Coagulation-centered three-step approach for removing by-product organic pollutants from tetrabromobisphenol A industrial wastewater: Experimental and theoretic investigations.

The challenge of meeting discharge standards for tetrabromobisphenol A (TBBPA) production wastewater, characterized by high concentrations of organic by-products, necessitates effective treatment methods. This study identifies 2,4-dibromophenol, 2,6-dibromophenol, 2,4,6-tribromophenol, chlorobenzene, and toluene as the primary organic by-product pollutants. A coagulation-centered three-step approach was established for TBBPA industrial wastewater treatment. The initial step involves acidification treatment to exploit the reduced solubility of 2,4-dibromophenol, 2,6-dibromophenol, and 2,4,6-tribromophenol under acidic conditions, with the optimal pH determined as 2.7-3.1. An acid-activated montmorillonite coagulant (AMC), prepared through roasting and high-pressure acid leaching, exhibits a distinctive "Core-shell" structure, contributing significantly to the combined coagulation and adsorption mechanism. The acid-soluble aluminum salts in AMC form positively charged flocs, electrostatically attracting negatively charged organic compounds in the wastewater. Simultaneously, the porous insoluble silicon framework displays strong adsorption capacity for pollutants. The removal efficiencies for toluene, chlorobenzene, 2,4-dibromophenol, 2,6-dibromophenol, and 2,4,6-tribromophenol reached 88.2%, 89.1%, 88.8%, 87.1%, and 89.4%, respectively. Elemental analysis reveals that the coloration of the wastewater stems from complexation reactions between phenolic compounds and Fe3+, originating from the corrosion of iron or steel reaction vessel. Post-treatment with cation exchange resin resulted in removal efficiencies of 5.2%, 59.1%, 80.2%, 77.9%, and 88.3% for the five substances, respectively. This study outlines a crucial pathway for the effective purification of TBBPA wastewater.

Occurrence differences of hexachlorobutadiene and chlorobenzenes in road dust and roadside soil media in an industrial and residential mixed area in Eastern China.

The road dust and roadside soil can act as both sinks and sources of hexachlorobutadiene (HCBD) and chlorobenzenes (CBzs), but comparative research on these two adjacent media is extremely limited. In this study, HCBD and CBzs were simultaneously analyzed in road dust and roadside soil samples from an area containing both industrial factories and residential communities in Eastern China. The road dust there was found to have 2-6 times higher contents of HCBD (mean 1.14 ng/g, maximum 6.44 ng/g) and ∑Cl3-Cl6CBzs (22.8 ng/g, 90.6 ng/g) than those in the roadside soil. The spatial distributions of HCBD and CBzs in road dusts were affected by various types of sources, showing no significant discrepancy among the sites. On the contrast, HCBD and CBzs contamination in roadside soils occurring near several factories were strongly correlated to their industrial point sources. Risk assessments showed, at current contamination levels in the road dust and roadside soil, HCBD and CBzs are not likely to induce carcinogenic or non-carcinogenic risks to residents in the studied area. Nevertheless, road dust ingestion, as the major exposure pathway of HCBD and CBzs, should be avoided to reduce the exposure risk. These findings based on the contamination differences between two media provide a new perspective and evidence for screening important sources and exposure pathway of HCBD and CBzs, which would be helpful to their source identification and risk control.

Identification and Quantification of Dimethachlon Degradation Products in Soils and Their Effects on Soil Enzyme Activities.

In this study, high-performance liquid chromatography-high-resolution mass spectrometry (HPLC-HRMS, Q-Exactive Orbitrap) and Compound Discoverer 3.3 were used to screen dimethachlon degradation products in soils. Four metabolites 4-(3,5-dichloroanilino)-4-oxobutanoic acid (DCBAA), 3,5-dichloroaniline (3,5-DCA), succinic acid, and muconic acid were confirmed by primary and secondary ion mass spectrometry comparisons between standards and samples. A quantitative analysis method of dimethachlon residues and four metabolites in soils was developed using HPLC-HRMS. Dimethachlon degradation in agricultural soil indoor unsterilized, sterilized, and field environments in three typical areas was measured. Dimethachlon degraded fast with a half-life of less than 1 day in three nonsterile soils. The maximum DCBAA and 3,5-DCA residues during degradation could reach 22.5-35.2% of the initial concentration of the parent dimethachlon. The metabolite DCBAA had a greater impact on soil enzyme activity than the parent dimethachlon.

