Safety risk assessment of loess tunnel construction under complex environment based on game theory-cloud model.

Due to the impact of the surrounding environment, the safety impact factors encountered during the construction of loess tunnels are complex and numerous, which causes frequent accidents, and there is a lack of safety risk assessment methods applicable to the construction of loess tunnels under complex environment. Based on the Luochuan tunnel project of the Xi'an-Yan'an High-Speed Railway, this paper analyzes the impact factors of loess tunnel construction risks, and 15 main impact factors involving subjective and objective factors are selected to establish the safety risk assessment system of loess tunnel construction under complex environment. To determine the weight of the impact factors, this paper introduces the combination weighting method based on game theory for the first time.

Evolved gas analysis and slow pyrolysis mechanism of bamboo by thermogravimetric analysis, Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry.

Slow pyrolysis of bamboo is an important conversion pathway to produce biofuels and chemicals such as biomass-derived fertilizer precursor (biochar). In this study, evolved gas analysis during pyrolysis of bamboo was conducted by a combination of TG, FTIR and GC-MS to establish a detailed pyrolysis mechanism of bamboo biomass. The main decomposition temperature zones were 300-400 °C and it reached the maximum mass loss intensity at 350 °C based on DTG curves.

Biodegradation of nonylphenol during aerobic composting of sewage sludge under two intermittent aeration treatments in a full-scale plant.

The urbanization and industrialization of cities around the coastal region of the Bohai Sea have produced large amounts of sewage sludge from sewage treatment plants. Research on the biodegradation of nonylphenol (NP) and the influencing factors of such biodegradation during sewage sludge composting is important to control pollution caused by land application of sewage sludge. The present study investigated the effect of aeration on NP biodegradation and the microbe community during aerobic composting under two intermittent aeration treatments in a full-scale plant of sewage sludge, sawdust, and returned compost at a ratio of 6:3:1.

Odor composition analysis and odor indicator selection during sewage sludge composting.

Unlabelled: On the basis of total temperature increase, normal dehydration, and maturity, the odor compositions of surface and internal piles in a well-run sewage sludge compost plant were analyzed using gas chromatography-mass spectrometry with a liquid nitrogen cooling system and a portable odor detector. Approximately 80 types of substances were detected, including 2 volatile inorganic compounds, 4 sulfur organic compounds, 16 benzenes, 27 alkanes, 15 alkenes, and 19 halogenated compounds. Most pollutants were mainly produced in the mesophilic and pre-thermophilic periods.

Impact of composting strategies on the degradation of nonylphenol in sewage sludge.

Nonylphenol can be present in sewage sludge, and this can limit the use of the sewage sludge to amend soil. Composting is one of the most efficient and economical methods of making sewage sludge stable and harmless. The nonylphenol degradation rates during composting with added bulking agents and with aeration applied were studied.