Performance and onsite regeneration of natural zeolite for ammonium removal in a field-scale non-sewered sanitation system.

Natural zeolite clinoptilolite was used as the primary ammonium removal method from the permeate of an anaerobic membrane bioreactor (AnMBR) treating high-strength blackwater generated from a community toilet facility. This zeolite-based nutrient capture system (NCS) was a sub-component of a non-sewered sanitation system (NSSS) called the NEWgenerator and was field tested for 1.5 years at an informal settlement in South Africa. The NCS was operated for three consecutive loading cycles, each lasting 291, 110, and 52 days, respectively. Both blackwater (from toilets) and blackwater with yellow water (from toilets and urinals) were treated during the field trial. Over the three cycles, the NCS was able to remove 80 ± 28%, 64 ± 23%, and 94 ± 11%, respectively, of the influent ammonium. The addition of yellow water caused the rapid exhaustion of zeolite and the observed decrease of ammonium removal during Cycle 2. After Cycles 1 and 2, onsite regeneration was performed to recover the sorption capacity of the spent zeolite. The regenerant was comprised of NaCl under alkaline conditions and was operated as a recycle-batch to reduce the generation of regenerant waste. Modifications to the second regeneration process, including an increase in regenerant contact time from 15 to 30 h, improved the zeolite regeneration efficiency from 76 ± 0.7% to 96 ± 1.0%. The mass of recoverable ammonium in the regenerant was 2.63 kg NH4-N and 3.15 kg NH4-N after Regeneration 1 and 2, respectively. However, the mass of ammonium in the regenerant accounted for only 52.8% and 54.4% of the estimated NH4-N originally sorbed onto the zeolite beds after Cycles 1 and 2, respectively. The use of zeolite clinoptilolite is a feasible method for ammonium removal by NSSS that observe variable nitrogen loading rates, but further research is still needed to recover the nitrogen from the regenerant waste.

Colectomías totalmente laparoscópicas con extracción de la pieza quirúrgica por orificios naturales / Totally laparoscopic colectomy with natural orifice specimen extraction

Objetivo: comunicación de la de la factibilidad de las colectomías totalmente laparoscópicas con extracción de la pieza quirúrgica por orificios naturales. Diseño: Trabajo descriptivo, retrospectivo, observacional. Pacientes y Método: Se incluyó una serie de 6 pacientes en quienes se realizó colectomía totalmente laparoscópica (con anastomosis intracorpórea) y extracción de la pieza quirúrgica por orificio natural. Resultados: Desde enero de 2007 a Agosto de 2011, en el Servicio de Cirugía General del Hospital San Roque, se llevaron a cabo 467 cirugías colorrectales, en 355 pacientes (76%), se realizó abordaje a cielo abierto y en 112 (24%), abordaje videolaparoscopico. En seis de ellos, una neoplasia de sigmoides (T2), y cinco enfermedades diverticulares recurrentes se realizó extracción de la pieza quirúrgica por orificios naturales con anastomosis colorrectal totalmente intracorporea. En 3 pacientes se extrajo la pieza por vía transrectoanal (masculinos) y en los 3 restantes por vía transvaginal. No se presentaron complicaciones intraoperatorias, tampoco postquirúrgicas inmediatas. La recuperación del tránsito intestinal, la ingesta de líquidos y el alta hospitalaria fueron similares a las observadas en las colectomías videoasistidas. Conclusiones: La resección de colon izquierdo por laparoscopía, realizando anastomosis intracorpórea, más extracción de la pieza por oríficios naturales (NOSE), puede ser considerada como una técnica alternativa para pacientes que requieren colectomías electivas, en patología benigna y neoplasias tempranas.

Objective: Communication of totally laparoscopic colectomy with natural orifice specimen extraction. Design: descriptive, retrospective, observational work. Patients and Methods: A series of 6 patients underwent totally laparoscopic colectomy (with intracorporeal anastomosis) and extraction of surgical specimen through natural orifice. Results: From January 2007 to August 2011, 467 colorectal surgeries were performed in the General Surgery Service of the Hospital San Roque. 355 (76%) underwent an open approach and 112 (24%) laparoscopic approach. In six of these cases, a sigmoid tumor (T2), and five recurrent diverticular diseases, we performed totally laparoscopic colectomy, with intracorporeal colorectal anastomosis. In 3 patients, the specimen was removed via transanal (male) and the remaining 3 by transvaginal route. There were no intraoperative or postoperative complications. The recovery of intestinal transit, fluid intake and hospital discharge were similar to those observed in video-assisted colectomy. Conclusions: The left colon resection by a totally laparoscopic technique, with intracorporeal anastomosis and the use of natural orifice specimell extraction (NOSE), can be considered as an alternative for patients requiring elective colectomy in benign disease and early neoplasia.

Multifocal aggressive lymphoma of the gastrointestinal tract in a renal transplant patient treated with cyclosporin A and prednisone.

This is a case report of an aggressive multifocal non-Hodgkin's lymphoma in a cadaver kidney recipient arising in the early phase of her immunosuppressive maintenance therapy program with cyclosporin A and prednisone.