[Research and development of an air sampling tube for chlorobenzene compounds and its supporting determination method].

Objective: To establish a GDH-3 air sample tube for simultaneous determination of twelve kinds of chlorobenzene compounds (CBs) in workplace air by gas chromatography. And to established a matching determination method. Methods: In October 2020, the vapor and aerosol CBs in workplace air were collected by GDH-3 air sampling tube, and desorption and elution with 3.00 ml toluene for 15 min, then the solution separated by DB-23 capillary column, and finally detected with microcell electron capture detector. Results: The quantitative determination ranges of twelve isomers of CBs were 0.71×10(-3)-2000.00 mg/L, with the correlative coefficients were 0.99967-0.99998. The minimum detectable concentrations were 0.04-112.63 µg/m(3), and the minimum quantification concentrations were 0.14-375.42 µg/m(3) (15.00 L sample, 3.00 ml sample solution) . The average elution efficiencies were 96.00%-104.00%. The within-run relative standard deviations (RSDs) were 2.54%-6.12%, and the between-run RSDs were 3.85%-7.87%. Sealed samples could be stable at room temperature for at least 15 days. Conclusion: GDH-3 air sample tube can be used for simultaneous determination of twelve kinds of CBs in workplace air by gas chromatography. The established supporting measurement method meets the measurement requirements of the occupational health standard detection method, and the it's suitable for the simultaneous determination of 12 kinds of CBS in the air.

Vis LED Photo-Fenton Degradation of 124-Trichlorobenzene at a Neutral pH Using Ferrioxalate as Catalyst.

Chlorinated organic compounds (COCs) are among the more toxic organic compounds frequently found in soil and groundwater. Among these, toxic and low-degradable chlorobenzenes are commonly found in the environment. In this work, an innovative process using hydrogen peroxide as the oxidant, ferrioxalate as the catalyst and a visible light-emitting diode lamp (Vis LED) were applied to successfully oxidize 124-trichlorobenzene (124-TCB) in a saturated aqueous solution of 124-TCB (28 mg L-1) at a neutral pH. The influence of a hydrogen peroxide (HP) concentration (61.5-612 mg L-1), Fe3+ (Fe) dosage (3-10 mg L-1), and irradiation level (Rad) (I = 0.12 W cm-2 and I = 0.18 W cm-2) on 124-TCB conversion and dechlorination was studied. A D-Optimal experimental design combined with response surface methodology (RSM) was implemented to maximize the quality of the information obtained. The ANOVA test was used to assess the significance of the model and its coefficients. The maximum pollutant conversion at 180 min (98.50%) was obtained with Fe = 7 mg L-1, HP = 305 mg L-1, and I = 0.12 W cm-2. The effect of two inorganic anions usually presents in real groundwater (bicarbonate and chloride, 600 mg L-1 each) was investigated under those optimized operating conditions. A slight reduction in the 124-TCB conversion after 180 min of reaction was noticed in the presence of bicarbonate (8.31%) and chloride (7.85%). Toxicity was studied with Microtox® (Azur Environmental, Carlsbad, CA, USA) bioassay, and a remarkable toxicity decrease was found in the treated samples, with the inhibition proportional to the remaining 124-TCB concentration. That means that nontoxic byproducts are produced in agreement with the high dechlorination degrees noticed.

Taxonomic profiling and functional gene annotation of microbial communities in sediment of river Ganga at Kanpur, India: insights from whole-genome metagenomics study.

The perennial river Ganga is recognized as one of India's largest rivers of India, but due to continuous anthropogenic activities, the river's ecosystem is under threat. Next-generation sequencing technology has transformed metagenomics in the exploration of microbiome and their imperative function in diverse aquatic ecosystems. In this study, we have uncovered the structure of community microbiome and their functions in sediments of river Ganga at Kanpur, India, at three polluted stretches through a high-resolution metagenomics approach using Illumina HiSeq 2500. Among the microbes, bacteria dominate more than 82% in the three polluted sediment samples of river Ganga. Pseudomonadota (alpha, beta, and gamma) is the major phylum of bacteria that dominates in three sediment samples. Genes involved in degradation of xenobiotic compounds involving nitrotoluene, benzoate, aminobenzoate, chlorocyclohexane, and chlorobenzene were significantly enriched in the microbiome of polluted stretches. Pathway analysis using KEGG database revealed a higher abundance of genes involved in energy metabolism such as oxidative phosphorylation, nitrogen, methane, sulfur, and carbon fixation pathways in the sediment metagenome data from the river Ganga. A higher abundance of pollutant degrading enzymes like 4-hydroxybenzoate 3-monooxygenase, catalase-peroxidase, and altronate hydrolase in the polluted microbiome indicates their role in degradation of plastics and dyes. Overall, our study has provided bacterial diversity and their dynamics in community structure and function from polluted river microbiome, which is expected to open up better avenues for exploration of novel functional genes/enzymes with potential application in health and bioremediation.

