Efficacy of Allium sativum oil to alleviate tebuconazol-induced oxidative stress in the liver of adult rats

The present study focused on the protective efficacy of Allium sativum oil (ASO) against tebuconazol (TEB)-induced oxidative stress in the liver of adult rats. Thirty-two rats were randomly divided into four groups of eight each: group I served as control rats, group II was treated with TEB (100 mg/kg bw), group III received ASO (5ml/kg bw). The animals of group IV were treated with TEB and ASO, during 4 weeks. The obtained results showed that TEB induced a significant change of some hematological parameters, including red blood cells (RBC), haemoglobin content (Hb), haematocrit (Ht), white blood cells (WBC) and platelet (Plt) compared to the control group. Moreover, while the total cholesterol levels and the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and γ-Glutamyltranspeptidase (γGT) significantly increased due to TEB administration, the concentrations of plasma total protein, albumin and triglyceride considerably decreased. Furthermore, the exposure to TEB significantly increased the malondialdehyde (MDA), protein carbonyl (PCO) and advanced oxidation protein products (AOPP) levels and decreased glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST) activities in the hepatic tissues. The results were confirmed by the histological impairments. Besides, the co-administration of ASO improved the status of all studied parameters. Therefore, our investigation revealed that ASO had protective effects against TEB-induced liver injury, which could be attributed to its phenolic compounds.

Growth behavior, glucose consumption and phenol removal efficiency of Chlorella vulgaris under the synergistic effects of glucose and phenol

The use of algae is an effective approach to remove phenol and its derivatives from polluted water. The growth behavior, glucose consumption and phenol removal efficiency of Chlorella vulgaris under the synergistic effects of glucose and phenol were investigated. The evolutions of tolerance and removal efficiency of C. vulgaris to phenol under different trophic modes and glucose contents were observed. The results revealed that growth of C. vulgaris were inhibited with the increase of phenol from 0 to 400 mg L^-1 in culture media; the tolerance to phenol enhanced with the addition of glucose from 2 to 10 g L^-1, while glucose consumption was inhibited with the increase of phenol content; phenol removal efficiency varied with glucose concentrations in mixotrophic media. The finding suggested that phenol inhibited the growth of C. vulgaris and glucose assimilation under mixotrophic cultivation, while appropriate glucose addition could enhance the tolerance of C. vulgaris to phenol and affect the phenol removal efficiency.

Degradation of phenol by coal-based carbon membrane integrating sulfate radicals-based advanced oxidation processes

Phenol, as a representative organic pollutant in aquatic environments, has posed a serious threat to humans and ecosystem. In this work, a novel integration system combined coal-based carbon membrane with sulfate radicals-based advanced oxidation processes (SR-AOPs) was designed for degradation of phenol. The integrated system achieved 100% removal efficiency under the optimal condition (peroxydisulfate dosage is 0.2 g/L, at alkaline condition with 2 mL/min flow velocity). The quenching experiments revealed that the efficient removal of phenol by the integrated system were attributed to the co-existence of radical and nonradical mechanisms. This study proposes a green and efficient technique for the removal of phenol.

Impact of dissolved O2 on phenol oxidation by δ-MnO2

Although redox reactions of organic contaminants with manganese oxides have been extensively studied, the role of dissolved O2 in these processes has largely been overlooked. In this study, the oxidative degradation of phenol by δ-MnO2 was investigated under both oxic and anoxic conditions. Dissolved O2 inhibited phenol degradation due to its promoting role in the reoxidation and precipitation of reduced Mn(ii) to Mn(iii) on the δ-MnO2 surface, resulting in partial transformation of δ-MnO2 to "c-disordered" H+-birnessite at pH 5.5 and feitknechtite, manganite, and hausmannite at pH 7.0 and 8.5. The reformed Mn(iii) phases could reduce phenol oxidation by blocking reactive sites of δ-MnO2. In addition, dissolved O2 caused a higher degree of particle agglomeration and a more severe specific surface area decrease, and hence lower reactivity of δ-MnO2. These findings revealed that after reductive dissolution by phenol and reoxidation by dissolved O2 throughout continuous redox cycling, δ-MnO2 became less reactive rather than being regenerated. These results can provide new insights into the understanding of the oxidation of organic contaminants by manganese oxides in the natural environment.

