Precipitation of heavy metals by lime mud waste of pulp and paper mill

Precipitation of heavy metals in synthetic and actual wastewater with lime mud (solid waste generated from the pulp and paper production process) was experimented using Jar-tests. Separate synthetic wastewater samples were prepared for each of the following heavy metals: lead (1,433.7 mgPb2+/L), chromium (506.7 mgCr3+/L), cadmium (1,095 mgCd2+/L) and mercury (9.37 mgHg2+/L). The actual wastewater was tanning wastewater containing 74.49 mgCr3+/L and COD wastewater containing 683 mgHg2+/L. Adjustments of pH in the acidic range, pH 2-7, were made for each type of synthetic wastewater except for the Hg synthetic wastewater. The optimum conditions obtained from the tests of the synthetic wastewater were used for theactual wastewater samples. Precipitation of heavy metals with lime mud was effective as indicated by the removal efficiency as high as 90% up for Pb, Cd and Hg and 100% for Cr. However, the removal efficiency for the Hg-COD wastewater was only 67%. The precipitating pH was in the range of 10 up, which is the common pH range for metal carbonate precipitation. The optimum dosage of lime mud for Pb, Cr, Cd and Hg synthetic wastewater was 0.4-1.0 g/L, 2.0-4.0 g/L, 1.6-2.0g/L and 0.8 g/L, respectively. While the optimum dosage of lime mud for precipitating chromium in tanning wastewater was 3.8 g/L and 3.6 g/L for precipitating mercury in COD wastewater

Water Quality Simulation and Dissolved Oxygen Change Scenarios in Lam Takhong River in Thailand

Dissolved oxygen (DO) in Lam Takhong River gradually reaches zero value during the dry season on several occasions in the past decade causing the unsuitable quality for use as the raw water for Nakhon Ratchasima Town. Discharges of point sources and diffuse sources containing pollutants with organics and nutrients are the major cause of water quality deterioration in the river. To find the sources of impact on the water quality in the river, a one- dimensional steady-flow systems river water quality model, QUAL2Kw, was constructed and simulated. The model was calibrated and validated using the water quality data from 2008 to 2017 for the Lam Takhong River by seven monitoring stations. The modelling was applied to simulate various water quality parameters during the critical period to compare to the designated surface water quality criteria third class in Thailand (minimum dissolved oxygen at or above 4 mg/L; maximum biochemical oxygen demand (BOD), nitrate-nitrogen, and ammonia-nitrogen at or below 2.0, 5.0 and 0.5 mg/L, respectively). The study reach of the river flows 122 km from Lam Takhong Dam to the Mun River at Chaloem Phra Kiat district through the urban central area. Several segments of the river have been alarmed for many constituents with the dissolved oxygen impairment is the focus of the study. The scenarios of loads and upstream dissolved oxygen modification were conducted to assess the change of dissolved oxygen concentration. The result of the QUAL2Kw model showed that the decomposition of organic matter and a poor reaeration were the primary cause of the impairment. The local oxygenation causes fluctuations in dissolved oxygen levels along the river and the dissolved oxygen concentration decreases downstream of the river with some values fell the meet the fourth class of surface water quality criteria in Thailand (DO above 2 mg/L and BOD5<4 mg/L). The QUAL2Kw model is suitable for simulating the current and future river water quality and help water resources managers to issue the appropriate policy options for the Lam Takhong River

