Use of reverse osmosis as a polish for the cationic surfactant after electro-oxidative treatment: Acute and chronic toxicity assessment.

The main purpose of this work was to evaluate the performance of a commercial reverse osmosis (RO) membrane regarding selectivity (rejection) and productivity (permeate flux) of the treatment of quaternary ammonium compounds (QAC) after electro-Fenton (EF) treatment. Pollutants treated after the EF process should be investigated for ecotoxicity, since excess ions and high conductivity are harmful to aquatic and terrestrial biota. The use of the membrane system after EF treatment acts as final polishing since some electro-oxidative treatments leave the sample with high conductivity. In this study, RO was operated with a constant flow of 1 L min-1 and feed pressures of 1 MPa, 2 MPa and 3 MPa to reject ions (sodium and iron) and to decrease the level of toxicity using representative species from different taxonomic groups: freshwater algae (Pseudokirchneriella subcapitata), microcrustaceans (Daphnia similis) and lettuce seeds (Lactuca sativa). Experiments carried out at different pressures showed that increased pressure caused a rise in rejection and permeate flux. At the applied pressure of 3 MPa, after 180 min, conductivity removal efficiency of 83% was obtained, 85% for sodium and 99% for iron at a flow of 13.87 L/h m2. In all bioassays, the use of the membrane was efficient to decrease the toxicity by rejecting the ions. The microcrustacean tested was the most sensitive organism, while alga was the most tolerant organism. The germination of lettuce seeds and the relative growth rate of the radicle after the combined EF+RO process was satisfactory.

Oilfield water treatment by electrocoagulation-reverse osmosis for agricultural use: effects on germination and early growth characteristics of sunflower.

This study aims to evaluate the effects of oilfield water (OW), treated by a hybrid process of electrocoagulation and reverse osmosis (EC-RO), on seed germination and early growth characteristics of sunflower (Heliantus annus L.). In the EC step, tests were conducted with 28.6 A m-2 current density and 4 min. reaction time. In the RO step, the system was operated with 1 L min-1 constant flow and 2 MPa, 2.5 MPa and 3 MPa feed pressures. In all feed pressures, RO polymeric membranes achieved very high removals of chemical oxygen demand (up to 89%) and oils and greases (100%) from EC-treated effluent. In best feed pressure (2.5 MPa), turbidity, total dissolved salts, electrical conductivity, salinity, toxic ions and sodium adsorption ratio values attained internationally recognized standards for irrigation water. Using EC-RO (feed pressure:2.5 MPa) treated OW, germinated sunflower seeds percentage (86 ± 6%), speed of germination (30 ± 2) and biomass production (49 ± 5 mg) were statistically similar to control (distilled water) results. Vigor index average values obtained using OW treated by EC-RO (3871)were higher than that obtained by OW water treated by EC (3300). The results of this study indicate that EC-RO seems to be a promising alternative for treatment of OW aiming sunflower crops irrigation, since the use of this treated effluent did not affect adversely seed germination and seedling development, and improved seedling vigor. Furthermore, OW treatment by EC-RO reduces sodium levels into acceptable standards values avoiding soil degradation.

Effects of untreated and treated oilfield-produced water on seed germination, seedling development, and biomass production of sunflower (Helianthus annuus L.).

This study aims to evaluate possible toxic effects of oil and other contaminants from oilfield-produced water from oil exploration and production, on seed germination, and seedling development of sunflower (Helianthus annuus L.). In comparison, as treated by electroflocculation, oilfield-produced water, with lower oil and organic matter content, was also used. Electroflocculation treatment of oilfield-produced water achieved significant removals of chemical oxygen demand (COD) (94 %), oil and grease (O&G) (96 %), color (97 %), and turbidity (99 %). Different O&G, COD, and salt levels of untreated and treated oilfield-produced water did not influence germination process and seedling biomass production. Normal seedlings percentage and vigor tended to decrease more intensely in O&G and COD levels, higher than 337.5 mg L(-1) and 1321 mg O2 L(-1), respectively, using untreated oilfield-produced water. These results indicate that this industrial effluent must be treated, in order to not affect adversely seedling development. This way, electroflocculation treatment appears as an interesting alternative to removing oil and soluble organic matter in excess from oilfield-produced water improving sunflower's seedling development and providing a friendly environmental destination for this wastewater, reducing its potential to harm water resources, soil, and biota.

