Landfill Leachate Samples Research Articles

Removal of COD and Ammonia Nitrogen by a Sawdust/Bentonite-Augmented SBR Process

Water pollutant removal by biomass adsorbent has been considered innovative and cost-effective, and thus commendable for application in industry. However, certain important aspects have been overlooked by researchers, namely the efficiency in the operation time and pollutant removal. In this research, landfill leachate samples with organic components were treated using a bentonite-enriched sawdust-augmented sequencing batch reactor (SBR) process. By modifying the pH, the sawdust samples were categorized into three groups: the acidic, the alkaline, and the neutral. To bentonite samples, the pH-adjusted sawdust was added at 10%, 20%, and 30% amounts by mass, respectively. At the optimum aeration rate of 7.5 L/min and contact period of 22 h, the treatment achieved 99.28% and 95.41% removal of chemical oxygen demand (COD) and NH3-N with bentonite, respectively. For both pollutants, in the presence of sawdust, the removal was only reduced by about 17% with the contact period reduced to 2 h, which was a considerable achievement.

Removal of pollutants with determination of power consumption from landfill leachate wastewater using an electrocoagulation process: optimization using response surface methodology (RSM)

Treatment of landfill leachate wastewater by electrocoagulation process using an aluminium electrode was investigated in a batch electrochemical cell reactor. Response surface methodology based on central composite design was used to optimize the operating parameters for the removal of % color and % total organic carbon (TOC) together with power consumption from landfill leachate. Effects of three important independent parameters such as current density (X1), inter-electrode distance (X2) and solution pH (X3) of the landfill leachate sample on the % color and % TOC removal with power consumption were investigated. A quadratic model was used to predict the % color and % TOC removal with power consumption in different experimental conditions. The significance of each independent variable was calculated by analysis of variance. In order to achieve the maximum % color and % TOC removal with minimum of power consumption, the optimum conditions were about current density (X1)—5.25 A/dm2, inter-electrode distance (X2)—1 cm and initial solution of effluent pH (X3)—7.83, with the yield of color removal of 74.57%, and TOC removal of 51.75% with the power consumption of 14.80 kWh/m3. Electrocoagulation process could be applied to remove pollutants from industrial effluents and wastewater.

Adsorptive removal capacity of gravel for metal cations in the absence/presence of competitive adsorption.

Locally available and low cost granular gravel as an adsorbent material was employed to determine its capacity to remove metal cations Cu(II), Fe(II), Ni(II), and Zn(II) from single metal solution and landfill leachate samples. Adsorption kinetics and mechanism under different parameters including dosage, time, and pH were studied. It was found that the experimental results fitted to the Freundlich model suggesting an adsorption process on a multilayer heterogeneous surface for both single metal solution and landfill leachate samples. The adsorption of metal cations followed second-order kinetics occurring in a single step on the surface of gravel. The order of removal efficiency of metals was found to be Cu(II)(98%) > Fe(II)(87.5%) > Zn(II)(76.05%) > Ni(II)(36.38%) in single metal solution and Cu(II)(98.3%) > Fe(II)(83%) > Zn(II)(48%) > Ni(II)(27.32%) in landfill leachate sample at pH 7. The regeneration efficiency of the metals adsorbed on the gravel resulted in the order of Fe(II)(99.54%) > Cu(II)(99%) > Ni(II)(49.46%) > Zn (II)(2.25%).

Pcb biodegration using bacteria isolated from landfill leachate

Polychlorinated biphenyls, PCBs are toxic, persistent organic pollutants (POP) which are harmful to human and environment due to their lipophilic characteristic and not easily degraded in the environment. Biodegradation is one of the alternative ways to reduce PCBs contamination. This study intended to isolate bacteria from landfill leachate using enrichment culture technique and optimize the growth condition of selected isolates for degradation of PCBs. PCB biodegradation efficiency by selected bacterial isolates was also determined using GC-MS. Three potential PCBs degraders were isolated from the samples of landfill leachate through enrichment culture technique, which utilised PCBs as sole carbon and energy sources but only isolate T12B shown significant effect on the degradation. Three different growth parameters were optimized involving the temperature, pH, and PCBs concentration. Central composite design (CCD) from Design Expert Software was used to design the experiment. The optimal growth condition of temperature at 37˚C with 10 ppm of PCB concentrations and pH 8 for the culture medium was achieved using Response Surface Methodology (RSM) analysis. Based on GC-MS analysis, the reduction of PCBs concentration indicates that they were utilized by isolates T12B as sole of carbon and energy sources. This may suggest that bacteria in landfill leachate play an important role in biodegradation process as well as more effective and economical.

