Performance evaluation of Anaerobic-Aerobic Hybrid Baffled Reactor Coupled with an Anaerobic Filter treating Landfill Leachate.

The Anaerobic Baffled Reactor (ABR) is an effective solution for landfill leachate treatment using an anaerobic fermentation process, which helps to reduce operating costs and sludge volume. To better understand the biological, chemical, and physical processes involved, especially when combining the ABR with an aerobic component, the study aimed to investigate the performance of an Anaerobic-Aerobic Hybrid Baffled Reactor (AABR) that includes an Anaerobic Filter (AF) for treating landfill leachate. This research utilized two glass reactors. The first reactor, designated as AABR-AF, consisted of six independent rectangular glass chambers arranged side by side. The third and sixth chamber designed for aerobic treatment and AF, respectively. The second reactor was used as a control reactor and did not include any aerobic chamber. The highest Removal Efficiencies (REs) for turbidity, COD, BOD, TP, TKN, nitrate, TOC, and TSS in the AABR-AF and ABR-AF were found to be (65.4% and 56.3%), (98.3% and 94.1%), (98.1% and 93.2%), (86.4% and 65%), (89.2% and 76.7%), (81.2% and 64.4%), (88.2% and 79.4%), and (72.4% and 68.5%), respectively. These optimal REs were achieved at an HRT of 48 h and an OLR of 10 kg/m3.d. Also, the highest and the lowest REs in Heavy Metals (HMs) were 89.57% for manganese in AABR-AF and 6.59% for nickel in ABR-AF, in an OLR of 10 kg/m3.d, respectively. The effective removal of Organic Matters (OMs) from landfill leachate using the AABR-AF and ABR-AF was found to be strongly influenced by HRT and OLR. The AABR-AF configuration, featuring a single aerobic chamber in the reactor, exhibited a higher efficiency in removing OMs compared to the ABR-AF configuration.

Evaluation of Azolla filiculoides potential in pyrene and phenanthrene accumulation and phytoremediation in contaminated waters.

Polycyclic aromatic hydrocarbons (PAHs) are a serious threat to the health of the environment. This study investigated the potential of Azolla filiculoides for the uptake, accumulation, and biodegradation of phenanthrene and pyrene. A- filiculoides plants were treated with 10 and 30 mg L-1 concentrations of phenanthrene and pyrene for the experimental duration of ten days. Phenanthrene and pyrene concentrations were measured using the high-performance liquid chromatography (HPLC) technique. Identification of the intermediate by-products resulting from the biological degradation of PAHs was performed by gas chromatography-mass spectrometry (GC/MS). The quantities of phenanthrene and pyrene in the ten-day treatments with 10 and 30 mg L-1 were 0.007 and 0.011 mg g-1 FW, and 0.048 and 0.079 mg g-1 FW, respectively. The growth parameters in the plants such as fresh weight, dry weight and RFN as well as the content of photosynthetic pigment of the plant decreased significantly compared to the control sample (p < 0.05). Ten compounds were identified from the plant tissue during the decomposition of pyrene and phenanthrene, and none of the PAHs were identified in the aquatic environment. Therefore, the use of A-filiculoides for phytoremediation of water resources contaminated with PAHs is an effective and promising method.

This study estimated the efficiency of Azolla filiculoides phytoremediation in the uptake, accumulation and biodegradation of phenanthrene and pyrene in polluted waters as a total of 100%. High accumulation of pyrene and phenanthrene in the plant tissue decreased plant growth and the number of photosynthetic pigments. GC-MS analysis, identified ten by-products resulting from the degradation of pyrene and phenanthrene in A-filiculoides plant tissue. HPLC analysis showed that there are no substances of PAHs in the water environment.

Global review, meta-analysis and health risk assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in chicken kebab using Monte Carlo simulation method.

