ABSTRACT
The pretreatment of bio-treated effluent of dye wastewater by UV/H2O2 process was studied. The influencing factors, such as H2O2 dosage, reaction time and pH values were evaluated for the removal efficiency of UV254, ADMI7.6, DOC and DOC of dye wastewater by UV/H2O2 process. The experimental results showed that,the optimal conditions determined were as follows: initial pH 7.4-8.1, H2O2 dosage 4.5 mmol x L(-1) and UV irradiation time of 50 min. Under the optimal conditions, UV254, ADMI7.6, DOC and COD removal rate could reach 77%, 94%, 40% and 69%. Removal effects of four different DOM fractions, hydrophobic acids, non-acid hydrophobics, tasnsphilics and hydrophilics separated by XAD-8 and XAD-4 resins. The experimental results show that: hydrophobic material was the main substance causing color, when it was characterized by ADMI7.6, the proportion could reach 92%, of which 53% was non-acid hydrophobics. It indicated that removal efficiencies of tasnsphilics, hydrophobic acids and non-acid hydrophobics were high through UV/H2O2, process, while hydrophilics' efficiencies were lower. The experimental results showed that organic molecules with molecular weight over 10,000 contributed greatly to UV254, ADMI7.6 and DOC removal rate.
Subject(s)
Coloring Agents/isolation & purification , Hydrogen Peroxide/chemistry , Ultraviolet Rays , Waste Disposal, Fluid/methods , Wastewater/chemistry , Bioreactors , Coloring Agents/chemistry , Organic Chemicals/chemistry , Organic Chemicals/isolation & purification , Oxidation-ReductionABSTRACT
OBJECTIVE: To develop a method to generate T lymphocytes that identify tumor specific carcinoembryonic antigen (CEA), and induce anti-tumor response such as apoptosis. METHODS: Peripheral blood samples were collected from 10 healthy persons and peripheral blood mononuclear cells (PBMCs) were isolated. 1, then CD8(+) T cells were isolated from the PBMCs by magnetic activated cell sorting (MACS) using magnetic beads-conjugated anti-CD8 monoclonal antibodies. Then the recombinant vector anti-CEA-scFv-CD3zeta-pcDNA3.0 was transfected into the CD8(+) T cells by lipofectamine 2000 and T lymphocytes with chimeric receptor were generated and cultivated. The T lymphocytes' activation was assessed by detecting the expression of CD69, an early signal of T cell activation. Human gastric carcinoma cells of the lines HGC-27 (CEA(+)) and SGC-7901 (CEA(-)) were cocultivated with the T lymphocytes with chimeric receptor. Flow cytometry (FCM) with annexin V-FITC/PI double staining was used to detect the expressions of annexin V, a signal of cell apoptosis, so as to observe the apoptosis of the gastric carcinoma cells. T cells activated by phytohemagglutinin (PHA) were used as positive controls, and T cells transfected with blank vector pcDNA3.0 were used as negative controls. RESULTS: T lymphocytes with chimeric receptor directed towards CEA(+) gastric carcinoma cells were generated. 12 and 24 hours after the co-culture of these T cells and HCG-27 cells, the CD69 expression rates were 40.5% +/- 3.4% and 48.3% +/- 2.8% respectively. However, the CD69 expression rates of the HGC-27 and SGC-7901 cells transfected with the T lymphocytes transfected with blank vector were both 0%. FCM showed that the apoptotic rates of the CEA(+) gastric tumor HGC-27 cells was 47.8% +/- 4.2%, significantly higher than that of the CEA(-) gastric tumor SGC-7901 cells (18.7% +/- 2.8%, P < 0.05). CONCLUSION: T lymphocytes with chimeric receptor targeting CEA specifically identify CEA positive gastric carcinoma cells and promote the apoptosis thereof, thus providing a promising method of cellular immunotherapy for gastric carcinomas.