Comparison of automated mixer-assisted mini-scale liquid-liquid extraction coupled with full evaporation dynamic headspace extraction with United States Environmental Protection Agency methods for the gas chromatography-mass spectrometric analysis of chlorinated benzenes.

Three modes of facilitating mini-scale-liquid-liquid-extraction (msLLE) prior to automated integration with full evaporation dynamic headspace (FEDHS) extraction were evaluated in this work. For msLLE, 1.2 mL of dichloromethane (DCM) was added to a conical-bottomed vial containing 7 mL of aqueous sample. The solution was then subjected to three different mixing modes, namely vortex-assistance (where a "whirlpool" was created in the solution), agitation-assistance (where the vial was rotated in circular motion) and quickMix-assistance (where the vial was shaken at a high speed). Vortex-assistance was performed manually while the other two modes were automated using a commercial autosampler. Following this, the DCM extract was transferred automatically to another vial and was then vaporized and sent through a Tenax TA sorbent tube in the FEDHS step. Due to the stronger π interaction between the sorbent and the analytes of interest, the analytes were selectively concentrated while the DCM vapor passed through unhampered. After FEDHS, the analytes were thoroughly desorbed into a gas chromatography-mass spectrometric system for analysis. The applicability of this procedure was validated in the extraction of six chlorinated benzenes (CBs) (1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzne and hexachlorobenzene) from aqueous samples. The quickMix-assisted msLLE-FEDHS approach achieved good absolute extraction recoveries (between 74.2% and 88.7%), low limits of detection (between 0.0006 and 0.0116 µg/L), good linearity (r2≥0.9920), good repeatability (between 1.9% and 8.4%, and good reproducibility (between 9.0% and 13.6%). It was found to be superior to the methods published by the United States Environmental Protection Agency. Five consecutive fully automated quickMix-assisted-msLLE-FEDHS-GC-MS runs spanned only ca. 4 hr.

Emissions of PAHs, PCDD/Fs, dl-PCBs, chlorophenols and chlorobenzenes from municipal waste incinerator cofiring industrial waste.

Concentrations and distributions of PAHs and chlorinated aromatic compounds including PCDD/Fs, dl-PCBs, chlorophenols (CPs), and chlorobenzenes (CBz) in the municipal waste incinerator are investigated to characterize their formation and emission via intensive stack sampling. In addition, the toxicity of fly ash contribution by PCDD/Fs and dl-PCBs is evaluated in this study. The results reveal that concentrations of PCDD/Fs and dl-PCBs in flue gas are significantly lower than those of CPs, CBz, and PAHs. Additionally, the removal efficiencies of PAHs and chlorinated aromatic compounds achieved with existing air pollution control devices are evaluated, indicating that the removal efficiencies achieved with activated carbon injection + baghouse (95-99%) are higher than those with semi-dry scrubber (SDS). Besides, PCDD/Fs and PCBs TEQ concentrations in SDS and BH ashes are within 1.61-2.66 WHO-TEQ/g and 0.09-0.19 WHO-TEQ/g, respectively. Furthermore, the calculated mass flow rates suggest that the input rate of PCDD/Fs and dl-PCBs of SDS are 60.24 mg/h and 59.74 mg/h, respectively. The mass flow rates of PCDD/Fs and dl-PCBs after SDS in flue gas are 32.47 mg/h and 49.73 mg/h, respectively. However, the discharge rates of PCDD/Fs and dl-PCBs from SDS are 120.60 mg/h and 27.05 mg/h, respectively, indicating that PCDD/Fs are significantly formed within the SDS. PCDD/Fs formation is attributed to the operating temperature of SDS (240 ± 11.5 °C), which is within the temperature window for de novo synthesis. Thus, operating parameters of the APCDs should be optimized to reduce the formation of PAHs and chlorinated aromatic pollutants from MWI.

