Does Indoxyl Sulfate Have a Role in Uremic Pruritus? A Laboratory and Interventional Study.

BACKGROUND: Pruritus is a common complaint in patients with end-stage renal disease. Indoxyl sulfate (IS) is a tryptophan end metabolite extremely renal excreted. Activated charcoal can interfere with IS intestinal absorption. OBJECTIVES: To evaluate the serum level of IS and the effect of activated charcoal on uremic pruritus. MATERIALS AND METHODS: In all, 135 participants were divided into 2 main groups. In total, 45 normal and healthy individuals as a control group and 90 patients on regular hemodialysis; 45 of these patients had uremic pruritus and the other 45 were not complaining of uremic pruritus. Serum IS was measured. Activated charcoal was used by patients with uremic pruritus. The severity of pruritus and Dermatology Life Quality Index (DLQI) were assessed. RESULTS: The serum IS was significantly elevated in uremic patients than in control subjects (P < .001) and significantly elevated in uremic patients without pruritus (P < .001). Furthermore, there were positive significant correlations between the serum IS and both severity of pruritus (P < .001) and DLQI (P < .001). After activated charcoal usage, there was a significant decrease in IS level with the improvement of pruritus and quality of life of patients. CONCLUSIONS: IS may play a role in uremic pruritus. Activated charcoal could be considered a treatment for uremic pruritus.

How renal toxins respond to renal function deterioration and oral toxic adsorbent in pH-controlled releasing capsule.

The number of patients with chronic kidney disease (CKD) is increasing. Oral toxin adsorbents may provide some value. Several uremic toxins, including indoxyl sulfate (IS), p-cresol (PCS), acrolein, per- and poly-fluoroalkyl substances (PFAS), and inflammation markers (interleukin 6 [IL-6] and tumor necrosis factor [TNF]-alpha) have been shown to be related to CKD progression. A total of 81 patients taking oral activated charcoal toxin adsorbents (AC-134), which were embedded in capsules that dissolved in the terminal ileum, three times a day for 1 month, were recruited. The renal function, hemoglobulin (Hb), inflammation markers, three PFAS (PFOA, PFOS, and PFNA), and acrolein were quantified. Compared with the baseline, an improved glomerular filtration rate (GFR) and significantly lower acrolein were noted. Furthermore, the CKD stage 4 and 5 group had significantly higher concentrations of IS, PCS, IL-6, and TNF but lower levels of Hb and PFAS compared with the CKD Stage 3 group at baseline and after the intervention. Hb was increased only in the CKD Stage 3 group after the trial (p = .032). Acrolein did not differ between the different CKD stage groups. Patients with improved GFR (responders) (about 77%) and nonresponders had similar baseline GFR. Responders had higher acrolein and PFOA levels throughout the study and a more significant reduction in acrolein, indicating a better digestion function. Both the higher PFOA and lower acrolein may be related to improved eGFR (and possibly to improvements in proteinuria, which we did not measure. Proteinuria is associated with PFAS loss in the urine), AC-134 showed the potential to improve the GFR and decrease acrolein, which might better indicate renal function change. Future studies are needed with longer follow-ups.

The effect of whitening toothpastes on the color stability and surface roughness of stained resin composite.

BACKGROUND: This study aimed to investigate the effect of whitening toothpastes on the color stability and surface roughness of resin composites stained with coffee and cigarette smoke. METHODS: Seventy-two disk-shaped specimens (6 × 2 mm) of suprananohybrid resin composite were randomly divided into two groups and exposed to coffee and cigarette smoke (n = 36). After staining, the samples randomly divided into four groups according to whitening toothpastes and were brushed for 4 min: Opalescence Whitening (OW); Colgate Optic White (COW); Curaprox Black is White (CPX) and, distilled water (control) (n = 9). Color was measured with spectrophotometer at the initial, after staining, and after brushing, and surface roughness was measured with profilometer at the initial and after brushing. A surface morphology analysis was examined using scanning electron microscopy and atomic force microscopy. The obtained data were statistically analyzed. (p < 0.05). RESULTS: Cigarette smoke caused a significantly higher color change than coffee in the resin composite (p < 0.05). Brushing with hydrogen peroxide and silica-containing whitening toothpaste showed significant differences in color change (p < 0.05). The lowest whitening effect was found in activated charcoal-containing toothpaste. While all toothpastes increased the degree of surface roughness of resin composites, the highest roughness was caused by whitening toothpastes containing activated charcoal. (p < 0.05). CONCLUSIONS: The color stability and surface properties of resin composites can be affected by brushing them with whitening toothpaste. The utilization of whitening toothpaste containing hydrogen peroxide can be considered a safe method for increasing the whiteness of discolored resin composites.

