterial communities in sediment

In the present study, sediment was spiked with bisphenol A (BPA) solution to explore the interaction between indigenous bacterial communities and BPA biodegradation in sediment. Results showed that BPA could be adsorbed to the sediment and then biodegraded rapidly. Biodegradation efficiency of BPA in treatments with 10 and 50 mg/L BPA reached 64.3 and 61.8% on the first day, respectively. Quantitative polymerase chain reaction and denaturing gradient gel electrophoresis analysis indicated that BPA affected the densities, species, and diversities of bacteria significantly. The response of bacterial community to BPA favored BPA biodegradation by promoting the growth of BPA-reducing bacteria and inhibiting other competitors. According to the results of sequencing, Pseudomonas and Sphingomonas played vital roles in the degradation of BPA. They presented over 73% of the original bacterial community, and both of them were promoted by BPA comparing with controls. Laccase and polyphenol oxidase contributed to the degradation of BPA and metabolic intermediates, respectively. This paper illustrates the rapid biodegradation of BPA induced by the response of indigenous bacterial communities to the BPA stress, which will improve the understandings of BPA degradation in sediment.

     

Characterization of hydrocarbon-degrading bacteria isolated from oil-contaminated sediments in the Sultanate of Oman and evaluation of bioaugmentation and biostimulation approaches in microcosm experiments

Two oil-polluted sediments (PD and KH) were sampled from a coastal region in Oman for the isolation of hydrocarbon-degrading bacteria and for testing different bioremediation approaches. Fourty strains were isolated, eighteen were affiliated to Marinobacter whereas the rest belonged to Pseudomonas, Halomonas, Hahella and Alcanivorax. All strains grew well at 2–7% salinity and between 20 and 60 °C. The strains exhibited a better growth on long chain than on short chain alkanes. Biostimulation and bioaugmentation were compared in both sediments and oil biodegradation was followed by measuring CO₂ evolution and by gas chromatography (GC). The evolved CO₂ reached 0.45 ± 0.02 and 2.23 ± 0.07 mg CO₂ g⁻¹ sediment after 88 days in the untreated PD and KH sediments, respectively. While the addition of inorganic nutrients resulted in 1.2–3.7 fold increase in CO₂ evolution in both sediments, the addition of the bacterial consortium was only effective in the PD sediment. The maximum CO₂ evolution was measured when both nutrients and bacteria were added and this corresponded to a total oil mineralization of 2.6 ± 0.12 and 1.49 ± 0.04% of the initial oil after 88 days in the PD and KH sediments, respectively. GC analysis confirmed the CO₂ data and showed that most of the degraded compounds belonged to alkanes. We conclude that the Omani polluted sediments contain halotolerant and thermotolerant bacteria and biostimulation is more efficient than bioaugmentation for their cleanup.     

Seasonal distribution of nitrifying bacteria and rates of nitrification in coastal marine sediments

The distribution of nitrification potential (NP) with depth in sediment and season was investigated in a shallow sandy sediment (0.5 m water) and a deeper muddy sediment (17m water). In both sediments, nitrifying bacteria were present in the anoxic strata (oxygen penetration was 5 mm below the surface). The NP at 6–8 cm depth in the sediment was 50% and 10% of the surface NP at the sandy and muddy sediment, respectively. It is suggested that bioturbation and physical disturbance of the sediment were the most likely reasons for this distribution. The NP increased as sediment temperature decreased. This effect was less marked in the muddy sediment. It is concluded that during the summer, the numbers or specific activity of nitrifying bacteria diminished for the following reasons: There was decreased O₂ penetration into the sediment and increased competition for O₂ by heterotrophs; there was increased competition for NH₄ ⁺ and there was inhibition by H₂S. These effects counteracted the potentially higher growth rates and increased rates of NH₄ ⁺ production at the elevated summer temperatures. The potential nitrification rates in the upper 1 cm, which were measured at 22°C, were converted to calculated rates at the in situ temperature (Q₁₀=2.5) and in situ oxygen penetration. These calculated rates were shown to closely resemble the measured in situ rates of nitrification. The relationship between the in situ rates of nitrification and the nitrification potential is discussed.     

