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The main objective of present study was to understand the community succession of microbial populations related to carbon-nitrogen-phosphorus-sulfur (CNPS) biogeochemical cycles during cow-manure-driven composting and their correlation with product maturity. The abundance of microbial populations associated with C degradation, nitrification, cellular-P transport, inorganic-P dissolution, and organic-P mineralization decreased gradually with composting but increased at the maturation phase. The abundance of populations related to N-fixation, nitrate-reduction, and ammonification increased during the mesophilic stage and decreased during the thermophilic and maturation stages. The abundance of populations related to C fixation and denitrification increased with composting; however, the latter tended to decrease at the maturation stage. Populations related to organic-P mineralization were the key manipulators regulating compost maturity, followed by those related to denitrification and nitrification; those populations were mediated by inorganic N and available P content. This study highlighted the consequence of microbe-driven P mineralization in improving composting efficiency and product quality.

Microalgae are the most prospective raw materials for the production of biofuels, pyrolysis is an effective method to convert biomass into bioenergy. However, biofuels derived from the pyrolysis of microalgae exhibit poor fuel properties due to high content of moisture and protein. Co-pyrolysis is a simple and efficient method to produce high-quality bio-oil from two or more materials. Tires, plastics, and bamboo waste are the optimal co-feedstocks based on the improvement of yield and quality of bio-oil. Moreover, adding catalysts, especially CaO and Cu/HZSM-5, can enhance the quality of bio-oil by increasing aromatics content and decreasing oxygenated and nitrogenous compounds. Consequently, this paper provides a critical review of the production of bio-oil from co-pyrolysis of microalgae with other biomass wastes. Meanwhile, the underlying mechanism of synergistic effects and the catalytic effect on co-pyrolysis are discussed. Finally, the economic viability and prospects of microalgae co-pyrolysis are summarized.

Carrier aerated biofilm reactor (CABR) with nylon silk as the biofilm growth carrier was constructed to treatment of polluted surface water, which could improve the practical application in comparison with MABR process. The results show that CABR process can effectively improve the self-purification capacity of the polluted surface water, efficient removal of COD and NH3-N, making water quality achieve the level V of Environmental Quality Standards for Surface Water (GB 3838-2002, China). Modified nylon silk can alter the community structures and increase bacteria during CABR process operation. Large pore size of nylon silk leads to the formation of special biofilm structure in CABR. Extracellular polymer (EPS) and membrane fouling resistance distribution indicated that the nylon silk fouling control ability of CABR reactor is much higher than that of membrane-aerated biofilm reactors (MABR). The results show that the CABR process can effectively purify surface water and improve the practical application.

As an alternative energy source for fossil energy, use of biomass pyrolysis to reduce pyrolusite is of great significance for energy conservation, emission reduction and environmental protection. Kinetics and thermodynamics of reducing pyrolusite using biomass pyrolysis was studied using thermogravimetric analysis analysis. Five non-isothermal methods, Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, Distributed Activation Energy Model, Starink and Friedman, were employed to calculate the pyrolysis kinetics and thermodynamic parameters. The results showed that pyrolusite reduction by biomass pyrolysis can be divided into four stages: drying stage (30–175 °C), rapid pyrolysis reduction stage (175–350 °C), slow pyrolysis reduction stage (350–680 °C) and char formation stage (680–900 °C). The apparent activation energy, reaction enthalpy, Gibbs free energy and entropy change of pyrolusite reduction by biomass pyrolysis was calculated ranges from 170 to 180 kJ/mol, 164 to 174 kJ/mol, 136.97 to 137.25 kJ/mol and 45.67 to 61.91 J/mol·K, respectively. This work provides theoretical basis and practical guidance for the reduction of pyrolusite by waste corn stalk.

Bioelectrochemically-assisted vermifilter (VBFBE) with sewage sludge as the anode fuel was constructed to accelerate composting of sewage sludge, which could increase the quality of the compost and harvest electric energy in comparison with vermicomposting and electrochemical only. Results revealed that the sludge stabilization with a higher soluble chemical oxygen demand (SCOD) and lower NH4+-H during 40 days of composting. At the composting, pH, C/N, electrical conductivity (EC) and germination index (GI) results demonstrated that the maturity degree of VBFBE4 was higher than that of other VBFBE. The VBFBE4 yielded a voltage of 1.024 V and maximum power density of 105.28 mW/m2 on 3th day. The bacteria in VBFBE4 were richer and higher in terms of diversity than those in other VBFBE, that was demonstrated that combination vermicomposting and electrochemistry could improve the sludge stabilization degree, accelerate sludge composting process and enhance composting maturity.

This study was conducted to determine the effects of lactic acid bacteria (LAB, Lactobacillus salivarius) inoculation on the microbial, physical and chemical properties of food waste mixture (FWM) stored at ambient temperature (25 degrees C) for 10 and 30 days. A complete pig diet including restaurant food waste, bakery by-product, barley and wheat bran, and broiler poultry litter was amended with LAB at the levels of 0.1%, 0.2%, 0.5% and 1.0% and fermented anaerobically. These treatments were compared with intact FWM before storage and non-anaerobically stored FWM. Non-anaerobic storage of FWM showed microbial putrefaction with the loss (P0.05) of water and water soluble carbohydrate (WSC) and increases (P0.005) in protein and fiber. Anaerobic fermentation of FWM with or without LAB seemed effective in both 10- and 30-day-storage. The addition of LAB inoculants to FWM showed a linear trend (P0.05) toward an increase in the number of total and lactic acid bacteria and toward the nutritional improvement with WSC increased and fiber decreased. Long-term (30 days) storage resulted in consistent reduction (P0.05) in numbers of total and lactic acid bacteria and pH and showed little change in chemical components, compared with short-term (10 days) storage. On the basis of these results, LAB inoculation improved fermentative characteristics of FWM. Among anaerobic treatments, further WSC increase and NDF reduction did not occur (P0.05) when LAB-added levels were over 0.2%. Based on these observations the optimum level of LAB addition to FWM was 0.2%.