Simple SummaryIn our previous study, slaughterhouse sludge cake was trans-esterified to produce biofuel and some organic waste, i.e., crude glycerol. The crude glycerol was evaluated for feasibility of using crude glycerol as the feedstock to produce biofuel by anaerobic co-digestion with dairy cattle wastewater. Addition of crude glycerol significantly increased production efficiency of biogas but decreased the removal efficiency of total solids and volatile solids with increased crude glycerol volume. The results showed that the slaughterhouse sludge cake is a feasible feedstock for producing biodiesel and the waste, crude glycerol, can promote biogas production.AbstractExcessive sludge in the wastewater treatment basins has to be removed periodically and collected as the form of sludge cake for promising good water quality of the effluent. This study aims to evaluate the feasibility of biogas production by anaerobic co-digestion of dairy cattle wastewater and crude glycerol from transesterification of sludge cake. Different ratios of crude glycerol, i.e., 2, 4, and 8% (v/v), from the previous experiment were mixed with dairy cattle wastewater and inoculated with anaerobic sludge in cap-sealed 1-L serum bottles as anaerobic digesters. Although the 8% crude glycerol set showed the highest total biogas and methane production, low pH from volatile fatty acid accumulation decreased the removal efficiency of chemical oxygen demand, biochemical oxygen demand, and suspended solids after a 14-d incubation period. The experimental sets with 2 and 4% of crude glycerol increased total methane production up to 177 and 226% compared to the control set, respectively. We found that addition of crude glycerol decreased removal efficiency of total solids and volatile solids. In our study, we proved that slaughterhouse sludge cake is a feasible feedstock for producing biogas through transesterification and anaerobic co-digestion.

To study the co-reaction of benzoxazine and triazine, a triazine-containing benzoxazine (P-tta) was prepared through nucleophilic substitution of 4-(2H-benzo[e][1,3]oxazin-3(4H)-yl)phenol (P-ap) with 2,4,6-trichloro-1,3,5-triazine.

Profiling cancer molecules has several advantages; however, using microarray technology in routine clinical diagnostics is challenging for physicians. The classification of microarray data has two main limitations: 1) the data set is unreliable for building classifiers; and 2) the classifiers exhibit poor performance. Current microarray classification algorithms typically yield a high rate of false-positives cases, which is unacceptable in diagnostic applications. Numerous algorithms have been developed to detect false-positive cases; however, they require a considerable computation time. To address this problem, this study enhanced a previously proposed gene expression graph (GEG)-based classifier to shorten the computation time. The modified classifier filters genes by using an edge weight to determine their significance, thereby facilitating accurate comparison and classification. This study experimentally compared the proposed classifier with a GEG-based classifier by using real data and benchmark tests. The results show that the proposed classifier is faster at detecting false-positives.

Biosludge is a normal form of accumulating microbial populations inside the sewage or wastewater treatment facilities. Excessive sludge in the wastewater treatment basins has to be removed periodically to ensure good water quality of the effluent. This study aims to evaluate the feasibility of biodiesel production by transesterification of slaughterhouse sludge cake. The sludge cake was collected from a selected commercial slaughterhouse and transesterified with methanol, n-hexane, and acids (e.g., sulfuric acid or hydrochloric acid) at 55 °C. Three acid concentrations (2%, 4%, and 8%, v/v) in methanol under four reaction time periods (4, 8, 16, and 24 h) were applied. Results showed that the highest accumulated fatty acid methyl ester (FAME) yields of 2.51 ± 0.08% and 2.27 ± 0.09% were achieved when 8% (v/v) of H2SO4 or HCl were added in a 4 h reaction time, respectively. Methyl esters of palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), and oleic acid (C18:1n9c) were the major components of biodiesel from acid methanolysis of slaughterhouse sludge cake. Experimental and analytical results of acid methanolysis of slaughterhouse sludge cake showed that acid methanolysis of sludge cake was one of the feasible and practical options to recycle sludge waste and produce renewable energy.