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1.
Chem Asian J ; : e202300926, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38721713

ABSTRACT

The transition of the global energy market towards an environment-friendly, sustainable society requires a profound transformation from fossil fuel to zero carbon emission fuel. To cope with this goal production of renewable energy is accelerating worldwide. Hydrogen is a clean energy carrier, due to its clean combustion and abundance. Nonetheless, its storage is a critical challenge to its success. Hydrogen must be stored long after being produced and transported to a storage site. Physical hydrogen storage (PHS) is vital among hydrogen storage modes, and its shortcoming needs to overcome for its successful and economic benefits. This review intends to discuss the techniques and applications of physical hydrogen storage in the state of compressed gas, liquefied hydrogen gas, and cold/cryo compressed gas concerning their working principle, chemical and physical properties, influencing factors for physical hydrogen storage, and transportation, economics, and global outlook. In addition, insights of several probable PHS systems are highlighted. The outcomes of this review envisioned that the PHS still necessitates technological advancements despite having remarkable success. The limitation opens the door to further research, which would be helpful for efficient and long-term physical hydrogen storage.

2.
J Family Med Prim Care ; 13(1): 278-284, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38482273

ABSTRACT

Introduction: Schizophrenia is a severe mental disorder affecting millions worldwide. Family caregivers play a vital role in patient treatment and recovery, but their responsibilities can be physically and emotionally exhausting. There is limited research on caregiver burden in Bangladesh, prompting this study to identify factors associated with the burden among caregivers of schizophrenic patients. Methods: This cross-sectional study collected data from 175 caregivers from January to December 2020 in Dhaka, Bangladesh. A semi-structured questionnaire and a validated Bangla version of the Zarit Burden Interview (ZBI) scale were used to assess the burden of primary caregivers and associated factors in caring for patients with schizophrenia. Results: Participants' mean age was 34.02 ± 10.45 years, with 26.9% in the 34-41 age group. 49.1% were housewives, with most earning 5000 to 15000 taka monthly. Spouses accounted for 28.6% of caregivers. Most patients had an illness duration of less than five years (66.3%). Mean ZBI score was 49.49 ± 12.06, indicating moderate to severe burden. Factors significantly associated with caregiver burden included age, gender, occupation, income, marital status, house condition, relationship with patients, illness stage, and duration. Conclusion: This study highlights the burden experienced by caregivers of schizophrenic patients in Bangladesh and identifies factors associated with the burden. It recommends community interventions and psychosocial provisions to address this issue and inform targeted interventions to reduce caregiver burden. These findings provide insights for a comprehensive plan to manage such cases in the future.

3.
Med Biol Eng Comput ; 62(5): 1549-1567, 2024 May.
Article in English | MEDLINE | ID: mdl-38308669

ABSTRACT

Radiofrequency ablation is a nominally invasive technique to eradicate cancerous or non-cancerous cells by heating. However, it is still hampered to acquire a successful cell destruction process due to inappropriate RF intensities that will not entirely obliterate tumorous tissues, causing in treatment failure. In this study, we are acquainted with a nanoassisted RF ablation procedure of cardiac tumor to provide better outcomes for long-term survival rate without any recurrences. A three-dimensional thermo-electric energy model is employed to investigate nanothermal field and ablation efficiency into the left atrium tumor. The cell death model is adopted to quantify the degree of tissue injury while injecting the Fe3O4 nanoparticles concentrations up to 20% into the target tissue. The results reveal that when nanothermal field extents as a function of tissue depth (10 mm) from the electrode tip, the increasing thermal rates were approximately 0.54362%, 3.17039%, and 7.27397% for the particle concentration levels of 7%, 10%, and 15% compared with no-particle case. In the 7% Fe3O4 nanoparticles, 100% fractional damage index is achieved after ablation time of 18 s whereas tissue annihilation approach proceeds longer to complete for no-particle case. The outcomes indicate that injecting nanoparticles may lessen ablation time in surgeries and prevent damage to adjacent healthy tissue.


