High Concentrations Of Phenol Research Articles

Allelopathic Effects of Cannabis sativa L. Aqueous Leaf Extracts on Seed Germination and Seedling Growth in Durum Wheat and Barley

In this study, the allelochemical-induced effects of the leaf water extract of hemp (Cannabis sativa) on seed germination and seedling growth were investigated in durum wheat (Triticum durum) cv. Mongibello and barley (Hordeum vulgare) cv. Alamo. The seeds were imbibed in 25%, 50%, 75%, or 100% solution concentrations, obtained from a 2% hemp leaf extract, and they were germinated at 20 and 10 °C. The 2% extract stock solution (i.e., 100% solution concentration) was obtained by extracting 20 g of leaf powder in 1 L distilled water (2%, w/v). A control of seeds imbibed in distilled water was considered. Germination was scored daily and at the end of the germination test, the final germination percentage (FGP), mean germination time (MGT), germination index (GI), and vigor index (VI) were calculated. The radicles and shoots of the germinated seeds of both species were also measured for their length and weight. The analyses revealed the presence of phenols in the hemp leaf extract, which were the highest in the 100% concentration (13.14 ± 0.20 mg gallic acid equivalent-GAE g−1 extract). At 20 °C, increasing the concentration had either minor (in wheat) or no effects (in barley) on the seed germination. At 10 °C, the germination was reduced by the increasing concentration, suggesting a potential allelopathic effect of the extract. However, at 100% concentration, the seeds germinated significantly better that those at 75% concentration. At 20 °C, increasing concentration progressively depressed both the radicle and shoot elongation in both species. At 10 °C, the radicle elongation was depressed by the extract, irrespective of the concentration, whilst the shoots were as long as those of the control in wheat, and smaller at the 50 and 75% concentrations in barley. We can conclude that the water extract of hemp leaves can have a negative impact on wheat and barley seed germination and seedling growth, particularly at temperatures below optimal. However, the high concentration of phenols in the extract may stimulate seed germination and seedling growth. Thus, in semi-arid areas, such as those of the Mediterranean regions, sowings of wheat and barley after hemp at an optimal (i.e., 20 °C) or nearly optimal temperature are recommended in order to minimize the combined stressing effects of the temperature and allelopathic leaf extract upon plant establishment, which may limit a successful crop establishment.

Characterization and Biodegradation of Phenol by Pseudomonas aeruginosa and Klebsiella variicola Strains Isolated from Sewage Sludge and Their Effect on Soybean Seeds Germination.

Phenols are very soluble in water; as a result, they can pollute a massive volume of fresh water, wastewater, groundwater, oceans, and soil, negatively affecting plant germination and animal and human health. For the detoxification and bioremediation of phenol in wastewater, phenol biodegradation using novel bacteria isolated from sewage sludge was investigated. Twenty samples from sewage sludge (SS) were collected, and bacteria in SS contents were cultured in the mineral salt agar (MSA) containing phenol (500 mg/L). Twenty colonies (S1 up to S20) were recovered from all the tested SS samples. The characteristics of three bacterial properties, 16S rDNA sequencing, similarities, GenBank accession number, and phylogenetic analysis showed that strains S3, S10, and S18 were Pseudomonas aeruginosa, Klebsiella pneumoniae, and Klebsiella variicola, respectively. P. aeruginosa, K. pneumoniae, and K. variicola were able to degrade 1000 mg/L phenol in the mineral salt medium. The bacterial strains from sewage sludge were efficient in removing 71.70 and 74.67% of phenol at 1000 mg/L within three days and could tolerate high phenol concentrations (2000 mg/L). The findings showed that P. aeruginosa, K. pneumoniae, and K. variicola could potentially treat phenolic water. All soybean and faba bean seeds were germinated after being treated with 250, 500, 750, and 1000 mg/L phenol in a mineral salt medium inoculated with these strains. The highest maximum phenol removal and detoxification rates were P. aeruginosa and K. variicola. These strains may help decompose and detoxify phenol from industrial wastewater with high phenol levels and bioremediating phenol-contaminated soils.

