Validation and Evaluation of Selected Organic Pollutants in Shrimp and Seawater Samples from the NW Portuguese Coast.

The development of coastal regions has contributed to the intensification of environmental contamination, which can accumulate in aquatic biota, such as shrimps. These crustaceans, besides being delicious and being a good source of nutrients, can also accumulate environmental pollutants. Amongst others, these include organochlorine pesticides (OCPs), organophosphorus pesticides (OPPs), brominated flame retardants (BFRs), polychlorinated biphenyls (PCBs) and synthetic musks (SMs). These pollutants, classified as endocrine disruptors, are related to adverse effects in humans and since one of the major routes of exposition is ingestion, this is a cause for concern regarding their presence in food. The aim of the present study was to quantify the presence of environmental pollutants in shrimp samples and in the water from their habitat along the northwest Portuguese coast. In seawater samples, only two OCPs (lindane and DDD) and one BFR (BTBPE) were detected, and in shrimp samples, one OCP (DDD) and three SMs (HHCB, AHTN and ketone) were found. Bioaccumulation and the risk assessment of dietary exposure of SMs in shrimp samples were investigated. It was observed that all shrimp samples analyzed significantly presented bioaccumulation of the three SMs found. Concentrations of SMs detected in shrimp samples do not present a health risk for the adult Portuguese population.

Automated liquid-liquid extraction of organic compounds from aqueous samples using a multifunction autosampler syringe.

Liquid-liquid extraction is one of the most widely used and simplest sample preparation techniques. However, consumption of large volumes of organic solvent and manual handling are two major drawbacks of this technique. A multifunction autosampler syringe is introduced which permits automated liquid-liquid extraction in an enclosed operating environment, with low consumption of organic solvents. The device described herein features a micromixer function in addition to common autosampler syringe features like accurate and precise aspirating and dispensing. To test the functionality of the micromixer syringe, manual extraction of caffeine from a tea infusion and semi-automated extraction of dichloroethane from water were carried out. Excellent recoveries of caffeine from a tea infusion (89% recovery with 1.3% RSD) and dichloroethane from water (107% recovery with 10% RSD) were obtained. Two automated workflows were tested using the micromixer syringe mounted in a laboratory autosampler. Standalone automated micro liquid-liquid extraction was performed for sample preparation of selected polychlorinated biphenyl (PCB) congeners prior to comprehensive two-dimensional gas chromatography - electron capture detection analysis. Extraction of PCBs using the described approach used substantially less solvent than a validated solid-phase extraction approach whilst delivering equivalent results for samples with high-level PCBs. Finally, fully automated extraction and GC-MS analysis of polynuclear aromatic hydrocarbons (PAHs) from water samples was performed. Mean recoveries of extraction for PCB and PAH analysis were > 70% using 4 min automated liquid-liquid extractions.

Optimization of hollow-fiber liquid phase microextraction for polychlorinated biphenyls in human breast milk.

A reliable and sensitive analytical approach has been optimized for the extraction of seven polychlorinated biphenyls (PCBs) from human breast milk. Hollow fiber liquid phase microextraction (HF-LPME) was applied for the first time for the extraction and pre-concentration of the analytes. Analytes were separated by gas chromatography with electron capture detector (GC-µECD) for the sensitive detection and mass spectrometry for the unequivocal identification. A rotable central composite design (RCCD) was performed for the multivariate optimization of the method. The best results were obtained at 40 °C during 30 min and 600 rpm of stirring speed using a hollow fiber length of 5 cm and toluene as an extractant phase and salt addition was not required. The detection limits were in the range 7-14 ng L-1 for PCBs. The coefficients of determination of the calibration curves indicated good linearity (R2> 0.96) and the enrichment factors ranged from 74 to 143. This type of study is of great importance due to the deleterious effect that the presence of contaminants can produce in infants health related to the immature character of the defense system. Moreover, exclusive breastfeeding is recommended by neonatologists up to six months of life and as complementary food during the first two years.

A multiresidue method for the analysis of pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in snails used as environmental biomonitors.