Does Mixing Activated Charcoal With Cola Improve Tolerability Without Affecting Pharmacokinetics? A Randomized Controlled Crossover Trial.

INTRODUCTION: Activated charcoal is the most common form of gastrointestinal decontamination used for the poisoned patient. One limitation to its use is patient tolerability due to palatability. Some recommend mixing activated charcoal with cola to improve palatability. An important question is whether mixing activated charcoal with cola affects the ability of the activated charcoal to adsorb xenobiotic. METHODS: This was a prospective randomized controlled crossover trial. Five healthy adults aged 18 to 40 years were recruited. Participants received 45 mg/kg acetaminophen rounded down to the nearest whole tablet. One hour later, they were randomized to receive 50 g of an activated charcoal-water premixture alone or mixed with cola. Acetaminophen levels were collected. The area under the curve of acetaminophen concentrations over time was measured as a marker for degree of absorption. Participants also completed an appeal questionnaire in which they rated the activated charcoal preparations. Participants would then return after at least 7 days to repeat the study with the other activated charcoal preparation. RESULTS: Four male participants and 1 female participant were recruited. There was no statistical difference in preference score for activated charcoal alone versus the cola-activated charcoal mixture. There was no statistical difference in the area under the curve of acetaminophen concentrations over time between activated charcoal alone and the cola-activated charcoal mixture. Of note, the study is limited by the small sample size, limiting its statistical power. DISCUSSION: The absorption of acetaminophen in an overdose model is no different when participants received activated charcoal alone or a cola-activated charcoal mixture as suggested by area under the curve. In this small study, there was no difference in preference for activated charcoal alone or a cola-activated charcoal mixture across a range of palatability questions. On an individual level, some participants preferred the activated charcoal-cola mixture, and some preferred the activated charcoal alone.

Whitening efficacy of activated charcoal-based products: A single-blind randomized controlled clinical trial.

OBJECTIVE: This randomized controlled clinical trial evaluated the whitening efficacy, tooth sensitivity (TS), and volunteers' satisfaction following the use of activated charcoal powder and toothpaste. METHODS: Fifty-six volunteers were randomly allocated into 4 groups (n = 14) according to a 14-day toothbrushing or whitening treatment with activated charcoal powder (ACPW), activated charcoal toothpaste (ACT), regular fluoridated toothpaste (RT), and 10 % carbamide peroxide (CP). Objective (ΔE00) and subjective (ΔSGU) color and whiteness index (ΔWID) changes were calculated. Patients self-reported the risk and intensity of TS using a visual analogue scale and the volunteer's satisfaction was determined by a questionnaire. Color assessments were analyzed by Kruskal-Wallis followed by Dwas-Steel-Crithlow-Fligner, and absolute TS risk and volunteer's satisfaction by Fisher exact test (p < 0.05). RESULTS: ACPW and ACT promoted similar effects in ΔE00, ΔSGU, and ΔWID to that observed for RT. No significant difference was found in terms of TS risk intensity. TS risk became high after 7 and 14 days, with higher TS prevalence in CP. Volunteers reported that ACPW exhibited the lowest ease-of-use, comfort, and whitening satisfaction among groups (p < 0.05). CONCLUSION: Activated charcoal-based products presented a minor and unsatisfactory whitening effect while CP resulted in optimal tooth whitening and the highest level of satisfaction among volunteers. Risk was higher from 7 days onwards and was more pronounced in the CP. CLINICAL RELEVANCE: Based on the whitening effect and patient satisfaction, this controlled-randomized clinical evidence supports that the use of activated charcoal-based products should be discouraged.

Effects of interrupting the enterohepatic circulation in amatoxin intoxications.

