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1.
World J Urol ; 42(1): 240, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38630158

RESUMEN

PURPOSE: To evaluate the impact of ureteroscope position within renal cavities as well as different locations of the tip of the ureteral access sheath (UAS) on fluid dynamics during retrograde intrarenal surgery (RIRS). MATERIALS AND METHODS: A prospective observational clinical study was performed. Measurements with a flexible ureteroscope placed in the upper, middle and lower calyces were obtained with the tip of the UAS placed either 2 cm below the pyelo-ureteric junction (PUJ), or at the level of the iliac crest. RESULTS: 74 patients were included. The outflow rates from the middle and upper calyxes were statistically significantly higher compared to the lower calyx, both with the UAS close to the pyelo-ureteric junction and at the iliac crest. When the UAS was withdrawn and positioned at the level of the iliac crest, a significant decrease in outflow rates from the upper (40.1 ± 4.3 ml/min vs 35.8 ± 4.1 ml/min) and middle calyces (40.6 ± 4.0 ml/min vs 36.8 ± 4.6 ml/min) and an increase in the outflow from the lower calyx (28.5 ± 3.3 ml/min vs 33.7 ± 5.7 ml/min) were noted. CONCLUSIONS: Our study showed that higher fluid outflow rates are observed from upper and middle calyces compared to lower calyx. This was true when the UAS was positioned 2 cm below the PUJ and at the iliac crest. Significant worsening of fluid dynamics from upper and middle calyces was observed when the UAS was placed distally at the level of the iliac crest. While the difference was statistically significant, the absolute change was not significant. In contrast, for lower calyces, a statistically significant improvement was documented.


Asunto(s)
Uréter , Ureteroscopios , Humanos , Hidrodinámica , Riñón , Endoscopía , Uréter/cirugía
2.
Curr Opin Urol ; 34(2): 116-127, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38038411

RESUMEN

PURPOSE OF REVIEW: There are enough publications on the use of telemedicine, wearable devices, and mobile applications in urology; however, their collective impact on urological care has not been adequately studied. This review seeks to address this deficiency by providing a descriptive analysis of the recent use of telemedicine, wearable technology, and mobile applications in urology as well as elucidating their associated challenges. RECENT FINDINGS: There are studies that were dedicated to the use of telemedicine, wearables, and mobile apps in urology according to inclusion criteria, respectively. They were successfully implemented in different urological subfields, such as urogynecology, endourology, pediatric urology, and uro-oncology, and led to time safety, remote monitoring, and better patient awareness. However, several concerns also exist, such as issues with data safety, measurement deviations, technical limitations, and lack ofquality. SUMMARY: Telemedicine, wearables, and mobile apps have already shown their potential in urological practice. However, further studies are needed to expand both our understanding of their current state and their potential for further development and clinical use.


Asunto(s)
Aplicaciones Móviles , Telemedicina , Urología , Dispositivos Electrónicos Vestibles , Niño , Humanos , Salud Digital
3.
Curr Urol Rep ; 25(1): 9-18, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37723300

RESUMEN

PURPOSE OF REVIEW: Artificial intelligence (AI) chatbots have emerged as a potential tool to transform urology by improving patient care and physician efficiency. With an emphasis on their potential advantages and drawbacks, this literature review offers a thorough assessment of the state of AI-driven chatbots in urology today. RECENT FINDINGS: The capacity of AI-driven chatbots in urology to give patients individualized and timely medical advice is one of its key advantages. Chatbots can help patients prioritize their symptoms and give advice on the best course of treatment. By automating administrative duties and offering clinical decision support, chatbots can also help healthcare providers. Before chatbots are widely used in urology, there are a few issues that need to be resolved. The precision of chatbot diagnoses and recommendations might be impacted by technical constraints like system errors and flaws. Additionally, issues regarding the security and privacy of patient data must be resolved, and chatbots must adhere to all applicable laws. Important issues that must be addressed include accuracy and dependability because any mistakes or inaccuracies could seriously harm patients. The final obstacle is resistance from patients and healthcare professionals who are hesitant to use new technology or who value in-person encounters. AI-driven chatbots have the potential to significantly improve urology care and efficiency. However, it is essential to thoroughly test and ensure the accuracy of chatbots, address privacy and security concerns, and design user-friendly chatbots that can integrate into existing workflows. By exploring various scenarios and examining the current literature, this review provides an analysis of the prospects and limitations of implementing chatbots in urology.