This paper reports an optimized multiresidue extraction strategy based on the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction procedure and on solid-phase microextraction (SPME) for the simultaneous screening of 120 pesticides, 16 polycyclic aromatic hydrocarbons, and 22 polychlorinated biphenyls from the terrestrial snail Helix aspersa. The optimized extraction method was based on QuEChERS using acetonitrile, followed by dispersive-Solid-phase extraction clean-up using primary secondary amine and octadecyl (C18) sorbents. The obtained extracts were analyzed by liquid chromatography coupled with tandem mass spectrometry and gas chromatography coupled with tandem mass spectrometry. This latest technique was preceded by a pre-concentration step using SPME with appropriate fibers. Afterwards, the method was validated for its linearity, sensitivity, recovery, and precision. Results showed high sensitivity, accuracy, and precision, with limits of detection and quantification lower than 20 ng g - 1 for most considered pollutants. Both inter and intra-day analyses revealed low relative standard deviation (%), which was lower than 20% for most targeted compounds. Moreover, the obtained regression coefficient (R2) was higher than 0.98 and the recoveries were higher than 60% for the majority of the assessed pollutants.

Magnetic stir bars with hyperbranched aptamer as coating for selective, effective headspace extraction of trace polychlorinated biphenyls in soils.

It is challenging to greatly increase of the extraction selectivity and efficiency by stir bar sorptive extraction of ultra-trace polychlorinated biphenyls (PCBs) in complex environmental matrix, e.g., soils. To fulfill this purpose, one of the critical works is to prepare some coatings with high selectivity, adsorptive capacity and reusability. It is also important to develop some green, simple methods for preperation the coatings. In this work, a kind of highly efficient and bioactive coating based on hyperbranched aptamer (HB-Apt) was constructed via hybridization chain reaction (HCR). Then, the HB-Apt was coated on a magnetic stir bar and applied to headspace extraction of PCB72 and PCB106 in soils. The core-shell gold magnetic particles (Fe3O4@AuNPs, AuMNPs for short) was employed as the substrate to immobilize the HB-Apt. The extracted PCBs on the stir bar could be easily eluted in ethanol by stirring, and then sampled in gas chromatography-mass spectrometry (GC-MS) for qualification. The ultra-low detection limit (0.003-0.005 ng•g-1), good linearity (0.01-500 ng•g-1, R2≥0.994) and reproducibility (RSD: 4.58-6.53%) were obtained. Compared with the common aptamer coating, the HB-Apt coating exhibited good selectivity and higher extraction capacity. The results might be related to the fact that there are more aptamer fragments grated on the HB-Apt coating than those of the common aptamer coating. The magnetic stir bar can not only be employed for easy headspace extraction, but also facilitate separation and elution. Moreover, the coating could be recycled for at least 60 times before recoveries of the PCB72 and PCB106 in the spiked samples drop below 90%. All these indicated that the assay is simple, robust, environment friendly and promising for detection of trace PCBs in complex environmental samples.

Label-free and highly selective electrochemical aptasensor for detection of PCBs based on nickel hexacyanoferrate nanoparticles/reduced graphene oxides hybrids.

In consideration of the urgent need to determine polychlorinated biphenyls (PCBs) in the environment, a label-free and highly selective electrochemical aptasensor was constructed for determining PCBs based on nickel hexacyanoferrate nanoparticles (NiHCF NPs)/reduced graphene oxides (rGO) hybrids. NiHCF NPs/rGO hybrids with small size of about 5 nm NiHCF NPs were synthesized for the first time by in situ co-deposition of NiHCF NPs on rGO surface. In the hybrids, rGO with large area and good conductivity can supply more space for loading NiHCF NPs and improve the conductivity of the hybrids. NiHCF NPs that can be used to be act as a signal probe exhibit a couple of well-defined peaks with highly reversible redox ability and good stability. Here, PCB77 as a model molecule, the anti-PCB77 aptamer was anchored on the NiHCF NPs/rGO hybrids by covalent bonding reaction. The design aptasensor for detecting PCB77 exhibits a favorable linear response from 1.0 to 100.0 ng/L with a low detection limit of 0.22 ng/L. Meanwhile, it displays good selectivity for PCB77 detection due to the specificity and high affinity of aptamer to PCB77. Additionally, the application of the aptasensor was evaluated in real environmental samples.

Ultra-high thermal stability perarylated ionic liquids as gas chromatographic stationary phases for the selective separation of polyaromatic hydrocarbons and polychlorinated biphenyls.