Synergistic effects of simultaneous coupling ozonation and biodegradation for coking wastewater treatment: Advances in COD removal, toxic elimination, and microbial regulation

Coking wastewater contains high concentrations of cyanide, phenols, pyridine, quinoline, and polycyclic aromatic hydrocarbons. Its high toxicity and low biodegradability leads to long hydraulic retention time of biological process and high cost of advanced oxidation process. In this study, the simultaneous combination of ozonation and biodegradation (SCOB) was proposed to treat coking wastewater. Through this process, ozonation breaks the refractory organics, and the biodegradable intermediates are rapidly mineralized by microorganisms protected by porous carriers. Thus, the performances of SCOB, individual biodegradation and ozonation systems were compared. The long-term stability of the SCOB system was evaluated, the contributions of ozonation and biodegradation were analyzed, and their synergistic mechanisms were elaborated. Results showed that biological activity was inhibited in the biodegradation system, and chemical oxygen demand (COD) removal was only 27.6% for the ozonation system. COD and total phenol removal of SCOB system reached 48.5% and 79.3%, respectively, and its kinetic degradation constant of COD was 55.6% higher than that of the ozonation system. Ozonation contributed to the oxidation of organics with unsaturated functional groups as well as soluble microbial products (SMPs), causing the effluent toxicity and chroma to decrease by 82.7% and 270 times, respectively. The higher abundances of microorganisms and functions were enriched in the core of carrier, which became dominant region for biodegradation. Consequently, COD removal of the SCOB system stabilized at >80% for real coking wastewater treatment, confirming its promising potential for the treatment of highly polluted industrial wastewater.

Avocado ( Persea americana Mill.) Seed Extract Cream 10% Inhibited The Increase MMP-12 Enzyme Levels And Elastosis In UVA Exposed Hairless Male Wistar Rats Skin

Background: Skin is the main target of environmental influences, especially chronic exposure to the suns UVA rays which will result in wrinkling, decreased skin elasticity, the appearance of loose skin, and a rough clinical appearance. In the dermal tissue, not only affects collagen fibers but also degradation of elastin fibers occurs through an increase in the MMP-12 enzyme levels called photoaging and is characterized by the accumulation of dystrophic elastin fibers throughout the dermal tissue in a process called Elastosis. Avocado seed (Persea americana Mill.) is a part of the fruit that contains high concentrations of flavonoids, phenols, and tannins, it has the potential as a powerful antioxidant. The aim of the present study is to evaluate the effectiveness of avocado (Persea americana Mill.) seed extract cream 10% inhibiting the increase in MMP-12 enzyme levels and elastosis in hairless male Wistar rats (Rattus norvegicus) which were exposed to ultraviolet A rays. Methods: A Randomized post-test-only control group design was conducted among 30 male Wistar rats for 10 consecutive days. They were divided into 3 groups as follows: group (K) as the negative control without any intervention, group (P1) with UVA rays exposure, and group (P2) with application of avocado (Persea americana Mill.) seed extraxt cream 10% and UVA rays exposure. The UVA dosage used is 5J/cm2 twice a day among P1 and P2 groups. Avocado (Persea americana Mill.) seed extract 10% was applied to the hairless Wistar rats 4 hours after the exposure of UVA rays. MMP-12 was calculated with Rat MMP-12 ELISA Test. Elastin fiber density was calculated by Imageraster software. Statistical analysis was carried out using SPSS version 25 in measure means, normality test, homogeneity test, and comparative test. Results: The results showed that the average MMP-12 enzyme level in the 10% avocado seed cream (P2) group 18.138 ± 0.168% was significantly different from the (K) group 1.073 ± 0.1553% as the negative control and the (P1) group 33.454 ± 1.068%. The mean density of elastin fiber in the cream of avocado seed extract group (P2) 12.42 ± 3.672% was significantly different from the group (K) 20.08 ± 4.994% and group (P1) 26.30 ± 6.822%. Comparative analysis using the Kruskal Wallis test for MMP-12 and the One Way Annova test for elastin fibers showed a p-value of < 0.05, thus indicating a significant difference between groups after treatment. The Least Significance Difference (LSD) test showed that there was a significant difference between the cream of avocado seed extract (P2) group and the other groups (p<0.05). Conclusions: The administration of avocado seeds (Persea americana Mill.) extract cream 10% effectively inhibits the increase in MMP-12 enzyme levels and elastosis in hairless male Wistar rat skin which was exposed to ultraviolet A irradiation.