National Estimate of Per- and Polyfluoroalkyl Substance (PFAS) Release to U.S. Municipal Landfill Leachate.

Landfills are the final stage in the life cycle of many products containing per- and polyfluoroalkyl substances (PFASs) and their presence has been reported in landfill leachate. The concentrations of 70 PFASs in 95 samples of leachate were measured in a survey of U.S. landfills of varying climates and waste ages. National release of PFASs was estimated by coupling measured concentrations for the 19 PFASs where more than 50% of samples had quantifiable concentrations, with climate-specific estimates of annual leachate volumes. For 2013, the total volume of leachate generated in the U.S. was estimated to be 61.1 million m3, with 79% of this volume coming from landfills in wet climates (>75 cm/yr precipitation) that contain 47% of U.S. solid waste. The mass of measured PFASs from U.S. landfill leachate to wastewater treatment plants was estimated to be between 563 and 638 kg for 2013. In the majority of landfill leachate samples, 5:3 fluorotelomer carboxylic acid (FTCA) was dominant and variations in concentrations with waste age affected total estimated mass. There were six PFASs that demonstrated significantly higher concentrations in leachate from younger waste compared to older waste and six PFAS demonstrated significant variation with climate.

Effect of pretreatment by coagulation on stabilized landfill leachate during anaerobic treatment

AbstractLandfill leachate contains both larger fractions of higher molecular weight organic materials and heavy metals. The study investigated the effect of coagulation as pretreatment during anaerobic treatment process on stabilized landfill leachate. Anaerobic studies were done on the raw stabilized leachate and on the pretreated leachate, where coagulation was used as a pre-treatment process for leachate. Landfill leachate samples were collected from India’s largest and oldest landfill i.e. Deonar landfill, Mumbai. The leachate was characterized by high TS (10,910 mg/l), COD (2,300 mg/l), BOD (238 mg/l), TOC (716 mg/l) and low BOD/COD ratio (0.10). FeCl3 and PACl were used as coagulants for the coagulation process. The highest removal efficiency obtained by FeCl3 and PACl for COD was 53 and 59%, respectively. The highest removals of TOC were 52 and 57% by FeCl3 and PACl, respectively. The optimum pH and dose for FeCl3 was found to be 8 and 7 g/l, respectively. The best pH and dose for PACl was found to...

Nanoporous Au-based chronocoulometric aptasensor for amplified detection of Pb2+ using DNAzyme modified with Au nanoparticles

The authors herein described an amplified detection strategy employing nanoporous Au (NPG) and gold nanoparticles (AuNPs) to detect Pb2+ ions in aqueous solution. The thiol modified Pb2+-specific DNAzyme was self-assembled onto the surface of the NPG modified electrode for hybridizing with the AuNPs labeled oligonucleotide and for forming the DNA double helix structure. Electrochemical signal, redox charge of hexaammineruthenium(III) chloride (RuHex), was measured by chronocoulometry. Taking advantage of amplification effects of the NPG electrode for increasing the reaction sites of capture probe and DNA-AuNPs complexes for bringing about the adsorption of large numbers of RuHex molecules, this electrochemical sensor could detect Pb2+ quantitatively, in the range of 0.05–100nM, with a limit of detection as low as 0.012nM. Selectivity measurements revealed that the sensor was specific for Pb2+ even with interference by high concentrations of other metal ions. This sensor was also used to detect Pb2+ ions from samples of tap water, river water, and landfill leachate samples spiked with Pb2+ ions, and the results showed good agreement with the found values determined by an atomic fluorescence spectrometer. This simple aptasensor represented a promising potential for on-site detecting Pb2+ in drinking water.