Biodegradation of nonylphenol by two alphaproteobacterial strains in liquid culture and sediment microcosm

Nonylphenol (NP) has been a contaminant of great environmental concern due to its ubiquity, toxicity and endocrine activity. Biodegradation is an ideal way to clean up NP pollution. In this study, two NP degraders were isolated from river sediment. Their ability to degrade NP was tested in both liquid culture and sediment microcosm. Phylogenetic analysis indicated that one isolate belonged to genus Rhizobium, while another was a Sphingobium species. The Rhizobium strain contained ALK gene, while the Sphingobium strain harbored ALK and C23O genes. Both of the two strains showed strong NP degradation ability in liquid culture. However, only the Rhizobium strain demonstrated a potential of bioremediating NP-contaminated sediment. This study can provide some new insights towards NP biodegradation and bioremediation.     

Biodegradation of methyl parathion in the presence of goethite: The effect of Pseudomonas sp. Z1 adhesion

In this research, the influence of goethite on biodegradation kinetic of methyl parathion was investigated in the presence of Pseudomonas sp. Z1. Semipermeable membrane experiments were performed to demonstrate the role of adhesion of degrading bacteria to surface of goethite in biodegradation of methyl parathion. Sorption of methyl parathion and bacteria onto goethite particles were also measured to assess the distribution of methyl parathion and bacteria between water and goethite surface. The first-order degradation rate constant of methyl parathion in different concentrations of goethite was in the order of 0.1 g L⁻¹ > 0.01 g L⁻¹ > 0 g L⁻¹ > 1 g L⁻¹ > 20 g L⁻¹, suggesting the presence of low concentrations of goethite accelerated the biodegradation of methyl parathion and high concentrations of goethite inhibited this biodegradation process. According to the result of semipermeable membrane experiment, when no bacterial attachment occurred in the system, the promotive effect of 0.1 g L⁻¹ goethite for microbial degradation was disappeared and the inhibition effect of 20 g L⁻¹ goethite increased. The results clearly demonstrated that the adhesion of bacteria to goethite was beneficial to the biodegradation of methyl parathion. The information obtained is of fundamental significance for the understanding of microbial degradation of organic pollution in soil.     

Biodegradation of estrogens by facultative anaerobic iron-reducing bacteria

Natural estrogens such as estrone, 17β-estradiol, estriol, and the synthetic component of contraceptive pills, 17α-ethinylestradiol, enter the municipal wastewater treatment plant via human excretions. A significant portion of these substances is found to remain in reject water produced after anaerobic digestion of activated sludge. In this study, the effect of the oxidant, Fe(III), and facultative anaerobic strain of iron-reducing bacteria on the anaerobic degradation of estrogens in reject water was investigated. Synthetic 17α-ethinylestradiol remained resistant to anaerobic biodegradation by iron-reducing bacteria, while natural estrogens such as 17β-estradiol, estriol, and estrone were removed by 92%, 60% and 27%, respectively, after 15 days of batch cultivation of iron-reducing bacteria in reject water with the addition of all estrogens to concentrations 100 μg l⁻¹ each. The ability of facultative anaerobic iron-reducing bacteria to degrade estrogens can be used for the anaerobic removal of trace organics from reject water in municipal wastewater treatment plant.     

Effect of biostimulation on the microbial community in PCB-contaminated sediments through periodic amendment of sediment with iron

Reductive dehalogenation of polychlorinated biphenyls (PCBs) by indigenous dehalorespiring microorganisms in contaminated sediments may be enhanced via biostimulation by supplying hydrogen generated through the anaerobic corrosion of elemental iron added to the sediment. In this study, the effect of periodic amendment of sediment with various dosages of iron on the microbial community present in sediment was investigated using phospholipid fatty acid analysis (PLFA) over a period of 18 months. Three PCB-contaminated sediments (two freshwater lake sediments and one marine sediment) were used. Signature biomarker analysis of the microbial community present in all three sediments revealed the enrichment of Dehalococcoides species, the population of which was sustained for a longer period of time when the sediment microcosms were amended with the lower dosage of iron (0.01 g iron per g dry sediment) every 6 months as compared to the blank system (without iron). Lower microbial stress levels were reported for the system periodically amended with 0.01 g of iron per g dry sediment every 6 months, thus reducing the competition from other hydrogen-utilizing microorganisms like methanogens, iron reducers, and sulfate reducers. The concentration of hydrogen in the system was found to be an important factor influencing the shift in microbial communities in all sediments with time. Periodic amendment of sediment with larger dosages of iron every 3 months resulted in the early prevalence of Geobacteraceae and sulfate-reducing bacteria followed by methanogens. An average pH of 8.4 (range of 8.2–8.6) and an average hydrogen concentration of 0.75% (range of 0.3–1.2%) observed between 6 and 15 months of the study were found to be conducive to sustaining the population of Dehalococcoides species in the three sediments amended with 0.01 g iron per g dry sediment. Biostimulation of indigenous PCB dechlorinators by the periodic amendment of contaminated sediments with low dosages of iron metal may therefore be an effective technology for remediation of PCB-contaminated sediments.     