BACKGROUND: Interruption of the enterohepatic circulation is regarded as an effective way to treat patients with amatoxin poisoning. Nonetheless, its effectiveness has not yet been systematically evaluated. Therefore, we performed a systematic review to investigate the role of enterohepatic circulation on patient outcome and clinical laboratory values. We specifically sought to evaluate the effect of activated charcoal, which absorbs drugs and toxins in the gastrointestinal tract. METHODS: A previously established database with data extracted from case reports and series from literature, supplemented with recent publications, was used. Patient characteristics, outcome, and laboratory values were evaluated. RESULTS: We included 133 publications describing a total of 1,119 unique cases. Survival was 75 per cent in the control group (n = 452), whereas in the group treated with single or multiple doses of activated charcoal (n = 667) survival was 83 per cent (P < 0.001, odds ratio 1.89 [95 per cent confidence interval 1.40-2.56]). Furthermore, no difference in peak values of alanine aminotransferase and aspartate aminotransferase activities were observed, whereas peak values of total serum bilirubin concentration and international normalized ratio were statistically significantly reduced in patients treated with activated charcoal. DISCUSSION: The ability of activated charcoal to enhance the elimination of amatoxin through interruption of the enterohepatic circulation offers a potentially safe and inexpensive therapy for patients in the post-absorptive phase. LIMITATIONS: Limitations include the potential for publication bias, the lack of universal confirmation of amatoxin concentrations, and the inability to directly measure enterohepatic circulation of amatoxin. CONCLUSION: Treatment with activated charcoal in patients with amatoxin poisoning was associated with a greater chance of a successful outcome. Additionally, activated charcoal was associated with a reduction in markers of liver function, but not markers of liver injury.

Influence of Sucrose and Activated Charcoal on Phytochemistry and Vegetative Growth in Zephyranthes irwiniana (Ravenna) Nic. García (Amaryllidaceae).

Zephyranthes irwiniana (Ravenna) Nic. García is an endemic, red list threatened species from the Brazilian savanna (Cerrado) with pharmacological potential to treat the symptoms of Alzheimer's Disease (AD). This work analyzed the vegetative growth and phytochemistry of its potential compounds, in response to variations in sucrose concentration and activated carbon (AC). Seeds were germinated in vitro and in the greenhouse. The in vitro bulbs were separated in six treatments with different sucrose concentrations (30, 45 and 60 gL-1) and/or AC (1 gL-1). Biomass increases in individuals grown in the greenhouse were higher than those cultivated in vitro. Sucrose concentration significantly increased biomass and root number. AC had a positive influence on leaf and root size, and a negative influence on root number. GC-MS analyses indicated great variation in the abundance of α-terpenyl-acetate, ethyl linoleate, clionasterol and lycorine between treatments, with maximum concentrations of 53.06%, 38.68, 14.34% and 2.57%, respectively. Histolocalization tests indicated the presence of alkaloids in the leaf chlorenchyma and bulb cataphylls. Finally, the present study provided new evidence that the constitution of the culture medium directly influences the vegetative growth and phytochemistry of this species, providing a good medium condition for propagating the species under threat.

An in vitro study of metformin adsorption to activated charcoal.

INTRODUCTION: Metformin is a biguanide used to manage patients with type 2 diabetes mellitus. However, metabolic acidosis with an elevated lactate concentration and death caused by metformin overdoses are toxicological concerns. Although activated charcoal has been widely used for gastrointestinal decontamination in cases of acute poisoning, there is no evidence regarding its efficacy in treating metformin overdoses. We therefore evaluated the adsorptive capacity of activated charcoal for metformin in vitro. METHODS: Activated charcoal (specific surface area: 1,080 m2/g) mixed with various concentrations of metformin solution was dissolved in simulated gastric and intestinal fluids at 37° Celsius. The suspension was then filtered and the metformin concentration in the filtrate was determined using high-performance liquid chromatography. The maximum adsorptive capacity for metformin was calculated using the Langmuir adsorption isotherm equation. RESULTS: The amount of metformin adsorbed per gram of activated charcoal ranged from 0.7 to 8.1 mg/g at pH 1.2, and from 8.4 to 48.2 mg/g at pH 6.8. The corresponding maximum adsorptive capacities were 10.6 mg/g and 55.9 mg/g respectively. DISCUSSION: The maximum adsorptive capacity of activated charcoal for metformin was similar to that of its capacity for other poorly adsorbed substances. This is likely because metformin is water-soluble and has high polarity-factors that correlate with poor adsorption on activated charcoal. CONCLUSIONS: The maximum adsorption of metformin by activated charcoal was low. Therefore, activated charcoal may not be effective for treating patients with metformin overdose.