Ionic liquids (ILs) are well-known in the field of separation science for their unique selectivity when used as stationary phases in gas chromatography (GC). While a significant amount of knowledge has been attained in correlating structural features of an IL to separation selectivity, developments in producing IL-based stationary phases suitable for high temperature GC studies have lagged behind. Column bleed is a result of the stationary phase undergoing volatilization/decomposition at high temperatures and is undesirable in separations coupled to GC/MS. It has been well-known that traditional classes of ILs with long alkyl side chain substituents are susceptible to Hofmann elimination at elevated temperatures. In this study, a new class of IL stationary phases containing perarylated cations exhibiting improved thermal stability are introduced. These ILs were used to prepare wall-coated open tubular columns with high column efficiency and produced very low bleed at temperatures up to 350 °C. Their unique chemical structures provide stronger π-π interactions compared to many commercially-available stationary phases. To exploit the unique interactions provided by these stationary phases, the separation of two classes of environmentally hazardous aromatic compounds, namely, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), was examined. Both classes of compounds contain structural isomers with high boiling points that are often challenging to separate. The perarylated sulfonium and phosphonium IL-based stationary phases exhibited excellent thermal stability as well as unique selectivity toward isomers of PAHs as well as toxic PCB analyte pairs.

Enhanced electrokinetic remediation of multi-contaminated dredged sediments and induced effect on their toxicity.

Electrokinetic (EK) remediation is often developed for metal decontamination but shows limitations for polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs) which are nonionic and involve low aqueous solubility. This paper reports many laboratory studies devoted to the investigations of EK efficiency on the mobility and the removal of metals, PAHs and PCBs from dredged sediments, using a mixture of chelating agent and surfactants. The results showed that increasing chelating agent concentration was favorable for both metal and PAH removal. Applying a periodic voltage gradient associated to a low concentration of additives provided the best removal of Zn, Cd and Pb and also the 16 priority PAHs. The tested fresh harbor sediment was highly resistant to metals and organics mobilization and transport because of an aged contamination, a high buffering capacity, a very low hydraulic permeability and a high organic matter content. However, experiments performed on a former sediment which was deposited many years ago provided better removal results, involving low organic matter and carbonates content. The efficiency of the EK process was also assessed by measuring the acute toxicity of the EK-treated sediment on the copepod Eurytemora affinis exposed to sediment elutriates.

Evaluation of selected polychlorinated biphenyls (PCBs) congeners and dichlorodiphenyltrichloroethane (DDT) in fresh root and leafy vegetables using GC-MS.

Persistent organic pollutants (POPs) are dangerous and toxic pollutants that may cause adverse effects on human and animal health, including death. POPs such as polychlorinated biphenyls (PCBs) and pesticides are subtly released into the environment from industrial and agricultural use. Global circulation is due to their trans-boundary transport capacity, contingent on aerodynamic and hydrological properties. Plants have capacity to take-up POPs, and these bio-magnify along heterotrophic transfer pathways. In this study, levels of selected 6-PCB congeners and 3- DDTs in some leaf and root vegetables were investigated. Leaf and root vegetables were collected from different horticultural farms areas in Cape Town. The 6-PCBs and 3-DDTs were recovered from the samples using solid phase extraction(SPE), followed by GC-MS analysis. The ΣPCBs and ΣDDT (on-whole basis), were ranged: 90.9-234 ng/g and 38.9-66.1 ng/g respectively. The 3-PCBs and 6-DDTs levels were slightly higher in leaf vegetables compared to root vegetables. The detection of PCBs and DDTs in the vegetables suggest the probable use of PCBs containing pesticides. Although the observed concentrations were below the WHO maximum residue limits, consumption of such contaminated leaf and root vegetables portend a health risk.

Co- and self-activated synthesis of tailored multimodal porous carbons for solid-phase microextraction of chlorobenzenes and polychlorinated biphenyls.

