Development of a novel submerged membrane electro-bioreactor for wastewater treatment

The principle objectives of this research were to design and investigate a novel approach to generate an excellent quality effluent, while minimizing the size of the treatment unit and energy consumption. To achieve these objectives a submerged membrane electro-bioreactor (SMEBR) was designed and its performance was investigated. Membrane processes, electrokinetic phenomena, and biological processes take place simultaneously leading to the control of the problem of membrane fouling which has been considered one of the major challenges to widespread application of membrane bioreactor technology. This design is the first attempt to combine electrokinetic principles, using electro-coagulation (EC) processes and submerged membrane bioreactor in one reactor vessel. Both water quantity and quality were monitored through different experimental phases to verify the feasibility of the SMEBR system for wastewater treatment under various operating conditions. Firstly, a preliminary experimental phase was conducted on a small-scale electro-bioreactor (without the operation of the membrane module) to identify the best electrokinetic conditions in terms of the appropriate current density so as not to impede the biological treatment, and to determine the best exposure time of DC when it should be applied intermittently in the SMEBR system. DC field of 1 V/cm with an operational mode of 15 minutes ON/45 minutes OFF of DC power supply were found to be the adequate electrical conditions to operate the SMEBR system. Two different anode materials--iron and aluminum--were used to validate the SMEBR system for wastewater treatment. At the operating mode of 15 minutes ON/45 minutes OFF, the applied DC field in the SMEBR system enhanced the membrane filterability up to 16.6% and 21.3% using iron and aluminum electrodes respectively. However, the significant improvement in membrane filterability was 52.5% when using an aluminum anode at an operational mode of 15 minutes ON/105 minutes OFF, which indicated that the operational mode of DC supply is a key parameter in the operation of a SMEBR system. In terms of pollutants removal, the overall removal efficiency for COD was greater than 96% and greater than 98% for phosphorus. In conjunction, the removal of NH 3 -N was on average 70%. It should be emphasized that the phosphorous removal efficiency was higher than other studies on MBR without the use of electrokinetics. Furthermore, the effluent of the SMEBR treatment, using synthetic wastewater, had no color and no odor. The designed SMEBR system may find a direct application in the treatment of various wastewaters, including sewage, without an extensive pretreatment. Such a solution is required by several small municipalities, mining areas, agriculture facilities, military bases, and in cold regions. Finally, such a compact hybrid system can easily be adapted to a mobile uni

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research