Sediments in the mangrove areas contribute to the removal of endocrine disrupting chemicals in coastal sediments of Macau SAR,China, and harbour microbial communities capable of degrading E2, EE2, BPA and BPS

The occurrence of endocrine disrupting chemicals (EDCs) is a major issue for marine and coastal environments in the proximity of urban areas. The occurrence of EDCs in the Pearl River Delta region is well documented but specific data related to Macao is unavailable. The levels of bisphenol-A (BPA), estrone (E1), 17α-estradiol (αE2), 17β-estradiol (E2), estriol (E3), and 17α-ethynylestradiol (EE2) were measured in sediment samples collected along the coastline of Macao. BPA was found in all 45 collected samples with lower BPA concentrations associated to the presence of mangrove trees. Biodegradation assays were performed to evaluate the capacity of the microbial communities of the surveyed ecosystems to degrade BPA and its analogue BPS. Using sediments collected at a WWTP discharge point as inoculum, at a concentration of 2 mg l^?1 complete removal of BPA was observed within 6 days, whereas for the same concentration BPS removal was of 95% after 10 days, which is particularly interesting since this compound is considered recalcitrant to biodegradation and likely to accumulate in the environment. Supplementation with BPA improved the degradation of bisphenol-S (BPS). Aiming at the isolation of EDCs-degrading bacteria, enrichments were established with sediments supplied with BPA, BPS, E2 and EE2, which led to the isolation of a bacterial strain, identified as Rhodoccoccus sp. ED55, able to degrade the four compounds at different extents. The isolated strain represents a valuable candidate for bioremediation of contaminated soils and waters.

     

Potential for polychlorinated biphenyl biodegradation in sediments from Indiana Harbor and Ship Canal

Polychlorinated biphenyls (PCBs) are carcinogenic, persistent, and bioaccumulative contaminants that pose risks to human and environmental health. In this study, we evaluated the PCB biodegradation of sediments from Indiana Harbor and Ship Canal (IHSC), a PCB-contaminated site (average PCB concentration = 12,570 ng/g dw). PCB congener profiles and bacterial community structure in a core sediment sample (4.57 m long) were characterized. Analysis of vertical PCB congener profile patterns in sediment and pore water strongly suggests that in situ dechlorination occurred in sediments. However, 16S rRNA genes from putative PCB-dechlorinating Chloroflexi were relatively more abundant in upper 2 m sediments, as were genes indicative of aerobic biodegradation potential (i.e. biphenyl dioxygenase (bphA)). Characterization of the bacterial community by terminal restriction fragment length polymorphism and comparison of these with sediment and pore water PCB congener profiles with the Mantel test revealed a statistical correlation (p < 0.001). Sequences classified as Acinetobacter and Acidovorax were highly abundant in deep sediments. Overall, our results suggest that PCB dechlorination has already occurred, and that IHSC sediments have the potential for further aerobic and anaerobic PCB biodegradation.     

Biodegradation of decabromodiphenyl ether (BDE-209) by bacterial mixed cultures in a soil/water system