Highly sensitive solid-phase microextraction (SPME) of broad-spectrum organic micropollutants is a significant challenge due to the limited available pore sizes and pore size distributions (PSDs) of the probes. In this work, we synthesized novel multimodal porous carbons (MPCs) using facile and environment-friendly route for the first time, through direct carbonization of a potassium citrate and calcium citrate mixture. The co-carbonization process formed hierarchical structures with super-high specific surface areas (up to 3270 m2 g-1) and pore volumes (up to 1.79 cm3 g-1). The PSD was easily controlled through adjustment of the mixture ratios of potassium citrate to calcium citrate. Moreover, the MPCs were partly graphitized, and showed great thermal stability (>450 ℃). MPC-coated probes were prepared and applied to extract chlorobenzenes (CBs) and polychlorinated biphenyls (PCBs) with improved performance, higher extraction capacity than commercial carboxen/polydimethylsiloxane probe. Under optimized conditions, a sensitive detection method for CBs and PCBs was developed by a MPC-coated probe coupled with gas chromatography-electron capture detector. Finally, this method was successfully applied to analyze real environmental water samples with satisfactory recoveries (85.56%-104.30%). The findings are expected to broaden our perspectives for improved design of efficient porous materials for broad-spectrum SPME and other applications.

A clean-up method for determination of multi-classes of persistent organic pollutants in sediment and biota samples with an aliquot sample.

In the present study, we developed a novel method to simultaneously detect eight classes of persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), polychlorinated naphthalenes (PCNs), organochlorine pesticides (OCPs), short-chain chlorinated paraffins (SCCPs) and Dechlorane Plus (DP), in sediment and fish tissue samples. The samples were extracted by accelerated solvent extraction (ASE) system, and the extracts were purified and fractionated into fraction1 and fraction2 with multi-layer silica gel column, followed by further fractionation using a basic alumina column (fraction1) and a Florisil column (fraction2), respectively. Finally, fractions were analyzed with different chromatographic columns and different detectors according to the properties of a chemical compound. The limit of detection for eight classes of POPs ranged from 1 to 30 pg/gdw in fish tissue samples, and from 1 to 33 pg/gdw in sediment samples, except for SCCPs (from 5.6 to 7.6 ng/g in fish tissue samples, and from 1.2 to 8.3 ng/gdw in sediment samples). The recoveries of eight classes of POPs spiked in fish tissue and sediment samples ranged from 43% to 120%, and from 45% to 115%, respectively. The relative standard deviation (RSD) was less than 25%. The accuracy of method was satisfactorily demonstrated by analysis of standard reference materials NIST SRM 1649b and WMF-01. In addition, the newly developed method was successfully applied for analysis of sediment and fish samples collected from the Baiyangdian Lake.

Design of a simple and novel photoelectrochemical aptasensor for detection of 3,3',4,4'-tetrachlorobiphenyl.

In view of the urgent need of determining polychlorinated biphenyls in the environment, we developed a highly sensitive and selective photoelectrochemical (PEC) aptasensor for determination of 3,3',4,4'-tetrachlorobiphenyl (PCB77) by immobilizing aptamer on N-doped TiO2 nanotubes (N-doped TiO2 NTs). To improve analytical performance of the PEC sensor, the complementary DNA functionalized CdS quantum dots (DNA-CdS QDs) were introduced onto N-doped TiO2 NTs by hybridization. In addition of PCB77, owing to high affinity of aptamer to PCB77, PCB77-aptamer complexes were formed by being bound of PCB77 whilst DNA-CdS QDs were released from the sensing surface. The complexes with poor conductivity hindered the interfacial electron transfer, leading to the photocurrent decrease. The more important is the release of DNA-CdS QDs enhanced the photocurrent decrease, playing the role of signal amplification. The photocurrent change was utilized to detect PCB77 quantitatively. The PEC aptasensor exhibited excellent analytical performance for detection of PCB77 with wide linear range of 0.1-100 ng/L and a low detection limit of 0.1 ng/L. It manifested outstanding selectivity for PCB77 in control experiments by employing six interferents which had similar structure or coexisted with PCB77. Besides, the PEC aptasensor was used to detect the content of PBC77 in the environment.

Kinetic and thermodynamic studies on partitioning of polychlorinated biphenyls (PCBs) between aqueous solution and modeled individual soil particle grain sizes.

