scholarly journals Bentonite blended with bagasse ash as an adsorbent for reactive red 198 dyes

Author(s):  
Teshale Adane ◽  
Amare Tiruneh Adugna ◽  
Esayas Alemayehu

Abstract Adsorption offers efficient, cost-effective, and eco-friendly method for the treatment of dye-laden wastewater. This work presents, reactive red 198 (RR198) removal by adsorption using bentonite clay (BC) blended with sugar cane bagasse ash (SCBA). The adsorbent's surface morphologies, crystalline phase structures, functional groups, and specific surface before and after adsorption were examined using SEM, XRD, FTIR, and BET respectively. Central composite design (CCD) under response surface methodology (RSM) was applied to optimize independent and dependent variable values. The optimal parameters for RR198 removal using the blended adsorbent were 107 minutes contact time, 0.934 g/L adsorbent dose, and 15 mg/L initial dye concentration, and 85.2% RR198 removal efficiency was achieved. The sorption isotherms and kinetics were evaluated using various existing models. The Freundlich isotherm model (R2 = 0.95) and the pseudo-second-order equation best described the adsorption parameters and the RR198 adsorption kinetic mechanism, respectively. Desorption and reusability experiments in batch study confirmed that BC blended with SCBA can be used multiple times for dye removal from wastewater.

2018 ◽  
Vol 877 ◽  
pp. 26-32
Author(s):  
Bhargavi Gunturu ◽  
Geethalakshmi Ramakrishnan ◽  
Renganathan Sahadevan

Removal of a basic textile dye Methylene Blue from an aqueous solution was evaluated using biosorbent derived from Kigelia africana in a batch system. The influence of adsorption parameters such as adsorbent dosage (0.10-0.50g), PH (2-12) and initial dye concentration (0.3 to 0.11 g/L) on the adsorption process was studied. It was noticed that with increase in adsorbent dosage, the uptake capacity was decreased. Dye uptake was increased by changing the PH up to 8, further increase in PH caused reduced uptake. It was observed that, dye uptake by the adsorbent increased linearly with that of initial dye concentration. Equilibrium isotherm for the adsorption of methylene blue on to adsorbent was studied through Langmuir and Freundlich isotherm models. The data best fit with Freundlich model. Maximum adsorption capacity (Q ̊) was found to be 119.05mg/g. SEM and FTIR analyses of the adsorbent was performed before and after the adsorption, suggest that adsorption of the dye was through chemical interaction of the functional groups on the surface of the adsorbent. From the experimental results, it was inferred that biosorbent derived from Kigelia africana can be a potential alternate to activated carbon for textile dyes removal.


2021 ◽  
Vol 10 (5) ◽  
pp. 971
Author(s):  
Kristoff Hammerich ◽  
Jens Pollack ◽  
Alexander F. Hasse ◽  
André El Saman ◽  
René Huber ◽  
...  

Background: A major disadvantage of current spacers for two-stage revision total knee arthroplasty (R-TKA) is the risk of (sub-) luxation during mobilization in the prosthesis-free interval, limiting their clinical success with detrimental consequences for the patient. The present study introduces a novel inverse spacer, which prevents major complications, such as spacer (sub-) luxations and/or fractures of spacer or bone. Methods: The hand-made inverse spacer consisted of convex tibial and concave femoral components of polymethylmethacrylate bone cement and was intra-operatively molded under maximum longitudinal tension in 5° flexion and 5° valgus position. Both components were equipped with a stem for rotational stability. This spacer was implanted during an R-TKA in 110 knees with diagnosed or suspected periprosthetic infection. Postoperative therapy included a straight leg brace and physiotherapist-guided, crutch-supported mobilization with full sole contact. X-rays were taken before and after prosthesis removal and re-implantation. Results: None of the patients experienced (sub-) luxations/fractures of the spacer, periprosthetic fractures, or soft tissue compromise requiring reoperation. All patients were successfully re-implanted after a prosthesis-free interval of 8 weeks, except for three patients requiring an early exchange of the spacer due to persisting infection. In these cases, the prosthetic-free interval was prolonged for one week. Conclusion: The inverse spacer in conjunction with our routine procedure is a safe and cost-effective alternative to other articulating or static spacers, and allows crutch-supported sole contact mobilization without major post-operative complications. Maximum longitudinal intra-operative tension in 5° flexion and 5° valgus position appears crucial for the success of surgery.


