Microplastic in the environment: identification, occurrencand mitigation measures

Microplastic is an emerging pollutant causing trouble worldwide due to its extensive distribution and potential hazards to the ecological system. Some fundamental questions about micro-plastics, such as their presence, source, and possible hazards, remain unanswered. These issues develop because of a lack of systematic and comprehensive microplastic analysis. As a result, we thoroughly evaluated current knowledge on microplastics, including detection, characterization, occurrence, source, and potential harm. Microplastics are found in seawater, soil, wetlands, and air matrices worldwide based on findings. Visual classification, which can be enhanced by com-bining it with additional tools, is one of the most used methods for identifying microplastics. As soon as is practicable, microplastics analytical methods ought to be standardized. New techniques for analyzing nano-plastics are urgently needed in the meantime. Numerous studies have shown that microplastics’ impacts on people and soil are significantly influenced by their size, shape, and surface physicochemical characteristics. Finally, this study suggests areas for future research based on the knowledge gaps in the area of microplastics. © 2022 Desalination Publications. All rights reserved

Biofuel production using cultivated algae: technologies, economics, and its environmental impacts

The process of looking for alternative energy sources is driven by the increasing demand for energy and environmental contamination caused by using fossil fuels. Recent investigations reported the efficiency of microalgae for biofuel production due to its low cost of production, high speed of growth, and ability to grow in harsh environments. In addition, many microalgae are photosynthetic, consuming CO2 and solar light to grow in biomass and providing a promising bioenergy source. This review presents the recent advances in the application of microalgae for biofuel production. In addition, cultivation and harvesting systems and environmental factors that affect microalgae cultivation for biofuel production have also been discussed. Moreover, lipid extraction and conversion technologies to biofuel are presented. The mixotrophic cultivation strategy is promising as it combines the advantages of heterotrophy and autotrophy. Green harvesting methods such as using bio-coagulants and flocculants are promising technologies to reduce the cost of microalgal biomass production. In the future, more investigations into co-cultivation systems, new green harvesting methods, high lipids extraction methods, and the optimization of lipid extraction and converting processes should be implemented to increase the sustainability of microalgae application for biofuel production

Thermal based remediation technologies for soil and groundwater: a review

Thermal remediation technologies are fast and effective tools for the remediation of contaminated soils and sediments. Nevertheless, the high energy consumption and the effect of high temperature on the soil properties may hinder the wide applications of thermal remediation methods. This review highlights the recent studies focused on thermal remediation. Eight types of thermal remediation processes are discussed, including incineration, thermal desorption, stream enhanced extraction, electrical resistance heating, microwave heating, smoldering, vitrification, and pyrol-ysis. In addition, the combination of thermal remediation with other remediation technologies is presented. Finally, thermal remediation sustainability is evaluated in terms of energy efficiency and their impact on soil properties. The developments of the past decade show that thermal-based technologies are quite effective in terms of contaminant removal but that these technologies are associated with high energy use and costs and can has an adverse impact on soil properties. Nonetheless, it is anticipated that continued research on thermally based technologies can increase their sustainability and expand their applications. Low temperature thermal desorption is a prom-ising remediation technology in terms of land use and energy cost as it has no adverse effect on soil function after treatment and low temperature is required. Overall, selecting the sustainable remediation technology depends on the contaminant properties, soil properties and predicted risk level. © 2022 Desalination Publications. All rights reserved

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

Background 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

Optimal Use of Nanofiltration for Nitrate Removal from Gaza Strip Municipal Wells

Groundwater is one of the most precious natural resources in the Gaza Strip as it is the only source of drinking water for the majority of the population. The quality of the water extracted from the aquifer varies by area and time but in general does not satisfy the WHO guideline values for drinking water quality in terms of the 50 mg/L as NO3. The nitrate sources in the groundwater of Gaza Strip are wastewater, septic tank, sewage sludge animal manure and N-fertilizer. The aim of this study is to optimize the use of Nanofltraiton for removal of nitrate in Gaza Strip as case study. One commercial membrane (NF90) was used in this study. The stirred dead end flow model was used in addition, two types of water was used: Aqueous solution and real water. The performance of the tested membrane was measured in terms of flux rate and nitrate rejection under different operation conditions: nitrate concentration was varied between 50-400mg/L, applied pressure (6-12) bar and TDS concentration (500-3570) mg/l. The results showed that, in aqueous solution, increasing operating pressure posed positive effects on both nitrate rejection and flux rate performance of nanofiltration. However, increasing the feed nitrate concentration reduced the rejection and flux performance. The percentage of nitrate removal was in the range of 21.67% and 66.68% and the flux rate range between 5.39 and 14.88- L/m2.hr. These values depend on operation conditions such as nitrate concentration and operation pressure. In real water, the percentage of nitrate removal was influenced by TDS value in general, but to be more specific, it was found that the concentration of sulphat has a great effect on nitrate removal, as the sulphat concentration increased the nitrate removal decreased. In addition, the flux rate influenced by TDS concentration and specific chloride concentration. NF90 was observed to be an effective membrane for nitrate removal of Gaza Strip at higher permeate flux and lower applied pressure, especially in North Gaza Strip were low TDS and Sulphat concentration were observed. In other Gaza Strip places TDS and sulphat need to be removed before using nanofiltration. The optimum operating pressure was tested by number of wells. The results indicated that NF90 is better than RO in nitrate removal and energy cost in terms of lower pressure

Removal of Reactive Red 141 and Disperse Red 13 Dyes from Aqueous Solutions Using Different Coagulants: An Optimization and Comparison Study

This study investigated the performance of different coagulants for the removal of different dye types from synthetic dye solutions. The ability to use each of the following: aluminium sulphate (Al2(SO4)3, aluminium chloride (AlCl3), and ferric chloride (FeCl3) as chemical coagulants were examined for removing reactive red 141 (RR 141) dye and disperse red 13 (DR 13) from dye solution. Coagulation studies determined the optimum pH, mixing time, coagulant dosages, and initial dye concentrations. The maximum efficiency for removing RR 141 was 65.7% by aluminium chloride at the operation condition of pH 8, mixing time 10 min, and dye concentration of 100 mg/L. In contrast, under the same conditions, ferric chloride could remove more than 98% of DR 13. Since the disperse dye type has better colour removal, the maximum volume of sludge was 0.3 kg/m3 which was produced when FeCl3 was used as a coagulant. The results demonstrated that coagulation is a promising technology for dye removal, especially for dispersed dyes as it has some characteristics such as colloidal dispersion and very low water solubility