【正文】 noxic basins were provided with low speed mixer to keep the mixed liquid suspended solids (MLSS) in suspension. In the aerobic zone, diffusers were used to generate air bubbles for oxidation of anics and ammonia. Dissolved oxygen (DO) concentration in the aerobic basin was maintained at mg/1 and was monitored continuously through online DO meter. The solid liquid separation happens in aerobic basin with the help of five flat sheet membranes having a pore size of pm. The area of each membrane was m2. They were connected together by a mon tube. A peristaltic pump was connected in the mon tube to generate suction pressure. In the mon tube provision was made to acmodate pressure gauge to measure transmembrane pressure (TMP) during suction. The suction pump was operated in sequence of timing, which consists of 10 min switch on, and 2 min switch off. . Thermo chemical digestion of sludge Mixed liquor from aerobic basin of MBR was withdrawn at the ratio of % of Q/day and subjected to thermo chemical digestion. Thermo chemical digestion was carried out at a fixed pH of 11(NaOH) and temperature of 75 ℃ for 3 h. After thermo chemical digestion the supernatant and sludge were separated. The thermochemically digested sludge was amenable to further anaerobic biodegradation (Vlyssides and Karlis, 2021), so it was sent to theanaerobic basin of the MBR . Phosphorus recovery Lime was used as a precipitant to recover the phosphorous in the supernatant. After the recovery of precipitant the content was sent back to anoxic tank as a carbon source and alkalinity supelement for denitrification. . Chemical analysis COD, MLSS, TP, TN of the raw and treated wastewater were analyzed following methods detailed in (APHA, 2021). The influent and effluent ammonia concentration was measured using an ionselective electrode (Thereto Orion, Model: 95 一 12). Nitrate in the sample was analyzed using cadmium reduction method (APHA, 2021). 3. Results and discussion Fig. 1 presents data of MLSS and yield observed during the operational period of the reactor. One of the advantages of MBR reactor was it can be operated in high MLSS concentration. The reactor was seeded with EBPR sludge from the Kiheung, sewage treatment plant, Korea. The reactor was startup with the MLSS concentration of 5700 mg/L. It starts to increase steadily with increase in period of reactor operation and reached a value of 8100 mg/L on day 38. From then onwards, MLSS concentration was maintained in the range of 7500 mg/L by withdrawing excess sludge produced and called run I. The observed yields (Yobs) for experiments without sludge digestion (run I) and with sludge digestion were calculated and given in Fig. 1. The Yobs for run I was found to be gMLSS/gCOD. It was paratively lower than a value of gMLSS/gCOD reported for the conventional activated sludge processes (Tchobanoglous et al., 2021). The difference in observed yield of these two systems is attributed to their working MLSS concentration. At high MLSS concentration the yield observed was found to be low (Visvanathan et al., 2021). As a result of that MBR generated less presently used MLSS ranges (一 g/L) are selected on the basis of the remendation by Rosenberger et al. (2021). In their study, they reported that the general trend of MLSS increase on fouling in municipal applications seems to result in no impact at medium MLSS concentrations (7 一 12 g/L). The thermo chemical sludge digestion was started on day 70 by withdrawing sludge at the ratio of ％ Q/day. The sludge digestion period was divided into two phases namely, run II (day 70139) and run III (day 140210). During run II, the MLSS concentration in MBR was maintained around 7500 mg/L and for run III it was maintained around 10500 mg/L. Both of these two runs (II and III) demonstrate the role of sludge disintegration in controlling the excess sludge production. The Yobs for run II and III were found to be , respectively. It accounts for 58% and 75% of sludge reduction when pared to run I. The observed yield for run III was found to be lower than run II. This is due to the fact that at run III more amount of biosolids were subjected to be sludge digestion. It is evident from the data that the COD removal efficiency of A2O system remains unaffected before and after the introduction of sludge digestion practices. A test analysis showed that the differences between the period without sludge digestion (run I) and with sludge digestion (run II and III) are not statistically significant. However, it has been reported that, in wastewater treatment processes including disintegrationinduced sludge degradation, the effluent water quality is slightly detonated due to the release of nondegradable substances such as soluble microbial products (Yasui and Shibata, 1994。 2H2O). The synthetic wastewater was prepared three times a week with concentrations of 210 177。s of enhanced biological phosphorus removal system (EBPR). The released phosphorous can be recovered in usable products using calcium salts precipitation method. Keeping this fact in mind, in the present study, a new advanced wastewater treatment process is developed by integrating three processes, which are: (a) thermo chemical pretreatment in MBR for excess sludge reduction (b) A2O process for biological nutrient removal (c) P recovery through calcium salt precipitation. The experimental data obtained were then used to evaluate the performance of this integrated system. 2. Methods . Wastewater The synthetic domestic wastewater was used as the experimental influent. It was basically posed of a mixed carbon source, macro nutrients (N and P), an alkalinity control (NaHCO3) and a microelement solution. The position contained (L39。 參考文獻(xiàn) 1. Akin, ., Ugurlu, A., 2021. The effect of an anoxic zone on biologic