A combined passivator of zeolite and calcium magnesium phosphate fertilizer: Passivation behavior and mechanism for Cd (II) in composting.

Passivation of heavy metals is one of the most efficient techniques to improve the quality of compost. Many studies confirmed the passivation effect of passivators (e.g., zeolite and calcium magnesium phosphate fertilizer) on cadmium (Cd), but passivators with single component could not effectively passivate Cd in the long-term operation of composting. In the present study, a combined passivator of zeolite and calcium magnesium phosphate fertilizer (ZCP) was used to explore its impacts of adding at different composting periods (heating period, thermophilic period, cooling period) on the Cd control, compost quality (e.g., temperature, moisture content and humification), microbial community structure as well as the compost available forms of Cd and addition strategy of ZCP. Results showed that Cd passivation rate could be increased by 35.70-47.92% under all treatments in comparison to the control treatment. By altering bacterial community structure, reducing Cd bioavailability and improving the chemical properties of the compost, the combined inorganic passivator could achieve high efficiency for Cd passivation. To sum up, the addition of ZCP at different composting periods has effects on the process and quality of composting, which could provide ideas for the optimization of the passivators addition strategy.

Pilot-scale two-phase anaerobic digestion of deoiled food waste and waste activated sludge: Effects of mixing ratios and functional analysis.

Anaerobic co-digestion of deoiled food waste (dFW) and waste activated sludge (WAS) can address the challenges derived from mono-digestion of FW. In the present study, a pilot-scale methanogenic bioreactor of a two-phase anaerobic digestion system was developed to explore the impact of dFW/WAS volatile solids ratios on the overall performance, microbial community, and metabolic pathways. Besides, the tech-economic of the system was analyzed. The results showed that the degradation efficiency of soluble chemical oxygen demand (SCOD) was more than 84.90% for all the dFW/WAS ratios (v/v) (1:0, 39:1, 29:1, 19:1 and 9:1). Moreover, the dominant genus of bacteria and archaea with different ratios were Lactobacillus (66.84-98.44%) and Methanosaeta (53.66-80.09%), respectively. Co-digestion of dFW and WAS (29: 1 in v/v ratios) obtained the highest yield of methane (0.41 L CH4/Ladded) with approximately 90% of SCOD being removed. In the pilot-scale experiment, the co-digestion of FW and WAS makes positive contribution to reusing solid waste for improving solid management.

[CT angiography features of the involved arterial branches of the spontaneous isolated superior mesenteric artery dissection].

OBJECTIVE: To explore the CT angiography features of the involved arterial branches of the spontaneous isolated superior mesentery artery dissection(SISMAD). METHODS: Clinical and CT angiogram data of 6 patients with SISMAD confirmed by dual source energy CT angiography were analyzed retrospectively. The CT angiography features and prognosis of patients were investigated. RESULTS: Average age of 6 patients was(45.83±5.60) years old. Ten branches of jejunoileal artery were involved in 4 patients. All the dissections of the superior mesenteric arteries(SMA) were extended from its proximal to its end. Intramural hematoma was found in all the involved branches, which showed eccentric target sign in the transverse section and sandwich sign in the longitudinal axial section. In 7 branches of 3 patients, the involved branches originated from the false lumina of the SMA. In one patient, the intramural hematoma of the jejunoileal arteries was found to be completely absorbed in a repeated CT angiography one year late. CONCLUSIONS: For the SISMAD, the involvement of the branches of the SMA may be associated with the extension of the dissection of the SMA. The inflation of the false lumina of the branches is worse than that of the SMA. With the improvement of the dissection of the SMA, the intramural hematoma of the branches can be absorbed. The conservative treatment may be the first choice for SISMAD without emergency.

[Experiment and numerical simulation of percolation control using evapotranspirative landfill cover system].

An Evapotranspirative Landfill Cover (ET Landfill Cover) is a simple and economical percolation control system that involves a monolithic soil layer with a vegetative cover.Percolation control in an ET cover system relies on the storage of moisture within the cover soils during precipitation events and subsequently returns it to the atmosphere by evapotranspiration. Percolation control experiments of a bare soil cover and 5 different ET covers were implemented in comprehensive experimental station of water environment of Wuhan University and the water balance calculation of each cover system was conducted, the results shown that the ET cover of 60 cm loamy soil layer with shrub was the most effective among the 6 experimental disposals. However, the experiments demonstrated 60 cm thick of soil layer was not enough to prevent percolation during rainy season and keep the shrub alive during drought season without irrigation. So the Hydrus 2D was selected to simulate the soil water movement in ET covers with different cover thicknesses, the simulations shown that the optimal ET cover in Wuhan area should be 120-140 cm loamy soil layer with shrub.