Phenolic composition and correlation with antioxidant properties of various organic fractions from Hertia cheirifolia extracts

Hertia cheirifolia L. is a medicinal plant that has been used for a long time in folk Mediterranean medicine. The aim of the present study was to analyze and compare the phenolic profile and the antioxidant potential of organic fractions from H. cheirifolia extracts. Crude methanolic extracts were firstly prepared from the different parts of the plant. Then four different organic fractions were obtained by fractioning each extract, using different solvents with increasing polarity (hexane, chloroform, and ethyl acetate). The Phenolic content was analyzed using a UV-Vis colorimetric methods followed by a qualitative and quantitative analysis by high performance liquid chromatography-diode array detector (HPLC-DAD) system. After that, the antioxidant potential of the different organic fractions was evaluated using DPPH and ABTS free radical scavenging assays, reducing power of iron (FRAP) and inhibition of β-carotene oxidation tests. Our results revealed that ethyl acetate fractions (EA) contained the highest content of total phenolics (100-250 mg GAE/g). Indeed, the ethyl acetate fraction from the flower extract (EA-F) displayed the lowest IC50 values for the scavenging of DPPH and ABTS free radicals (38.83 ± 0.34 µg/ml and 23.76 ± 0.11 µg/ml, respectively). Also, the strongest iron reducing power (2628.87 ± 16.47 µmol Fe2+Eq/ml) and the best rate of inhibition of the β-carotene oxidation (58.91 ± 5.79 %) were recorded. In sum, the present study suggests that, the organic fractions from H. cherifolia are potential natural antioxidants and this is probably related to their phenolics content and structure.

Anaerobic digestion of organic fraction combinations from food waste, for an optimal dynamic release of biogas, using H2 as an indicator

The objective of this study is to assess the effects of mixing the three elemental organic waste fractions (fruit and vegetable, meat, and fish) during anaerobic digestion. Batch experiments were carried out with fraction mixtures of different proportions. The results were compared, concerning the single digestion of each fraction, the gas generation, and the process performance, using H₂ as an indicator. It was determined that the optimal mixture was the one with the fractions in equal proportion. This mixture achieved a balanced composition, a faster process by 58 %, and a 12 % increase in methane production. It was also determined that, as a rule, mixtures increase the hydrolysis speed and that the meat fraction mixtures manage to make this substrate suitable for anaerobic treatment by increasing the rate of hydrolysis by 148 % and buffering the acidification inhibition that suffers in its single digestion.

Co-digestion of municipal solid waste with lignocellulosic waste in mesophilic Environment

The present study deals with the dual problem of municipal solid waste and lignocellulosic waste in which authors tried to use these two waste materials as clean and renewable energy source. In the present study, anaerobic digestion of organic fraction of municipal solid waste and lignocellulosic waste in varying combinations was carried out. Five-set of experiments (S1, S2, S3, S4, and S5) under mesophilic conditions were conducted in batch reactors. From all the combinations, reactor S3 (organic fraction of municipal solid waste: lignocellulosic waste, 1:1 ratio) was observed to be the best combination producing 70.09 ml concentration of methane out of 78.76 ml of biogas as compared to all other combinations. The increase in methane production rate was observed by 53.67% due to the addition of lignocellulosic waste. The decline in methane production at the end of the 50th day was observed due to a fall in pH, which created acidic conditions, thus inhibiting the conversion process. It was found that the mesophilic condition acted as a governing factor in the process of digestion.

Comprehensive investigation of the relationship between organic content and waste activated sludge dewaterability

The relationship between sludge organic fraction and its dewaterability is well known in practice. However, the formal study to reveal the underlying reason is limited. To improve understanding of the nature of organic content on sludge dewatering process, this study systematically evaluated the effects of sludge organic content on its dewaterability and revealed the underlying mechanism. Analysis of 10 waste activated sludge (WAS) samples with varying organic contents showed that capillary suction time (CST) increased linearly from 34.90 ± 0.10 s to 104.90 ± 0.30 s (R² = 0.92, p < 0.01), whereas the solid content of centrifuge cake decreased from 21.23 %±0.45 % to 12.52 %±0.14 % (R² = 0.89, p < 0.01) when organic fractionincreased from 35.72 % to 61.11 %. These results first confirmed that WAS dewatering performance was negatively correlated to its organic content. Then, the underlying mechanism was revealed by studying the basic physicochemical properties of WAS with various organic content. The results showed that sludge with a higher organic content generally had greater extracellular polymeric substances (EPS) content, lower density and higher negative zeta potential, which hinder the aggregation and flocculation of floc particles. These properties endow the WAS with a higher organic content generally possessed more bound water content, small pores, poorer fluidity, and stronger network strength. These characteristics can hamper the separation of water from sludge cake during dewatering. Based on which, this study discussed the potential of organic fraction as a surrogate of EPS for evaluating WAS dewaterability and indicated the organic fraction can be a useful and strong indicator of WAS dewaterability.