Subject(s)
Catheter Ablation , Heart Neoplasms , Radiofrequency Ablation , Humans , Computer Simulation , Catheter Ablation/methods , Heart Atria/surgery
5.
Lifetime Data Anal ; 30(1): 181-212, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37659991

ABSTRACT

To achieve the goal of providing the best possible care to each individual under their care, physicians need to customize treatments for individuals with the same health state, especially when treating diseases that can progress further and require additional treatments, such as cancer. Making decisions at multiple stages as a disease progresses can be formalized as a dynamic treatment regime (DTR). Most of the existing optimization approaches for estimating dynamic treatment regimes including the popular method of Q-learning were developed in a frequentist context. Recently, a general Bayesian machine learning framework that facilitates using Bayesian regression modeling to optimize DTRs has been proposed. In this article, we adapt this approach to censored outcomes using Bayesian additive regression trees (BART) for each stage under the accelerated failure time modeling framework, along with simulation studies and a real data example that compare the proposed approach with Q-learning. We also develop an R wrapper function that utilizes a standard BART survival model to optimize DTRs for censored outcomes. The wrapper function can easily be extended to accommodate any type of Bayesian machine learning model.


Subject(s)
Decision Making , Humans , Bayes Theorem , Computer Simulation , Precision Medicine , Survival Analysis , Transplantation, Homologous , Hematopoietic Stem Cells
6.
RSC Adv ; 13(34): 23558-23569, 2023 Aug 04.
Article in English | MEDLINE | ID: mdl-37555094

ABSTRACT

A comprehensive investigation of the gas sensing potential of BeS monolayer has been conducted using DFT calculations. Twelve common pollutant gases: NH3, NO2, NO, CO, CO2, CH4, H2, O2, N2, H2S, H2O and SO2, have been studied. Our analysis reveals defect states in the band structure near the Fermi level and strong hybridization between gas molecule orbitals and the BeS monolayer. We observe higher adsorption energies for NH3 and CO compared to other popular gas sensing materials. The optical properties of CO2 and NO2 adsorbed on the BeS monolayer show increased reflectivity and absorption coefficient in the UV and far infrared region. Tensile strain has minimal impact on adsorption energy, while biaxial compressive strains enhance the gas sensing capability of the BeS monolayer. The application of an electric field offers control over gas adsorption and desorption. We propose the BeS monolayer as a promising candidate for future gas molecule sensing applications due to its high adsorption energy, rapid recovery time, and distinct optical properties.

7.
J Adv Vet Anim Res ; 9(3): 374-382, 2022 Sep.
Article in English | MEDLINE | ID: mdl-36382039

ABSTRACT

Objective: The study aimed to develop and assess an Android app designed for farmers with a low educational status that can formulate a least-cost ration. Materials and Methods: First, a computer-android-based app named BLRI FeedMaster was developed to guide users in formulating a balanced ration at the least cost. A survey was conducted on 30 livestock officers and 18 farmers with 50 cattle to evaluate its efficacy at the field level. The study outcomes were milk yield, feeding cost, milk composition, time, and cost for management before and after using the BLRI FeedMaster app. Descriptive statistics and paired sample t-tests were used to analyze the data. Results: After adopting the BLRI FeedMaster app, a significant increase was observed in daily average milk yield (9.39 ± 0.32 l from 8.37 ± 0.36 l), while a considerable decrease was observed in daily average feed quantity (4.88 ± 0.15 kg from 5.60 ± 0.17 kg) and feed cost (BDT 28.00 ± 0.50 from BDT 29.75 ± 0.49). Besides, the number of visits, time, and cost for seeking professional services regarding feed, health care, and other information was significantly minimized. The number of visits decreased to 0.36 ± 013 from 3.07 ± 0.38, and the consumed time was reduced from 270 ± 34.30 to 235.71 ± 59.42 min (p < 0.05) after adopting the app. Conclusion: Hence, this app was very beneficial for farmers with a low economic and educational background and may ultimately help farmers with profitable animal farming and sustainable production in the least developed countries like Bangladesh.