The primary concern with Polycyclic Aromatic Hydrocarbons (PAHs) is their harmful effects on health, including the risk of causing cancer. This study aimed to investigate the occurrence and concentration of 16 priority PAHs (PAH16) in chicken kebabs using a systematic review approach with meta-analysis. Additionally, the study estimated the possible risk assessment of the potential carcinogenic and non-carcinogenic effects of PAHs on consumers of chicken kebabs using the Monte Carlo simulation (MCS) method. The researchers collected data on the concentration of PAHs in chicken kebabs (grilled, smoked, roasted, or barbecued) from 99 original articles searched in the Web of Science, PubMed, Scopus, Science Direct, and Google Scholar databases from 2012 to April 2022. The concentration of PAHs was then analyzed using meta-analysis, and the Monte Carlo simulation (MCS) was used to evaluate the associated human health risks. The analysis showed that 68.6%, 21.1%, 7.1%, and 3.2% of chicken kebabs were prepared by grilling, smoking, barbecuing, and roasting, respectively. The meta-analysis and health risk assessment indicated that the mean values of HQ (hazard quotient) in Bap, Ace, Acy, Pyr, Flt, Flr, Nap, and Ant PAHs were 1.64, 1.38 × 10^-2, 1.10 × 10^-1, 1.09 × 10^-1, 2.55 × 10^-2, 1.60 × 10^-1, 8.13 × 10^-1, and 6.20 × 10^-3, respectively. Additionally, the mean values of LTCR (Incremental Lifetime Cancer Risk) in Bap, Ace, Acy, Pyr, Flt, Flr, Nap, and Ant were 4.85 × 10^-10, 8.06 × 10^-13, 6.65 × 10^-12, 3.23 × 10^-12, 1.01 × 10^-12, 6.38 × 10^-12, 1.62 × 10^-11, and 6.20 × 10^-3, respectively. The consumption of chicken kebabs prepared by barbecuing was found to be associated with an increased risk of cancer due to the formation of carcinogenic compounds, including benzo[a]pyrene (BaP). However, the non-cancer risk ratio of consuming grilled chicken other than BaP was found to be less than 1 (HQ < 1), indicating that there is no risk of carcinogenesis caused by PAHs from the consumption of chicken kebabs worldwide. The calculated values of the LTCR caused by PAHs in the consumption of chicken kebab throughout life were compared to the maximum acceptable risk value suggested by the EPA, which in the strictest case equals one cancer case per 10,000 people. The results indicate that there is no risk of carcinogenesis caused by PAHs due to the consumption of chicken kebab worldwide.

The Adsorption and Degradation of 2, 4-D Affected by Soil Organic Carbon and Clay.

More has yet to be indicated on the adsorption and degradation processes, determining herbicides recycling in the environment. The sorption and degradation of 2, 4-D, affected by organic carbon (1.92-2.81%), soil clay (20-30%) and pH of the citrus orchards of Mazandaran province, Iran was investigated using HPLC equipped with UV detector for the identification and quantification of soil 2, 4-D. The adsorption (kd) and degradation (Kdeg) coefficients were determined using Freundlich and the first-degree kinetic equations. Gardens C (2.45 mL g-1), and B (0.3 mL g-1), with the highest (8.2 g day-1) and least (2.7 g day-1) degradation coefficients, had the highest and lowest Kd values. Kd variations with pH indicated higher adsorption of 2, 4-D in acidic pH. Due to the high presence of functional groups and soil biological activities, organic carbon affected the adsorption and degradation rates more effectively, which is of economic and environmental significance.

Variability of TOC and DBPs (THMs and HAA5) in drinking water sources and distribution system in drought season: the North Iran case study.

The aim of this study is tracing seasonal variability of total organic carbon (TOC), trihalomethanes (THMs) and haloacetic acids (HAA5) as disinfection by-products (DBPs) in drinking water sources and the distribution system in the north of Iran. The results showed that the concentrations of TOC were within the range of 0.013-1.42 mg/L. In addition, the results showed that most of the water sources had nearly the same concentration level (i.e. <1 mg/L), with the exception of one peak for groundwater source and middle drinking water distribution system in the city of Sari (1.42 mg/L) and Babol (1.37 mg/L). It was demonstrated that brominated HAA (MBAA) presented the highest concentration in the Sari City (17.3 µg/L) followed by the City of Behshahr (8.9-11.19 µg/L). The Babol City showed the highest concentration of chlorinated HAA (22.403 and 22.503 µg/L for DCAA and TCAA, respectively). Among the different compounds of THMs, the concentration of CHBr3 was nearly in the same order of magnitude in the cities of Sari, Babol and Behshahr for both spring and summer seasons. The brominated THM (BDCM) concentrations were also high (14.7 µg/L) in the Behshahr City. The results of independent t-test indicated that the seasonal (spring and summer) difference was statistically significant in the case of temperature and TTHM (p < 0.05). Furthermore, total HAA5 ≤ 60 µg/L and THM ≤100 µg/L in all the considered cities over the period of the study. The TTHMs concentration was 56 µg/L in treating surface water (TSW) source in the summer season at the Sari city.