The significance of soil mineral properties and secondary environmental conditions such as pH, temperature, ionic strength and time in the partitioning of eight selected polychlorinated biphenyl (PCB) congeners between aqueous solution and soil particles with different grain sizes was studied. The mineral properties of a model soil sample were determined, and Brunauer-Emmett-Teller (BET) adsorption-desorption isotherms were employed to observe the surface characteristics of the individual modeled soil particles. Batch adsorption experiments were conducted to determine the sorption of PCBs onto soil particles of different sizes. The results revealed that the sorption of PCB congeners onto the soil was dependent on the amount of soil organic matter, surface area, and pore size distribution of the various individual soil particles. Low pH favored the sorption of PCBs, with maximum sorption occurring between pH6.5 and 7.5 with an equilibration period of 8hr. Changes in the ionic strength were found to be less significant. Low temperature favored the sorption of PCBs onto the soil compared to high temperatures. Thermodynamic studies showed that the partition coefficient (Kd) decreased with increasing temperature, and negative and low values of ΔH° indicated an exothermic physisorption process. The data generated is critical and will help in further understanding remediation and cleanup strategies for polluted water.

Metal-organic framework-coated stainless steel fiber for solid-phase microextraction of polychlorinated biphenyls.

For solid phase microextraction (SPME), effective immobilization of sorbent on a stainless steel fiber surface is very essential. But, it still remains challenging because the chemical inertness of stainless steel fiber. In this work, chemical bonding method was introduced to fabricate a series of metal-organic frameworks (MOFs)-coated stainless steel fibers, and some representative MOFs (ZIF-90 (Zn), MOF-199 (Cu), MIL-101 (Cr), MOF-5 (Zn))-coated stainless steel fibers were successfully synthesized. Such strategy can noticeably increase the mechanical and chemical stability, and prolong the service lifetime due to it combine the advantages of stainless steel fiber and chemical bonding method. The stability of MOF-ZIF-90 (Zn)-coated stainless steel fibers which were preparated by different methods (chemical bonding method, adhesive method and deposition method) were studied, and results showed the chemical bonding method proved the best stability. Based on the ZIF-90 (Zn)-coated fiber, the SPME-GC-MS method was developed for detecting traces of polychlorinated biphenyls (PCBs) and satisfactory results were obtained. The linear ranges were 0.01-600 ng L-1 and the coefficient of determination was higher than 0.993. The limits of detection for the PCBs were 0.0013-0.053 ng L-1. The recoveries for the spiked PCBs in the Minjiang water, soil and vegetable oil samples were in the range of 85.9-105.8%. The extraction capacity of the ZIF-90 (Zn)-coated stainless steel fiber prepared by chemical bonding method did not show measurable change under different temperatures or organic solvents for up to 5 days.

Direct immersion solid-phase microextraction analysis of multi-class contaminants in edible seaweeds by gas chromatography-mass spectrometry.

The present work aimed at the development of a simple and accurate direct immersion-solidphase microextraction-gas-chromatography-mass spectrometry (DI-SPME-GC-MS) method for simultaneous determination of PAHs, PCBs, and pesticide residues in edible seaweeds. As the target contaminants possess a wide range of physical-chemical properties, multivariate experimental design was used for method optimization. In particular, two different methods were optimized and validated: one that allows for simultaneous determination of all targets, and an ad hoc method for determination of hydrophobic analytes, a class that often poses a challenge for extraction from food matrices. Optimum conditions suitable for simultaneous quantitation of all targeted compounds, namely buffer at pH = 7.0, 20% acetone (v/v), 10% NaCl (w/w), 0.02% NaN3, 60 min DI extraction at 55 °C, and 20 min desorption at 270 °C, afforded limits of quantitation (LOQs) in the range of 1-30 µg kg-1, a wide linear range of 5-2000 µg kg-1, the attainment of satisfactory determination coefficients (R2˃0.99) with no significant lack of fit (p > 0.05) at the 5% level, and satisfactory accuracy and precision values. By modifying the extraction conditions to favor extraction of the most hydrophobic analytes (e.g. higher amount of organic modifier and pH, and lower salt content) lower LOQs were obtained for these compounds ranging from 0.2 to 13.3 µg kg-1. The established methods were then used for screening of commercial, edible dry seaweeds, with PCBs (≤16.0 ng g-1) and PAHs (≤15.5 ng g-1) detected in some samples. This method overcomes most challenges commonly encountered in dry sample analysis applications, and represents the first report of a DI-SPME method employing the matrix-compatible fiber for simultaneous multiclass and multiresidue analysis of seaweeds.

