Physicochemical processes have been used to remove nonbiodegradable organic compounds in leachate generated from sanitary landfills. In this study, a coagulation process combined with Fenton oxidation was evaluated for the removal of refractory organics in leachate. Recycling of sludge generated from Fenton oxidation to a coagulation process was attempted to reduce operation cost and to improve organic removal rate. The addition mode of Fenton reagent was also modified to obtain a better organic removal rate and more cost-effective operation. With Fenton sludge recycling, 9% higher COD removal was obtained, and the sludge to be disposed could be reduced up to 50%. Also, the coagulant could be reduced by 50%. For Fenton oxidation process, stepwise addition of reagents gave a 5% higher COD removal, and a 25% reduction in chemical consumption.

Despite the numerous investigations on resistance mechanisms, drug resistance in cancer therapies still limits favorable outcomes in cancer patients. The complexities of the inherent characteristics of tumors, such as tumor heterogeneity and the complicated interaction within the tumor microenvironment, still hinder efforts to overcome drug resistance in cancer cells, requiring innovative approaches. In this review, we describe recent studies offering evidence for the essential roles of amino acid metabolism in driving drug resistance in cancer cells. Amino acids support cancer cells in counteracting therapies by maintaining redox homeostasis, sustaining biosynthetic processes, regulating epigenetic modification, and providing metabolic intermediates for energy generation. In addition, amino acid metabolism impacts anticancer immune responses, creating an immunosuppressive or immunoeffective microenvironment. A comprehensive understanding of amino acid metabolism as it relates to therapeutic resistance mechanisms will improve anticancer therapeutic strategies.

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A B S T R A C TFouling control is generally taken by selective pre-treatments, proper membrane operation conditions, and various membrane cleaning methods. The compactness and growth of cake layer on the membrane surface should be timely controlled by mechanical force or hydraulic action. In this work, the sequence of physical cleaning method was strategically introduced by changing cross-flow velocity (CFV), backwash intensity, and backwash waste discharge method from membrane housing. Intensive backwash flush was automatically applied when delta TMP obtained after backwash events was more than 2%. It provided higher pressure on the permeate side of the membrane compared to the normal backwashing, resulting in the reduction of sharp increase of TMP during several operation modes. In addition, the variation of CFV from 0 to 16 m/d based on the membrane fouling index caused turbulence on the membrane fiber, resulting in the discharge of particles accumulated on the membrane surface from membrane module. Finally, flushing mode followed by filtration was more effective in maintaining the TMP stable rather than discharging mode. Flushing effect could induce another shear force to the suspended solids in the bulk and remove cleaning wastes effectively from membrane housing. Large particulates and colloidal matters could be controlled by the proper sequence of physical cleaning based on the TMP monitoring. Furthermore, the strategic physical cleaning could sufficiently reduce not only TMP increase but also the damage of membrane, which is resulted from the more frequent and aggressive chemical cleanings.

The pipe system roles as a main bridge between membrane modules and pumps in membrane water treatment plants. Membrane operation modes generally consist of filtration and backwash processes in a normal mode, a pressure decay test as an integrity test and a chemical circulation through pipe system in a cleaning mode. Thus factors effecting on membrane performance should be sufficiently considered before design and operation. This study evaluated flow analysis for vibration diagnostic and evaluation of the fatigue lifetime in the microfiltration system applied for a drinking water treatment plant. Vibration of main membrane pipelines was measured to identify the source of vibration. Also natural frequency and fluid dynamics was calculated by computational fluid dynamics. It showed that maximum magnitude frequencies were at 12 Hz and 22 Hz, respectively at water and air pipeline during filtration and backwash. Backwash process caused mainly vibration on the backwash water pipe. The calculated frequency from analysis of frequency response and CFD was in a good agreement with the measured frequency. Fatigue analysis showed that pipelines were getting little damage caused by vibration. Fatigue lifetime was predicted more than 15 years under the operation condition of daily filtration, and more than 27 years under the operation condition of a daily backwash mode, resulting in minor damage on the pipe lifetime.