Pepsin immobilization on activated carbon and functionalized with glutaraldehyde and genipin for the synthesis of antioxidant peptides of goat casein.

In this article, the synthesis of antioxidant peptides in the enzymatic hydrolysis of caprine casein was analyzed at three different time points (60 min, 90 min, and 120 min) using immobilized pepsin on activated and modified carbon (AC, ACF, ACG 50, ACG 100). The immobilization assays revealed a reduction in the biocatalysts' activity compared to the free enzyme. Among the modified ones, ACG 50 exhibited greater activity and better efficiency for reuse cycles, with superior values after 60 min and 90 min. Peptide synthesis was observed under all studied conditions. Analyses (DPPH, ß-carotene/linoleic acid, FRAP) confirmed the antioxidant potential of the peptides generated by the immobilized enzyme. However, the immobilized enzyme in ACG 50 and ACG 100, combined with longer hydrolysis times, allowed the formation of peptides with an antioxidant capacity greater than or equivalent to those generated by the free enzyme, despite reduced enzymatic activity.

Simplified Method for Removing Direct Oral Anticoagulant Interference in Mechanical Coagulation Test Systems-A Proof of Concept.

BACKGROUND: Direct oral anticoagulants (DOACs) cause unwanted interference in various hemostasis assays, including lupus anticoagulant (LA) testing, where false positive and false negative identification may occur. DOAC Stop (DS) is an activated charcoal (AC) product used to specifically and effectively adsorb DOACs from test plasma. This process normally requires plasma treatment, centrifugation and plasma separation prior to tests, but inexperienced operators may also inadvertently transfer residual AC particles, thereby potentially adversely affecting clot detection. METHODS: We hypothesized that residual DS might not be problematic for mechanical clot detection. We therefore investigated the potential impact of DS and a new DS liquid (DS-L) product on clotting tests using a mechanical clot detection system. Varying concentrations of DS were added to normal and abnormal plasmas with and without DOAC presence. Clotting tests including PT, APTT and dRVVT were performed directly in the analyzer without plasma/DS centrifugation. RESULTS: DS up to double the recommended treatment level had only minor effects on all test results, despite completely obscuring visibility in the plasma/reagent mix. This confirms that the centrifugation step may be able to be omitted when using mechanical detection systems. CONCLUSIONS: Should DS carryover into treated plasmas occur, this should not cause issues with testing performed on mechanical clot-sensing devices. Moreover, we hypothesize that DS can be used directly in these systems, without the need for centrifugation, thereby simplifying its many potential applications.

Prophylactic Oral Application of Activated Charcoal Mitigates Acute Campylobacteriosis in Human Gut Microbiota-Associated IL-10-/- Mice.

The incidence of human Campylobacter jejuni infections is increasing worldwide. It is highly desirable to prevent campylobacteriosis in individuals at risk for severe disease with antibiotics-independent non-toxic compounds. Activated charcoal (AC) has long been used as an anti-diarrheal remedy. Here, we tested the disease-mitigating effects of oral AC versus placebo in human gut microbiota-associated (hma) IL-10-/- mice starting a week prior to C. jejuni infection. On day 6 post-infection, the gastrointestinal C. jejuni loads were comparable in both infected cohorts, whereas campylobacteriosis symptoms such as wasting and bloody diarrhea were mitigated upon AC prophylaxis. Furthermore, AC application resulted in less pronounced C. jejuni-induced colonic epithelial cell apoptosis and in dampened innate and adaptive immune cell responses in the colon that were accompanied by basal concentrations of pro-inflammatory mediators including IL-6, TNF-α, IFN-γ, and nitric oxide measured in colonic explants from AC treated mice on day 6 post-infection. Furthermore, C. jejuni infection resulted in distinct fecal microbiota shift towards higher enterobacterial numbers and lower loads of obligate anaerobic species in hma mice that were AC-independent. In conclusion, our pre-clinical placebo-controlled intervention study provides evidence that prophylactic oral AC application mitigates acute murine campylobacteriosis.

Management of Acute Ferrous Sulfate Poisoning Using Activated Charcoal Monotherapy: A Case Report.