Esophageal Replacement in Children: A 10-Year, Single-Center Experience

Objective: Various esophageal replacement grafts have been used in children, although none can equal the native esophagus. The purpose of this study was to review the complications and outcomes associated with using different techniques in a single institute. Methods: A retrospective medical record review was conducted from 2006 to 2016. Patient demographics, perioperative clinical courses, complications and long-term outcomes were reported as percentages and categorized according to the surgical procedure performed. Results: A total of 15 children underwent esophageal replacement procedures, comprising 7 (47%) isoperistaltic gastric tubes, 3 (20%) colonic interpositions, 3 (20%) gastric transpositions and 2 (13%) reversed gastric tubes. Indications for esophageal replacement included long-gap esophageal atresia (5; 33%), esophageal atresia with severe postoperative complications (6; 40%), and caustic injury (4; 27%).The mean age of patients was 2.9 years (range: 0.2–15 years). The average follow-up duration was 3.6 years (range: 0.4–8 years). There was no perioperative mortality and no graft loss in any group. The long-term outcomes were acceptable, with no late stricture. Eightysix percent of the patients in the isoperistaltic gastric tube group and all patients in the other procedural groups achieved full oral feeding. Nevertheless, the patients had various degrees of malnutrition. Conclusion: Esophageal replacement remains a major challenge in children. Our experience indicates that children can be safely operated on using any of these methods, with acceptable outcomes and no deaths. Nevertheless, the long-term consequences and complications should be monitored throughout adulthood

International Liver Transplantation Society Global Census:First Look at Pediatric Liver Transplantation Activity Around the World

Background. Over 16 000 children under the age of 15 died worldwide in 2017 because of liver disease. Pediatric liver transplantation (PLT) is currently the standard of care for these patients. The aim of this study is to describe global PLT activity and identify variations between regions. Methods. A survey was conducted from May 2018 to August 2019 to determine the current state of PLT. Transplant centers were categorized into quintile categories according to the year they performed their first PLT. Countries were classified according to gross national income per capita. Results. One hundred eight programs from 38 countries were included (68% response rate). 10 619 PLTs were performed within the last 5 y. High-income countries performed 4992 (46.4%) PLT, followed by upper-middle- (4704 [44·3%]) and lower-middle (993 [9·4%])-income countries. The most frequently used type of grafts worldwide are living donor grafts. A higher proportion of lower-middle-income countries (68·7%) performed ≥25 living donor liver transplants over the last 5 y compared to high-income countries (36%; P = 0.019). A greater proportion of programs from high-income countries have performed ≥25 whole liver transplants (52.4% versus 6.2%; P = 0.001) and ≥25 split/reduced liver transplants (53.2% versus 6.2%; P &lt; 0.001) compared to lower-middle-income countries. Conclusions. This study represents, to our knowledge, the most geographically comprehensive report on PLT activity and a first step toward global collaboration and data sharing for the greater good of children with liver disease; it is imperative that these centers share the lead in PLT.</p

Factors Related to the Clinical Outcomes of the Kasai Procedure in Infants with Biliary Atresia

Objective: The Kasai portoenterostomy has been accepted as the primary therapeutic treatment for biliary atresia. However, successful bile drainage does not always promise a long-term native liver survival. Several clinical factors were evaluated to discover associations with the outcomes. Methods: A retrospective chart review was conducted of infants with biliary atresia who underwent the conventional Kasai portoenterostomy at Siriraj Hospital, January 2006-August 2018. The patient demographics, perioperative clinical and laboratory data, adjuvant therapies, complications, and interventions were analyzed in correlation to the short- and long-term outcomes. The short-term outcome evaluated was the resolution of jaundice, while the long-term outcome was remaining jaundice-free with the native liver. Results: The complete medical records of 80 patients were retrospectively reviewed. Their mean age at the time of the Kasai portoenterostomies was 97 days. Overall, 66.3% achieved jaundice clearance. The mean follow-up duration was 50.5 months, with 51.3% of the patients remaining jaundice-free with their native liver. A prolonged duration of a prophylactic antibiotic was significantly related to the jaundice clearance, with a p-value of 0.002. Moreover, a lower number of episodes of cholangitis was significantly related to a good long-term outcome (p-value, 0.024). Conclusion: The prolonged provision of a prophylactic antibiotic as adjuvant therapy after the Kasai portoenterostomy was associated with jaundice clearance. An increased incidence of cholangitis episodes was associated with poor long-term outcomes. Postoperative adjuvant therapy should be standardized and maintained for the care of biliary atresia patients to improve their outcomes