Decabromodiphenyl ether (DBDE) is a brominated flame retardant that is commonly used in many commercial products. Sorption of DBDE within a soil/water system can result in serious bioaccumulation within the ecological system and be a threat to human health. Little is known about aerobic DBDE biodegradation, and the influence of the UV light radiation on DBDE biodegradation has not been considered. This study, for the first time, isolates DBDE biodegrading aerobic mixed bacterial cultures from DBDE-contaminated soil/water systems in Taiwan. The aerobic biodegradation of DBDE as a sole carbon source in the presence of 365 nm UVA irradiation over 10 months was investigated using a clay/water system. The rate constants for DBDE degradation gave values ranging from 0.0121 to 0.0134 day⁻¹ in the presence of UV irradiation, which were significantly higher than the 0.0092–0.0102 day⁻¹ values obtained in complete darkness. The aerobic metabolites: 2′,3′-dihydroxy-4-bromodiphenyl ether and 2′,3′-dihydroxy-diphenyl ether were identified by GC–MS. Debromination was ascribed to UV irradiation and biodegradation by facultative aerobic bacteria in the micro-anaerobic environment of the clay/water system. The products of debromination included 12 PBDE congeners (tri- to hexa-BDEs) and their concentrations ranged from 34.28 to 83.80 mg l⁻¹. Specific bacteria capable of degrading PBDEs and carrying out nitrification/denitrification were identified. The present findings suggest that systems using a novel combination of photolysis and biodegradation could be developed to carry out DBDE remediation in the future.     

Effects of Spilled Oil on Bacterial Communities of Mediterranean Coastal Anoxic Sediments Chronically Subjected to Oil Hydrocarbon Contamination

The effects of spilled oil on sedimentary bacterial communities were examined in situ at 20 m water depth in a Mediterranean coastal area. Sediment collected at an experimental site chronically subjected to hydrocarbon inputs was reworked into PVC cores with or without a massive addition of crude Arabian light oil (∼20 g kg⁻¹ dry weight). Cores were reinserted into the sediment and incubated in situ at the sampling site (20 m water depth) for 135 and 503 days. The massive oil contamination induced significant shifts in the structure of the indigenous bacterial communities as shown by ribosomal intergenic spacer analysis (RISA). The vertical heterogeneity of the bacterial communities within the sediment was more pronounced in the oiled sediments particularly after 503 days of incubation. Response to oil of the deeper depth communities (8–10 cm) was slower than that of superficial depth communities (0–1 and 2–4 cm). Analysis of the oil composition by gas chromatography revealed a typical microbial alteration of n-alkanes during the experiment. Predominant RISA bands in oiled sediments were affiliated to hydrocarbonoclastic bacteria sequences. In particular, a 395-bp RISA band, which was the dominant band in all the oiled sediments for both incubation times, was closely related to hydrocarbonoclastic sulfate-reducing bacteria (SRB). These bacteria may have contributed to the main fingerprint changes and to the observed biodegradation of n-alkanes. This study provides useful information on bacterial dynamics in anoxic contaminated infralittoral sediments and highlights the need to assess more precisely the contribution of SRB to bioremediation in oil anoxic contaminated areas.     

Malathion biodegradation by a psychrotolerant bacteria Ochrobactrum sp. M1D and metabolic pathway analysis

An organophosphorus pesticide malathion biodegradation was investigated by using the bacteria Ochrobactrum sp. M1D isolated from a soil sample of peach orchards in Palampur, District Kangra, Himachal Pradesh (India). The bacterium was able to utilize malathion as the sole source of carbon and energy. The isolated bacterium was found psychrotolerant and could degrade 100% of 100 mg l⁻¹ malathion in minimal salt medium at 20°C, pH 7·0 within 12 days with no major significant metabolites left at the end of the study. Through GCMS analysis, methyl phosphate, diethyl maleate, and diethyl 2-mercaptosuccinate were detected and identified as the major pathway metabolites. Based on the GCMS profile, three probable degradation pathways were interpreted. The present study is the first report of malathion biodegradation at both the psychrophilic and mesophilic conditions by any psychrotolerant strain and also through multiple degradation pathways. In the future, the strain can be explored to bio-remediate the malathion contaminated soil in the cold climatic region and to utilize the enzymatic systems for advanced biotechnology applications.     

Biodegradation of lindane by a native bacterial consortium isolated from contaminated river sediment

The aerobic biodegradation of lindane (γ-hexachlorocyclohexane) by a consortium of acclimated bacteria from sediment at a polluted site on the Suquia River, Cordoba, Argentina, is reported. The bacteria were acclimated for 30 days under aerobic conditions, using a minimal culture medium containing lindane (0.034 mM) as sole carbon source. Growth of the bacterial consortium decreased at a lindane concentration of 1.03 mM and was totally inhibited at 2.41 mM. The consortium showed initial lindane degradation rates of 4.92×10⁻³, 11.0×10⁻³ and 34.8×10⁻³ mM h⁻¹ when exposed to lindane concentrations of 0.069, 0.137 and 0.412 mM, respectively. Chloride concentration increased during aerobic biodegradation, indicating lindane mineralization. A metabolite identified as γ-2,3,4,5,6-pentachlorocyclohexene appeared during the first 24 h of biodegradation. Four different bacteria, identified as Sphingobacterium spiritivorum, Ochrobactrum anthropi, Bosea thiooxidans and Sphingomonas paucimobilis, were isolated. Pure strains of B. thiooxidans and S. paucimobilis degraded lindane after 3 days of aerobic incubation. This is the first report of lindane biodegradation by B. thiooxidans.     