Magnetic palm kernel biochar potential route for phenol removal from wastewater

The pollution of water resources due to the disposal of industrial wastes that have organic material like phenol is causing worldwide concern because of their toxicity towards aquatic life, human beings and the environment. Phenol causes nervous system damage, renal kidney disease, mental retardation, cancer and anaemia. In this study, magnetic palm kernel biochar is used for removal of phenol from wastewater. The effect of parameters such as pH, agitation speed, contact time and magnetic biochar dosage are validated using design of experiments. The statistical analysis reveals that the optimum conditions for the highest removal (93.39%) of phenol are obtained at pH of 8, magnetic biochar dosage of 0.6 g, agitation speed at 180 rpm and time of 60 min with the initial concentration of 10 mg/L. The maximum adsorption capacities of phenol were found to be 10.84 mg/g and Langmuir and Freundlich isotherm models match the experimental data very well and adsorption kinetic obeys a pseudo-second order. Hence, magnetic palm kernel can be a potential candidate for phenol removal from wastewater.

Hexavalent chromium reduction ability and bioremediation potential of Aspergillus flavus CR500 isolated from electroplating wastewater

Hexavalent chromium reduction by microbes can mitigate the chromium toxicity to the environment. In the present study Cr_[VI] tolerant fungal isolate (CR500) was isolated from electroplating wastewater, was able to tolerate 800 mg/L of Cr_[VI. Based on the ITS region sequencing, the isolate was identified as Aspergillus flavus CR500, showed multifarious biochemical (reactive oxygen species, antioxidants response and non-protein thiol) and morphological (protrusion less, constriction and swelling/outwards growth in mycelia) response under Cr_[VI] stress. Batch experiment was conducted at different Cr_[VI] concentration (0-200 mg/L) to optimize the Cr_[VI] reduction and removal ability of isolate CR500; results showed 89.1% reduction of Cr_[VI] to Cr_[III] within 24 h and 4.9 ± 0.12 mg of Cr per gram of dried biomass accumulation within 144 h at the concentration of 50 mg/L of Cr_[VI]. However, a maximum of 79.4% removal of Cr was recorded at 5 mg/L within 144 h. Fourier-transform infrared spectroscopy, energy dispersive x-ray spectroscopy and X-ray diffraction analysis revealed that chromium removal also happened via adsorption/precipitation on the mycelia surface. Fungus treated and without treated 100 mg/L of Cr_[VI] solution was subjected to phytotoxicity test using Vigna radiata seeds and result revealed that A. flavus CR500 successfully detoxified the Cr_[VI] via reduction and removal mechanisms. Isolate CR500 also exhibited efficient bioreduction potential at different temperature (20-40 °C), pH (5.0-9.0), heavy metals (As, Cd, Cu, Mn, Ni and Pb), metabolic inhibitors (phenol and EDTA) and in sterilized tannery effluent that make it a potential candidate for Cr_[VI] bioremediation.

Biodegradation of phenol in saline or hypersaline environments by bacteria: A review

With the continuous demand from industry for chemical raw materials, a large amount of high-salinity wastewater containing phenol is discharged into the aquatic environment, and the leakage of dangerous chemicals into the sea may lead to phenol pollution of the ocean. Phenol is a common chemical posing serious environmental hazard. Biodegradation is an effective, low-cost, environment-friendly method of removing phenol from water, but in hypersaline environments, traditional freshwater organisms are less efficacious. Here, at least 17 genera of bacteria from three phyla are found that can degrade phenol in different saline environments. The sources and taxonomy of halotolerant and halophilic bacteria are reviewed. Moreover, the pathway of phenol removal, kinetics of biodegradation, influencing factors, and recent treatment processes of wastewater are discussed.

