外文翻译---在启动过程中加装膜生物反应器的氧化沟的性能(编辑修改稿)

外文翻译---在启动过程中加装膜生物反应器的氧化沟的性能(编辑修改稿)内容摘要：

month respectively. The change in MLSS concentration shown in Fig. 3 reveals that a relatively high MLSS concentration (such as on day 14 and 56) affects the membrane permeability dramatically. The results imply that the permeate flux variation is an inverse function of MLSS concentration. Similar result was found by InSoung Chang and SuNa Kim [12], who proposed that the MLSS concentration caused a cake filtration resistance on membrane and decrease in MLSS concentration led to a reduction in the resistance of filtration [12]. MLSS CONCENTRATION AND DO As can be shown, the MLSS concentrations (Fig. 3) are interrelated to the DO concentration (Fig. 4) and pH (Fig. 5).Coarse bubble aeration was provided in the MBR system in order to scrub and prevent biofouling on membrane surface. Due to greater DO levels in the MBR, the average MLSS concentration in MBR tank was higher than in OD. On the other hand, sharp increase in MLSS concentration can influence sudden drop in DO levels. For example, on days 14 and 56, the MLSS in OD and MBR reduced a lot of DO in the systems. TURBIDITY From Fig. 6, the inlet wastewater has lower turbidity than that of in the MBR and OD. Turbidity and MLSS concentration display similar trends, due to the fact that both are related with 6 the amount of suspended solids present in wastewater. Therefore, the first and second peaks of MLSS concentration give rise to similar peaks of turbidity. However, the overall average turbidity in MBR is greater than that in the OD. As expected, this submerged microfiltration membrane can separate sludge cells from wastewater very well and it can be seen from Fig. 6 that the membrane shows a 100% filterability with no significant turbidity in permeate flux. PH From Fig. 5, the raw wastewater pH displayed higher average level (– ) than that of permeate (– ) from the MBR due to a high ammonia loading in raw wastewater. Moreover, optimum pH range strongly impact the MLSS concentration as well as DO. For instance, sharp drop of Ph in the inlet and permeate on the day 21 and 63 caused a large decrease in MLSS concentration only in MBR, while it did not affect MLSS in the OD. It can be concluded that as long as the fluctuation of pH is within the acceptable range, no significant change would occur in the MLSS concentration. The optimum pH range of this system should be around 6– . SOULUBLE PROTEIN AND CARBOHYDRATE All EPS were mainly posed of carbohydrate, protein and humic substance. Carbohydrate was predominant in the acidogenic sludge (62% in the EPS extracted by formaldehyde– NaOH), whereas protein was predominant in the methanogenic sludge (41%) [13]. With NaOH extraction of EPS, change in protein and carbohydrate content along the treatment train are shown in Figs. 7 and 8. The inlet position posed of much higher soluble protein than carbohydrate, while OD and MBR systems had more carbohydrate than protein. It agrees with the work of Hong Liu and Herbert . Fang in 2020 [13]. Soluble protein (see Fig. 7) fluctuated in the 7 beginning and converged to about 5– 10 mg/L in both OD and MBR systems, while average carbohydrate (see Fig. 8) were mg/L for OD and 37 mg/L for MBR. The ratios of carbohydrate to protein converged to some fixed value since the 4th week and they were around and 5 for OD and MBR respectively. Ratios between protein and carbohydrate within the EPS of the sludge increased with time in the first few weeks corresponding to the changes of physicochemical properties of the sludge, and remained constant. This was similar to the results。