Asunto(s)
Médicos , Urología , Humanos , Inteligencia Artificial , Atención al Paciente
4.
Curr Urol Rep ; 25(1): 37-47, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38112900

RESUMEN

PURPOSE OF REVIEW: Artificial intelligence (AI) can significantly improve physicians' workflow when examining patients with UTI. However, most contemporary reviews are focused on examining the usage of AI with a restricted quantity of data, analyzing only a subset of AI algorithms, or performing narrative work without analyzing all dedicated studies. Given the preceding, the goal of this work was to conduct a mini-review to determine the current state of AI-based systems as a support in UTI diagnosis. RECENT FINDINGS: There are sufficient publications to comprehend the potential applications of artificial intelligence in the diagnosis of UTIs. Existing research in this field, in general, publishes performance metrics that are exemplary. However, upon closer inspection, many of the available publications are burdened with flaws associated with the improper use of artificial intelligence, such as the use of a small number of samples, their lack of heterogeneity, and the absence of external validation. AI-based models cannot be classified as full-fledged physician assistants in diagnosing UTIs due to the fact that these limitations and flaws represent only a portion of all potential obstacles. Instead, such studies should be evaluated as exploratory, with a focus on the importance of future work that complies with all rules governing the use of AI. AI algorithms have demonstrated their potential for UTI diagnosis. However, further studies utilizing large, heterogeneous, prospectively collected datasets, as well as external validations, are required to define the actual clinical workflow value of artificial intelligence.


Asunto(s)
Médicos , Infecciones Urinarias , Humanos , Inteligencia Artificial , Algoritmos , Infecciones Urinarias/diagnóstico , Benchmarking
5.
Curr Urol Rep ; 25(11): 299-310, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38980521

RESUMEN

PURPOSE OF REVIEW: Researchers have examined how telemedicine affects endourological patients. This review analyzes the literature to determine telemedicine's benefits and limitations in endourology. RECENT FINDINGS: Many studies were devoted to describing the effect of telemedicine on endourological patient satisfaction, optimization of the clinical decision-making among patients with kidney and ureteric stones, the effectiveness of telemedicine in the management of patients with indications for PCNL, follow-up for patients with urolithiasis and describing financial effectiveness for the patients after BOO surgery. The authors describe phone calls, video calls, and online booking platforms as used as telemedicine technology. However, several concerns also exist, such as the necessity of internet connections and appropriate devices, different receptivity among certain subgroups, data safety, and different regulatory environments among countries. Telemedicine offers the potential to reduce patient travel time, expedite decision-making, and save costs in endourology. However, its everyday implementation is challenging due to various obstacles faced by patients and providers, hindering the realization of its full potential and necessitating a systematic approach to problem-solving.


Asunto(s)
Telemedicina , Humanos , Atención a la Salud , Predicción , Urología/métodos , Satisfacción del Paciente , Urolitiasis/terapia
6.
Curr Opin Urol ; 33(2): 90-94, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36622261

RESUMEN

PURPOSE OF REVIEW: With advancements in surgical technology along with procedural techniques, this article throws light on the latest developments and applications of artificial intelligence (AI), extended reality, 3D (three-dimensional) printing and robotics in percutaneous nephrolithotomy (PCNL). RECENT FINDINGS: This review highlights the applications of AI in PCNL over the past 2 years. Mostly studies have been reported on development of machine learning (ML) based predicting models and identification of stone composition using deep learning convolutional neural network (DL-CNN). But owing to the complexity of the models and lack of generalizability, it is still not incorporated in the routine clinical practice. Extended reality based simulation and training models have enabled trainees to enhance their skills and shorten the learning curve. Similar advantages have been reported with the use of 3D printed models when used to train young and novice endourologists to improve their skills in percutaneous access (PCA). Applications of robotics in PCNL look promising but are still in nascent stages. SUMMARY: Future research on PCNL should focus more on generalizability and adaptability of technological advancements in terms of training and improvement of patient outcomes.