Characterization of plastic degrading bacteria isolated from sewage wastewater

Plastic is a fundamental polymer used in routine life and disposed of in sewage. It leads to microplastic pollution in aquatic organisms, introducing it into the food chain and affecting human health. In the present study, samples were collected from sewage wastewater to isolate the bacteria that could potentially reduce plastic. The six samples were incubated with plastic pieces in minimal salt media for 120 days. After 120 days, the weight loss experiment showed that samples SH5B and SH6B degraded 25% plastic. After chemical and molecular characterization, these strains were identified as Pseudomonas sp. SH5B and Pseudomonas aeruginosa SH6B. The Fourier-transform infrared spectroscopy (FTIR) analysis showed peaks shifting, indicating bond stretching, bond bending, and new bond formation. The Gas Chromatography-Mass Spectrometry (GC–MS) analysis revealed various new compounds produced during plastic degradation by these bacterial strains. The plastic biodegradation potential makes these bacteria an impending foundation for green chemistry to eradicate tough pollutants from the environment.     

Microbial degradation of nonylphenol and other alkylphenols—our evolving view

Because the endocrine disrupting effects of nonylphenol (NP) and octylphenol became evident, the degradation of long-chain alkylphenols (AP) by microorganisms was intensively studied. Most NP-degrading bacteria belong to the sphingomonads and closely related genera, while NP metabolism is not restricted to defined fungal taxa. Growth on NP and its mineralization was demonstrated for bacterial isolates, whereas ultimate degradation by fungi still remains unclear. While both bacterial and fungal degradation of short-chain AP, such as cresols, and the bacterial degradation of long-chain branched AP involves aromatic ring hydroxylation, alkyl chain oxidation and the formation of phenolic polymers seem to be preferential elimination pathways of long-chain branched AP in fungi, whereby both intracellular and extracellular oxidative enzymes may be involved. The degradation of NP by sphingomonads does not proceed via the common degradation mechanisms reported for short-chain AP, rather, via an unusual ipso-substitution mechanism. This fact underlies the peculiarity of long-chain AP such as NP isomers, which possess highly branched alkyl groups mostly containing a quaternary α-carbon. In addition to physicochemical parameters influencing degradation rates, this structural characteristic confers to branched isomers of NP a biodegradability different to that of the widely used linear isomer of NP. Potential biotechnological applications for the removal of AP from contaminated media and the difficulties of analysis and application inherent to the hydrophobic NP, in particular, are also discussed. The combination of bacteria and fungi, attacking NP at both the phenolic and alkylic moiety, represents a promising perspective.     

Adsorption and aerobic biodegradation of four selected endocrine disrupting chemicals in soil–water system

Adsorption and aerobic biodegradation characteristics of four selected endocrine disrupting chemicals (EDCs), 17β-estradiol (E2), 17α-ethinylestradiol (EE2), bisphenol A (BPA) and nonylphenol (NP) were investigated in soil–water system. The sorption of EDCs onto the soil was in the following order: NP > E2 > EE2 > BPA. Sorption isotherms of the four compounds fitted Freundlich models well. The aerobic biodegradation rates of these selected EDCs in the soil–water system could be described by pseudo-first-order kinetic equation. In a single chemical system, the half-lives of EDCs were 1.7, 5.3, 2.7 and 3.3 d for E2, EE2, NP and BPA, respectively, indicating that EE2 was not as readily biodegradable as the others. In a binary-chemical system, the half-lives of EDCs in all cominations were 1.5–2.2 times prolonged than the single chemical system. The following biotransformation pathway of estrogen was proposed: E2/EE2 → E1 → E3. An aerobic conversion of EE2 to E3 was also observed. The result of this research could be useful for predicting environmental fate and ecological risks of EDCs in natural environments especially when soil is their depository.