Membrane fouling and performance of anaerobic ceramic membrane bioreactor treating phenol- and quinoline-containing wastewater: granular activated carbon vs polyaluminum chloride

Although anaerobic membrane bioreactor (AnMBR) has been proposed for the treatment of phenolic wastewater, the membrane fouling is still a major obstacle. The effects of dosing of granular activated carbon (GAC) and polyaluminum chloride (PACl) on the treatment performance and membrane fouling of anaerobic ceramic membrane bioreactor were investigated for treating phenol- and quinoline-containing wastewater. The results suggested that the one-off dosing of GAC resulted in a decrease of protein/carbohydrate ratio, which might account for the aggravation of membrane fouling alongside with the decreased flocs size. Nevertheless, the substrate uptake rates (SUR) of phenol and quinoline, and the specific methanogenic activity of sludge at the GAC dosing stage of experimental reactor (R1) were 8.79 ± 0.63 mg phenol g^-1 MLVSS d^-1, 7.01 ± 0.09 mg quinoline g^-1 MLVSS d^-1 and 0.27 ± 0.01 g COD_CH4 g^-1 MLVSS d^-1, which were 1.69, 3.59 and 1.93 times higher than that of the control reactor (R2). The dosing of PACl reduced the membrane fouling rate by changing the floc structure of sludge, as well as the component of SMP and EPS. However, the substrate uptake rate of quinoline was declined. This work provides a comprehensive evaluation on the effect of GAC and PACl dosing on membrane fouling and performance of anaerobic ceramic membrane bioreactor treating phenol-and quinoline-containing wastewater.

Effect of ultrasound treatment on microbial inhibition and quality maintenance of green asparagus during cold storage

The study focused on inhibiting microorganism and improving preservation of green asparagus (Asparagus officinalis L.) during cold storage. Green asparagus is treated with ultrasound (US), acetic acid and gibberellin acid (AG) separately as well as combination (US + AG) and then stored at 4 °C for 20 days. Microorganism, physicochemical qualities and sensory characteristics were monitored at regular intervals. Results showed that the US treatment significantly (p < 0.05) reduced the total number of colonies, mold and yeast merely in the 12th and 16th day of storage, while the US + AG treatment not only achieved an effective decontamination (up to 2 log reduction) of green asparagus throughout the storage, but also retained the physicochemical characteristics to a higher level in comparison to other treatments. The US + AG treatment exhibited lower weight loss, higher levels of total soluble solid (TSS), ascorbic acid, chlorophyll content and total phenolic content (TPC), as well as kept better sensory attributes. Moreover, the US + AG treatment significantly inhibited the activities of phenylalanine ammonia lyase (PAL) and peroxidase (POD) (p < 0.05), suppressing the biosynthesis of lignin. These results suggested that the US + AG treatment could be a potential strategy to preserve quality of green asparagus during cold storage.

Performance and recovery of a completely separated partial nitritation and anammox process treating phenol-containing wastewater

Anammox process is considered as a promising technology for removing total nitrogen from low-strength ammonium and phenol-containing wastewater. However, it is still a challenge for the anammox process to treat high-strength ammonium and phenol-containing wastewater. A completely separated partial nitritation and anammox (CSPN/A) process was developed to remove total nitrogen from high-strength phenol-containing wastewater. About 92% of COD, 100% of phenol, and 82.4% of total nitrogen were successfully removed at a NH₄⁺-N concentration of 200 mg L^-1 with a phenol/NH₄⁺-N mass ratio of 0.5 in the CSPN/A process. Furthermore, a shock loading of 300 mg phenol L^-1 with a phenol/NH₄⁺-N mass ratio of 1.5 led to a complete failure of partial nitritation, but the performance was rapidly recovered by the increase of NH₄⁺-N concentration. Although the activities of ammonium-oxidizing bacteria and anammox bacteria were severely inhibited at a phenol/NH₄⁺-N mass ratio of 1.5, the enrichment of efficient phenol degraders in the CSPN stage could strengthen the performance robustness of partial nitritation and anammox process. Therefore, this study presented a new insight on the feasibility of the anammox process for treating high-strength ammonium and phenol-containing wastewater.