Asunto(s)
Cálculos Renales , Nefrolitotomía Percutánea , Urolitiasis , Humanos , Nefrolitotomía Percutánea/efectos adversos , Nefrolitotomía Percutánea/métodos , Urólogos , Inteligencia Artificial , Urolitiasis/cirugía , Impresión Tridimensional , Cálculos Renales/cirugía
7.
Curr Urol Rep ; 24(8): 355-363, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37079196

RESUMEN

PURPOSE OF REVIEW: The prevalence of uric acid (UA) urolithiasis contributes significantly to global disease burden, due to high rates of recurrence and diagnostic challenges. Dissolution therapy plays a valuable role in the conservative management of UA calculi, reducing the requirement for surgical intervention. This review summarises the existing evidence for the efficacy of medical dissolution of uric acid urolithiasis. RECENT FINDINGS: A systematic search was conducted of worldwide literature according to PRISMA methodology and Cochrane standards for systematic review. Studies were included if they reported outcome data for the administration of medical therapy for the dissolution of UA calculi. A total of 1075 patients were included in the systematic review. Complete or partial dissolution of UA calculi was observed in 80.5% of patients (865/1075 patients), with 61.7% (647/1048 patients) achieving complete dissolution and 19.8% (207/1048 patients) achieving partial dissolution. A discontinuation rate of 10.2% (110/1075 patients) was noted, and 15.7% (169/1075 patients) required surgical intervention. Dissolution therapy is a safe and effective method of conservatively managing uric acid stones in the short term. Despite the significant disease burden of UA calculi, current guidelines are limited by deficiencies in the existing body of research. Further research should be undertaken to develop evidence-based clinical guidelines for diagnosis, treatment, and prevention of UA urolithiasis.


Asunto(s)
Cálculos Renales , Nefrolitiasis , Cálculos Urinarios , Humanos , Ácido Úrico/uso terapéutico , Solubilidad , Cálculos Urinarios/terapia , Tratamiento Conservador , Cálculos Renales/terapia
8.
Indian J Urol ; 39(3): 195-201, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37575157

RESUMEN

Introduction: Oligometastatic prostate cancer (OMPC) has gained profound interest lately due to its different tumor biology and our ability to use multimodality therapy for cure or prolonged survival. Selecting the appropriate patient for treatment has become the aim of treating urologists, medical oncologists, and radiation oncologists. Through this review, we try to highlight the management of OMPC in light of recent literature. Methods: Literature search was performed on Pubmed, Scopus and Embase using keywords "Oligometastatic", " Prostate Cancer" using operators such as "And" & "Or". Relevant articles were screened and all the latest articles on this emerging entity were included in this review. Results: All trials relevant to oligometastatic prostate cancer defining the role of surgery, radiotherapy and systemic therapy were included and appropriate inferences were drawn. Relevant studies were compiled in tabular form for this article. Conclusion: The current standard of care of management for OMPC remains systemic therapy on the lines of hormone-sensitive metastatic prostate cancer. The evolving role of surgery, and radiotherapy along with systemic therapy is highlighted in this article.

9.
Curr Urol Rep ; 23(9): 165-174, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35877059

RESUMEN

PURPOSE OF REVIEW: Kidney stone disease (KSD) and recurrent urinary tract infections (rUTI) are frequently concomitant conditions. We conducted a systematic review to determine the association of UTI in patients with KSD and to assess the outcomes of kidney stone treatment in the resolution of rUTI. RECENT FINDINGS: Our systematic review included 17 papers and a strong association between KSD and rUTI was demonstrated by numerous studies. Surgical clearance of kidney stones usually resulted in the resolution of UTI, but discordant data persist regarding recurrence rates after surgery. In vitro studies might unveil the causative role of bacteria in the formation of "metabolic" stones. Our SR clearly shows that UTI and KSD are mutually coexisting, and reciprocally causal and such patients should be counselled for proactive intervention by stone removal especially when UTIs are recurrent or additional risk factors are present irrespective of stone composition. To prevent further UTI episodes, if possible, a stone culture must be obtained for an effectively targeted antibiotic treatment regime tailored to bacterial prevalence.