2020 ◽  
Vol 32 (S1) ◽  
pp. 116-116
Author(s):  
M Pires ◽  
A Antunes ◽  
C Gameiro ◽  
C Pombo

Community-focused programs that promote active and healthy aging can help preserve cognitive capacities, prevent or reverse cognitive deficits. Computer-based cognitive training (CCT) is a promising non-pharmacological, cost -effective and accessible intervention to face the effects of age-related cognitive decline. Previous studies proved CCT to have equal or better efficacy compared to traditional interventions. This comparative multifactorial study aims to test the efficacy of a CCT in a non-randomized community sample of 74 older adults: G1-CCT Experimental group (n=43) (Mean age M=72.21, SD=12.65) and G2- Paper-Pencil Control group (n=31; M=77.94, SD=10.51). Pensioners (97.3%), mostly women (83.8 %) with basic education (51.4%) and without dementia diagnosis, completed a cognitive training program of 17 or 34 group sessions (twice a week). G2 undertook a classic cognitive paper-pencil stimuli tasks. G1, performed, additionally, individual CCT with COGWEB® in a multimodal format (intensive training of attention, calculation, memory, gnosis, praxis, executive functions). Both groups completed Portuguese versions of Mini -Mental State Examination (MMSE),Montreal Cognitive Assessment (MOCA); Geriatric Depressive Scale (GDS); Mini Dependence Assessment (MDA); WHOOQL 5 and Social Support Satisfaction Scale (ESSS) before and after participating in the program. Both groups reported better post-test scores on basic cognitive functions (MMSE, MOCA), Depression symptoms (GDS-30), subjective well-being and quality of life (WHOOQL-5). G1 presented higher MOCA and lower GDS scores before and after CCT, although, group differences become less expressive when interaction effects are considered. Results are in line with findings from past studies, CCT supported by the new technologies, is as a relevant cost-effective therapeutic tool for health professionals working with older adults. Particularly for preventive purposes of neuro-cognitive disorders.


2021 ◽  
Vol 16 ◽  
pp. 155892502110034
Author(s):  
Xiongfang Luo ◽  
Pei Cheng ◽  
Wencong Wang ◽  
Jiajia Fu ◽  
Weidong Gao

This study establishes an eco-friendly anti-wrinkle treating process for cotton fabric. Sodium hydroxide-liquid ammonia pretreatment followed by 6% (w/w) PU100 adding citric acid pad-cure-dry finishing. In this process, citric acid (CA) was used as the fundamental crosslinking agent during finishing because it is a non-formaldehyde based, cost-effective and well wrinkle resistance agent. Environmental-friendly waterborne polyurethane (WPU) was used as an additive to add to the CA finishing solution. Six commercial WPUs were systematically investigated. Fabric properties like wrinkle resistance, tensile strength retention, whiteness, durable press, softness, and wettability were well investigated. Fourier transform infrared spectra and X-ray diffraction spectra were also measured and discussed before and after adding waterborne polyurethane. Tentative mechanism of the interaction among the WPU, CA, and modified cotton fabrics is provided. The effect of cotton fabric pretreatment on fabric performance was also investigated. After the eco-process’s treatment, the fabric wrinkle resistant angle was upgraded to 271 ± 7°, tensile strength retention was maintained at 66.77% ± 3.50% and CIE whiteness was elevated to 52.13 ± 3.21, which are much better than the traditional CA anti-wrinkle finishing based on mercerized cotton fabrics. This study provides useful information for textile researchers and engineers.


Open Heart ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. e001380
Author(s):  
Rasmus Bo Hasselbalch ◽  
Mia Marie Pries-Heje ◽  
Sarah Louise Kjølhede Holle ◽  
Thomas Engstrøm ◽  
Merete Heitmann ◽  
...  

ObjectiveTo prospectively validate the CT-Valve score, a new risk score designed to identify patients with valvular heart disease at a low risk of coronary artery disease (CAD) who could benefit from multislice CT (MSCT) first instead of coronary angiography (CAG).MethodsThis was a prospective cohort study of patients referred for valve surgery in the Capital Region of Denmark and Odense University Hospital from the 1 February 2015 to the 1 February 2017. MSCT was implemented for patients with a CT-Valve score ≤7 at the referring physician’s discretion. Patients with a history of CAD or chronic kidney disease were excluded. The primary outcome was the proportion of patients needing reevaluation with CAG after MSCT and risk of CAD among the patients determined to be low to intermediate risk.ResultsIn total, 1149 patients were included. The median score was 9 (IQR 3) and 339 (30%) had a score ≤7. MSCT was used for 117 patients. Of these 29 (25%) were reevaluated and 9 (7.7%) had CAD. Of the 222 patients with a score ≤7 that did not receive an MSCT, 14 (6%) had significant CAD. The estimated total cost of evaluation among patients with a score ≤7 before implementation was €132 093 compared with €79 073 after, a 40% reduction. Similarly, estimated total radiation before and after was 608 mSv and 362 mSv, a 41% reduction. Follow-up at a median of 32 months (18–48) showed no ischaemic events for patients receiving only MSCT.ConclusionThe CT-Valve score is a valid method for determining risk of CAD among patients with valvular heart disease. Using a score ≤7 as a cut-off for the use of MSCT is safe and cost-effective.


