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• Fe(III) could accelerate the growth rate of MAB under nitrogen shock loading. • ΔNO 2 −-N/ΔNH 4 +-N was lower than theoretical ratio due to marine Feammox process. • Haldane model was proper to analyze and predict nitrite inhibition on MAB. • MAB had better tolerance to nitrite than FAB under high saline surroundings. • MAB were synergized with Marinicella and Caldithrix to better remove total nitrogen. Marine anammox bacteria (MAB) were used to treat nitrogen-rich saline wastewater with Fe(III) addition under nitrogen shock loading. Ammonia loading rate (ALR) and nitrite loading rate (NLR) gradually increased from 0.033 and 0.039 to 0.68 and 0.89 kg/(m3·d), respectively. With 5 mg/L Fe(III) addition, ammonia removal rate (ARR) and nitrite removal rate (NRR) reached maximal values of 0.56 and 0.60 kg/(m3·d), respectively. The value of ΔNO 2 −-N/ΔNH 4 +-N was lower than theoretical ratio due to existing marine Feammox process. The growth rate of MAB was accelerated by Fe(III) and it dominated the reactor (27.70%). Besides, MAB were synergized with Marinicella and Caldithrix to achieve higher total nitrogen removal. Haldane model was proper to analyze and predict the effect resulting from nitrite on the activity of MAB under nitrogen shock loading. Overall, this study provides novel insights into the effect of Fe(III) on MAB treating nitrogen-rich wastewater. [ABSTRACT FROM AUTHOR]

Modern flood slackwater deposits (SWD) were investigated and sampled in the upper reaches of Hanjiang River and the Weihe River valleys, China. Magnetic susceptibility and grain-size distribution were analyzed in the laboratory. The results show that the magnetic susceptibility values of the modern flood SWD vary between 20 × 10 −8 m 3 kg −1 and 60 × 10 −8 m 3 kg −1 , very close to that of the Malan Loess over the Weihe River basin. These sediments were newly deposited and uninfluenced by weathering and pedogenesis. The grain-size distribution of the modern flood SWD is dominated by silt, with sand and clay, indicating that these sediments were sourced from the suspended sediment load of floodwater. However, the grain-size distribution of the modern flood SWD has more sand-sized sediments in the upper reaches of Hanjiang River valley than that in the Weihe River valley. The modern flood SWD are defined as sandy silt and silty sand in the upper reaches of Hanjiang River valley, whereas the modern flood SWD are defined as silt, sandy silt and clayey silt in the Weihe River valley. The modern flood SWD have different sediment sources and transporting forces. The modern flood SWD are sourced mainly from the Qinling and the Bashan bedrock mountains and the related residual deposits, slopewash and mud-rock flow deposits in the upper reaches of Hanjiang River valley. During rainstorms, torrential tributary rivers can bring much coarse deposits into the mainstream of the Hanjiang River. However, the sources of the modern flood SWD are the eolian loess and the related surface soil in the Weihe River valley. Comparative study shows different sedimentary features between the modern flood SWD in the upper reaches of Hanjiang River valley and that in the Weihe River valley. These results give insight into the different sediment sources and transporting force of the modern flood SWD, which provide a basic reference to mitigate flood disasters, and to soil and water conservation. [ABSTRACT FROM AUTHOR]