Effects of olive mill wastewater discharge on benthic biota in Mediterranean streams

Olive mill wastewaters (OMW) discharging in river ecosystems cause significant adverse effects on their water chemistry and biological communities. We here examined the effects of OMW loads in four streams of a Mediterranean basin characterized by changing flow. The diatom and macroinvertebrate community structures were compared between upstream (control) and downstream (impacted) sites receiving OMW discharge. We also tested if effects occurred at the organism level, i.e. the occurrence of deformities in diatom valves, and the sediment toxicity on the midge Chironomus riparius. We evaluated these effects through a two-year analysis, at various levels of chemical pollution and dilution capacity. The impacted sites had high phenol concentrations and organic carbon loads during and after olive mill (OM) operation, and were characterized by higher abundances of pollution-tolerant diatom and macroinvertebrate taxa. Diatom valve deformities occurred more frequently at the impacted sites. The development of C. riparius was affected by phenolic compounds and organic carbon concentrations in the sediments. The similarity in the diatom and macroinvertebrate assemblages between control and impacted sites decreased at lower flows. Diatoms were more sensitive in detecting deterioration in the biological status of OMW receiving waterways than macroinvertebrates. Our results indicate that the negative effects of OMW extended to the whole benthic community, at both assemblage and organism level.

Effect of peroxydisulfate on the degradation of phenol under dielectric barrier discharge plasma treatment

The activation of peroxydisulfate (PDS) by gas/liquid dielectric barrier discharge (DBD) plasma in a flat plate configuration was assessed through phenol removal. The results indicated that PDS addition exhibited a significantly promoting effect on phenol removal and mineralization. In the reaction lacking PDS, phenol in aqueous solution was removed from the initial 10 mg L^-1 to 4.75 mg L^-1 (by 52.5%), whereas the addition of 1770 mg L^-1 PDS increased the overall removal to 78.7%, as indicated by a one-fold increase in the pseudo-first-order kinetic constant. In addition, the corresponding total organic carbon (TOC) removal was increased from 27.5% to 48.4%. Furthermore, an increased input voltage was favourable for increases in phenol removal, the kinetic constant and PDS utilization, which were also influenced by the PDS dose, initial solution pH and water matrix. In addition, through the analysis of radical quenching experiments, the enhancement could be mainly attributed to the production of SO₄^•- and •OH by PDS activation by discharge plasma. The DBD system coupled with PDS exhibited a high removal efficiency for phenol, and thus, the overall findings could provide new insight into wastewater treatment.

Biodegradation of high concentration phenol using sugarcane bagasse immobilized Candida tropicalis PHB5 in a packed-bed column reactor

Biodegradation of phenolic compounds in wastewater can be effectively carried out in packed bed reactors (PBRs) employing immobilized microorganisms. A low-cost, reusable immobilization matrix in PBR can provide economic advantages in large scale removal of high concentration phenol. In this study, we evaluated the efficiency and reusability of sugarcane bagasse (SCB) as a low-cost immobilization support for high strength phenol removal in recirculating upflow PBR. An isolated yeast Candida tropicalis PHB5 was immobilized onto the SCB support and packed into the reactor to assess phenol biodegradation at various influent flow rates. Scanning electron microscopy exhibited substantial cell attachment within the pith and onto the fibrous strand surface of the SCB support. The PBR showed 97% removal efficiency at the initial phenol concentration of 2400 mg L^-1 and 4 mL min^-1 flow rate within 54 h. Biodegradation kinetic studies revealed that the phenol biodegradation rate and biodegradation rate constant were dependent on the influent flow rate. A relatively higher rate of biodegradation (64.20 mg g^-1 h^-1) was found at a flow rate of 8 mL min^-1, indicating rapid phenol removal in the PBR. Up to six successive batches (phenol removal >94%) were successfully applied in the PBR using an initial phenol concentration of 400-2400 mg L^-1 at a flow rate of 4 mL min^-1 indicating the reusability of the PBR system. The SCB-immobilized C. tropicalis could be employed as a cost-effective packing material for removal of high strength phenolic compounds in real scale PBR.

