Feeding frequency efficacy on biogas yield of oily substrate anaerobic digestion in continuous stir tank reactor.

Anaerobic treatment of oily substrate, known as grease trap waste (GTW), was investigated for its practicability via continuous stirred tank reactor (CSTR) at different operating conditions and selected recovery strategies of feeding frequency efficacy. This study determine the performance of feeding frequency efficacy, namely feeding every 24 hours (R24H) and feeding every 12 hours (R12H). Under organic loading rate (OLR) of 2.2 gCOD/L.day, R12H exhibited methane composition of 57%, methane production rate of 0.27 LCH4/L.day, and methane yield of 0.14 LCH4/gCODremoved. At the same OLR, R24H recorded methane composition of 60%, methane production rate of 0.29 LCH4/L.day and similar methane yield as R12H. Findings indicated that R24H showed performance comparable to that of R12H. Given minor variation observed in performance, it is recommended that plant operators may consider scheduling two feedings per day for low loading conditions and switch to one feeding per day for higher loading conditions. This strategy is designed to balance the system and prevent shock loads, which could lead to plant shutdowns. This mechanism will induce their conversion to volatile fatty acids (VFAs); thus, reducing the risk of acid accumulation and pH drops, which could inhibit methanogens to produce methane, especially for oily substrate.

Co-digestion of palm oil mill effluent for enhanced biogas production in a solar assisted bioreactor: Supplementation with ammonium bicarbonate.

Lack of sufficient nitrogenous substrate and buffering potential have been acknowledged as impediments to the treatment of palm oil mill effluent through co-digestion processes. In this study, ammonium bicarbonate was used to provide the nitrogenous substrate and buffering potential. To regulate the impact of ammonium bicarbonate toxicity on the anaerobic co-digestion system, dosages from 0 to 40 mg/L were supplemented. The biogas yield was used to indicate the effects of NH4+ toxicity. In a solar-assisted bioreactor, solar radiation was first collected by a solar panel and converted into electricity, which was then used to heat a mixture of palm oil mill effluent and cattle manure to maintain the reactor in the mesophilic temperature range. This co-digestion operation was performed semi-continuously and was analyzed at a 50:50 mixing ratio of palm oil mill effluent and cattle manure. The results indicate that the additional dosing of ammonium bicarbonate can significantly enhance biogas production. Maximum cumulative biogas and methane productions of 2034.00 mL and 1430.51 mL, respectively, were obtained with the optimum addition of 10 mg/L ammonium bicarbonate; these values are 29.80% and 42.30% higher, respectively, than that obtained in the control co-digestion operation without addition of ammonium bicarbonate. Utilization of a mathematical equation (G = Gmk/t) to describe a kinetic analysis of the biogas yield also indicated that the optimum ammonium bicarbonate dose was 10 mg/L. The results of this study suggest that supplementation with ammonium bicarbonate doses of up to 40 mg/L can be used to provide nitrogenous substrates and buffering potential in anaerobic co-digestion processes. The determination of the optimal dose provides an alternative and efficient option for enhanced biogas production, which will have obvious economic advantages for feasible industrial applications.

Enhanced Methane Yield by Codigestion of Sewage Sludge with Microalgae and Catering Waste Leachate.

The codigestion of different wastes is a promising concept to improve methane generation during anaerobic processes. However, the anaerobic codigestion of catering waste leachate with algal biomass and sewage sludge has not been studied to date. The present study investigated methane generation by the anaerobic codigestion of different mixtures of catering waste leachate, microalgal biomass, and sewage sludge. Codigestion of waste mixture containing equal ratios of three substrates had 39.31% higher methane yield than anaerobic digestion of raw sludge. This was possibly because of a proliferation of methanogens during the codigestion period, induced by multiphase digestion of different wastes with different degrees of digestibility. Therefore, codigestion of catering waste leachate, microalgal biomass, and sewage sludge appears to be an efficient technology for energy conversion from waste resources. The scientific application of this codigestion technology with these three substrates may play a role in solving important environmental issues of waste management.