Dual Role of Plant Phenolic Compounds as Antioxidants and Prooxidants

Natural phenolic compounds are secondary metabolites found in a wide range of plants including food crops. As many of them are known to be antioxidants and can prevent several chronic and degenerative diseases in humans, they are a part of a healthy diet. However, these antioxidants can act as prooxidants under high phenolic concentration, high pH, or in the presence of transition metal ions such as Cu2+ or Fe3+, producing reactive oxygen species (ROS) including hydroxyl radicals resulting in oxidative stress and cell toxicity. While this can lead to pathogenesis including the development of various types of cancers, elevated levels of ROS are beneficial to kill malignant cells and foodborne pathogens to improve food safety. Thus, the dual nature of phenolic compounds allows them to act as antioxidants and prooxidants. Similarly, depending on the level of prooxidant activity, ROS can induce either pathogenesis or serve as a potential agent to kill malignant cells and foodborne pathogens.

GC/MS analiza otpadnih ulja i njihova karakterizacija

Waste oils are dangerous waste, because they can contain high concentrations of metals, hydrocarbons, PAHs, chlorinated compounds, phenols and other substances that come from additives and are created as a result of the operation of different types of engines. This type of waste can cause major problems and contamination of the environment, both soil and water, if they are not treated in the right way and they are wasted. Their identification and further characterization as hazardous waste according to the waste regulations of the Republic of Serbia - Rulebook on categories, testing and classification of waste ("Official Gazette of the RS" no. 56/2010, 93/2019, 39/2021) and Rulebook on the conditions, method and procedure of waste oil management ("Official Gazette of the RS", no. 71/2010). In this paper, GC/MS analysis of different types of waste oils (engine, hydraulic, machine, mineral non-chlorinated oil, synthetic oil) was performed. The obtained chromatograms were compared with the chromatogram of the standard (Dr. Ehrenstorfer) which contains the same ratio of diesel oil and mineral oil without additives. In this way, the analysis of the so-called "fingerprint" and characterization for different types of waste oils was performed, which is very important for comparison with analysis of oil in natural samples (water, soil) in order to determine the original source of pollution.

Leaf manganese and phenolics as proxies of soil acidification and phosphorus acquisition mechanisms in lentil cultivars on alkaline soil.

Leaf manganese (Mn) concentration has been used as a proxy for root exudation and phosphorus (P) uptake under controlled conditions, but there are limited field studies that confirm its validity. On an alkaline, P-poor soil, four lentil cultivars ('Samos', 'Thessaly', 'Flip', 'Algeria') received two P rates (0 and 26.2kgPha-1 ), for two growing seasons, to study whether aboveground assessments [leaf P, Mn, phenolic concentration (TPhe)] can approximate rhizosphere physiological traits related to P acquisition [soil acidification (ΔpH), arbuscular mycorrhizal fungi (AMF) colonisation, acid phosphatase activity (APase)]. Phosphorus addition had no effect on the determined traits. Cultivars differed in leaf P, Mn, TPhe and AMF, but there was no clear pattern relating aboveground traits to rhizosphere traits related to P acquisition, thus not confirming that leaf Mn can be a proxy of root exudation. Of three growth stages [V 7-8, R1 (first bloom), R4 (flat pod)], R1 seemed to be critical, showing the highest leaf P, ΔpH, AMF and TPhe. Precipitation and temperatures over the growing season were determinants of lentil responses affecting rhizosphere activity, soil P availability and finally leaf traits. In conclusion, in lentil on alkaline and P-limiting soils, high leaf Mn and phenolic concentration are not reliable indicators of rhizosphere P-acquiring mechanisms.