Carbon nanotube-grafted chitosan and its adsorption capacity for phenol in aqueous solution

Chitosan was covalently grafted onto the surface of multi-walled carbon nanotubes to create a novel chitosan/multi-walled carbon nanotube. The structure of the new material was characterized using Fourier transform-infrared spectroscopy, cross polarization magic angle spinning ¹³C nuclear magnetic resonance, thermogravimetric analysis, XRD ray diffraction analysis, differential scanning calorimetry and scanning electron microscopy. The phenol adsorption capacity was determined and the Langmuir and Freundlich models were used to describe the adsorption isotherms. The adsorption capacity of the novel chitosan/multi-walled carbon nanotube material for phenol (86.96 mg/g) was improved compared to the original chitosan (61.69 mg/g). The kinetic studies showed rapid adsorption, exhibiting Lagergren second-order kinetics. Therefore, this study provides a reference for preparing functional materials from biological substrates that are able to remove toxic pollutants from an aqueous environment.

Effect of reclamation treatments on microbial activity and phytotoxicity of soil degraded by the sulphur mining industry

The aim of the work was to determine the trend, intensity and changes of selected microbial and phytotoxic parameters of degraded soil in the area of former sulphur mine reclaimed by post-flotation lime (PFL), sewage sludge (SS), mineral wool (MW- mixed with soil, MWP-pad) and mineral fertilizer (NPK). The following parameters: number of proteolytic bacteria and fungi, ammonification, nitrification, activities of alkaline phosphatase and arylsulphatase Lepidium sativum growth index (GI) and phenolic compounds were analysed in the soil in second and third year of the experiment. The addition of the SS separately or in combination with other remediation agents was found to be the most valuable for the number of microorganisms, intensification of nitrification process and enzymatic activities. In objects where other materials were added without sewage sludge, the inhibition of fungal growth as well as alkaline phosphatase and arylsulphatase activities was observed, however the inhibitory effect declined with time. The observed increase of GI shows the long-term, positive effect of treatments on soil properties concerning plant growth. The use of lime and lime together with sewage sludge contributed to the decrease in the content of phenolic compounds in the reclaimed soil.

Removal of phenol and phosphate from aqueous solutions using activated carbons prepared from oily sludge through physical and chemical activation

Preparation and characterization of activated carbons (ACs) from oily sludge by physical and chemical activation using steam, ZnCl₂ and FeCl₃ were investigated. The characteristics of produced adsorbents were determined by iodine number, Brunauer-Emmett-Teller (BET) equation, Fourier transform infrared spectrometry and scanning electron microscopy analyses. Batch adsorption experiments for phenol and phosphate were performed to evaluate the efficiency of adsorbents. The optimum porous structure of adsorbents with a BET surface area of 1,259 m² g^-1, total pore volume of 1.22 cm³ g^-1 and iodine number of 994 mg g^-1 was achieved by ZnCl₂ activation at 500 °C and impregnation ratio of 1:1. The adsorption data were well fitted to the pseudo-second-order kinetic model (R²>0.99) and Freundlich isotherm (R²>0.99). The maximum adsorption capacity of phenol (238 mg g^-1) and phosphate (102 mg g^-1) based on the Langmuir model was achieved at pH of 6.0 and adsorbent dose of 1 g L^-1. Thermodynamic parameters were negative and showed that adsorption of phenol and phosphate onto the AC was feasible, spontaneous and exothermic. The results suggested that prepared AC was an effective adsorbent for removal of phenol and phosphate ions from the polluted water.