Asunto(s)
Cálculos Renales , Litotricia , Infecciones Urinarias , Antibacterianos/uso terapéutico , Humanos , Cálculos Renales/cirugía , Litotricia/métodos , Ureteroscopía/métodos , Infecciones Urinarias/complicaciones , Infecciones Urinarias/epidemiología
10.
Curr Urol Rep ; 22(6): 34, 2021 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-34027628

RESUMEN

PURPOSE OF REVIEW: We aim to provide an up-to-date literature review to further characterise the association of kidney stone disease (KSD) with gastrointestinal (GI) surgery. As KSD is associated with significant morbidity, it is important to quantify and qualify this association to provide better care and management for the patient subgroup. OBJECTIVE: To perform a systematic review of the existing literature to evaluate the association of KSD following GI surgery. METHODS: A literature search was performed of the following databases: MEDLINE, EMBASE, Scopus, Google Scholar, Key Urology, Uptodate and Cochrane Trials from January 2000 to June 2020. RECENT FINDINGS: A total of 106 articles were identified, and after screening for titles, abstracts and full articles, 12 full papers were included. This involved a total of 9299 patients who underwent primary GI surgery. Over a mean follow-up period of 5.4 years (range: 1-14.4 years), 819 (8.8%) developed KSD, varying from 1.2 to 83% across studies. The mean time to stone formation was approximately 3 years (range: 0.5-9 years). In the 4 studies that reported on the management of KSD (n = 427), 38.6% went on to have urological intervention. There is a high incidence of KSD following primary GI surgery, and after a mean follow-up of 3 years, around 9% of patients developed KSD. While the GI surgery was done for obesity, inflammatory bowel disease or cancer, the risk of KSD should be kept in mind during follow-up, and prompt urology involvement with metabolic assessment, medical and or surgical management offered as applicable.


Asunto(s)
Procedimientos Quirúrgicos del Sistema Digestivo/efectos adversos , Cálculos Renales/etiología , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Humanos , Incidencia , Cálculos Renales/diagnóstico , Cálculos Renales/epidemiología , Masculino , Persona de Mediana Edad , Obesidad/complicaciones , Adulto Joven
11.
Curr Urol Rep ; 22(10): 53, 2021 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-34626246

RESUMEN

PURPOSE OF REVIEW: To highlight and review the application of artificial intelligence (AI) in kidney stone disease (KSD) for diagnostics, predicting procedural outcomes, stone passage, and recurrence rates. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist. RECENT FINDINGS: This review discusses the newer advancements in AI-driven management strategies, which holds great promise to provide an essential step for personalized patient care and improved decision making. AI has been used in all areas of KSD including diagnosis, for predicting treatment suitability and success, basic science, quality of life (QOL), and recurrence of stone disease. However, it is still a research-based tool and is not used universally in clinical practice. This could be due to a lack of data infrastructure needed to train the algorithms, wider applicability in all groups of patients, complexity of its use and cost involved with it. The constantly evolving literature and future research should focus more on QOL and the cost of KSD treatment and develop evidence-based AI algorithms that can be used universally, to guide urologists in the management of stone disease.


Asunto(s)
Cálculos Renales , Calidad de Vida , Algoritmos , Inteligencia Artificial , Lista de Verificación , Humanos , Cálculos Renales/terapia
12.
Curr Urol Rep ; 21(4): 17, 2020 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-32211985

RESUMEN

PURPOSE OF REVIEW: To present the latest evidence related to the impact of increased operative times in retrograde intrarenal surgery and identify possible important factors that can facilitate ureteroscopy procedures. RECENT FINDINGS: Ureteroscopy constitutes the mainstay treatment of renal stones and is characterized by a huge variation in techniques and instrumentation. It has been suggested that increased operative times can mitigate the outcomes of the procedures by increasing complication rates. Nevertheless, little is known about the time limits, above which complications are likely to occur. Furthermore, complication rates in different procedure durations have not yet been assessed. Prolonged operative times are linked to increased complication rates in ureteroscopy. Stone complexity, patient risk factors, surgeon experience, bilateral surgery, and instrumentation constitute important factors that can hamper or facilitate a procedure and should be taken into account beforehand. Keeping procedural times below 90 min can dissuade potential predicaments and achieve improved stone-free rates.


Asunto(s)
Cálculos Renales/cirugía , Tempo Operativo , Complicaciones Posoperatorias/epidemiología , Ureteroscopía , Humanos , Factores de Riesgo , Resultado del Tratamiento
14.
J Environ Manage ; 252: 109617, 2019 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-31605906

