ABSTRACT
In this study, a higher concentration of (reactive dyestuff and salt) mixed water was used to verify the feasibility of separation by membrane techniques. The commercial nano filtration ceramic membrane (MWCO 200 Da) has been used in cross flow mode for separation of dyes and salts from highly concentrated mixed water solution. NF ceramic membrane presents good permeability (pure water flux 54.15 Lm-2 h-1, TMP 8 bar), 8% dye rejection and reduced salt rejection of NaCl (<8%) and Na2SO4 (<25%). Consequently, the operation parameters (TMP, temperature) and solution environment (solution pH, salt concentration and dye concentration) have been intensively evaluated for separation efficiency in the NF ceramic membrane process. Significantly, the NF ceramic membrane has performed less rejection to chloride ions than sulphate ions due to the Donnan effect. Solution pH, concentration of salt and dye concentration have shown significant effects on ceramic membrane separation performance. In addition, pollutant removals were achieved with noteworthy values for the chemical oxygen demand for permeate solution also color difference between concentrate and permeate. In conclusion, the strong rejection of dyes by the NF ceramic membranes proves that it can be suitable alternatives for textile wastewater treatment process.
ABSTRACT
The quality of the images published in the original version was not satisfactory. The better version images are provided below.
ABSTRACT
BACKGROUND: Esophageal replacement is a challenge to the therapeutic skills of surgeons and a technically demanding operation in the pediatric age group. Various conduits and routes have been described in the literature, each with their specific advantages and disadvantages. We carried out this retrospective study to share our experience of esophageal replacement. METHODOLOGY: This study was conducted at the department of pediatric surgery The Children's Hospital and The Institute of Child Health, Lahore. The records of patients treated for esophageal replacement were reviewed. The patients under follow-up were called for clinical evaluation and assessed of long terms complications if any. RESULTS: A total of 93 patients with esophageal replacement were included in the study. Esophageal replacement was done with gastric transposition in 84 cases (90%), colon interposition in 7 cases (7.5%) including one case of redo colonic interposition, and jejunal interposition in 2 cases (2%). Routes of esophageal replacement were trans-hiatal in 71 (76%), retrosternal in 13 (14%), and trans-hiatal with thoracotomy in 9 (10%) patients. Postoperatively, all of the conduits maintained viability. Wound infection was seen in 10 (11%), wound dehiscence in 5 (5%), anastomotic leak in 9 (10%), anastomotic stenosis in 12 (13%), fistula formation in 4 (4%), aortic injury 1 (1%), dumping syndrome 8 (9%), reflux 18 (19%), dysphagia 15 (16%) and death occurred in 12 patients (13%). CONCLUSION: There are problems with esophageal replacement in developing countries. In this context, gastric conduit appeared as the best conduit for esophageal replacement, using the trans-hiatal route for replacement, in the authors' experience.