Efficient Removal of Basic Fuchsin from Synthetic Medical Wastewater and Competitive Adsorption in the Mixture

The Ziehl-Neelsen stain is a mixture of Basic Fuchsin (BF), phenol (Ph), and methylene blue. It is used to stain the cell walls of Mycobacterium species. In this study, Basic Fuchsin was efficiently removed from synthetic wastewater using natural clay of Gankawa (GC) from Sulaimanyah city, and the effect of the presence of high concentrations of phenol in the adsorption mixture is demonstrated. In addition, X-ray diffraction (XRD), X-ray fluorescence (XRF), N2 gas adsorption analyzer, and field-emission scanning electron microscopy (FESEM) were used to characterize the natural clay. The clay was found to be mostly calcite, with a minor percentage of smectite, and contaminated with low percentages of illite. The adsorption kinetics show a relatively fast equilibration time (60-70 minutes). A second-order pseudokinetic model better fits the experimental kinetic data. The effect of the initial pH of the solution mixture was negligible at the experimental concentration range of the study. Freundlich and Langmuir’s adsorption isotherm models were applied to the equilibrium experimental data using nonlinear regression curve fitting. Both kinetics and isotherm studies point to a chemical adsorption mechanism for the process. For adsorption in the mixture, phenol molecules were found to compete with BF molecules for the active adsorption sites, while a synergetic effect of BF exists on phenol adsorption. As a naturally abundant cheap material, GC shows a superior adsorption capacity toward BF (287.0 mg g-1) over all natural materials and most of the synthetic or modified materials found in the literature.

CONDITION AND QUALITY OF THE AIR OF THE CHERNIVTSI REGION

The question of rating of the condition of the air in the regions of Ukraine is very relevant. An important component is the choice of the optimal rating method. The purpose of the work is to review methodological approaches to the rating of the condition of atmospheric air (on the example of the city of Chernivtsi). The results of the calculation of CAPI and I5 showed that the maximum was noted in 2017 due to abnormally high concentrations of phenol, the minimum was in 2018. The value of I5 is fully correlated with the value of CAPI, which means the expediency of using I5 in particular for rating. According to the value of I5, the quality of the air is characterized by the level of "slightly polluted". Nitrogen dioxide, hydrogen fluoride and formaldehyde were included in the "three" priority pollutants. The value of In changes similarly to CAPI. In comparative analysis for individual regions, it can be used as an alternative indicator. The dynamics of changes in the index AQI for individual pollutants are similar to their time course. At index values of 100%, the air quality is characterized as "poor", although this corresponds to the level of the MRS. According to indicators of sustainable development in the "Ecological systems" category, a significant deterioration of circumstances is noted, for the "Environmental load" category - a significant improvement in circumstances is noted. The condition of the air underwent positive changes until 2018. Since 2019, indicators have deteriorated.

Substrate Inhibition Kinetics Models for Fitting the Growth Rate of Phenol by an Immobilized Pseudomonas putida

Phenol, in particular, is one of several dangerous synthetic compounds created by humans. There were more than 80,000 chemicals produced in the US for industrial use, and many of these are phenol and phenolic compounds that end up in the environment without being subjected to adequate safety assessment. There are several types of bacteria that may use phenol as a carbon source, making bioremediation of this dangerous material a promising possibility. We found that at very high concentrations of phenol, the growth rate of Pseudomonas putida NAUN-16 was significantly slowed down. The primary growth model modified Gompertz was utilized to obtain the growth parameter specific growth rate. In this study, we continue the work by further modelling the effect of substrate or phenol on the growth rate of the bacterium using several substrate inhibition kinetic models such as Monod, Haldane, Teissier, Aiba, Yano and Koga, Han and Levenspiel, Luong, Moser, Webb and Hinshelwood. The resultant fittings show appreciable fitting with the exception of the Monod model. The Teissier model, as opposed to the more widely used Haldane model, better suited the growth rate data at different concentrations of phenol as judged by the results of the RMSE, AICc, adjustedR2, F-test, and bias and accuracy factor. The designated values of the Teissier constants were maximal reduction rate, half saturation constant for maximal reduction and half inhibition constant which are symbolized by max, Ks and Ki were 0.150 1/hr (95% confidence interval 0.120 to 0.180), 162.19 mg/L (95% C.I.55.58 to 268.79) and 1291.94 mg/L (95% C.I. 1067.24 to 1516.65), respectively. The value generated from curve fitting interpolation should not be taken as the actual value and it should be warned of this as the true mumax should be where the gradient for the slope is zero and in this case the value was approximately 0.097 1/h at 385 mg/L phenol.