RESUMEN

Pharmaceuticals are a wide class of emerging pollutants due to their continuous and the increasing consumption of users. These pollutants are usually found in the real environment as mixtures alone or with metal ions. Thus, the migration risk increases, which complicates the removal of pharmaceuticals because of the combined and synergistic effects. The focus of treatment of pharmaceutical mixtures and their coexistence with metals is of considerable importance. For this purpose, adsorption has been efficiently applied to several studies for the treatment of such complex systems. In this article, the coadsorption behavior of pharmaceuticals in the absence and existence of metals on several adsorbents has been reviewed. The adsorption isotherms and kinetics of these two systems have been analyzed using different models and discussed. Important challenges and promising routes are suggested for the future development of the coadsorption of the studied systems. This article provides an overview on the most utilized and effective adsorbents, widely studied adsorbates, best applied isotherm and kinetic models, and competitive effect in coadsorption of pharmaceuticals, both with and without metals.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Adsorción , Iones , Cinética , Metales
15.
Ecotoxicol Environ Saf ; 149: 257-266, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29248838

RESUMEN

Pharmaceutical pollutants substantially affect the environment; thus, their treatments have been the focus of many studies. In this article, the fixed-bed adsorption of pharmaceuticals on various adsorbents was reviewed. The experimental breakthrough curves of these pollutants under various flow rates, inlet concentrations, and bed heights were examined. Fixed-bed data in terms of saturation uptakes, breakthrough time, and the length of the mass transfer zone were included. The three most popular breakthrough models, namely, Adams-Bohart, Thomas, and Yoon-Nelson, were also reviewed for the correlation of breakthrough curve data along with the evaluation of model parameters. Compared with the Adams-Bohart model, the Thomas and Yoon-Nelson more effectively predicted the breakthrough data for the studied pollutants.


Asunto(s)
Modelos Teóricos , Preparaciones Farmacéuticas/análisis , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Adsorción
16.
Am J Gastroenterol ; 112(9): 1389-1396, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28440304

RESUMEN

OBJECTIVES: Acute liver failure (ALF) is classically defined by coagulopathy and hepatic encephalopathy (HE); however, acute liver injury (ALI), i.e., severe acute hepatocyte necrosis without HE, has not been carefully defined nor studied. Our aim is to describe the clinical course of specifically defined ALI, including the risk and clinical predictors of poor outcomes, namely progression to ALF, the need for liver transplantation (LT) and death. METHODS: 386 subjects prospectively enrolled in the Acute Liver Failure Study Group registry between 1 September 2008 through 25 October 2013, met criteria for ALI: International Normalized Ratio (INR)≥2.0 and alanine aminotransferase (ALT)≥10 × elevated (irrespective of bilirubin level) for acetaminophen (N-acetyl-p-aminophenol, APAP) ALI, or INR≥2.0, ALT≥10x elevated, and bilirubin≥3.0 mg/dl for non-APAP ALI, both groups without any discernible HE. Subjects who progressed to poor outcomes (ALF, death, LT) were compared, by univariate analysis, with those who recovered. A model to predict poor outcome was developed using the random forest (RF) procedure. RESULTS: Progression to a poor outcome occurred in 90/386 (23%), primarily in non-APAP (71/179, 40%) vs. only 14/194 (7.2%) in APAP patients comprising 52% of all cases (13 cases did not have an etiology assigned; 5 of whom had a poor outcome). Of 82 variables entered into the RF procedure: etiology, bilirubin, INR, APAP level and duration of jaundice were the most predictive of progression to ALF, LT, or death. CONCLUSIONS: A majority of ALI cases are due to APAP, 93% of whom will improve rapidly and fully recover, while non-APAP patients have a far greater risk of poor outcome and should be targeted for early referral to a liver transplant center.


Asunto(s)
Sistemas de Registro de Reacción Adversa a Medicamentos/estadística & datos numéricos , Enfermedad Hepática Inducida por Sustancias y Drogas/epidemiología , Sistema de Registros , Adulto , Alanina Transaminasa/sangre , Enfermedad Hepática Inducida por Sustancias y Drogas/sangre , Enfermedad Hepática Inducida por Sustancias y Drogas/complicaciones , Interpretación Estadística de Datos , Femenino , Encefalopatía Hepática/complicaciones , Humanos , Relación Normalizada Internacional , Masculino , Persona de Mediana Edad , Pronóstico , Índice de Severidad de la Enfermedad , Estados Unidos/epidemiología
17.
Ecotoxicol Environ Saf ; 138: 279-285, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28081490

RESUMEN

Hydrothermal carbonization of biomass wastes presents a promising step in the production of cost-effective activated carbon. In the present work, mesoporous activated carbon (HAC) was prepared by the hydrothermal carbonization of rattan furniture wastes followed by NaOH activation. The textural and morphological characteristics, along with adsorption performance of prepared HAC toward methylene blue (MB) dye, were evaluated. The effects of common adsorption variables on performance resulted in a removal efficiency of 96% for the MB sample at initial concentration of 25mg/L, solution pH of 7, 30°C, and 8h. The Langmuir equation showed the best isotherm data correlation, with a maximum uptake of 359mg/g. The adsorbed amount versus time data was well fitted by a pseudo-second order kinetic model. The prepared HAC with a high surface area of 1135m2/g and an average pore size distribution of 35.5Å could be an efficient adsorbent for treatment of synthetic dyes in wastewaters.