Electrochemical oxidation of humic acid and sanitary landfill leachate: Influence of anode material, chloride concentration and current density

The influence of applied current density and chloride ion concentration on the ability of Ti/Pt/PbO2 and Ti/Pt/SnO2–Sb2O4 anodes for the electrochemical oxidation of humic acid and sanitary landfill leachate samples was assessed and compared with that of BDD anode. For the experimental conditions used, results show that both organic load and nitrogen removal rates increase with the applied current density and chloride ion concentration, although there is an optimum COD/[Cl−]0 ratio below which there is no further increase in COD removal. Metal oxide anodes present a similar performance to that of BDD, being the results obtained for Ti/Pt/PbO2 slightly better than for Ti/Pt/SnO2–Sb2O4. Contrary to BDD, Ti/Pt/PbO2 promotes lower nitrate formation and is the most suitable material for total nitrogen elimination. The importance of the optimum ratio of Cl−/COD/NH4+ initial concentrations is discussed.

Determination of personal care products and hormones in leachate and groundwater from Polish MSW landfills by ultrasound-assisted emulsification microextraction and GC-MS.

Determination of the endocrine disrupting compounds (EDCs) in leachate and groundwater samples from the landfill sites is very important because of the proven harmful effects of these compounds on human and animal organisms. A method combining ultrasound-assisted emulsification microextraction (USAEME) and gas chromatography–mass spectrometry (GC-MS) was developed for simultaneous determination of seven personal care products (PCPs): methylparaben (MP), ethylparaben (EP), propylparaben (PP), buthylparaben (BP), benzophenone (BPh), 3-(4-methylbenzylidene)camphor (4-MBC), N,N-diethyltoluamide (DEET), and two hormones: estrone (E1) and β-estradiol (E2) in landfill leachate and groundwater samples. The limit of detection (LOD)/limit of quantification (LOQ) values in landfill leachate and groundwater samples were in the range of 0.003–0.083/0.009–0.277 μg L−1 and 0.001–0.015/0.002–0.049 μg L−1, respectively. Quantitative recoveries and satisfactory precision were obtained. All studied compounds were found in the landfill leachates from Polish municipal solid waste (MSW) landfills; the concentrations were between 0.66 and 202.42 μg L−1. The concentration of pollutants in groundwater samples was generally below 0.1 μg L−1.

Measuring 81 characterization parameters from different tropical landfill leachates and potential treatment techniques

<div> <p>Raw municipal landfill leachate is extremely polluted wastewater and it regards as one of the drawbacks of the sanitary landfill treatment method. If the untreated landfill leachate is discharged to the natural environment, a great problem for the environment can be created, particularly for the water resources. To assess fresh leachate; collection, analyzing for various parameters, and comparing with the standards are essential. Thus, this study was purposed to examine the characteristics of different landfill leachate samples collected from three tropical landfill sites. The results of the formed leachate at the anaerobic Kulim Sanitary Landfill, semi-aerobic Pulau Burung Landfill Site, and anaerobic Kuala Sepetang landfill leachate in the northern region of Malaysia have been analyzed for 27 parameters and compared. The studied parameters in the present study were  phenols, zeta potential, oxidation-reduction potential (ORP), chemical oxygen demand (COD), biochemical oxygen demand (BOD<sub>5</sub>),  heavy metals, nitrogen compounds, salinity, electrical conductivity etc. For checking the risks of the leachate on the environment, the obtained results were compared with the Malaysia Standards. In addition, the leachate treatment opportunities upon the characterization are highlighted in this study. The effectiveness of various applications in treating leachate collected from municipal landfill was presented and discussed. It could be concluded that the knowledge of leachate quality is particularly significant in choosing an appropriate treatment techniques</p> </div> <p> </p>

Bacterial community diversity in municipal waste landfill sites.

Little is known about the bacterial diversity of landfills and how environmental factors impact the diversity. In this study, PCR-based 454 pyrosequencing was used to investigate the bacterial communities of ten landfill leachate samples from five landfill sites in China. A total of 137 K useable sequences from the V3-V6 regions of the 16S rRNA gene were retrieved from 205 K reads. These sequences revealed the presence of a large number of operational taxonomic units (OTUs) in the landfills (709-1599 OTUs per sample). The most predominant bacterial representatives in the landfills investigated, regardless of geographic area, included Gammaproteobacteria, Firmicutes, and Bacteroidetes. The phyla Fusobacteria and Tenericutes were also found for the first time to be predominant in the landfills. The phylum Fusobacteria predominated (51.5 and 48.8%) in two semi-arid landfills, and the phylum Tenericutes dominated (30.6%) at one humid, subtropical landfill. Further, a large number of Pseudomonas was detected in most samples, comprising the dominant group and accounting for 40.9 to 92.4% of the total abundance. Principal component analysis (PCA) and cluster analysis based on OTU abundance showed that the abundant taxa separated the bacterial community. Canonical correlation analysis (CCA) suggested that precipitation and landfilling age significantly impact on the bacterial community structure. The bacterial community function (e.g., cellulolytic bacteria, sulfate-reducing bacteria (SRB), sulfate-oxidizing bacteria, and xenobiotic organic compound (XOC)-degrading bacteria) was also diverse, but the pattern is unclear.