Evidence for the therapeutic effect of the organic content in Szigetvár thermal water on osteoarthritis: a double-blind, randomized, controlled clinical trial

The therapeutic effects of mineral waters have been attributed to the inorganic components alone; however, biologically active organic components are also present. We aimed to investigate whether the healing effect of Szigetvár thermal mineral water could relate to the organic matter in patients suffering from osteoarthritis of the hips and the knees. XAD macroreticular resins were used to prepare the organic fraction. Patients received a 30-min thermal water (34 °C) treatment in a bath tub, five times a week for 3 weeks. After randomization, patients were divided into three groups: tap water, mineral water, and organic fraction group. Primary outcomes were range of movement (ROM), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and visual analog scale (VAS) for pain severity, and the Short Form 36 (SF-36) questionnaire was used. These scores and indices were measured at baseline, after the last treatment, and at the end of the 3-month follow-up period. Seventy-four patients (age 67.3 ± 4.48 years) were enrolled: tap water n = 24, mineral water n = 26, and organic fraction n = 24. Treatment with the redissolved organic fraction significantly improved ROM, WOMAC, and SF-36 scores compared to the tap water. Our clinical trial provided evidence for the beneficial health effects of the organic fraction of Szigetvár medicinal water.

Impact of the pre-collection phase at different intensities of source segregation of bio-waste: An Italian case study

The contribution of the N2O and CH4 emissions generated during pre-collection of the organic fraction of municipal solid waste was investigated for an existing Italian collection district in a life cycle perspective. This district consisted of about 24,000 inhabitants generating 35.6Mg/day of municipal solid waste, of which 7.27Mg/day was the organic fraction. Different source segregation intensities and collection frequencies (day(-1)) were analyzed. The amount of the organic fraction not segregated at source was assumed to be collected commingled with the residual waste. The main findings showed that the lower was the collection frequency, the lower was the fuel consumption of the collection vehicles. For a source segregation intensity of 0%, the amount of fuel consumed ranged from 3.92L to 1.73L for each Mg of organic fraction as the collection frequency was decreased from 1day(-1) to 14day(-1), respectively. The maximum fuel consumption for the collection of 1Mg of organic fraction for a source segregation intensity of 50% was from 8.6L/Mg to 2.07L/Mg for a collection frequency of 1day(-1) and 14day(-1), respectively. On the other hand the lower was the collection frequency, the higher was the amount of greenhouse gas generated during the pre-collection phase. The life cycle analysis showed that these emissions could affect the global warming potential of the scenarios analyzed up to 40%, exceeding the reduction of the emissions due to lower fuel consumption. In any case, as already reported by other authors, the uncertainty analysis confirmed the higher value for the uncertainty associated to the emissions from biological processes compared to those generated by industrial and combustion ones.

Spatial and temporal assessment of metal pollution in the sediments of the Qaraoun reservoir, Lebanon

This study reports on metal (Cd, Cr, Cu, Ni, Pb, and Zn) pollution in the sediments of the Qaraoun reservoir over a span period of 9 years (2004, 2008, and 2013) along with key major environmental indicators. This time period corresponds with the onset of the rapid economic and industrial development of the reservoir region. For the first time, this study assessed the degree of environmental pollution by using indices such as enrichment factors (EF), contamination factors (CF), pollution load index (PLI), and geoaccumulation index (I geo). Moreover, sequential extraction was used to study the operationally determined chemical forms of the metals and their spatial and temporal distribution in the sediments. Correlation coefficients were also calculated to delineate the origin and association of the metals. Total metal concentrations and the environmental indices indicated increased pollution with time. Total organic carbon data showed a remarkable and significant increase in the organic fraction in 2013 relative to previous years. The increase in the organic fraction in the sediments was accompanied with a shift in cadmium [Cd] and lead [Pb] fractionation from the carbonate fraction to the organic fraction. The enrichment of the metal in the sediments along with the increased organic content is expected to exacerbate the metal bioavailability in the reservoir.

Characterization of the precursors of trihalomethanes and haloacetic acids in the Yuqiao Reservoir in China

To identify the primary precursors of trihalomethanes and haloacetic acids in the Yuqiao Reservoir in China, dissolved organic matters in the source water were isolated and fractionated into five different fractions (with XAD resin), and both trihalomethane and haloacetic acid formation potentials in each fraction were analysed by liquid-liquid extraction and GC-ECD. The primary precursors of trihalomethanes and haloacetic acids were identified using the index of disinfection by-product formation potential and specific disinfection by-product formation potential. In addition, the relationship between the specific ultraviolet absorbance and the specific disinfection by-product formation potential was studied using correlation analysis. The results indicated that during the sampling period, the hydrophobic acids and hydrophilic matter are the primary organic fractions in the Yuqiao Reservoir, accounting for 27.6-40.9% and 21.2-32.5%, respectively. Among the five fractions, the hydrophobic acids had the highest disinfection by-product formation potential and specific disinfection by-product formation potential, indicating that the hydrophobic acids were the primary precursors of the disinfection by-products in the Yuqiao Reservoir. A correlation analysis indicates that the specific ultraviolet absorbance had a moderately positive correlation with the specific disinfection by-product formation potential; therefore, the specific ultraviolet absorbance can be a reference index to analyse the ability of organic matter to generate disinfection by-products.

Biogenic and anthropogenic organic components of Saharan sands

Till now, the Sahara desert sands have scarcely characterized for their organic contents, despite they are known to heavily affect Europe and America when transported by winds. In this study, the composition of sands collected in ten oasis lying in two regions of the Algerian Sahara during 2011 was investigated with regards to organic fraction. Attention was paid to anthropogenic and biogenic sources of organics associated to sands, through the characterization of n-alkanes, n-alkanoic and n-alkanedioic acids, n-alkanols, sterols, PAHs and caffeine. The organic fraction load on sands associable to natural sources was higher in the Region of Biskra than in that of Ouargla. The biogenic contribution to the total amount of organics in sands exceeded that of the anthropogenic sources. The composition of sands from Hassi Messaoud, compared to that observed there in 2006, showed that the anthropic impact over the region was not changed.