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Combined heat and power production from biogas is now playing an important role in energy and resource utilization as well as pollution control in waste water treatment. This research used biogas from the Bali Sewage Treatment Plant in New Taipei City, Taiwan, as a major source of fuel for the electricity generation. A micro gas turbine electricity generator, Capstone CR-30, which possesses a maximum rated power load (PWL) of 30 kW, was equipped to convert biogas into electricity. The biogas is mainly composed of CH4 (56.1 ± 8.0 vol.%), CO2 (25.5 ± 9.8 vol.%), H2 (0.5 vol.%), and H2S (0.99 ± 0.07 ppmv). During the test operation period of the generator, it was found that the thermal efficiency increases from 19.8% to 23.4% kWhe/kWhth, while the electricity generation efficiency (ηEB) also rises from 0.93 to 1.09 kWhe/m3 biogas as the PWL increases from 10 kW to 30 kW. The results indicated that the generator has a better performance with higher PWL. At PWL = 30 kW, the average adjusted concentrations of CO and NOx (adjusted to 15 vol.% O2) emitted from the generator are 86 ppmv and 17 ppmv, respectively. Both are much lower than the emission standards of stationary sources in Taiwan of 2000 ppmv and 150 ppmv, respectively. Thus, PWL of 30 kW was selected in cooperation with biogas inflow = 0.412 m3/min and air/fuel ratio (i.e., air/biogas ratio) = 76.0 vol./vol. for the long-term regular operation. At the above setting conditions for long-term operation, the generator continuously consumed the biogas and provided stable electricity generation at a rate of 19.64 kWhe/h for a 2-year running period. Moreover, the greenhouse gas can be cut off with a rate of 10.78 kg CO2e/h when using biogas as fuel for electricity generation. Overall, this research proves that the application of a micro gas turbine electricity generator not only has promising performance for using biogas but also gives a significant reduction of greenhouse gas emission, which fits the concepts of the circular economy and environmental protection.

In silico algorithms have been the common approach for transmembrane (TM) protein topology prediction. However, computational tools may produce questionable results and experimental validation has proven difficult. Although biochemical strategies are available to determine the C-terminal orientation of TM proteins, experimental strategies to determine the N-terminal orientation are still limited but needed because the N-terminal end is essential for membrane targeting. Here, we describe a new and easy method to effectively determine the N-terminal orientation of the target TM proteins in Escherichia coli plasma membrane environment. D94N, the mutant of bacteriorhodopsin from Haloarcula marismortui, can be a fusion partner to increase the production of the target TM proteins if their N-termini are in cytoplasm (Nin orientation). To create a suitable linker for orientating the target TM proteins with the periplasmic N-termini (Nout orientation) correctly, we designed a three-TM-helix linker fused at the C-terminus of D94N fusion partner (termed D94N-3TM) and found that D94N-3TM can specifically improve the production of the Nout target TM proteins. In conclusion, D94N and D94N-3TM fusion partners can be applied to determine the N-terminal end of the target TM proteins oriented either Nin or Nout by evaluating the net expression of the fusion proteins.

Concurrent nitrification and denitrification (CND) are natural phenomena in the soil environment that can be applied in wastewater treatment for enhanced total nitrogen removal. However, significant renovation is necessary for existing plants to equip them for nutrient removal. At a domestic wastewater treatment plant, we performed a pilot test by installing bioplates with entrapped biomass in a conventional aeration basin for CND, and investigated the effects of bioplate packing ratio (PR), hydraulic retention time (HRT), dissolved oxygen (DO) level, on/off aeration mode, and supplemental carbon and alkalinity on nitrogen removal. With the pilot aeration basin of 1.3 m 3 loaded with mixed liquor suspended solids of 1,500-2,500 mg/L and bioplates at PR of 3.2% INTRODUCTIONEngineers employ bacteria to treat human and industrial wastes to preserve environmental quality and ecosystems. The goal was to demonstrate TN removal that could be implemented in municipal WWTPs without significant interruption and renovation of existing facilities. METHODS Pilot system setup and operationsThe bioplates were prepared by immobilizing activated sludge in cellulose triacetate as a carrier as originally described The amendment of carbon and alkalinity was evaluated for the bioplate-augmented aeration basin under varied PR of 3.2, 6.5, 9.1, and 11.4% while holding HRT constant at 6 h and DO at 4-6 mg/L via intermittent aeration of 1 h on/ 1 h off. Table 2 presents When increasing presence of bioplates to a PR of 9.1% without supplemental carbon or alkalinity, the residual TN remained at about 11 ± 0.3 mg/L and the residual TKN at about 3.9 ± 0.5 mg/L (reduced from an influent TN of 25 ± 1.9 mg/L). COD removal was 72 ± 3.0% and TN removal was 57 ± 4.5% with 84 ± 2.7% nitrification. When supplemented with carbon or with both carbon and alkalinity, the effluent TN was reduced to 4.7 ± 1.5 and 3.6 ± 1.9 mg/ L, respectively. At the same time, the effluent TKN was reduced to 2.9 ± 1.2 mg/L, indicating excellent nitrification performance. The results show that increasing the PR of bioplates has not led to proportionally increased TN removal.Further increasing bioplate PR to 11.4% did not result in TN removal beyond those with PR of 6.5 and 9.1%. Without supplemental carbon or alkalinity, the effluent TN was 8.5 ± 1.0 mg/L from an influent TN of 27 ± 0.1 mg/L. With supplemental carbon or with both supplemental carbon and alkalinity, the effluent TN lowered to 5.2 ± 2.3 mg/L.The results in Table 2 showed no enhanced TN removal with increased packing of bioplates. Although improved treatment using entrapped biomass had been studied since 1985, much work had focused on the performance and mechanisms of simultaneous nitrification and denitrification with little attention on the extent of immobilized biomass.Morita et al. (, ) developed the packed gel envelopes system using PVA-SbQ gel that occupied 25% of the reactor volume, and they achieved 95% TN removal with supplemental carbon. In the present case, extensive biopla...