Influence of the Solvent on the Extraction of Phenolic Com-pounds from the Coffee Grounds by Soxhlet Leaching

In this study, phenolic compounds were extracted from the essential oil of coffee grounds originated in the coffee industry in the city of Guayaquil, Ecuador. The selected method was Soxhlet leaching, with three types of solvents (methanol, ethanol, and hexane), in its conventional form (solid-liquid), with two polar solvents and one nonpolar solvent, and in four extraction periods (30, 60, 90, and 120 minutes). The highest phenolic concentration and the best associative capacity were obtained with ethanol as the solvent for extraction, while the use of methanol yielded the second-best results. The extraction performance regarding the coffee grounds oil obtained higher results when using methanol, but close values were obtained with ethanol. Methanolic extracts obtained from coffee grounds can cause the formation of undesirable substances and be responsible for the methanolysis of gallic depsides. Therefore, the solvent-assisted technique depends on the selectivity and affinity of the compounds, according to their polar covalent character, the molecular geometry of the solvent, its relationship with its dielectric constant, and the null generation of unwanted reactions during extraction.

Comparison of solid and liquid fractions of pretreated Norway spruce as reductants in LPMO-supported saccharification of cellulose.

The role of lignin in enzymatic saccharification of cellulose involving lytic polysaccharide monooxygenase (LPMO) was investigated in experiments with the solid and liquid fractions of pretreated Norway spruce from a biorefinery demonstration plant using hydrothermal pretreatment and impregnation with sulfur dioxide. Pretreated biomass before and after enzymatic saccharification was characterized using HPAEC, HPLC, Py-GC/MS, 2D-HSQC NMR, FTIR, and SEM. Chemical characterization indicated that relatively harsh pretreatment conditions resulted in that the solid phase contained no or very little hemicellulose but considerable amounts of pseudo-lignin, and that the liquid phase contained a relatively high concentration (∼5g/L) of lignin-derived phenolics. As judged from reactions continuously supplied with either air or nitrogen gas, lignin and lignin fragments from both the solid and the liquid phases efficiently served as reductants in LPMO-supported saccharification. When air was used to promote LPMO activity, the enzymatic conversion of cellulose after 72h was 25% higher in reactions with pretreated solids and buffer, and 14% higher in reactions with pretreatment liquid and microcrystalline cellulose. Research in this area is useful for designing efficient saccharification steps in biochemical conversion of lignocellulosic biomass.

Partitioning of nutritional and phytochemical constituents in nine Adzuki bean genotypes from Australia

With an increasing demand for the efficient use of farmland resources, there is growing interest in value-adding to crops through using them or their by-products in various food processing industries. Adzuki bean is one emerging crop which shows promise for use in the value-adding chain; however, there is limited information on the phytochemical contents of various parts of this plant when grown under Australian conditions. Consequently, this study investigated the within-plant partitioning of nutritional and phytochemical constituents in nine newly developed adzuki bean genotypes from Australia. The crop took about 80–85 days to reach maturity and showed moderate to high protein and gross energy contents in both the seed (20–25%, and 16–17 MJ/kg) and leaf (19–24% and 16–18 MJ/kg) material. The leaves also showed high levels of phenolics and antioxidants, which may be linked to improved health or growth rates if fed to livestock. Additionally, the adzuki bean seedcoat contained exceptionally high concentrations of phenolics and antioxidant compounds, indicating high potential health benefits of this crop for humans. However, there was also a significant difference in the level of health-benefitting and nutritional compounds between the different genotypes. These results support the prospect of using adzuki bean as a future high-value crop for the Central Queensland region. • Phytochemical constituents are partitioned within the adzuki bean plant. • Seedcoat showed the highest phenolic content and antioxidant capacity. • Vegetative material also showed high phenolic and nutritional content. • Adzuki bean and byproducts show promise for value-added processing.