A 13-year-old schoolgirl presented to a public hospital having ingested over 70 tablets of 65 mg of prescription ferrous sulphate within the last hour. She complained of a 7/10 sharp abdominal pain. Signs included lethargy, agony, diaphoresis, and frequent eructation. Gastrointestinal movements were audible and frequent. Heart rate was at 50 beats per minute with intact but weak pulsations. Blood pressure was at 95/65 mmHg. During the clerking, she started vomiting in pouts separated by few-minute intervals. The vomitus was watery, yellowish, and had a rusty-ironic smell. Serum iron was at 200 mcg/dL and 230 mcg/dL at the time of admission to the hospital and the time of discharge, respectively. The patient received intravenous Ringer's lactate solution. She was detoxified by the chewing of a single dose of 100 g activated charcoal. She stayed in remission throughout the follow-up. It was concluded that monotherapy with oral activated charcoal arrests the progress of the toxicodrome.

Protective effect of activated charcoal against progression of chronic kidney disease: A randomized clinical study.

Chronic kidney disease (CKD) is a non-reversible and progressive disease affecting the kidneys, significantly impacting global public health. One of the complications of chronic kidney disease is impaired intestinal barrier function, which may allow harmful products such as urea to enter the bloodstream and cause systemic inflammation. This study aimed to investigate whether supplementation with activated charcoal could reduce uremic toxins in patients with end-stage renal disease (ESRD). The study was a randomized clinical trial conducted at the Dialysis Center of al Diwaniyah Medical Hospital in the Diwaniyah Governorate. Eighty-two patients with ESRD on regular hemodialysis were enrolled, with 15 patients receiving oral supplementation with activated charcoal in addition to standard care and 13 patients receiving only standard care. Blood samples were collected at baseline and after eight weeks, and several biomarkers were measured, including estimated glomerular filtration rate (eGFR), creatinine, urea, phosphorus, albumin, and indoxyl sulfate. The results showed a significant reduction in both serum urea and serum phosphorus levels after eight weeks of oral-activated charcoal treatment. However, the other biomarkers were not affected by the treatment. In conclusion, the use of oral-activated charcoal for eight weeks in Iraqi patients undergoing maintenance hemodialysis improved urea and phosphorus levels.

Facile Synthesis of Electrically Conductive Membranes.

A facile and effective strategy that can be used to fabricate electrically conductive membranes (ECMs) of diverse filtration performance (i.e., water productivity and solute rejection) is not available yet. Herein, we report a facile method that enables the fabrication of ECMs of a broad performance range. The method is based on the use of polyethylenimine (PEI), glutaraldehyde, and any of a diverse set of conductive materials to cast an electrically conductive layer atop any of a diverse set of substrates (i.e., from microfiltration to reverse osmosis membranes). We developed the reported ECM fabrication method using graphite as the conductive material and PVDF membranes as substrates. We demonstrate that graphite-PVDF ECMs were stable and electrically conductive and could be successfully used for solute filtration and electrochemical degradation. We also confirmed that the PEI/glutaraldehyde-based ECM fabrication method is suitable for conductive materials other than graphite, including carbon nanotubes, reduced graphene oxide, activated charcoal, and silver nanoparticles. Compared with the substrates used for their fabrication, ECMs showed low electrical sheet resistances that varied with conductive material, increased solute rejection, and reduced water permeance. Taken together, this work presents a promising general strategy for the fabrication of ECMs for environmental applications from diverse substrates and conductive materials.

Characterization of whitening toothpastes and their effect on the physical properties of bulk-fill composites

Abstract Objective To characterize activated charcoal and 2% hydrogen peroxide-based toothpastes and investigate their effects on roughness, color change, and gloss of bulk-fill composite resin. Methodology Composite resin specimens (Aura Bulk Fill, SDI) were subjected to 5,000 brushing cycles with regular toothpaste (Colgate Total 12, [RT]), activated charcoal toothpaste (Bianco Dental Carbon, [AC]), or hydrogen peroxide-containing toothpaste (Colgate Luminous White Advanced, [HP]), with or without coffee exposure. The pH, particle characterization by scanning electron microscopy (SEM), and weight% of solid particles in the toothpaste were assessed. Roughness (Ra) was evaluated using a surface profile-measuring device, color change (∆Eab/∆E00) by reflectance spectrophotometer, and gloss unit (GU) by glossmeter. Kruskal-Wallis, Dunn, Friedman, and Nemenyi tests were used, and the correlation coefficient test was performed between Ra and GU (α=0.05). Results RT presented a higher Ra after brushing and did not change after staining with coffee; moreover, the ∆Eab/∆E00 values were higher for RT than HP. Regarding gloss, AC and HP obtained higher values compared to RT. A significant negative correlation between gloss and Ra was found for RT exposed to coffee. All toothpastes had a neutral pH; however, RT had the largest percentage of solids by weight. SEM images showed particles of many sizes: irregular shape (RT), more regular particles (AC), and spherical clusters (HP). Although surface roughness, color change, and gloss may compromise the longevity of restorations, the whitening toothpastes tested did not promote more morphology changes than regular toothpastes.