8.
BMJ Glob Health ; 7(Suppl 3)2022 06.
Article in English | MEDLINE | ID: mdl-35750345

ABSTRACT

The purpose of this study is to evaluate Iraq's health facility preparedness for the surge of hospitalised cases associated with the ongoing COVID-19 pandemic. In this article, we review pandemic preparedness at both general and tertiary hospitals throughout all districts of Iraq. COVID-19 pandemic preparedness, for the purpose of this review, is defined as: (1) staff to patient ratio, (2) personal protective equipment (PPE) to staff ratio, (3) infection control measures training and compliance and (4) laboratory and surveillance capacity. Despite the designation of facilities as COVID-19 referral hospitals, we did not find any increased preparedness with regard to staffing and PPE allocation. COVID-19 designated hospital reported an increased mean number of respiratory therapists as well as sufficient intensive care unit staff, but this did not reach significant levels. Non-COVID-19 facilities tended to have higher mean numbers of registered nurses, cleaning staff and laboratory staff, whereas the COVID-19 facilities were allocated additional N-95 masks (554.54 vs 147.76), gowns (226.72 vs 104.14) and boot coverings (170.48 vs 86.8) per 10 staff, but none of these differences were statistically significant. Though COVID-19 facilities were able to make increased requisitions for PPE supplies, all facility types reported unfulfilled requisitions, which is more likely a reflection of global storage rather than Iraq's preparedness for the pandemic. Incorporating future pandemic preparedness into health system strengthening efforts across facilities, including supplies, staffing and training acquisition, retention and training, are critical to Iraq's future success in mitigating the ongoing impact of the ongoing COVID-19 pandemic.


Subject(s)
COVID-19 , Pandemics , Delivery of Health Care , Hospitals , Humans , Iraq
10.
Antibiotics (Basel) ; 11(1)2022 Jan 13.
Article in English | MEDLINE | ID: mdl-35052973

ABSTRACT

Zoonotic and antimicrobial-resistant Escherichia coli (hereafter, E. coli) is a global public health threat which can lead to detrimental effects on human health. Here, we aim to investigate the antimicrobial resistance and the presence of mcr-1 gene in E. coli isolated from chicken feces. Ninety-four E. coli isolates were obtained from samples collected from different locations in Bangladesh, and the isolates were identified using conventional microbiological tests. Phenotypic disk diffusion tests using 20 antimicrobial agents were performed according to CLSI-EUCAST guidelines, and minimum inhibitory concentrations (MICs) were determined for a subset of samples. E. coli isolates showed high resistance to colistin (88.30%), ciprofloxacin (77.66%), trimethoprim/sulfamethoxazole (76.60%), tigecycline (75.53%), and enrofloxacin (71.28%). Additionally, the pathotype eaeA gene was confirmed in ten randomly selected E. coli isolates using primer-specific polymerase chain reaction (PCR). The presence of mcr-1 gene was confirmed using PCR and sequencing analysis in six out of ten E. coli isolates. Furthermore, sequencing and phylogenetic analyses revealed a similarity between the catalytic domain of Neisseria meningitidis lipooligosaccharide phosphoethanolamine transferase A (LptA) and MCR proteins, indicating that the six tested isolates were colistin resistant. Finally, the findings of the present study showed that E. coli isolated from chicken harbored mcr-1 gene, and multidrug and colistin resistance. These findings accentuate the need to implement strict measures to limit the imprudent use of antibiotics, particularly colistin, in agriculture and poultry farms.