Deep eutectic solvent dependent carbon dioxide switching as a homogeneous extracting solvent in liquid-liquid microextraction.

A miscible-immiscible deep eutectic solvent (DES) containing monoethanolamine/4-methoxyphenol was used as an extraction solvent in a homogeneous liquid-liquid microextraction (HLLME). The method was used to preconcentrate chlorobenzenes in water samples followed by separating and analyzing them by gas chromatography-mass spectroscopy (GC-MS). A special feature of the new extraction method is that a green miscible solvent was used as an extractant in the HLLME method. The developed extraction technique provided enrichment factors in the range of 13.1-42.1 for extraction from only 1.0 mL of the aqueous sample solution. The effects of various experimental parameters were investigated and optimized. The optimal conditions were as follows: vortex time: 30.0 s, bubbling CO2 gas: 1.0 min, salt concentration: 5.0% w/v, rate and time of centrifuge: 4000.0 rpm and 3.0 min, respectively, and DES volume: 30.0 µL. The limit of detections and the limit of quantifications for the four targeted analytes varied from 0.01-0.15 and 0.025-0.5 µg L-1, respectively. The precision and long-term precision tests for the developed method were found to be less than 11.0%. Two real samples, including toilet air freshener and car perfume, were analyzed. The applied DES in the HLLME method provides a fast means of sample preparation for environmental aqueous sample solutions.

Can we associate environmental footprints with production and consumption using Monte Carlo simulation? Case study with pork meat.

BACKGROUND: Growing population demands more animal protein products. Pork remains one of the traditional and relatively sustainable types of meats for human consumption. In this paper, life-cycle assessment was performed using data from 12 pig farms. In parallel, a survey on the consumption of pork meat products was conducted analyzing responses from 806 pork meat consumers. The study aims to provide a quantitative calculation of six environmental footprints associated with the consumption of pork meat products in Serbia by analyzing data from pig farms and a pork meat consumption survey. RESULTS: Results revealed that pork meat production is responsible for the emission of 3.50 kg CO2e kg-1 live weight, 16.1 MJe kg-1 , 0.151 mg R11e kg-1 , 31.257 g SO2e kg-1 , 55.030 g PO4e kg-1 and 3.641 kg 1.4 dBe kg-1 . Further calculations reveal that weekly emissions of various environmental potentials associated with an average consumer of pork meat products in Serbia are estimated at values of 4.032 kg CO2e week-1 , 18.504 MJe week-1 , 0.17435 mg R11e week-1 , 35.972 g SO2e week-1 and 63.466 g PO4e week-1 . CONCLUSIONS: Results show that, on the one hand, pork products are responsible for environmental production impacts that mainly occur on farms while, on the other hand, consumption is characterized with high meat inclusion rates. As a leverage strategy it is recommended for producers to concentrate on lowering the production impacts rather than trying to reach consumers for sustainability conciseness. © 2020 Society of Chemical Industry.

Determination of pesticide residues in edible snails with QuEChERS coupled to GC-MS/MS.

A QuEChERS multi-residue GC-MS/MS method was developed for determining 160 pesticides in fresh edible snails. The method was validated according to the EU guidance SANTE/12682/2019. Twenty-seven different pesticides were quantified in the 824 samples analysed. Of these, 22.09% contained pesticide residues; in one case six different pesticides. The most frequently quantified pesticides were chlorpyrifos (108 samples), cypermethrin (50), difenoconazole (24), oxyfluorfen (13), lambda-cyhalothrin (12), tetraconazole and azoxystrobin (7). Other pesticides were found in <5 samples. Of the samples containing residues, 154 exceeded the EU legal limit. However, the estimated daily intake of pesticide residues showed that snail consumption does not represent appreciable risks to consumer health.

[Determination of trichlorobenzene in workplace air by solvent desorption gas chromatography].