New alternative for adsorption of 2, 4-dichlorophenoxyacetic acid herbicide (2, 4-D)

The adsorptive capacity of charcoal from the husk of the brazil nut fruit, called "ouriço" (the hard ball with nuts inside) for the herbicide dichlorophenoxyacetic acid (2,4-D) was evaluated. Activated carbons were produced from the brazil nut in a tubular oven at 800 °C and activated with CO2 or water steam. The specific surface area was determined by the Brunauer, Emmett and Teller (BET) method, demonstrating the mean density of micropores. Analysis of N2 adsorption/desorption isotherms was undertaken and the morphology of activated carbons was visualized by Scanning Microscopy (SEM). The activated carbons were successfully obtained and had a specific surface area of 395 m2.g-1 and 401 m2.g-1 after activation with either CO2 or water steam, respectively. The highest pore mean density occurred with a diameter of 1.17 nm for carbons activated in both atmospheres. The graph of the adsorption/desorption isotherms of N2 showed Type I isotherms, regardless of the activation atmosphere. The SEM analysis showed that, for both activation atmospheres, pore formation occurred in the shape of uniform honeycomb craters. Adsorption kinetics followed the pseudo-second order model, indicating chemisorption. Regardless of the activation atmosphere, the activated carbon from the brazil nut "ouriço", was highly efficient for 2,4-D adsorption.

Experimental acute anti-inflammatory activity of preparations with complexed cannabidiol in carriers

Abstract Cannabidiol (CBD) is a bioactive compound with promising anti-inflammatory results but has low aqueous solubility. Complexation of drugs with this characteristic in carriers is an alternative to improve their efficiency. This study aimed to prepare and characterize CBD complexes in different carriers, and to evaluate the anti-inflammatory effect of such preparations using an experimental model of edema induction in rat paws. The results were compared to a reference drug, ibuprofen (IBU). The carriers evaluated were beta cyclodextrin (bCD) and activated charcoal (AC). Quantification of the drugs in the complexes was determined, and different qualitative analyses were also performed. Oral treatments in single doses with CBD showed inhibitory effects similar to that of IBU, potentiating its bioactivity without significant adverse effects. CBD*bCD doses at 4.375, 8.75, 17.5, and 35 mg/kg significantly reduced the intensity of edema compared to equivalent doses of pure bioactive. In contrast, CBD*AC did not generate benefits. There was no significant inhibitory effect on myeloperoxidase activity, requiring more specific analyses to assess this parameter. The results suggest that the CBD*bCD complexation is perfectly feasible, increasing its anti-edematogenic efficacy in the experimental model used.

Estratégias para recuperação de xilooligossacarídeos do licor de resíduos de eucalipto para avaliação do seu efeito estimulante em Staphylococcus xylosus / Strategies for xylooligosaccharides recovery from eucalyptus waste liquor to evaluate their stimulatory effect on Staphylococcus xylosus

Xilooligossacarídeos (XOS) são reconhecidos pelo seu potencial prebiótico relevante para diversos setores industriais e foram obtidos após o pré-tratamento hidrotérmico da biomassa lignocelulósica residual de galhos de eucalipto. Subprodutos inibitórios são gerados durante o processo de solubilização dos oligossacarídeos e acabam comprometendo a utilização do licor em microrganismos. Neste trabalho, o processo de destoxificação, hidrólise enzimática e atividade estimulantes de crescimento da bactéria Staphylococcus xylosus foram estabelecidos. Os resultados mostraram que a adsorção com carvão ativado em pó removeu cerca de 55% do ácido acético e mais de 90% do ácido fórmico, compostos fenólicos, lignina solúvel, furfural e 5-hidroximetilfurfural, e que a soma dos oligossacarídeos xilobiose (X2) e xilotriose (X3) foram maximizadas de 0,57 g/L para 1,21 g/L com 110 U/gXOS da enzima endoxilanase e 6,3% do licor destoxificado na hidrólise enzimática. O consumo de cerca de 63% de X2 e de 46% de X3 pela bactéria em meio basal deficiente em fontes de carbono, mas acrescido com os oligômeros, proporcionou maior crescimento celular em relação aos meios basais com alta composição de carbono, com e sem XOS, revelando seu potencial prebiótico pelo efeito estimulante de crescimento. (AU)