Hepatic artery reconstruction in pediatric living donor liver transplantation under 10 kg, without microscope use.

Arterial reconstructions are pivotal, particularly in pediatric LDLT. We describe microsurgical reconstruction technique with 6x loupes and the clinical course of the first 23 less than 10 kg recipients in an initial LDLT program at a developing country. From March 2002 to October 2008, 286 liver transplantation were performed in 279 patients at our unit. There were 73 children and 206 adults. Among the children, 23 weighing less than 10 kg were recipients from living donors. Arterial reconstructions were with end-to-end interrupted suture using a 6x magnification loupe, according to the untied suture technique. All patients were prospectively followed by color Doppler ultrasound protocol. In our initial experience there were no arterial complications. With mean 24 months of follow-up, 19 patients (82%) are alive with good graft function. Hepatic artery in LDLT can be safely reconstructed with microsurgical techniques without microscope using, with 6x loupe magnification, and can achieve good results in patients under 10 kg.

Selection of donors for living donor liver transplantation in a single center of a developing country: lessons learned from the first 100 cases.

The selection of donors for living donor liver transplantation (LDLT) is one of the most important features in this kind of surgery. The aim of this study is to describe our initial experience in the donor evaluation process. From December 2001 to January 2005, 104 donors were evaluated for 70 recipients (65 potential donors were evaluated for 39 adult recipients, and 39 donors for 31 pediatric recipients). Only 30 donors were able to donate: 13 for the adult group, and 17 for the pediatric one. In general, the utilization rate of potential donors was 28.8% (30/104). For the adult patients, 65 potential donors were seen to perform 13 LDLT, which represents a utilization rate of potential donors of 20%. For the pediatric patients, this rate was 43.6%. The exclusion criteria were clinical in 22 cases (21%), anatomical in 13 cases (13%), psychosocial in nine cases (9%), and others in 12 (12%). Death of recipients led to exclusion 18 of donors (17%). Thirty-three percent of adults and 55% of pediatric recipients who had at least one potential donor to start the evaluation process were able to identify a living donor. In conclusion, the first limit for LDLT is the rigorous donor evaluation.

Liver transplantation with monosegments. Technical aspects and outcome: a meta-analysis.

The shortage of organ donors for low-weight liver transplant recipients, especially small children, has led to the development of new surgical techniques to increase the donor pool. Almost all of these techniques use the left lateral segment (Couinaud's segments II and III), but even this graft could be too large for children under 10 kg, and further reduction could be necessary. Few articles address the issue of monosegmental liver transplantation. Available articles are with small sample sizes or even case reports, which makes it difficult to draw conclusions about indication and outcome for monosegmental grafts. A search of the MEDLINE databases using the terms "Liver Transplantation" and "Monosegmental" or "Monosegments" limited to title or abstract with publication in the English language was conducted. The data from each study were selected and analyzed, regarding donor status (living or cadaveric), donor weight, surgical techniques used in left lateral further reduction, recipient indication for liver transplantation, age and recipient weight, graft-to-recipient body weight ratio, segment utilized, type of abdominal closure, postoperative complications, and survival. Seven publications were identified from 1995 to 2004 and fulfilled the criteria. A total of 27 pediatric patients who received a monosegment transplant were identified, median age 211 days (range, 27 to 454 days) and median weight 4.6 kg (range, 2.45 to 7.4 kg). Segment III was utilized in 21 (78%) and segment II in 6 (22%). Patient survival was 85.2%. In conclusion, monosegment liver transplantation appears to be a satisfactory option for infants weighing less than 10 kg who require a liver transplant.

Liver transplantation with monosegment from a living donor.

The shortage of organ donors for low-weight liver transplant recipients, especially for small children, has led to the development of new surgical techniques to increase the donor pool. Almost all of these techniques use the left lateral segment (Couinaud's segments II and III), but even this graft could be too large for children under 10 kg. We report here the case of an 8-month-old boy, weighing 6.1 kg, who received a monosegmental graft (segment III) from his grandmother weighing 68 kg. The graft was reduced at the donor surgery, before clamping of the vessels. The donor was discharged on the fourth post-operative day; the recipient had an uneventful post-operative period and was discharged after 22 days.