Occurrence and prevalence of antibiotic resistance in landfill leachate.

Antibiotic resistance (AR) is extensively present in various environments, posing emerging threat to public and environmental health. Landfill receives unused and unwanted antibiotics through household waste and AR within waste (e.g., activated sludge and illegal clinical waste) and is supposed to serve as an important AR reservoir. In this study, we used culture-dependent methods and quantitative molecular techniques to detect and quantify antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in 12 landfill leachate samples from six geographic different landfills, China. Five tested ARGs (tetO, tetW, bla(TEM), sulI, and sulII) and seven kinds of antibiotic-resistant heterotrophic ARB were extensively detected in all samples, demonstrating their occurrence in landfill. The detected high ratio (10(-2) to 10(-5)) of ARGs to 16S ribosomal RNA (rRNA) gene copies implied that ARGs are prevalent in landfill. Correlation analysis showed that ARGs (tetO, tetW, sulI, and sulII) significantly correlated to ambient bacterial 16S rRNA gene copies, suggesting that the abundance of bacteria in landfill leachate may play an important role in the horizontal spread of ARGs.

Perfluoroalkyl acids in municipal landfill leachates from China: Occurrence, fate during leachate treatment and potential impact on groundwater

Raw and treated landfill leachate samples were collected from 5 municipal landfill sites in China to measure the concentrations and contamination profile of perfluoroalkyl acids (PFAAs) in leachate during different steps of treatment. The total concentration of PFAAs (∑PFAAs) ranged from 7280 to 292,000ngL−1 in raw leachate and from 98.4 to 282,000ngL−1 in treated leachate. The dominant compounds measured were PFOA (mean contribution 28.8% and 36.8% in raw and treated leachate, respectively) and PFBS (26.1% and 40.8% in raw and treated leachate, respectively). A calculation of mass flows during the leachate treatment processes showed that the fate of individual PFAAs was substance and treatment-specific. The Chinese national leakage of ∑PFAAs to groundwater from landfill leachate was estimated to be 3110kgyear−1, which is a significant environmental release that is potentially threatening the sustainable use of groundwater as a drinking water source.

Archaeal community diversity in municipal waste landfill sites.

Despite the pivotal role of archaea in methane production in landfills, the identity, ecology, and functional diversity of these microorganisms and their link to environmental factors remain largely unknown. We collected 11 landfill leachate samples from six geographically distinct landfills of different ages in China and analyzed the archaeal community by bar-coded 454 pyrosequencing. We retrieved 121,797 sequences from a total of 167,583 sequences (average length of 464 bp). The archaeal community was geographically structured, and nonabundant taxa primarily contributed to the observed dissimilarities. Canonical correlation analysis (CCA) suggested that the total phosphorous (TP), nitrate, and conductivity are important drivers for shaping the archaeal community. The hydrogenotrophic methanogens Methanomicrobiales and Methanobacteriales greatly dominated 9 of 11 samples, ranging from 83.7 to 99.5 %. These methanogens also dominated the remaining two samples, accounting for 70.3 and 58.8 %, respectively. Interestingly, for all of the studied Chinese landfills, 16S rRNA analysis indicated the predominance of hydrogenotrophic methanogens.