11.
J Environ Manage ; 301: 113783, 2022 Jan 01.
Article in English | MEDLINE | ID: mdl-34592662

ABSTRACT

Microalgae-based wastewater treatment (and biomass production) is an environmentally benign and energetically efficient technique as compared to traditional practices. The present study is focused on optimization of the major treatment variables such as temperature, light-dark cycle (LD), and nitrogen (N)-to-phosphate (P) ratio (N/P) for the elimination of N and P from tertiary municipal wastewater utilizing Chlorella kessleri microalgae species. In this regard, a hybrid support vector regression (SVR) technique integrated with the crow search algorithm has been applied as a novel modeling/optimization tool. The SVR models were formulated using the experimental data, which were furnished according to the response surface methodology with Box-Behnken Design. Various statistical indicators, including mean absolute percentage error, Taylor diagram, and fractional bias, confirmed the superior performance of SVR models as compared to the response surface methodology (RSM) and generalized linear model (GLM). Finally, the best SVR model was hybridized with the crow search algorithm for single/multi-objective optimizations to acquire the global optimal treatment conditions for maximum N and P removal efficiencies. The best-operating conditions were found to be 29.3°C, 24/0 h/h of LD, and 6:1 of N/P, with N and P elimination efficiencies of 99.97 and 93.48%, respectively. The optimized values were further confirmed by new experimental data.


Subject(s)
Chlorella , Crows , Microalgae , Water Purification , Algorithms , Animals , Biomass , Nitrogen , Wastewater
12.
Cureus ; 13(11): e19236, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34877213

ABSTRACT

Cocaine is a powerfully addictive recreational drug that is extracted from the leaves of the Erythroxylon coca plant native to Central and South America. It is a widely abused substance, despite being banned since the early 19th century due to fatalities. Cocaine may result in acute kidney injury (AKI) by different mechanisms, but acute interstitial nephritis (AIN) is scarcely recognized as the cause of acute kidney injury (AKI). Here, we present a case of AKI from both AIN and acute tubular necrosis (ATN) following cocaine insufflation. The purpose of this article is to review the rare but significant association of AIN associated with cocaine use. The nature of the treatment of cocaine-related kidney disease may differ from other causes of acute kidney insult. Prompt recognition of the underlying cause of renal dysfunction is vital for this group of patients to prevent the rapid deterioration of renal function.

13.
Confl Health ; 15(1): 76, 2021 Oct 18.
Article in English | MEDLINE | ID: mdl-34663395

ABSTRACT

OBJECTIVES: The objective of this study was to assess the resilience of health systems in four governorates affected by conflict from 2014 to 2018, and to convey recommendations. METHODS: Health managers from Al Anbar, Ninawa, Salah al-Din, and Kirkuk governorates discussed resilience factors of Primary Health Care services affected by the 2014-2017 ISIS insurgency in focus groups, and general discussions. Additional information was gathered from key informants and a UNICEF health facility survey. Three specific aspects were examined: (1) meeting health needs in the immediate crisis response, (2) adaptation of services, (3) restructuring and recovery measures. Data from a MoH/UNICEF national health facility survey in 2017 were analyzed for functionality. RESULTS: There were many common themes across the four governorates, with local variations. (1) Absorption The shock to the public sector health services by the ISIS invasion caught health services in the four governorates unprepared, with limited abilities to continue to provide services. Private pharmacies and private clinics in some places withstood the initial shock better than the public sector. (2) Adaptation After the initial shock, many health facilities adapted by focusing on urgent needs for injury and communicable disease care. In most locations, maternal, neonatal, and child health (MNCH) preventive and promotive PHC services stopped. Ill persons would sometimes consult health workers in their houses at night for security reasons. (3) Restructuring or transformative activities In most areas, health services recovery was continuing in 2020. Some heavily damaged facilities are still functioning, but below pre-crisis level. Rebuilding lost community trust in the public sector is proving difficult. CONCLUSION: Health services generally had little preparation for and limited resilience to the ISIS influx. Governorates are still restructuring services after the liberation from ISIS in 2017. Disaster planning was identified by all participants as a missing component, as everyone anticipated future similar emergencies.