One-at-a-time sensitivity analysis of pollutant loadings to subsurface properties for the assessment of soil and groundwater pollution potential

Chemical leak was numerically simulated for four chemical substances: benzene (light non-aqueous phase liquid (NAPL)), tetrachloroethylene (dense NAPL), phenol (soluble in water), and pentachlorophenol (white crystalline solid) in a hypothetical subsurface leak situation using a multiphase compositional transport model. One metric ton of chemical substances was assumed to leak at a point 3.51 m above the water table in a homogeneous unconfined aquifer which had the depth to water table of 7.135 m, the hydraulic gradient of 0.00097, the recharge rate of 0.7 mm/day, and the permeability of 2.92 × 10^-10 m². For comparison, surface spill scenarios, which had a long pathway from source to the water table, were simulated. Using the model results, point-source pollutant loadings to soil and groundwater were calculated by multiplying mass, impact area, and duration above and below the water table respectively. Their sensitivity to subsurface properties (depth to water table, recharge rate, porosity, organic carbon content, decay rate, hydraulic gradient, capillary pressure, relative permeability, permeability) was analyzed, with changing each parameter within acceptable ranges. The study result showed that the pollutant loading to groundwater was more sensitive to the subsurface properties than the pollutant loading to soil. Decay rate, groundwater depth, hydraulic gradient and porosity were influential to pollutant loadings. The impact of influential parameters on pollutant loadings was nonlinear. The dominant subsurface properties of pollution loadings (e.g., decay rate, groundwater depth, hydraulic gradient, and porosity for groundwater) also affect the vulnerability, and the subsurface pollutant loadings defined in this study are dependent on chemical properties as well, which indicates that the influential hydrogeological and physicochemical parameters to pollutant loadings can be used for pollution potential assessment. The contribution of this work is the suggestion that the sensitivity of pollutant loadings can be used for pollution potential assessment. Soil and groundwater pollution potential of chemicals are discussed altogether for leak scenarios. A physics-based model is used to understand the impact of subsurface properties on the fate and transport of chemicals above and below the water table, and consequently their impact on the pollutant loading to soil and groundwater.

Optimization of treating phenol from wastewater through the TiO2-catalyzed advanced oxidation process and response surface methodology

The use of dispersed catalysts in aqueous medium inside reactors in advanced oxidative processes is common among researchers. However, due to the difficult separation of these species after treatment, in many cases, the treatment process is unfeasible. In this context, the main target of the work was the evaluation of degradation of the phenolic solution by ozonation titanium dioxide (TiO₂/P25), supported on zeolite spheres. The process was investigated through the response surface methodology (RSM) and optimized by the generalized reduced gradient (GRG) algorithm. The effects of various operating parameters including pH, power ozone (O₃) generation, flow rate, and treatment time were investigated, using as a response to removal of chemical oxygen demand (COD). It was made in optimum conditions the ratio of biochemical oxygen demand (BOD)/chemical oxygen demand to check the increasing biodegradability, aiming ozonation as preliminary treatment, with the possibility of subsequent biological treatments. There was an increase in this ratio from 0.17 to 0.50 in 48 min, which would facilitate the use of the subsequent biological process. The proposed model showed good fit to the experimental data with R² and R²_adj correlation coefficients of 0.9964 and 0.9932, respectively.

A novel phenol and ammonia recovery process for coal gasification wastewater altering the bacterial community and increasing pollutants removal in anaerobic/anoxic/aerobic system

Coal gasification wastewater (CGWW) is a typical toxic and refractory industrial wastewater. Here, a novel phenol and ammonia recovery process (IPE) was employed for CGWW pretreatment, and the coupled system assemble by the IPE process with A²/O system (IPE-A²/O) were operated to enhance the treatment performance of CGWW. The results showed that the IPE pre-treated effluent had a higher BOD₅/COD ratio and lower refractory compounds compared to a typical process (MIBK). Subsequent A²/O biological treatment indicated that the A²/O-p system (A²/O system followed IPE process) obtained a higher average COD removal of 92% compared to 87.7% of the control (A²/O-m, A²/O system followed MIBK). The GC-MS analysis suggested that the content of alkanes in the IPE-A²/O effluent was lower than that of the MIBK-A²/O. The high-throughput sequencing revealed Levilinea, Alcaligenes, Acinetobacter, Thauera and Thiobacillus were the core genera in A²/O system. The genera Alcaligenes, Acinetobacter, Thauera and Thiobacillus in the degrading consortium were enriched in the A²/O-p system, leading to increased removals of organic pollutants and TN. These results suggested that the IPE process was a feasible pretreatment method, and the coupled IPE-A²/O system was an alternative technique for treating CGWW.