Evaluation of chilli genotypes and understanding biochemical basis of whitefly (Bemisia tabaci Genn.) resistance

• Two resistant genotypes (IHR 4300 and IHR 4338) have been identified. • Cuticle thickness significantly negative correlated with adult survival, oviposition and nymphal population of whiteflies. • Higher concentration of phenolics and flavonoids are metabolic candidates for indirect selection of resistant genotypes. Whitefly is most devastating insect pest which causes damage by direct feeding on the host plant and also act as vector for transmission of many plant viruses causing severe yield losses in chilli. Host plant resistance is best advocated strategy in controlling the damage. We have screened the selected genotypes for white fly resistance using more accurate no-choice screening assays. Three types of assays i.e. clip-on-cage, detached branch and detached leaf methods of screening have been followed. Two resistant genotypes (IIHR 4300 and IIHR 4338) have been identified based on highest adult mortality, low oviposition rate, higher egg mortality and nymphal death. Cuticle thickness found significantly negative correlated with adult survival, oviposition and nymphal population. Semio-chemicals differing significantly amongst resistant and susceptible genotypes were identified through GC–MS and LC-MS and these can be used as metabolic candidates for indirect selection in screening genotypes/ populations for resistance. These two resistant chilli genotypes viz ., IIHR 4300 and IIHR 4338 can be explored for breeding for white fly resistance.

Effects of soil types on phytochemical constituents and antioxidant properties of Solanum nigrum

• The influence of soil textural types on phytochemical constituents and antioxidant properties of cultivated S. nigrum was evaluated. • The bioactive compounds evaluated in S. nigrum cultivated on sandy clay loam, silty clay loam, clay loam and loam soils are phenols, flavonoids, proanthocyanidins, tannins, saponins, and alkaloids. • Antiradical scavenging activity of S. nigrum was evaluated with 1, 1-diphenyl-2-picryl-hydrazyl (DPPH), 2, 2′-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and iron reducing power (FRAP). • Different soil textures influence the phytochemical contents and antioxidant properties of S. nigrum cultivated on them. Solanum nigrum L. , a nutraceutical vegetable found in most tropical African countries is known for its medicinal properties imparted by antioxidant rich phytochemicals. This study evaluates the influence of soil textural types on the phytochemical constituents and antioxidant properties of cultivated S. nigrum . Bioactive compounds such as phenols, flavonoids, pro-anthocyanidins, tannins, saponins, and alkaloids were evaluated in S. nigrum cultivated on sandy loam (control soil), sandy clay loam, silty clay loam, clay loam and loam soils of University of Fort Hare, Alice, Eastern Cape, South Africa. Antiradical scavenging activity was evaluated with 1, 1-diphenyl-2-picryl-hydrazyl (DPPH), 2, 2′-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and Iron Reducing Power (FRAP). Data were analysed statistically using MINITAB Release 17. The highest concentrations of phenolics (73.87 mg/g), flavonoids (58.41 mg/g), pro-anthocyanidins (875.74 mg/g), tannins (49.32 mg/g), saponins (875.74 mg/g) and alkaloids (47.50 mg/g) were recorded in silty clay loam soil, which proved to be the best soil type. Moreover, this same soil type had the highest IC 50 values of DPPH (0.0102 mg/g) and ABTS (0.1062 mg/g) scavenging power, and absorbance (0.8395 mg/g) in FRAP reducing power. From the foregoing, we conclude that different soil textures influence the phytochemical contents and antioxidant properties of S. nigrum cultivated on them. Specifically, silty clay loam soil increased the bioactivity as well as oxygen radical scavenging properties of S. nigrum when cultivated on it. Therefore, silty clay loam can be recommended for cultivation of S. nigrum for pharmaceutical purposes.