14.
Clin Epidemiol Glob Health ; 12: 100836, 2021.
Article in English | MEDLINE | ID: mdl-34693077

ABSTRACT

INTRODUCTION: Due to the extended lockdown imposed for SARS-CoV-2 pandemic, many people have experienced problematic sleep patterns and associated health issues worldwide. This study was conducted to assess the sleep quality and psychological states of the Bangladeshi population during the COVID-19 pandemic, respondent's behavioral traits as well as psychological or sleep-related problems induced self-medication practice among the respondents, along with the probability of development of drug dependency. METHODS: The survey was conducted among 2941 respondents from 25th November 2020 to 4th December 2020 where the responses were analyzed by SPSS V22. RESULTS: 10-29.5% experienced a significant degree of sleep problems whereas some experienced severe anxiety and depression. The associations between the behavioral traits and parameters concerning sleep quality, anxiety and depression showed 5% level of significance in all cases. Self-medication practice of sleep aids during this pandemic was reported by 7.14% of the respondents, with a greater percentage belonging to the female or senior age group. Tendency to repeatedly self-medication was observed in 18.86% of this self-medicating populace, and a greater number of male (10.26%) respondents displayed such tendency as opposed to their female (8.6%) equivalents. However, 48.10% of the respondents reported perceptions of improved physical and/or psychological health following self-medication, and this trait was predominant in men (52.14%). CONCLUSION: Results showed a significant number of Bangladeshi populaces were suffering from psychological issues during this COVID-19 which also influenced a certain number of people towards self-medication practice where signs of drug dependency were observed in a significant number of respondents.

15.
Field Crops Res ; 260: 107977, 2021 Jan 01.
Article in English | MEDLINE | ID: mdl-33390645

ABSTRACT

The complexity of genotype × environment interactions under drought reduces heritability, which determines the effectiveness of selection for drought tolerance and development of drought tolerant varieties. Genetic progress measured through changes in yield performance over time is important in determining the efficiency of breeding programmes in which test cultivars are replaced each year on the assumption that the new cultivars will surpass the older cultivars. The goal of our study was to determine the annual rate of genetic gain for rice grain yield in a drought-prone rainfed system in a series of multi-environment trials conducted from 2005 to 2014 under the Drought Breeding Network of Indian sites in collaboration with the International Rice Research Institute (IRRI). Our results show a positive trend in grain yield with an annual genetic yield increase of about 0.68 % under irrigated control, 0.87 % under moderate reproductive stage drought stress and 1.9 % under severe reproductive stage drought stress due to breeding efforts. The study also demonstrates the effectiveness of direct selection for grain yield under both irrigated control as well as managed drought stress screening to improve yield in typical rainfed systems. IRRI's drought breeding programme has exhibited a significant positive trend in genetic gain for grain yield over the years under both drought stress as well as favorable irrigated control conditions. Several drought tolerant varieties released from the programme have outperformed the currently grown varieties under varied conditions in the rainfed environments on farmers' fields.