Asunto(s)
Arecaceae , Carbón Orgánico/química , Colorantes/química , Azul de Metileno/química , Adsorción , Biomasa , Cinética , Hidróxido de Sodio , Purificación del Agua/métodos
18.
J Environ Manage ; 196: 323-329, 2017 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-28314221

RESUMEN

In this work, an activated electric arc furnace slag (A-EAFS) was investigated as an effective Fenton catalyst for the photodegradation of methylene blue (MB) and acid blue 29 (AB29). Fourier transform infrared spectroscopy and UV-visible absorption analyses indicated that A-EAFS offers additional Fe3O4 because of the changes in the iron oxide phase and the favorable response to visible light. It has been found that the highest degradation efficiency can reach up to 94% for MB under optimal conditions of 1 g L-1 of A-EAFS, 20 mM H2O2, and pH 3. The optimal conditions for AB29 were 0.1 g L-1 A-EAFS, 4 mM H2O2, and pH 3 to reach 98% degradation efficiency. Visible light enhanced the degradation of both dyes. In addition, A-EAFS, could be easily separated magnetically, exhibited good chemical stability after seven successive photodegradation cycles.


Asunto(s)
Compuestos Azo , Azul de Metileno , Naftalenos , Fotólisis , Catálisis , Peróxido de Hidrógeno
19.
J Environ Manage ; 203(Pt 1): 237-244, 2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-28783020

RESUMEN

Mesoporous activated carbon was prepared using a hydrochar derived from coconut shell waste through hydrothermal carbonization and NaOH chemical activation process (COSHTC). Three sets of activated carbons were obtained with different hydrochar:NaOH impregnation ratios (1:1, 1:2, and 1:3). Among these ratios, 1:3 (COSHTC3) exhibited the optimum adsorption for methylene blue (MB). COSHTC3 adsorbed MB with an initial concentration of 25-250 mg/L at pH 3-11 and 30 °C. The adsorption isotherm of MB on COSHTC3 demonstrated that Langmuir isotherm could be better applied at a maximum monolayer adsorption capacity of 200.01 mg/g at 30 °C. The data was well fitted to the pseudo-second-order (PSO) kinetic model. These results show that the COSHTC3 prepared from low-cost agricultural waste (coconut shell) with average pore diameter 28.6 Å and surface area 876.14 m2/g acts as a better adsorbent for removal of cationic dyes and could pave the way for more low-cost adsorbents for dye removal.


Asunto(s)
Cocos , Azul de Metileno , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Colorantes , Concentración de Iones de Hidrógeno , Cinética
20.
J Environ Manage ; 154: 138-44, 2015 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25721981

RESUMEN

The removal of toxic herbicide from wastewater is challenging due to the availability of suitable adsorbents. The Langsat empty fruit bunch is an agricultural waste and was used in this study as a cheap precursor to produce activated carbon for the adsorption of herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) at different initial concentrations ranging from 50 to 400 mg/L. The produced Langsat empty fruit bunch activated carbon (LEFBAC) was mesoporous and had high surface area of 1065.65 m(2)/g with different active functional groups. The effect of shaking time, temperature and pH on 2,4-D removal were investigated using the batch technique. The adsorption capacity of 2,4-D by LEFBAC was decreased with increase in pH of solution whereas adsorption capacity increased with temperature. The adsorption data was well described by Langmuir isotherm followed by removal capacity of 261.2 mg/g at 30 °C. The results from this work showed that LEFBAC can be used as outstanding material for anionic herbicide uptake from wastewater.


Asunto(s)
Ácido 2,4-Diclorofenoxiacético/química , Frutas , Herbicidas/química , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Adsorción , Agricultura , Carbón Orgánico/química , Humanos , Meliaceae/química
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