Detection of phenol contamination in RNA samples and its impact on qRT-PCR results

Residual phenol, carried over from RNA purification, can alter RNA concentration measurements and is assumed to inhibit PCR. Here, we demonstrate that Impurities A260 values of spectral content profiling (SCP) UV/Vis measurements correlated with phenol concentration, whereas absorbance ratios of classical UV/Vis systems failed to reliably detect phenol in RNA samples. Phenol contamination led to over- or underestimation of RNA concentration on UV/Vis systems, whereas it had no influence on fluorometry quantification. Wrong RNA concentration results led to altered template input in qRT-PCR and consequently caused quantification cycle (Cq) shifts, although ≤ 0.01% phenol had no direct influence.

Influence of Extraction Methods on Total Phenolic Content and Antioxidant Properties of Some of the Commonly Used Plants in Thailand

BACKGROUND AND OBJECTIVE

Several plants have been commonly used in Thailand for health improvement, but the phytochemical content and its bio-activities are not yet elucidated completely. The aim of this research was to study the influence of extraction method on total phenolic content (TPC) and antioxidant activity of representative plants such as Punica granatum, Hibiscus sabdariffa, leistocalyx operculatus (Roxb.) Merr., litoria ternatea Linn., Mulberry and Oryza sativa L. indica.

METHODOLOGY

The samples were subjected to different extraction procedures. The TPC and phenolic compounds were determined by Folin-Ciocalteu colorimetric assay and HPLC, respectively. The antioxidant capacity of the extracts was measured by 2, 2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assays and ferrous ion (Fe2+) chelating assay.

RESULTS

The maximum TPC was observed in pomegranate peel (TTP) extract (0.1 M HCl: Ethanol extraction) and low TPC was recorded in aqueous extract of butterfly pea flower (BP) samples. The high content of protocatechuic, p-hydroxybenzoic acid were observed in pomegranate seed and seed coat (TTS). Gallic and syringic acids were found to be rich in pomegranate peel (TTP) and flower of butterfly pea (BP), respectively. Roselle flower samples (KJ) showed high content of chlorogenic, p-coumaric and caffeic acids.

CONCLUSION

The maximum antioxidant activity was observed in extracts obtained by 0.1 M HCl: Ethanol extraction methods, especially pomegranate peel exhibited high free radical scavenging activity compared to that of the other samples. The results strongly revealed that the extraction method greatly influences the phytochemical content and bioactivity and strongly recommends that any plant samples, intended to study, must undergo several extraction processes to reveal the actual phytochemical content.

Novel photocatalytic system Fe-complex/TiO2 for efficient degradation of phenol and norfloxacin in water

Photocatalysis is one of the effective strategies to eliminate various organic pollutants in water body. In this paper we have prepared a series of new composite photocatalysts to degrade phenol and norfloxacin under visible light irradiation. They were [Fe^II(dpbpy)₂(H₂O)₂]/TiO₂, [Fe^II(dpbpy)(phen)₂]/TiO₂ and [Fe^II(dpbpy)(bpy)₂]/TiO₂ (dpbpy: 2,2'-bipyridine-4,4'-diphosphoric acid, phen: 1,10-phenanthroline, bpy: 2,2-bipyridyl). The results show that their photocatalytic performance and cyclic stability are much better than that of pure TiO₂ or P25. Phenol can be degraded almost completely and the active groups or substituents of norfloxacin (NOR) can be destroyed also, which greatly reduced the biological toxicity of phenol and norfloxacin in water. The possible mechanisms of improving the photocatalytic activity and stability of TiO₂ by using Fe-complex are proposed based on free radical capture test and density functional theory calculation. It is clearly that the interfacial interaction between Fe-complex and titanium dioxide directly affects the photocatalytic activity and stability of the composite photocatalyst. The conjugated structure of the complexes plays a crucial role.