Biologically evolved dual-pathway catalytic pattern indicating an efficient bioremediation strategy for phenol removal

Bioremediation of phenol has been developed for years, however, its actual application is challenged by low efficiency and environmental intolerance. In addition, although multiple phenol degradation pathways have been reported to coexist in bacteria, the potential significance and value have not been clearly revealed. Here, highly efficient phenol catalytic patterns were identified, and multi-pathway catalytic mechanism was investigated. Parageobacillus thermoglucosidasius W-36 employing a dual-pathway pattern exhibited superior degradation performance than P. thermoglucosidasius W-2 that employed a single-pathway pattern. An exogenous copy of degradation pathway in dual-pathway pattern was obtained via horizontal gene transfer. Based on homology modeling and molecular docking, the three-dimensional structures and substrate-binding sites of exogenous key enzymes were distinct from those of isofunctional enzymes encoded by the chromosome. The dual-pathway pattern was expressed in response to substrate levels in a time-dependent manner, indicating that synergistic effect of degradation pathways conferred strain adaptability to high-concentration phenol. Evolutionary analysis showed that the artful single/dual-pathway patterns in this species may be a natural selection phenomenon caused by high-concentration phenol. Collectively, this naturally evolved pattern enlightens the new strategy and feasibility of introducing auxiliary metabolic pathways to improve degradation efficiency of pollutants.

Impact of gradually-achieved high phenol loads on the nitrification and COD removal performance of an MBBR fed with synthetic wastewater

ABSTRACT Phenol is a noteworthy pollutant, found in effluents of many industrial processes, like oil refining and drugs production, which can impair the treatment efficiency of bioreactors. This study evaluated the performance of phenol, COD, and nitrogen removal of an aerobic bench-scale Moving Bed Biofilm Reactor (MBBR) exposed to gradually increasing phenol content over 233 days. The reactor had Hydraulic Retention Time (HRT) set at 3 h and 40% filling degree (K1 media), and was fed with synthetic wastewater containing phenol (10, 20, 50, 100, 250 and 400 mg/L), glucose (400 mgCOD/L), and 40 mgN-NH3/L. Phenol, COD, and ammoniacal nitrogen removal averages were high – above 88%, 81%, and 82%, respectively –, even when the MBBR was exposed to the greatest phenol loads, indicating that the biofilm was able to acclimate and resist high phenol concentrations. However, the intense EPS production revealed the impact caused by phenol to the biofilm from the concentration of 250 mg/L onwards. Even though, at this concentration, the average removals of COD and phenol were 87.2% and 89.7%. The removal of ammoniacal nitrogen by nitrification was compromised, being 91.6% of the ammoniacal nitrogen removed by assimilation and only 0.35% removed by nitrification. At 400 mg phenol/L, the reactor provided COD and phenol average removals equal 88.6% and 80.9%, respectively. On the last day of operation, the removal of COD dropped to 55.4% and phenol removal was equal 49.0%. Novel microscopical evaluation of the MBBR’s biofilm revealed some negative effects of the phenol on the microbiota composition.

Urinary Phenols in Early to Midpregnancy and Risk of Gestational Diabetes Mellitus: A Longitudinal Study in a Multiracial Cohort.

Environmental phenols are ubiquitous endocrine disruptors and putatively diabetogenic. However, data during pregnancy are scant. We investigated the prospective associations between pregnancy phenol concentrations and gestational diabetes mellitus (GDM) risk. In a nested matched case-control study of 111 individuals with GDM and 222 individuals without GDM within the prospective PETALS cohort, urinary bisphenol A (BPA), BPA substitutes (bisphenol F and bisphenol S [BPS]), benzophenone-3, and triclosan were quantified during the first and second trimesters. Cumulative concentrations across the two times were calculated using the area under the curve (AUC). Multivariable conditional logistic regression examined the association of individual phenols with GDM risk. We conducted mixture analysis using Bayesian kernel machine regression. We a priori examined effect modification by Asian/Pacific Islander (A/PI) race/ethnicity resulting from the case-control matching and highest GDM prevalence among A/PIs. Overall, first-trimester urinary BPS was positively associated with increased risk of GDM (adjusted odds ratio comparing highest vs. lowest tertile [aORT3 vs. T1] 2.12 [95% CI 1.00-4.50]). We identified associations among non-A/Ps, who had higher phenol concentrations than A/PIs. Among non-A/PIs, first-trimester BPA, BPS, and triclosan were positively associated with GDM risk (aORT3 vs. T1 2.91 [95% CI 1.05-8.02], 4.60 [1.55-13.70], and 2.88 [1.11-7.45], respectively). Triclosan in the second trimester and AUC were positively associated with GDM risk among non-A/PIs (P < 0.05). In mixture analysis, triclosan was significantly associated with GDM risk. Urinary BPS among all and BPA, BPS, and triclosan among non-A/PIs were associated with GDM risk. Pregnant individuals should be aware of these phenols' potential adverse health effects.

