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A B S T R A C TIn recent years, membrane-based ultrafiltration (UF) and reverse osmosis (RO) have become popular worldwide as possible alternative methods to conventional ion exchange and clarification processes for the production of potable water. The performance of UF and RO membranes was evaluated for treatment of surface and ground water from Prakasam District of Andhra Pradesh, India; namely, jagarlamudi well water (JWW), jagarlamudi pond water (JPW), veerannapalem old pond water (VOPW), and veerannapalem new pond water (VNPW). Pilot-scale UF and RO systems were built indigenously by incorporating commercial hollow fiber polyacrylonitrile UF and thin film composite polyamide RO modules, respectively. Operating parameters such as feed concentration, pressure, and cross-flow velocity were varied to study their effect on membrane performance. Effect of fouling on flux and rejection characteristics of the membrane was evaluated. RO membrane exhibited a rejection of 96.4% for JWW and VOPW feeds with reasonable flux of 42.5 and 48 L m À2 h À1 , respectively, whereas, UF experiments with JPW and VNPW feeds revealed corresponding turbidity rejections of 95.6 and 98.2%. A mathematical model was developed for commercial RO system to simulate the process for establishing optimum operating conditions. A comparison of UF and RO processes for this application is presented along with useful details of equipment list, process flow diagram of commercial membrane plant, schematic of compact hollow fiber pilot plant, and detailed estimation of operating costs.

Background and Aims: The return of consciousness (ROC) after general anesthesia (GA) is by stopping the administration of anesthetic agents. At present, no drug is given to reverse the loss of consciousness produced by general anesthetic agents. This study is conducted to find whether caffeine and aminophylline hasten the ROC. Material and Methods: This study was conducted on 75 American Society of Anesthesiologists (ASA) I and II female patients undergoing laparoscopic hysterectomy, aged between 18 and 60 years. The patients were divided into three equal groups (Group C: caffeine citrate, Group A: aminophylline, and Group S: saline) of 25 each by a computer-generated random number table. GA was induced with propofol, fentanyl, and maintained with propofol infusion. On completion of the surgery, the neuromuscular blocking agent was reversed and then the infusion of propofol was stopped. The study drug was administered intravenously when the BIS 60 was achieved. Time to achieve BIS 90, return of first gag reflex, eye-opening on verbal command, and extubation after study drug administration were noted. Hemodynamic parameters and SpO2 were also monitored. Results: The time for BIS 60 to 90 was 10 (4.25) min in the caffeine group, 13 (4.25) min in the aminophylline group, and 26 (9.0) min in the saline group. The time to return of gag reflex and time to extubation were shorter in the caffeine and aminophylline group compared to the saline group. The time to eye-opening on verbal command was shorter in the aminophylline group compared to the saline group. Hemodynamic parameters after infusion of the study drug were comparable in all three groups. Conclusion: Caffeine hastens the recovery from total intravenous anesthesia with propofol and fentanyl in laparoscopic hysterectomy as effectively as aminophylline.