Performance of photocatalytic ozonation process for pentachlorophenol (PCP) removal in aqueous solution using graphene-TiO2 nanocomposite (UV/G-TiO2/O3).

The aim of this study was to evaluate the efficiency of photocatalytic ozonation process using graphene-dioxide titanium nanocomposite in removing Pentachlorophenol (PCP) from aqueous solutions. In this study, nanocomposites with graphene to TiO2(G/T) ratios of 1:10 and 1:20 were synthesized by hydrothermal method, and its characteristics were assessed using various analyses, SEM, XRD, FTIR, TEM, BET and TGA. In this process, the effects of parameters including O3 concentration (0.25-1.25 mg/L), nanocomposite concentration (50-500 mg/L), initial PCP concentration (10-100 mg/L), and time (10-60 min), were studied. The results showed that PCP removal efficiency was increased by decreasing solute concentration. Increasing nanocomposite dose to 100 mg/L was led to an increase in efficiency (99.1%), but then a decreasing trend was observed. Increasing the concentration of ozone, up to specific value, also enhanced the efficiency but then had a negative effect on process efficiency. Furthermore, the optimum ratio of the catalyst was determined to be 1:20. The highest efficiency of the process for initial pentachlorophenol concentration of 100 mg/L was obtained 98.82% in optimum conditions (catalyst dose of 100 mg/L and 60 min). It is concluded that the photocatalytic ozonation process using graphene-dioxide titanium nanocomposite had the highest efficiency in removal and mineralization of PCP.

Determination of Bortezomib in API Samples Using HPLC: Assessment of Enantiomeric and Diastereomeric Impurities.

A new, normal phase high performance liquid chromatography (NP-HPLC) method was developed for separation of Bortezomib (BZB) enantiomers and quantitative determination of (1S,2R)-enantiomer of BZB in active pharmaceutical ingredient (API) samples. The developed method was validated based on International Conference on Harmonisation (ICH) guidelines and it was proved to be accurate, precise and robust. The obtained resolution (RS) between the enantiomers was more than 2. The calibration curve for (1S,2R)-enantiomer was found to be linear in the concentration range of 0.24-5.36 mg/L with regression coefficient (R2) of 0.9998. Additionally, the limit of detection (LOD) and limit of quantification (LOQ) were 0.052 and 0.16 mg/L, respectively. Also, in this study, a precise, sensitive and robust gradient reversed-phase HPLC (RP-HPLC) method was developed and validated for determination of BZB in API samples. The detector response was linear over the concentration range of 0.26-1110.5 mg/L. The values of R2, LOD and LOQ were 0.9999, 0.084 and 0.25 mg/L, respectively. For both NP-HPLC and RP-HPLC methods, all of the RSD (%) values obtained in the precision study were <1.0%. System suitability parameters in terms of tailing factor (TF), number of theoretical plates (N) and RS were TF < 2.0, N > 2,000 and RS > 2.0. The performance of two common integration methods of valley to valley and drop perpendicular for drawing the baseline between two adjacent peaks were investigated for the determination of diastereomeric impurity (Imp-D) in the BZB-API samples. The results showed that the valley to valley method outperform the drop perpendicular method for calculation of Imp-D peak areas. Therefore, valley to valley method was chosen for peak integration.

Membrane protected conductive polymer as micro-SPE device for the determination of triazine herbicides in aquatic media.