16.
Animals (Basel) ; 11(1)2021 Jan 15.
Article in English | MEDLINE | ID: mdl-33467777

ABSTRACT

Colistin (polymyxin E) is widely used in animal and human medicine and is increasingly used as one of the last-resort antibiotics against Gram-negative bacilli. Due to the increased use of colistin in treating infections caused by multidrug-resistant Gram-negative bacteria, resistance to this antibiotic ought to be monitored. The study was undertaken to elucidate the molecular mechanisms, genetic relationships and phenotype correlations of colistin-resistant isolates. Here, we report the detection of the mcr-1 gene in chicken-associated Salmonella isolates in Bangladesh and its in-silico functional analysis. Out of 100 samples, 82 Salmonella spp. were isolated from chicken specimens (liver, intestine). Phenotypic disc diffusion and minimum inhibitory concentration (MIC) assay using different antimicrobial agents were performed. Salmonella isolates were characterized using PCR methods targeting genus-specific invA and mcr-1 genes with validation for the functional analysis. The majority of the tested Salmonella isolates were found resistant to colistin (92.68%), ciprofloxacin (73.17%), tigecycline (62.20%) and trimethoprim/sulfamethoxazole (60.98%). When screened using PCR, five out of ten Salmonella isolates were found to carry the mcr-1 gene. One isolate was confirmed for Salmonella enterica subsp. enterica serovar Enteritidis, and other four isolates were confirmed for Salmonella enterica subsp. enterica serovar Typhimurium. Sequencing and phylogenetic analysis revealed a divergent evolutionary relationship between the catalytic domain of Neisseria meningitidis lipooligosaccharide phosphoethanolamine transferase A (LptA) and MCR proteins, rendering them resistant to colistin. Three-dimensional homology structural analysis of MCR-1 proteins and molecular docking interactions suggested that MCR-1 and LptA share a similar substrate binding cavity, which could be validated for the functional analysis. The comprehensive molecular and in-silico analyses of the colistin resistance mcr-1 gene of Salmonella spp. of chicken origin in the present study highlight the importance of continued monitoring and surveillance for antimicrobial resistance among pathogens in food chain animals.

17.
Environ Technol ; 42(26): 4057-4063, 2021 Nov.
Article in English | MEDLINE | ID: mdl-32181707

ABSTRACT

Wide application of 2, 4-dichlorophenol (2, 4-DCP) in industry has resulted in environmental contamination of soils and groundwater. Approaches to cost-effectively remove 2, 4-DCP from water need to be found. 2, 4-DCP uptake onto pine chips from aqueous solution were evaluated in column studies under different particle sizes and flow conditions. The breakthrough curves (BTCs) showed evidence of non-equilibrium with early breakthroughs. The uptake capacity increased from 3.0-6.0 mg g-1 with decreasing flow rate from 10 to 5 mL min-1 but did not show significant differences for particle sizes 1.18 and 4.75 mm at the same flow rate. The BTC for all cases could not be adequately fitted using an equilibrium model with batch derived sorption parameters. They could be better fitted by two site non-equilibrium model using parameters derived from both batch and inverse modelling. At a higher flow rate, the fraction of instantaneous sorption decreased suggesting a higher degree of non-equilibrium. Non-equilibrium processes need to be considered in the design of these types of treatment and operational systems.


Subject(s)
Groundwater , Water Pollutants, Chemical , Adsorption , Soil , Water
18.
Mymensingh Med J ; 29(4): 793-799, 2020 Oct.
Article in English | MEDLINE | ID: mdl-33116079

ABSTRACT

Prevalence of heart failure (HF) among end stage renal disease (ESRD) patients is high and HF remains the main cardiovascular co-morbidity at dialysis initiation. There is paucity of data comparing change of NYHA class, improvement of ejection fraction (EF) and major cardiac events in ESRD patients with concomitant heart failure on haemodialysis to those on peritoneal dialysis. The objective of the study was to compare the cardiac outcome of continuous ambulatory peritoneal dialysis (CAPD) & hemodialysis (HD) in chronic kidney disease 5 (CKD5) patients with HF. This prospective observational study was carried out from March 2018 to February 2019 in seventy CKD 5 patients with HF who opted for CAPD or HD. Seven patients dropped out during the follow-up & sixty three patients (CAPD=31; HD=32) were followed up for symptomatic assessment of cardiac status in terms of NYHA class as well as echocardiography and serum haemoglobin at baseline and at 3rd & 6th month. Major cardiovascular events like non fatal MI, non fatal stroke & death duo to cardiovascular diseases and co-morbidities were recorded during the study period. Statistical analysis was done using SPSS 22.0. Mean age was 53.33±6.38 and 54.23±10.15 years & male to female ratio was 1.81:1 and 1.46:1 in CAPD and HD groups respectively. Both NYHA class & left ventricular ejection fraction (EF) were significantly increased after six months compared to baseline in each group and significantly more increased in the CAPD group than the HD group. Left ventricular internal diameter in diastole (LVIDd) was reduced significantly after six months compared to baseline in both groups and there was no significant difference in LVIDd reduction between the CAPD and HD groups. Major cardiovascular events were found to occur more frequently in the HD group. According to NYHA functional class, echocardiographic findings and major cardiovascular events during six months, improvement of cardiac function in CKD 5 patients with HF was better on CAPD in comparison to HD.