Objective: To develop a solvent desorption-gas chromatography method for determination of trichlorobenzene in workplace air. Methods: Trichlorobenzene in workplace air were captured by Sampling tube consisting of glass fiber filter and solvent desorption activated carbon and desorbed with carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-electron capture detector. Results: The linear ranges of 1, 2, 3-trichlorobenzene, 1, 2, 4-trichlorobenzene and 1, 3, 5-trichlorobenzene were 12.20-1220.00, 16.60-1660.00 and 14.80-1480.00 µg/L, respectively, and the related coefficients were between 0.99946 to 0.99948. The relative standard deviations (RSD) within the groups of 1, 2, 3-trichlorobenzene, 1, 2, 4-trichlorobenzene and 1, 3, 5-trichlorobenzene were 1.96%-2.68%, 1.73%-2.82% and 1.81%-2.56%, respectively, and the RSD between the groups were 3.27%-4.25%, 2.85%-4.83% and 3.46%-4.43%, respectively. The average recovery efficiencies were 92.4%, 92.0% and 93.6%, respectively. The minimum quantification concentrations were 0.81, 1.53 and 1.18 µg/m(3), respectively (3 ml desorption solution, 15.00 L sample) . The samples could be stored at room temperature for at least 5 days. Conclusion: This method could be used for monitoring of 1, 2, 3-trichlorobenzene, 1, 2, 4-trichlorobenzene and 1, 3, 5-trichlorobenzene in workplace air.

In vitro decontamination efficacy of the RSDL® (Reactive Skin Decontamination Lotion Kit) lotion component against riot control agents: Capsaicin, Mace™ (CN) and CS.

The study examined the degradation of riot control agents (RCAs): 2-chloroacetophenone (CN), 2-chlorobenzalmalononitrile (CS), and capsaicin, using the Reactive Skin Decontamination Lotion Kit (RSDL®) lotion and evaluated the the direct liquid phase reactivity of the RSDL lotion component with each RCA. RSDL lotion was mixed with the selected RCAs at different molar ratios. Reactivity of the active ingredient potassium 2,3-butanedione monoximate (KBDO) with the RCA was observed for one hour. Samples of 10 µL were taken and quenched, analyzed for residual RCA using LC-MS. CN, was degraded at molar ratios of two and above in less than 2 min. At a molar ratio of 1:1 KBDO:CN, ∼90 % of CN was degraded within 2 min, the remaining 10 % residual CN was observed for one hour without any change. CS, degradation of more than 68 % of CS was achieved at 20:1 M ratio of KBDO:CS within 1 h of reaction time. For capsaicin, no degradation was observed regardless of the higher molar ratios of up to 20:1 and longer reaction times of up to one hour. This study provides evaluation of neutralizing action of the RSDL lotion without assessment of the physical removal component by the RSDL Kit.

GC-MS/MS analysis for source identification of emerging POPs in PM2.5.

Emerging POPs have received increasing attention due to their potential persistence and toxicity, but thus far the report regarding the occurrence and distribution of these POPs in PM2.5 is limited. In this study, an extremely sensitive and reliable method, using ultrasonic solvent extraction and silica gel purification followed by gas chromatography coupled with electron ionization triple quadrupole mass spectrometry, was developed and used for the trace analysis of hexachlorobutadiene (HCBD), pentachloroanisole (PCA) and its analogs chlorobenzenes (CBs) in PM2.5 from Taiyuan within a whole year. The limits of detection and limits of quantitation of analytes were 1.14 × 10-4‒2.74 × 10-4 pg m-3 and 3.80 × 10-4‒9.14 × 10-4 pg m-3. HCBD and PCA were detected at the mean concentrations of 3.69 and 1.84 pg m-3 in PM2.5, which is reported for the first time. Based on the results of statistical analysis, HCBD may come from the unintentional emission of manufacture or incineration of chlorinate-contained products but not coal combustion, while O3-induced photoreaction was the potential source of PCA in PM2.5. The temporal distributions of CBs in PM2.5 were closely related to coal-driven or agricultural activities. Accordingly, our study reveals the contamination profiles of emerging POPs in PM2.5 from Taiyuan.

Determination of organochlorine priority substances in fish tissue: Optimisation of the clean-up step balancing removal of lipids with analytes' recovery.

