RESUMEN
In this study, recovery of phenolic substances with Soxhlet extraction, (SE) ultrasound-assisted extraction (UAS), and supercritical CO2 (SC-CO2) extraction methods from chemical sludge obtained with chemical precipitation (FeCl3/PACS, Ca(OH)2/PACS, perlite/PACS, FeCl3/cationic polyelectrolyte) of lemon processing wastewater was investigated. The effect of used coagulants/flocculants and pH on COD and total phenolic substance content (TPC) removal was researched. Recovered phenolic substance profiles were also determined with HPLC-DAD. Additionally, response surface methodology was used to determine optimum treatment conditions. ANOVA analysis showed that pH is a more important variable than coagulant/flocculant doses for all chemical precipitation experimental sets. The highest removal efficiencies for COD and TPC was obtained in FeCl3/PACS (COD: 72.0 %, TPC: 93.7 %). Optimum dose values were determined as pH: 4, FeCl3: 3000 mg/L, PACS: 400 mg/L for FeCl3/PACS, pH: 6.5, Ca(OH)2: 1500 mg/L, PACS: 300 mg/L for Ca(OH)2/PACS, pH: 5.5, PACS: 7000 mg/L, perlite: 50 g/L for perlite/PACS, pH: 4.5, FeCl3: 500 mg/L, polyelectrolyte: 4 mg/L for FeCl3/polyelectrolyte. TPC removal efficiencies were determined as 55 %, 35 %, 57 % and 58 % in these conditions, respectively. Maximum TPC in extracts was determined as 39.03 mg GAE/g extract, 8.81 mg GAE/g extract, and 4.34 mg GAE/g extract for SE, UAS, and SC-CO2, respectively. TPC recovery efficiencies (RTPC) for all chemical sludge were SE > UAS > SC-CO2. Additionally, the TPC profile has shown a difference depending on the extraction method. According to the results of this study, it was concluded that the coagulation-flocculation process may be a suitable alternative for fruit juice processing industry wastewater in terms of both reducing environmental pollution and recovering polyphenolics from formed sludge. Consequently, this study presented a different perspective on the recovery from wastes with valuable substance recovery from chemical sludge.
Asunto(s)
Óxido de Aluminio , Cloruros , Compuestos Férricos , Aguas del Alcantarillado , Dióxido de Silicio , Aguas Residuales , Aguas del Alcantarillado/química , Frutas , Dióxido de Carbono , Polielectrolitos , Eliminación de Residuos Líquidos/métodos , Precipitación Química , Floculación , Extractos VegetalesRESUMEN
BACKGROUND/AIMS: Serum pepsinogen levels are considered as a non-endoscopic blood test in the diagnosis of atrophic gastritis. The objective of the present study was to investigate whether there is any difference between pepsinogen levels in Helicobacter pylori-positive and -negative patients with atrophic gastritis, and to analyze the relationship between histopathology and pepsinogen levels after treatment in H. pylori-positive patients with atrophic gastritis. METHODS: The study enrolled a total of 30 cases with atrophic gastritis (18 H. pylori-positive and 12 H. pylori-negative). The H. pylori-positive cases received a one-week eradication treatment. Initially for all and after the treatment for H. pylori-positive cases, serum pepsinogen I and II levels, anti-H. pylori IgG titration and histopathologic analysis were carried out. RESULTS: In the H. pylori-positive patients with atrophic gastritis, the levels of pepsinogen I and pepsinogen I/II ratio were lower while the levels of pepsinogen II were higher compared to the H. pylori-negative patients (p<0.05 for all). The post-treatment serum pepsinogen I levels and pepsinogen I/II ratios did not change in the H. pylori-positive group, while the levels of pepsinogen II, H. pylori antibody titration and gastric atrophy degree remarkably decreased (p<0.05 for all). CONCLUSIONS: In atrophic gastritis, the levels of serum pepsinogen and pepsinogen I/II ratio show a difference in H. pylori-negative versus -positive cases. Additionally, the usage of pepsinogen II as a serum marker in predicting the eradication of H. pylori with atrophic gastritis could be more reliable than pepsinogen I or the I/II ratio.