Impact of Phenol on Membranes during Bipolar Membrane Electrodialysis for High Salinity Pesticide Wastewater Treatment

To achieve a cleaner production, pesticide wastewater with concentrated NaCl can be treated by using a bipolar membrane electrodialysis (BMED) and converted to NaOH and HCl, which minimizes acid and alkali consumption in a pesticide production process. However, ion-exchange membranes (IEMs) are vulnerable to fouling by phenolic substances present in the concentrated NaCl solutions. This work aimed to understand the performance and fouling mechanism of BMED from phenol during the desalination of NaCl and explore an effective cleaning method. The results firstly showed that for the NaCl solutions with higher phenol concentrations, the selectivity of the IEMs was reduced after processing six successive batches of BMED, which led to reverse migration of ions, organics leakage, and an obvious increase in the energy consumption and the concentration of generated acid and alkali. Secondly, IEMs characterization analysis detected that the structure of the IEMs was deformed, while phenol fouling deposits were observed on the surface and interior of the IEMs, especially for the anion exchange membranes (AEMs). Then, the results of soaking tests proved that the phenol could bring about swelling-like degradation to the AEMs and 0.1 wt.% NaOH solution was studied to be the optimized cleaning agent since the performance of the fouled IEMs in the short-running process could be recovered after 5 h of in situ cleaning that removed the phenol fouling deposits efficiently. Finally, the results of a long-running BMED operation treating NaCl solution containing 10 g/L phenol concentration showed that the IEMs were severely fouled, and the fouling was firstly due to the swelling-like mechanism during the initial 12 successive batches, and then should belong to the blockage-like mechanism during the following 20 successive batches. The seriously fouled IEMs could no longer be recovered even after a deep in situ cleaning. This research proves that under appropriate pretreatment or operating conditions, the BMED process is an alternative way of treating wastewater with high salinity and the presence of phenol molecules.

Similar structural complexity of phenols in plant morphotypes with contrasting soluble phenol concentration and richness in arid rangelands of Patagonia

Phenols can play a significant role in plant tolerance of drought and herbivory. We assessed the concentration, richness and structural complexity of soluble phenols (hereafter phenols) in leaves of different species representing different plant morphotypes of arid ecosystems. We selected seven species representative of the three main plant morphotypes of the Patagonia Monte (Argentina): tall evergreen shrubs (TES), medium evergreen shrubs (MES), and perennial grasses (PG). These morphotypes differed in plant height, rooting depth, proportion of photosynthetic tissues, specific leaf area, and concentration of phenols and N in leaves. We found 48 compounds belonging to six types of phenols differing in structural complexity (low complexity: simple phenols, phenolic acids and phenolic esters; medium complexity: hydroxycinnamic acids and phenylpropenes; and high complexity: quinones, flavonols and flavones). Phenols of low and medium complexity were the most abundant in all morphotypes, while those of high complexity, probably the most costly for plants, were nearly exclusive of some tall evergreen shrubs. In general, PG, MES and TES had low, intermediate and high phenol concentration (8.5, 27.2, 202.5 mg g−1DW, respectively) and richness (15, 25, 37 compounds, respectively) in leaves. The richness of phenols was significantly and positively related to phenol concentration. However, we did not find distinctive phenol compound patterns among morphotypes. Our results suggest that drought and, to some extent, herbivory have exerted selective selection pressure on richness and phenol concentration in leaves of contrasting morphotypes but the type of phenols accumulated probably depends on intrinsic species attributes within each morphotype.