Investigating landfill leachate as a source of trace organic pollutants

Landfill leachate samples (n=11) were collected from five USA municipal solid waste (MSW) landfills and analyzed for ten trace organic pollutants that are commonly detected in surface and municipal wastewater effluents (viz., carbamazepine, DEET, fluoxetine, gemfibrozil, PFOA, PFOS, primidone, sucralose, sulfamethoxazole and trimethoprim). Carbamazepine, DEET, PFOA and primidone were detected in all leachate samples analyzed and gemfibrozil was detected in samples from four of the five-landfill sites. The contaminants found in the highest concentrations were DEET (6900–143000ngL−1) and sucralose (<10–621000ngL−1). Several compounds were not detected (fluoxetine) or detected infrequently (sulfamethoxazole, trimethoprim and PFOS). Using the average mass of DEET in leachate amongst the five landfills and scaling the mass release from the five test landfills to the USA population of landfills, an order of magnitude estimate is that over 10000kg DEETyr−1 may be released in leachate. Some pharmaceuticals have similar annual mean discharges to one another, with the estimated annual discharge of carbamazepine, gemfibrozil, primidone equating to 53, 151 and 128kgyear−1. To the authors knowledge, this is the first time that primidone has been included in a landfill leachate study. While the estimates developed in this study are order of magnitude, the values do suggest the need for further research to better quantify the amount of chemicals sent to wastewater treatment facilities with landfill leachate, potential impacts on treatment processes and the significance of landfill leachate as a source of surface water contamination.

Use of Doehlert and constrained mixture designs in the development of a photo-oxidation procedure using UV radiation/H₂O₂ for decomposition of landfill leachate samples and determination of metals by flame atomic absorption spectrometry.

This work proposes the use of photo-oxidation degradation with UV radiation/H2O2 as sample treatment for the determination of Fe, Zn, Mn, Ni and Co in municipal solid waste landfill leachate by flame atomic absorption spectrometry (FAAS). Three variables (pH, irradiation time and buffer concentration) were optimized using Doehlert design and the proportions of mixture components submitted to UV radiation (leachate sample, buffer solution and H2O2 30%, v/v) were optimized using a constrained mixture design. Using the experimental conditions established, this procedure allows limits of detection of 0.075, 0.025, 0.010, 0.075 and 0.041 µg mL-1, and the precision levels expressed as relative standard (%RSD, 0.5 µg mL-1) were 3.6, 1.8, 1.3, 3.3 and 1.7%, for Fe, Mn, Zn, Ni and Co respectively. Recovery tests were carried out for evaluation of the procedure accuracy and recoveries were between 92 and 106% for the studied metals. This procedure has been applied for the analysis of the landfill leachate collected in Jequié, a city of the southwestern region of the State of Bahia, Brazil. The results were compared with those obtained by acid digestion. There was no significant difference between the results obtained by the two methods based on paired t-test at 95% confidence level.

Precipitates in landfill leachate mediated by dissolved organic matters

Clogging of landfill leachate collection system is so ubiquitous that it causes problems to landfills. Although precipitations of calcite and other minerals have been widely observed, the mechanism of precipitation remains obscure. We examined the clog composition, dissolved organic matters, leachate chemical compositions and the correlation of these variables in view of the precipitation process. It is shown that Dissolved Organic Carbon (DOC) inhibits precipitation of landfill leachate. Using the advanced NICA-Donnan model, the analysis of aqueous chemical reactions between Mg–Ca–DOC–CO2 suggests a good agreement with experimental observations. Calcite and dolomite are both found to be oversaturated in most of the landfill leachate samples. DOC is found to preferentially bind with Mg than Ca, leading to more likely precipitation of Calcite than dolomite from landfill leachate. The NICA-Donnan model gives a reasonable estimation of dolomite saturation index in a wide range of DOC. Modeling confirms the major precipitation mechanism in terms of alkaline earth metal carbonate. Uncertainties in model parameters are discussed with particular focus on DOC composition, functional group types and density concentration and the influential factors.

Overestimation of geogenic arsenic in landfill leachate: interference of humic and phosphinic acid in a commercial test kit

