Coupling of (methane + air)-membrane biofilms and air-membrane biofilms: Treatment of p-nitroaniline wastewater.

Membrane biofilm (MBf) technology is a promising biological water treatment process that combines membrane aeration with biofilms. To expand its application in the treatment of toxic organic wastewater, methane/air gas mixture-MBfs ((CH4 + Air)-MBfs) and air-MBfs were coupled to enhance the treatment of p-nitroaniline (PNA) wastewater. Based on exploration of the membrane permeability of methane and oxygen, a hybrid MBf reactor was constructed, and the degradation characteristics of PNA and the coupling effects of (CH4 + Air)-MBfs and air-MBfs were studied. The permeation flux of methane was found to be 1.114 g/(m2 d) when using a methane/air gas mixture at an aeration pressure of 10 kPa, and this result was better than that when methane was used as the aeration gas alone. Aeration with a methane/air gas mixture provided conditions for realizing aerobic methane oxidation; the aerobic methane oxidation that occurred in the (CH4 + Air)-MBfs promoted the reduction of PNA, and the intermediates of PNA degradation were further degraded by the air-MBfs. At an influent PNA membrane area load of 1.67 g/(m2 d), the PNA removal load reached 187.30 g/(m3 d). The coupling of MBfs took advantage of different matrix-based MBfs and promoted the degradation of PNA by utilizing the synergistic effects of various functional microorganisms.

[Vessel Emission Inventories and Emission Characteristics for Inland Rivers in Jiangsu Province].

Based on ship visas, lockage data, and automatic identification system (AIS) data, vessel emission inventories for inland rivers of Jiangsu Province were established by using a vessel power-based approach, and the characteristics of vessel emissions were also discussed. The results showed that NOx, SO2, PM2.5, PM10, hydrocarbons (HC), CO, and CO2 emissions of inland ships in 2014 were 1.87×105, 5.13×104, 8.2×103, 1.1×104, 6.4×103, 1.67×104, and 1.05×107 t, respectively, for inland vessels (excluding the Yangtze River), and dry cargo ships had the largest pollutant emissions. The highest pollutant emissions were found in the tonnage range of 200-600 t, and the highest pollutant emissions were found during the normal navigation conditions of ships. For the arrival of ships in the Jiangsu section of the Yangtze River, the non-container cargo ships had the highest pollutant emissions, and the emissions of pollutants were the highest under loading and unloading conditions. Under a cruise state, the main engine and auxiliary engine were the main emission units for different power units; for transit ships in the Jiangsu section of the Yangtze River, non-container cargo ships had the highest pollutant emissions, followed by oil tankers. The highest emissions of all pollutants occurred under slow driving conditions, and for different power units, the emissions of SO2, PM2.5, and PM10 from the main engine were higher than those from the auxiliary engine. The emissions of atmospheric pollutants along the channel length of the channel of the North Jiangsu section of the Beijing-Hangzhou Grand Canal were relatively large, followed by those of the South Jiangsu Channel. The inland ship emissions in Jiangsu Province were less affected by time, except for the slightly smaller proportion of emissions in February, and the proportion of emissions in other months was basically uniform, where values ranged from 8% to 10%.