Xylooligosaccharides (XOS) are recognized for their prebiotic potential relevant to several industrial sectors and were obtained after hydrothermal pretreatment of residual lignocellulosic biomass from eucalyptus branches. Inhibitory by-products are generated during the solubilization process of oligosaccharides and end up compromising the utilization of the liquor in microorganisms. In this work, the detoxification process, enzymatic hydrolysis and growth stimulating activity of Staphylococcus xylosus bacteria were established. The results showed that adsorption with powdered activated carbon removed about 55% of acetic acid and more than 90% of formic acid, phenolic compounds, soluble lignin, furfural, and 5-hydroxymethyl furfural and the sum of the oligosaccharides xylobiose (X2) and xylotriose (X3) were maximized from 0.57 g/L to 1.21 g/L with 110 U/gXOS of the enzyme endoxylanase and 6.3% of the detoxified liquor in the enzymatic hydrolysis. The consumption of X2 and X3 were about 63% and 46%, respectively, by the bacteria in basal medium deficient in carbon sources, but in medium added with the oligomers, provided higher cell growth compared to basal medium with high carbon composition, with and without XOS, revealing its prebiotic potential by its growth-stimulating effect. (AU)

Produção, caracterização e aplicação de carvão ativado de caroço de pêssego no tratamento de efluente têxtil / Production, characterization, and application of activated charcoal from peach kernel in textile effluent treatment

RESUMO O objetivo deste estudo foi caracterizar a produção de um carvão de caroço de pêssego e também avaliar a adsorção de corantes têxteis pelo carvão ativado de caroço de pêssego. A ativação do carvão foi realizada utilizando cloreto de zinco como agente oxidante. O carvão ativado foi então utilizado na adsorção de corantes, para posterior aplicação no tratamento de um efluente têxtil. Primeiramente, realizou-se a produção de carvão ativado com as temperaturas de 500, 700 e 900°C e tempo de carbonização de 10 15 e 20 minutos e verificou-se a remoção dos corantes preto reativo 5 e azul de metileno. De acordo com a metodologia de superfície de resposta, a melhor temperatura de produção apresentou-se acima de 700°C com tempo de exposição de 10 minutos para os dois corantes. Desse carvão ativado, avaliaram-se os dados de densidade, teor de umidade e cinzas, pH e rendimento. Também foram realizados ensaios cinéticos e de equilíbrio. Os dados foram ajustados a três modelos cinéticos. As medidas para determinação da eficiência na remoção de cor do efluente têxtil foram realizadas pelo método espectrofotométrico e demonstraram média de remoção superior a 62% da cor presente no efluente bruto. Desse modo, o caroço de pêssego demonstrou elevado potencial para a produção de carvão ativado visando o tratamento de efluentes contendo corantes, podendo servir como alternativa de baixo custo.

ABSTRACT The aim of this study was to characterize the production of activated charcoal from the peach kernel and assess the adsorption of textile dyes by this activated charcoal. The activation of the charcoal was performed using zinc chloride as the oxidizing agent. The activated charcoal was then used in the adsorption of dyes for later application in the treatment of a textile effluent. Firstly, the production of activated carbon was carried out at temperatures of 500, 700, and 900°C and carbonization time of 10, 15, and 20 minutes and the removal of the Reactive Black 5 and Methylene Blue dyes was verified. According to the methodology of response surface, the best production temperature was above 700°C with 10 min exposure for both dyes. From this activated carbon, data on density, moisture and ash content, pH, and yield were evaluated. Kinetic and equilibrium tests were also performed. The data were fitted to three kinetic models. The measures to determine the efficiency in the color removal of the textile effluent were carried out by the spectrophotometric method and demonstrated an average removal greater than 62% of the color present in the raw effluent. In this way, the peach kernel demonstrated a high potential for the production of activated carbon aiming at the treatment of effluents containing dyes and can serve as a low cost alternative.