2001 ◽  
Vol 19 (3) ◽  
pp. 197-210 ◽  
Author(s):  
A. Hashem ◽  
Reda M. El-Shishtawy

The factors influencing the cationization of microcrystalline cellulose with 3-chloro-2-hydroxypropyl triethylammonium chloride in the presence of NaOH were investigated. The course of the reaction was followed by estimating the nitrogen content of the cationized product while its structural features were confirmed by IR analysis. The ability of cationized cellulose to adsorb anionic dyes, viz. Acid Orange 7, Direct Blue 75 and Direct Violet 31, was investigated at 25°C and 50°C. The equilibrium data obtained were fitted by the Langmuir and Freundlich isotherm models, allowing the corresponding adsorption parameters to be determined. The results showed that the adsorption capacity was dependent on the adsorbent, temperature, the nature of the dye and (to some extent) on van der Waals and hydrogen bonding. Cationized cellulose exhibited a much better adsorption capacity towards anionic dyes than cellulose.


2021 ◽  
Vol 108 (Supplement_7) ◽  
Author(s):  
Ethlinn Patton ◽  
Dapo Olaleye ◽  
Stella Smith

Abstract Aims Methods Data was collected retrospectively between October to December 2020. Patient paper notes were reviewed on three dates before and after implementation of the ward round sticker, gathering data from 26 and 27 patients respectively. Data was collected across a series of weeks to ensure a variety of clinicians present on ward round, in order to accurately reflect current practice. Results An improvement in rate of documentation was seen in 10 out of 12 key clinical variables. Some of the largest increases were seen in consideration of VTE status; 96.3% (n = 26) from 7.69% (n = 2), and recording oral intake; 85.2% (n = 23) from 23.1% (n = 6.) Conclusions We know that poor quality documentation is associated with increased rates of adverse events for patients,[1] so it is imperative to address both what is being covered, and how it is being recorded. Staff reported that the use of ward round stickers improved legibility of documentation and made it easier to locate important information. This simple, cost effective intervention has improved the consistency of daily reviews, and streamlined communication within the multidisciplinary team.


2015 ◽  
Vol 19 (6) ◽  
pp. 2663-2672 ◽  
Author(s):  
A.-M. Kurth ◽  
C. Weber ◽  
M. Schirmer

Abstract. In this study, we investigated whether river restoration was successful in re-establishing groundwater–surface water interactions in a degraded urban stream. Restoration measures included morphological changes to the river bed, such as the installation of gravel islands and spur dykes, as well as the planting of site-specific riparian vegetation. Standard distributed temperature sensing (DTS) and novel active and passive DTS approaches were employed to study groundwater–surface water interactions in two reference streams and an experimental reach of an urban stream before and after its restoration. Radon-222 analyses were utilized to validate the losing stream conditions of the urban stream in the experimental reach. Our results indicated that river restoration at the study site was indeed successful in increasing groundwater–surface water interactions. Increased surface water downwelling occurred locally at the tip of a gravel island created during river restoration. Hence, the installation of in-stream structures increased the vertical connectivity and thus groundwater–surface water interactions. With the methods presented in this publication, it would be possible to routinely investigate the success of river restorations in re-establishing vertical connectivity, thereby gaining insight into the effectiveness of specific restoration measures. This, in turn, would enable the optimization of future river restoration projects, rendering them more cost-effective and successful.


2018 ◽  
Vol 8 (10) ◽  
pp. 2010 ◽  
Author(s):  
Yongqian Wu ◽  
Shaojian Song ◽  
Dachang Chen ◽  
Xiaoxing Zhang

Based on the first-principles of density functional theory, the SF6 decomposition products including single molecule (SO2F2, SOF2, SO2), double homogenous molecules (2SO2F2, 2SOF2, 2SO2) and double hetero molecules (SO2 and SOF2, SO2 and SO2F2, SOF2 and SO2F2) adsorbed on Pt doped graphene were discussed. The adsorption parameters, electron transfer, electronic properties and energy gap was investigated. The adsorption of SO2, SOF2 and SO2F2 on the surface of Pt-doped graphene was a strong chemisorption process. The intensity of chemical interactions between the molecule and the Pt-graphene for the above three molecules was SO2F2 > SOF2 > SO2. The change of energy gap was also studied and according to the value of energy gap, the conductivity of Pt-graphene before and after adsorbing different gas molecules can be evaluated.


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