Large-scale groundwater contamination by arsenic (As) requires economical yet reliable analytical procedures to monitor the quality of well water and the effluent of As elimination processes. The silver diethyldithiocarbamate (AgDDTC) method provides the basis of a series of colourimetric tests used as a compromise between semi-quantitative field-test kits and expensive instrumental analytics. This study aimed at understanding the significant As overestimation by the AgDDTC method observed in landfill leachate samples. Results of the AgDDTC test were up to threefold the levels obtained by reference analyses. Overestimation broadly agreed with the time course of chemical oxygen demand and total phosphorus in the leachate. We hypothesised that the interference was caused by reduced P species or humic acid (HA), respectively. To test this, As-AgDDTC determinations from As standards were conducted with phosphonic (H3PO3) and phosphinic acid (H3PO2) as well as two commercial HA as matrix components. While H3PO3 showed no effect, H3PO2 in concentrations of 0.06 to 28 mg P L−1 yielded As recoveries of up to 130%. This was probably due to the evolution of phosphine (PH3) as suggested by the absorption spectra recorded after reacting pure PH3 with AgDDTC in pyridine. The HA in concentrations of 0.6–320 mg dissolved organic carbon L−1 gave As recoveries of up to 600%, possibly due to a chromophoric reaction of volatile HA digestion products formed during the reduction step. Significant As overestimation in the presence of the above-named compounds may require pre-oxidation of the samples. To recognise interference effects, the acquisition of full absorbance spectra may be recommendable in lieu of fixed wavelength analyses.

Trace determination of bisphenol-A in landfill leachate samples by dispersive liquid- liquid microextraction followed by high performance liquid chromatography

A simple, rapid and efficient sample pretreatment technique, termed dispersive liquid-liquid microextraction (DLLME), was developed as an extraction methodology to determine bisphenol-A (BPA), in landfill leachate samples prior to high performance liquid chromatography (HPLC)-ultraviolet detection. Some effective parameters, such as pH, extraction and disperser solvent type and their volumes, time of extraction and salt effect have been optimized using the one-factor-at-a-time approach. Under the optimum conditions, the preconcentration factor 25 was obtained from only 5 mL of the sample. The calibration graph was linear in the range of 5-500 µg L -1 with the detection limit of 1.5 µg L -1 . The relative standard deviation (RSD) for ten replicate measurements of 20 µg L -1 of BPA was 2.5%. Finally, the method was successfully applied for the extraction and determination of BPA in some landfill leachate samples with a relative recovery of 98–109% and RSD less than 5%. KEY WORDS : Dispersive liquid-liquid microextraction, Bisphenol-A, Landfill leachate samples, High-performance liquid chromatography Bull. Chem. Soc. Ethiop. 2014 , 28(3), 329-338. DOI: http://dx.doi.org/10.4314/bcse.v28i3.2

Influence of physicochemical and chemical parameters on polybrominated diphenyl ethers in selected landfill leachates, sediments and river sediments from Gauteng, South Africa.

Polybrominated diphenyl ethers (PBDEs) are known to be persistent, endocrine disruptors and bioaccumulative and can cause adverse health effects in animals and humans. In this study, river and landfill sediment samples were collected from selected rivers and municipal solid waste landfill (MSWL) sites across Gauteng Province in South Africa to determine the levels of common PBDEs (BDE-17, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183 and BDE-209). The mean and median concentrations of Σ8 PBDEs from river sediment samples was 2.4 and 0.4 ng g(-1), respectively, and a range of 0.8-114 ng g(-1). The highest concentration of Σ8 PBDEs (43.6 ng g(-1)) was observed at Jukskei River with more than two orders of magnitude greater than the rest. The observed total PBDE concentrations in landfill sediment and leachate samples ranged from 0.8 to 8.4 ng g(-1) and 127-3,702 pg L(-1) for the two matrices. BDE-209 was predominantly detected in most of the sediment samples. Two of the MSWLs which are lined with geomembranes gave the highest concentrations of ∑7 PBDEs (2,678 and 3,702 pg L(-1)). Correlation values for ∑7 PBDEs versus Co (r = 0.65), Cu (r = 0.52), Mn (r = 0.10), Mg (r = 0.76), Ca (r = 0.66) and Ni (r = 0.77) with a statistical significance (p < 0.05) were observed except for Na, Cr, Pb, K, Fe and Zn (p > 0.05). The observed positive correlation may suggest a possible influence of trace metals on PBDE concentrations in leachates. Furthermore, a test of relationship between major anions and PBDEs yielded positive relationship with Cl(-) (r = 0.94, p = 0.16), F(-) (r = 0.97, p = 0.21), Br(-) (r = 0.6, p = 0.29) and NO3 (2-) (r = 0.96, p = 0.08) with an insignificant statistical difference. However, evaluation of the relationship between some water quality parameters (pH, dissolved oxygen and electrical conductivity) gave negative correlation with PBDE concentrations.