Mango phenolics increase the serum apolipoprotein A1/B ratio in rats fed high cholesterol and sodium cholate diets

BACKGROUND

Serum lipoproteins are in dynamic equilibrium, partially controlled by the apolipoprotein A1 to apolipoprotein B ratio (APOA1/APOB). Freeze-dried mango pulp (FDM) is a rich source of phenolic compounds (MP) and dietary fiber (MF), although their effects on lipoprotein metabolism have not yet been studied.

RESULTS

Thirty male Wistar rats were fed with four different isocaloric diets (3.4 kcal g^-1 ) for 12 weeks: control diet, high cholesterol (8 g kg^-1 ) + sodium cholate (2 g kg^-1 ) diet either alone or supplemented with MF (60 g kg^-1 ), MP (1 g kg^-1 ) or FDM (50 g kg^-1 ). MP and FDM reduced food intake, whereas MF and MP tended to increase serum APOA1/APOB ratio, independently of their hepatic gene expression. This suggests that lipoprotein metabolism was favorably altered by mango bioactives, MP also mitigated the non-alcoholic steatohepatitis that resulted from the intake of this diet.

CONCLUSION

We propose that phenolics are the most bioactive components of mango pulp, acting as anti-atherogenic and hepatoprotective agents, with a mechanism of action tentatively based on changes to the main protein components of lipoproteins. © 2018 Society of Chemical Industry.

Biodegradation of phenol by cold-tolerant bacteria isolated from alpine soils of Binaloud Mountains in Iran

Degradation of phenol is considered to be a challenge because of harsh environments in cold regions and ground waters. Molecular characterization of phenol degrading bacteria was investigated to gain an insight into the biodegradation in cold areas. The psychrotolerant and psychrophiles bacteria were isolated from alpine soils in the northeast of Iran. These strains belonged to Pseudomonas sp., Stenotrophomonas spp. and Shinella spp. based on analysis of the 16S rRNA gene. These strains were capable of the complete phenol degradation at a concentration of 200 mg L^-1 at 20 °C. Moreover, the strains could degrade phenol at a concentration of 400 and 600 mg L^-1 at a higher time. Effects of environmental factors were studied using one factor at a time (OFAT) approach for Pseudomonas sp.ATR208. When the bacterium was grown in a liquid medium with 600 mg L^-1 of concentration supplemented with optimum carbon and nitrogen sources, more than 99% of phenol removal was obtained at 20 °C and 24 h. Therefore, the present study indicated the potential of the local cold tolerant bacteria in the phenol bioremediation.

Synthetic olive mill wastewater treatment by Fenton's process in batch and continuous reactors operation

Degradation of total phenol (TPh) and organic matter, (expressed as total organic carbon TOC), of a simulated olive mill wastewater was evaluated by the Fenton oxidation process under batch and continuous mode conditions. A mixture of six phenolic acids usually found in these agro-industrial wastewaters was used for this purpose. The study focused on the optimization of key operational parameters of the Fenton process in a batch reactor, namely Fe²⁺ dosage, hydrogen peroxide concentration, pH, and reaction temperature. On the assessment of the process efficiency, > 99% of TPh and > 56% of TOC removal were attained when [Fe²⁺] = 100 ppm, [H₂O₂] = 2.0 g/L, T = 30 °C, and initial pH = 5.0, after 300 min of reaction. Under those operational conditions, experiments on a continuous stirred-tank reactor (CSTR) were performed for different space-time values (τ). TOC and TPh removals of 47.5 and 96.9%, respectively, were reached at steady-state (for τ = 120 min). High removal of COD (> 75%) and BOD₅ (> 70%) was achieved for both batch and CSTR optimum conditions; analysis of the BOD₅/COD ratio also revealed an increase in the effluent's biodegradability. Despite the high removal of lumped parameters, the treated effluent did not met the Portuguese legal limits for direct discharge of wastewaters into water bodies, which indicates that coupled chemical-biological process may be the best solution for real olive mill wastewater treatment.