A micro-SPE technique was developed by fabricating a rather small package including a polypropylene membrane shield containing the appropriate sorbent. The package was used for the extraction of some triazine herbicides from aqueous samples. Solvent desorption was subsequently performed in a microvial and an aliquot of extractant was injected into GC-MS. Various sorbents including aniline-ortho-phenylene diamine copolymer, newly synthesized, polypyrrole, multiwall carbon nanotube, C18 and charcoal were examined as extracting media. Among them, conductive polymers exhibited better performance. Influential parameters including extraction and desorption time, desorption solvent and the ionic strength were optimized. The developed method proved to be rather convenient and offers sufficient sensitivity and good reproducibility. The detection limits of the method under optimized conditions were in the range of 0.01-0.04 ng/mL. The RSDs at a concentration level of 0.1 ng/mL were obtained between 4.5 and 9.3% (n=5). The calibration curves of analytes showed linearity in the range of 0.05-10 ng/mL. The developed method was successfully applied to the extraction of selected triazines from real water samples. The whole procedure showed to be conveniently applicable and quite easy to manipulate.

An interior needle electropolymerized pyrrole-based coating for headspace solid-phase dynamic extraction.

A headspace solid-phase dynamic extraction (HS-SPDE) technique was developed by the use of polypyrrole (PPy) sorbent, electropolymerized inside the surface of a needle, as a possible alternative to solid-phase microextraction (SPME). Thermal desorption was subsequently, employed to transfer the extracted analytes into the injection port of a gas chromatography-mass spectrometry (GC-MS). The PPy sorbent including polypyrrole-dodecyl sulfate (PPy-DS) was deposited on the interior surface of a stainless steel needle from the corresponding aqueous electrolyte by applying a constant deposition potential. The homogeneity and the porous surface structure of the coating were examined using the scanning electron microscopy (SEM). The developed method was applied to the trace level extraction of some polycyclic aromatic hydrocarbons (PAHs) from aqueous sample. In order to enhance the extraction efficiency and increase the partition coefficient of analytes, the stainless steel needle was cooled at 5 degrees C, while the sample solution was kept at 80 degrees C. Optimization of influential experimental conditions including the voltage of power supply, the time of PPy electrodeposition, the extraction temperature, the ionic strength and the extraction time were also investigated. The detection limits of the method under optimized conditions were in the range of 0.002-0.01 ng mL(-1). The relative standard deviations (R.S.D.) at a concentration level of 0.1 ng mL(-1) were obtained between 7.54 and 11.4% (n=6). The calibration curves of PAHs showed linearity in the range of 0.01-10 ng mL(-1). The proposed method was successfully applied to the extraction of some selected PAHs from real-life water samples and the relative recoveries were higher than 90% for all the analytes.

A novel sol-gel-based amino-functionalized fiber for headspace solid-phase microextraction of phenol and chlorophenols from environmental samples.

A novel amino-functionalized polymer was synthesized using 3-(trimethoxysilyl) propyl amine (TMSPA) as precursor and hydroxy-terminated polydimethylsiloxane (OH-PDMS) by sol-gel technology and coated on fused-silica fiber. The synthesis was designed in a way to impart polar moiety into the coating network. The scanning electron microscopy (SEM) images of this new coating showed the homogeneity and the porous surface structure of the film. The efficiency of new coating was investigated for headspace solid-phase microextraction (SPME) of some environmentally important chlorophenols from aqueous samples followed by gas chromatography-mass spectrometry (GC-MS) analysis. Effect of different parameters influencing the extraction efficiency such as extraction temperature, extraction time, ionic strength and pH was investigated and optimized. In order to improve the separation efficiency of phenolic compounds on chromatography column all the analytes were derivatized prior to extraction using acetic anhydride at alkaline condition. The detection limits of the method under optimized conditions were in the range of 0.02-0.05ngmL(-1). The relative standard deviations (R.S.D.) (n=6) at a concentration level of 0.5ngmL(-1) were obtained between 6.8 and 10%. The calibration curves of chlorophenols showed linearity in the range of 0.5-200ngmL(-1). The proposed method was successfully applied to the extraction from spiked tap water samples and relative recoveries were higher than 90% for all the analytes.

Modified solvent microextraction with back extraction combined with liquid chromatography-fluorescence detection for the determination of citalopram in human plasma.

