Preparation and characterization of activated carbon produced from tannery solid waste applied for tannery wastewater treatment

The removal of toxic compounds (azo dyes) from dyeing wastewater was investigated by an environmentally friendly activated carbon produced from solid waste generated in the tannery process, the cattle hair (CHW), activated with H₃PO₄ (AC-CHW), suggesting a life cycle extension for this material from leather processing. Preliminary tests with aqueous solutions containing Acid Brown 414 (AB-414) and Acid Orange 142 (AO-142) removed 71.06% and 73.05%, respectively. The activated carbon was characterized by zeta potential (ZP), functional groups (FTIR), elemental composition, sorbent specific surface area, and pore size distribution (BET/BJH). The specific surface area showed low values when compared to commercial activated carbon, but average pore diameter was higher, which facilitates the adsorption of larger and complex molecules, such as those present in real wastewaters. Through SEM and FTIR, the presence of the toxic compounds studied in the AC-CHW after sorption process was observed, where the results indicated that the functional groups of -CH=CH- participated in the removal process for these compounds. The removal efficiency obtained with AC-CHW was 51.94% and 49.73% for the dyeing wastewater containing AB-414 and AO-142, respectively. The obtained results open a promising via to use AC-CHW as efficient eco-friendly sorbent for the treatment of leather wastewater.

Fungal biomass as biosorbent for the removal of Acid Blue 161 dye in aqueous solution

Physical and thermal treatment was used to inactivate Trametes sp. SC-10 fungus. The resulting biomass was named BTV, characterized by analytical techniques such as SEM, EDX, FTIR, BET, and Barrett-Joyner-Halenda (BJH) model. pH, kinetic, and equilibrium adsorption studies with the Acid Blue 161 (AB-161) dye were investigated at 303.15 K. The kinetics of the biosorption process were examined at 600.00 and 1300 mg L^-1, using pseudo-first-order, pseudo-second-order, and Avrami fractional-order models. The maximum biosorption capacity of BTV for AB-161 dye was 221.6 mg g^-1. Considering the biosorption data and the functional groups of BTV, it can be inferred that the sorption mechanism of AB-161 is regulated by electrostatic interactions between ionized dye molecules and negative charges on BTV in an aqueous solution. Finally, the BTV was tested with a simulated effluent with 89.47% efficiency, presenting the BTV as a biosorbent for real effluents polluted with dyes.

[Esophagogastric varix hemorrhage. Experience with cyanpoacrylate and polidocanol in 68 patients with active hemorrhage]

BACKGROUND

Sclerosis, injection of cianoacrylate and rubber band ligation are the most commonly used endoscopic techniques for the treatment of bleeding esophageal varices.

AIM

To assess the effectiveness of cianoacrylate and polidocanol in the treatment of bleeding esophageal varices.

PATIENTS AND METHODS

Sixty eight patients with active variceal bleeding were studied. Bleeding varices were classified as thin, thick or gastric. Bleeding from thin varices was treated with polidocanol. Bleeding from thick or gastric varices was treated with cianoacrylate. Variceal eradication was done with polidocanol.

RESULTS

Bleeding came from thin esophageal varices in 23% of patients and endoscopic treatment stopped bleeding in 95% of them, from thick esophageal varices in 62% and endoscopic treatment was successful in 94% of these, and from gastric varices in 12% and treatment stopped bleeding in 87% of these (in 3% bleeding was considered subcardial). Twenty-five percent of patients bled again during variceal eradication, 12% died due to uncontrollable bleeding and 20% died due to liver failure. During variceal eradication 59% of patients classified as Child Pugh C, died.

CONCLUSIONS

Treatment of bleeding esophageal varices with cianoacrylate or polidocanol is effective. Patients classified as Child Pugh C have a had prognosis.

Use of a very flexible guide wire to permit dilation of complex malignant strictures of the esophagus

Risk of perforation is a major impediment to the use of polyvinyl bougies in palliative dilation of cancerous strictures of the esophagus. We encountered 23 patients with complex malignant strictures in whom initial dilation with Savary-Gilliard bougies was thwarted because attempts to pass a conventional Eder-Puestow guide wire were unsuccessful. As a recourse, we probed these strictures with a very flexible guide wire of the type used to implant prostheses in the biliary tract. The purpose was to establish a passage through which a standard guide wire could then be inserted. The procedure was successful in all but 4 of the 23 patients. We conclude that in such cases the preliminary use of the very flexible guide, even though time-consuming, improves the chance of effective dilation with minimal added risk.

Leukocyte mitosis: suppression in vitro associated with acute infectious hepatitis

Inhibition of mitosis in vitro was observed in leukocytes from patients with acute infectious hepatitis. Similarly, in cultures of normal leukocytes, after the addition of small amounts of serum from patients with hepatitis, mitosis was suppressed. Althoutgh the incidence of mitosis became normal in leukocytes from convalescent patients, there were chromosomal abnormalities.