Anti-inflammatory Potential of Artemisia capillaris and Its Constituents in LPS-induced RAW264.7 Cells

Artemisia capillaris has been widely used as an alternative therapy for treating obesity and atopic dermatitis. It has been used as a hepatoprotactant. It is also used for ameliorating inflammatory reactions. Although there are several investigations on other Artemisia species, there is no systematic study describing the role of A. capillaris MeOH extract, its solvent soluble fractions, or derived anti-inflammatory principal components in regulating inflammatory conditions. Therefore, the objective of this study was to elucidate anti-inflammatory mechanisms of A. capillaris. Results revealed that MeOH extract of A. capillaris could decrease LPS-stimulated NO secretion. Of tested fractions, CH₂Cl₂, EtOAc, and n-BuOH strongly inhibited NO release from RAW264.7 cells. Bioactive mediators derived from CH₂Cl₂ and n-BuOH fractions elicited potent anti-inflammatory actions and strikingly abrogated LPS-triggered NO accumulation in RAW264.7 cells. Of particular interest, capillin and isoscopoletin possessed the most potent NO suppressive effects. Western blot analysis validated the molecular mechanism of NO inhibition and showed that capillin and isoscopoletin significantly down-regulated iNOS and COX-2 protein expression. Taken together, our results provide the first evidence that MeOH extract, CH₂Cl₂, EtOAc, and n-BuOH fractions from A. capillaris and its derived lead candidates can potently suppress inflammatory responses in macrophages by hampering NO release and down-regulating iNOS and COX-2 signaling.

Inhibition of advanced glycation endproducts formation by Korean thistle, Cirsium maackii

OBJECTIVE@#To evaluate inhibitory potential of seven Korean thistles against the advanced glycation endproducts (AGE) formation as well as to identify responsible compounds from the most active species.@*METHODS@#We used an in vitro AGE inhibition assay to evaluate the anti-diabetic complication potential of the methanol extracts of the selected Korean thistles.@*RESULTS@#Among the seven Korean thistles, the leaves of Cirsium maackii (C. maackii) exhibited the most significant inhibitory activity against AGE formation. By means of bioassay-directed fractionation, a lignan, chlorogenic acid and 14 flavonoids were isolated from the active ethyl acetate soluble fraction of a methanol extract from C. maackii leaves. Luteolin and its 5-O-glucoside have been previously isolated; however, a lignan and 13 known compounds were isolated for the first time from C. maackii leaves in this study. Most of the isolated compounds exhibited inhibitory activities against potential AGE formation. Among them, cernuoside was shown to be the most potent AGE inhibitor with an IC50 value of 21.21 μ mol/L. Most importantly, two major flavonoids, luteolin and its 5-O-glucoside, also significantly inhibited AGE formation, with IC50 values of 36.33 and 37.47 μ mol/L, respectively. Structure activity relationship revealed that the presence of free 3' and 4' dihydroxyl group in flavonoids skeleton played an important role in AGE inhibition.@*CONCLUSIONS@#These results indicate that C. maackii and C. maackii-derived flavonoids might be explored further to develop therapeutic agents for the prevention of diabetic complications due to their significant inhibitory activity against AGE formation.

Inhibition of advanced glycation endproducts formation by Korean thistle, Cirsium maackii

Objective: To evaluate inhibitory potential of seven Korean thistles against the advanced glycation endproducts (AGE) formation as well as to identify responsible compounds from the most active species. Methods: We used an in vitro AGE inhibition assay to evaluate the anti-diabetic complication potential of the methanol extracts of the selected Korean thistles. Results: Among the seven Korean thistles, the leaves of Cirsium maackii (C. maackii) exhibited the most significant inhibitory activity against AGE formation. By means of bioassay-directed fractionation, a lignan, chlorogenic acid and 14 flavonoids were isolated from the active ethyl acetate soluble fraction of a methanol extract from C. maackii leaves. Luteolin and its 5-O-glucoside have been previously isolated; however, a lignan and 13 known compounds were isolated for the first time from C. maackii leaves in this study. Most of the isolated compounds exhibited inhibitory activities against potential AGE formation. Among them, cernuoside was shown to be the most potent AGE inhibitor with an IC50 value of 21.21 μ mol/L. Most importantly, two major flavonoids, luteolin and its 5-O-glucoside, also significantly inhibited AGE formation, with IC50 values of 36.33 and 37.47 μ mol/L, respectively. Structure activity relationship revealed that the presence of free 3' and 4' dihydroxyl group in flavonoids skeleton played an important role in AGE inhibition. Conclusions: These results indicate that C. maackii and C. maackii-derived flavonoids might be explored further to develop therapeutic agents for the prevention of diabetic complications due to their significant inhibitory activity against AGE formation.