A modified solvent microextraction with back extraction method (SME/BE) combined with high performance liquid chromatography and fluorescence detection (HPLC-FD) was developed for the determination of citalopram in human plasma. Extraction process was performed in a home-made total glass vial without using a teflon ring, usually employed in SME/BE. Citalopram was first extracted from 0.5 mL of plasma, modified with sodium hydroxide, into hexane. Back extraction step was then performed into 5.2 microL of 45 mM ammonium formate solution (pH 4) using a GC microsyringe. The extract was subsequently transferred into a liner-like vial and then injected into the HPLC system. An enrichment factor of 150 along with a good sample clean-up was obtained. The calibration curve showed linearity in the range of 1.0-130.0 ng mL(-1) with regression coefficient corresponding to 0.992. This range covers therapeutic window and even lower amounts which is important in pharmacokinetic studies. Limits of detection and quantification, based on a signal to noise ratio (S/N) of 3 and 10, were 0.3 and 0.8 ng mL(-1), respectively. The method was also applied for the determination of citalopram in plasma samples after oral administration of 40 mg single dose of citalopram.

Hydrocarbon degradation by thermophilic Nocardia otitidiscaviarum strain TSH1: physiological aspects.

Indigenous thermophilic hydrocarbon degraders are of special significance for the bioremediation of oil-contaminated desert soils with ambient temperature of 45-50 degrees C. The first objective of this study was to demonstrate the hydrocarbon-degrading capability of Nocardia otitidiscaviarum TSH1 (DSM 45,036) which grows optimally at 50 degrees C. Analysis of the metabolic profile of the strain TSH1 showed that it could metabolize phenol, intermediate-chain-length n -alkanes and some polycyclic aromatic hydrocarbons (PAHs) ranging in size from two to four fused rings efficiently, but not toluene and xylene. N. otitidiscaviarum TSH1 was able to survive and grow at phenol concentrations up to 875 mg l(-1). For the first time, the physiological response of a thermophilic Nocardia strain to poorly available hydrophobic compounds was also investigated. When grown on a mineral salt medium with hexadecane, N. otitidiscaviarum TSH1 showed very high affinity for the organic phase. Additionally, PAH-grown cells were considerably hydrophobic. The capacity of PAH-utilizing N. otitidiscaviarum TSH1 isolate to produce biosurfactants was also investigated. Fatty acids (C(14)-C(18)) were detected by GC-MS analysis during bacterial growth in PAH supplemented mineral media. High cell surface hydrophobicity and capability of N. otitidiscaviarum TSH1 to degrade different hydrocarbons at 50 degrees C may make it an ideal candidate to treat oil-contaminated desert soils.

An aniline-based fiber coating for solid phase microextraction of polycyclic aromatic hydrocarbons from water followed by gas chromatography-mass spectrometry.

A fiber coating from polyaniline (PANI) was electrochemically prepared and employed for solid phase microextraction (SPME) of some polycyclic aromatic hydrocarbons (PAHs) from water samples. The PANI film was directly electrodeposited on the platinum wire surface in sulfuric acid solution using cyclic voltammetry (CV) technique. The applicability of this coating was assessed employing a laboratory-made SPME device and gas chromatography with mass spectrometry (GC-MS) for the extraction of some PAHs from the headspace of aqueous samples. Application of wider potential range in CV led to a PANI with more stability against the temperature. The homogeneity and the porous surface structure of the film were examined by the scanning electron microscopy (SEM). The study revealed that this polymer is a suitable SPME fiber coating for extracting the selected PAHs. Important parameters influencing the extraction process were optimized and an extraction time of 40 min at 40 degrees C gave maximum peak area, when the aqueous sample was added with NaCl (20%, w/v). The synthesis of the PANI can be carried out conveniently and in a reproducible manner while it is rather inexpensive and stable against most of organic solvents. The film thickness of PANI can be precisely controlled by the number of CV cycles. The resulting thickness was roughly 20 microm after 20 cycles. At the optimum conditions, the relative standard deviation (RSD) for a double distilled water spiked with selected PAHs at ppb level were 8.80-16.8% (n = 3) and detection limits for the studied compounds were between 0.1-6 pg mL(-1). The performance of PANI was, also, compared with a commercial solid coated-based SPME fiber, carbowax/divinylbenzene (CW/DVB), under similar experimental conditions.