Subject(s)
Heart Failure , Kidney Failure, Chronic , Peritoneal Dialysis, Continuous Ambulatory , Renal Insufficiency, Chronic , Female , Heart Failure/epidemiology , Heart Failure/therapy , Humans , Kidney Failure, Chronic/complications , Kidney Failure, Chronic/therapy , Male , Middle Aged , Renal Dialysis , Stroke Volume , Ventricular Function, Left
19.
Polymers (Basel) ; 12(10)2020 Oct 21.
Article in English | MEDLINE | ID: mdl-33096763

ABSTRACT

Several publications by authors in the field of petrochemical engineering have examined the use of chemically enhanced oil recovery (CEOR) technology, with a specific interest in polymer flooding. Most observations thus far in this field have been based on the application of certain chemicals and/or physical properties within this technique regarding the production of 50-60% trapped (residual) oil in a reservoir. However, there is limited information within the literature about the combined effects of this process on whole properties (physical and chemical). Accordingly, in this work, we present a clear distinction between the use of xanthan gum (XG) and hydrolyzed polyacrylamide (HPAM) as a polymer flood, serving as a background for future studies. XG and HPAM have been chosen for this study because of their wide acceptance in relation to EOR processes. To this degree, the combined effect of a polymer's rheological properties, retention, inaccessible pore volume (PV), permeability reduction, polymer mobility, the effects of salinity and temperature, and costs are all investigated in this study. Further, the generic screening and design criteria for a polymer flood with emphasis on XG and HPAM are explained. Finally, a comparative study on the conditions for laboratory (experimental), pilot-scale, and field-scale application is presented.

20.
Sci Rep ; 10(1): 15068, 2020 09 15.
Article in English | MEDLINE | ID: mdl-32934284

ABSTRACT

This study investigates the use of microalgae as a biosorbent to eliminate heavy metals ions from wastewater. The Chlorella kessleri microalgae species was employed to biosorb heavy metals from synthetic wastewater specimens. FTIR, and SEM/XRD analyses were utilized to characterize the microalgal biomass (the adsorbent). The experiments were conducted with several process parameters, including initial solution pH, temperature, and microalgae biomass dose. In order to secure the best experimental conditions, the optimum parameters were estimated using an integrated response surface methodology (RSM), desirability function (DF), and crow search algorithm (CSA) modeling approach. A maximum lead(II) removal efficiency of 99.54% was identified by the RSM-DF platform with the following optimal set of parameters: pH of 6.34, temperature of 27.71 °C, and biomass dosage of 1.5 g L-1. The hybrid RSM-CSA approach provided a globally optimal solution that was similar to the results obtained by the RSM-DF approach. The consistency of the model-predicted optimum conditions was confirmed by conducting experiments under those conditions. It was found that the experimental removal efficiency (97.1%) under optimum conditions was very close (less than a 5% error) to the model-predicted value. The lead(II) biosorption process was better demonstrated by the pseudo-second order kinetic model. Finally, simultaneous removal of metals from wastewater samples containing a mixture of multiple heavy metals was investigated. The removal efficiency of each heavy metal was found to be in the following order: Pb(II) > Co(II) > Cu(II) > Cd(II) > Cr(II).


Subject(s)
Algorithms , Biomass , Chlorella/chemistry , Metals, Heavy/chemistry , Microalgae/chemistry , Models, Chemical , Wastewater/chemistry , Water Purification
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