Aptamer-Functionalized Magnetic Conjugated Organic Framework for Selective Extraction of Traces of Hydroxylated Polychlorinated Biphenyls in Human Serum.

A solid-phase extraction adsorbent based on an aptamer-functionalized magnetic conjugated organic framework (COF) was developed for selective extraction of traces of hydroxylated polychlorinated biphenyls. This material has advantages such as superparamagnetism of the magnetic core, high surface area and porous structure of the COF, and high specific affinity of the aptamer. In combination with HPLC-MS, the aptamer-functionalized magnetic COF was used for the capture of hydroxy-2',3',4',5,5'-pentachlorobiphenyl in human serum. The method provided a linear range of 0.01-40 ng mL-1 with a good correlation coefficient (R2 =0.9973). The limit of detection was as low as 2.1 pg mL-1 . Furthermore, the material showed good reusability and could be applied in at least ten extraction cycles with recoveries greater than 90 %.

Evaluation of ionic liquid gas chromatography stationary phases for the separation of polychlorinated biphenyls.

The feasibility of six ionic liquid- (IL-) based stationary phases for the analysis of environmentally important polychlorinated biphenyls (PCBs) by gas chromatography combined with either electron capture micro-detector (GC-micro-ECD) or quadrupole mass spectrometry (GC-MS, for confirmation) have been evaluated. These IL-based columns showed a separation mechanism different from that observed for other commercial phases, such a low bleed high temperature 8% phenyl (equiv.) polycarborane-siloxane suggested shape-selective phase for non-ortho and mono-ortho-CBs, HT-8, or a polar poly(ethylene glycol), resulting in a different elution order of the 69 investigated PCBs. However, no all phases provided equality satisfactory resolutions for the most environmentally relevant congeners, the 12 toxic and the 7 priority PCBs. From this point of view, the best results were obtained with the SLB-IL76 and SLB-IL59 phases, which showed a number of coelutions for these specific congeners only slightly higher to that observed on HT-8. Interestingly, the SLB-IL59 phase was the only one among the evaluated phases allowing a complete resolution of the most toxic non-ortho substituted congeners # 77, 126 and 169 from all other PCBs investigated. SLB-IL76 and SLB-IL59 also demonstrated a superior chromatographic performance concerning peak symetry, retention time stability and column bleeding, compared to the other four IL-based columns evaluated. Altogether, results obtained for the analysis of pure standards illustrated the potential of, in particular, SLB-IL 59 as an alternative phase for confirmation of the identity of PCBs typically detected in environmental matrices that coeluted on conventional non-polar phases in use for this type of determination. However, the long-term stability and quantitative behaviour of these stationary phases during the analysis of real samples still need to be addressed.

PCB in the environment: bio-based processes for soil decontamination and management of waste from the industrial production of Pleurotus ostreatus.

Polychlorinated biphenyls (PCBs) are hazardous soil contaminants for which a bio-based technology for their recovery is essential. The objective of this study was to validate the exploitation of spent mushroom substrate (SMS), a low or null cost organic waste derived from the industrial production of P. ostreatus, as bulking agent in a dynamic biopile pilot plant. The SMS shows potential oxidative capacity towards recalcitrant compounds. The aim was consistent with the design of a process of oxidation of highly chlorinated PCBs, which is independent from their reductive dehalogenation. Feasibility was verified at a mesocosm scale and validated at pilot scale in a dynamic biopile pilot plant treating ten tons of a historically contaminated soil (9.28±0.08mg PCB/kg soil dry weight). Mixing of the SMS with the soil was required for the depletion of the contaminants. At the pilot scale, after eight months of incubation, 94.1% depletion was recorded. A positive correlation between Actinobacteria and Firmicutes active metabolism, soil laccase activity and PCB removal was observed. The SMS was found to be exploitable as a versatile low cost organic substrate capable of activating processes for the oxidation of highly chlorinated PCBs. Moreover, its exploitation as bulking agent in biopiles is a valuable management strategy for the re-utilisation of an organic waste deriving from the industrial cultivation of edible mushrooms.