Quality-assessed analytical methods are required to determine organic priority substances (PS) in biota for the monitoring of the water status according to the EU Water Framework Directive. Although the literature describes several analytical methods to determine these substances in fish, discussion about the efficiency of the clean-up procedures to remove the lipids in the final organic extract (and decrease the disturbance of co-extractives at the detection step) is scarce. This work highlights the results of the development of an analytical method for organochlorines in fish tissue focused on the optimisation of the clean-up step in order to obtain a final extract with the lowest amount of lipids. The efficiency of the purification of the final extract was assessed by quantifying the removal of co-extractives gravimetrically, by considering the sensitivity of the gas chromatography-mass spectrometry (GC-MS) method for the analytes and by assessing the analytes' recovery. An analytical method based on accelerated solvent extraction followed by gel permeation chromatography and dual solid phase extraction (as clean-up steps) and quantification via isotope dilution GC-MS was applied to the analysis of seven PS [α-, ß-, γ- and δ-hexachlorocyclohexane (HCH) isomers, pentachlorobenzene (PeCB), hexachlorobenzene (HCB) and hexachlorobutadiene (HCBD)]. A preliminary validation of the method was carried out with satisfactory results for all analytes in terms of intermediate precision (2.9-9.4%, except 11.8% for ß-HCH). Repeatability values were satisfactory for α-, γ-HCH, PeCB and HCB (4.3-6.9%), while the obtained results for ß-, δ-HCH and HBCD showed the need for further optimisation. Trueness was within the target performance (recovery range: 96.0-107.5%) for all analytes except ß- and δ-HCH. Limits of quantification between 0.5 and 3.3 ng/g wet weight were achieved, depending on the analytes. The proposed method can be employed to determine the mentioned PS in fish tissue with up to approximately 6% lipid content. The presented results show the challenges in establishing an analytical method which aims at balancing the required accuracy with the routine applicability (and a minimised impact on the detection system) as needed in the context of environmental monitoring.

Chlorobenzene levels, component distribution, and ambient severity in wastewater from five textile dyeing wastewater treatment plants.

Chlorobenzenes (CBs) present in synthetic dyes are discharged into natural waters during the treatment of textile dyeing wastewater, which may have adverse effects on human and environment. In this study, the existence and removal of 12 CBs in different units of five treatment plants were examined. The ecological risk of CBs in textile dyeing wastewater was assessed by ambient severity (AS) and risk quotients (RQs). The results showed that trichlorobenzene, tetrachlorobenzene, pentachlorobenzene and hexachlorobenzene were ubiquitous in textile dyeing wastewater, and their distribution was similar. In one of the plants, the content of hexachlorobenzene was found to be as high as 9.277 µg/L in the raw water, which was an oil-water mixture. In other plants, there was no significant difference in the content and composition of CBs among influent and effluent suggesting that the conventional wastewater treatment plants cannot improve the existence of them. Monochlorobenzene and dichlorobenzene were not detected, which may have been related to strong volatility, biochemical properties, and weak instrument sensitivity. In the treatment process and effluent, trichlorobenzene is the main pollutant and accounted for 39.51% of all CB. CB removal was found only in the anaerobic system, while the aerobic system did not have the corresponding removal effect on CB and total organic carbon. According to ecological risk assessment, CBs in effluent has not been found the significant potential harm to human health (AS < 1), but posed moderate ecological risk to aquatic ecosystem (RQs > 0.1).

Integrated Assessment of Bioconcentration, Toxicity, and Hazards of Chlorobenzenes in the Aquatic Environment.

The evaluation of bioconcentration, toxicity, and hazard (BTH) of persistent lipophilic organic compounds (LOCs) are generally performed as separate rather than integrated assessments. There are adequate data sets in the literature for chlorobenzenes (CBs) consisting of (a) concentrations in aquatic biota (CB) and water (Cw) in the natural environment, (b) laboratory-derived bioconcentration factors (KB) and field concentration ratios (CR), the field equivalent factor of KB, (c) measured internal lethal concentrations (ILC50) and model estimated ILC50 calculated from KB and lethal concentrations (LC50), and (d) calculated hazard quotients in aquatic biota (HQB) and in water (HQW). However, there have been no integrated studies of those parameter values based on the respective lipid-based parameters (CBL, KBL, CRL, ILC50L, HQBL) performed. This study utilized the lipid-based parameters for CBs; a group of widely occuring, bioaccumulative, and toxic LOCs, and integrated those parameters into a bioconcentration-toxicity-hazard (BTHL) index. The values of the parameters were obtained from selected literature with known lipid contents of the aquatic biota. The results showed that the laboratory derived bioconcentration factors, KBLs, were comparable to the corresponding field based factors, CRLs, and the measured internal lethal concentrations, ILC50L, showed comparable values with the estimated ones. The integrated BTHL index was less than an order of magnitude or moderately acceptable for the assessment of variability, uncertainty, and predictive power of the index. This integrated assessment can be used to support decision making dealing with CBs in specific and LOCs in general, both in regional and global aquatic environments.

First Detections of Dichlorobenzene Isomers and Trichloromethylpropane from Organic Matter Indigenous to Mars Mudstone in Gale Crater, Mars: Results from the Sample Analysis at Mars Instrument Onboard the Curiosity Rover.

Chromatographic analysis of the Cumberland mudstone in Gale crater by the Sample Analysis at Mars (SAM) instrument revealed the detection of two to three isomers of dichlorobenzene. Their individual concentrations were estimated to be in the 0.5-17 ppbw range relative to the sample mass. We also report the first detection of trichloromethylpropane and the confirmation of the detection of chlorobenzene previously reported. Supporting laboratory experiments excluded the SAM internal background as the source of those compounds, thus confirming the organic carbon and chlorine of the newly detected chlorohydrocarbons are indigenous to the mudstone sample. Laboratory experiments also demonstrated that the chlorohydrocarbons were mainly produced from chemical reactions occurring in the SAM ovens between organic molecules and oxychlorines contained in the sample. The results we obtained show that meteoritic organics and tested chemical species (a polycyclic aromatic hydrocarbon, an amino acid, and a carboxylic acid) were plausible organic precursors of the chlorinated aromatic molecules detected with SAM, thus suggesting that they could be among the organic molecules present in the mudstone. Results from this study coupled with previously reported detections of chlorinated aromatics (<300 ppbw) indigenous to the same mudstone highlight that organics can be preserved from the harsh surface conditions even at shallow depth. The detection of new chlorohydrocarbons with SAM confirms that organic molecules should have been available in an environment favorable to life forms, strengthening the habitability aspect of Gale crater.

The geometrical characteristics of nickel-based metal organic framework on its entrapment capability.

Here, a three dimensional nickel-based metal organic framework (MOF) was synthesized via solvothermal and room temperature protocols. In order to study the effects of the synthesis conditions on the physical properties such as pore sizes and shapes of the prepared MOFs, their extraction capabilities were examined. Both MOFs were characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller and thermogravimetric analyses. Brilliant properties such as porous structure, high surface area and considerable thermal stability make them reasonable candidates to be employed as efficient extractive phases. The efficiency of the superior nickel-based MOF was evaluated for headspace needle trap extraction of chlorobenzenes as model compounds in conjunction with gas chromatography-mass spectrometry (GC-MS). The MOF-based extractive phase was conveniently packed in a needle trap device and after extraction, the desorption process was performed via direct insertion of needle into the GC inlet. After optimizing the extraction/desorption conditions, the figures of merit such as linear dynamic range was in the range of 5-1000 ng L-1 (R2 > 0.987) while the limits of detection and quantification values were 2-10 and 6-30 ng L-1, respectively. The intra- and inter-day relative standard deviations for three replicates at the concentration level of 50 ng L-1 were in the range of 7-9% and 9-12%, respectively. The needle-to-needle reproducibility was also found to be in the range of 5-11%. Acceptable relative recovery values at the concentration level of 50 ng L-1 ranged from 85 to 96%, showing no significant matrix effect.

Effective biodegradation of pentachloronitrobenzene by a novel strain Peudomonas putida QTH3 isolated from contaminated soil.

To eliminate pentachloronitrobenzene (PCNB) residue in PCNB-contaminated environment, the degradation potential of Pseudomonas putida QTH3 to PCNB was evaluated in this study. Peudomonas putida QTH3 could grow well in mineral salt medium (MSM) containing PCNB as sole carbon and was able to degrade PCNB efficiently, whereas the degradation rate of P. putida QTH3 to PCNB increased gradually, and reached 49.84% in 35 days. The degradation rates of P. putida QTH3 to 13 tested organochlorine compounds found to be 10.85%-42.51% after 14 days. The metabolites during PCNB biodegradation by P. putida QTH3 were identified as catechol, 2, 3, 5, 6-tetrachloroaniline (TCA), 2, 3, 4, 5- TCA, 2, 3, 4, 5, 6-pentachloroaniline (PCA) and pentachlorothioanisole (PCTAs). Furthermore, possible degradation pathway of PCNB by P. putida QTH3 was proposed. The degradation rates of intracellular enzyme and extracellular enzyme were 44.73% and 8.93% after incubation with 100 mg L-1 PCNB for 30 min, respectively. Thus, intracellular enzyme is a major enzyme responsible for PCNB degradation. The results indicate that P. putida QTH3 can be a suitable organism for the degradation of PCNB, and facilitate its potential for the bioremediation of the environments contaminated with major organochlorine compounds used during this study.