sewage sludge will continue to be used on the soil (either directly or after composting), and then the recycling of the substantial part P removed from the wastewater is realized already traditionally (the main task will be the optimal realization) [ 6
Authors:H. Ortiz-Oliveros, R. Flores-Espinosa, H. Jiménez-Domínguez, M. Jiménez-Moleón, and D. Cruz-González
Preliminary testing of dissolved air flotation (DAF) for wastewater treatment is presented. A combined coagulation-flocculation/DAF
column system is used to remove oil and 60Co from nuclear industry wastewater. In this work, operational conditions and coagulant/flocculant concentrations are optimized
by varying pH. Determinations of air-solids ratio (G/S), retention time (θ), pressure (P), volume of depressurized air–water mixture (V), turbidity and 60Co concentrations are reported. The effect of the treatment on the efficiency of separation of oily residues is also discussed.
The results establish that the coagulant/flocculant system, formed by a modified polyamine (25 mgL−1) and a slightly cationic polyacrylamide (1.5 mgL−1), under specific operational conditions (pH = 7, mixing intensity Im1 = 300 s−1 and Im2 = 30 s−1), allowed the destabilization of colloidal matter, resulting in resistant flocs. It was concluded that by using G/S = 0.3, θ = 15 min, P = 620 kPa and V = 0.0012 m3, the greatest percentage removals of oil, turbidity, total cobalt and 60Co were obtained. These preliminary results then show that dissolved air flotation represents a good alternative for treatment
of nuclear industry wastewater contaminated with radionuclides.
Authors:Florina Copaciu, Virginia Coman, Mihaela Vlassa, and Ocsana Opriş
The objective of this paper is to report a procedure for the extraction and the determination of five textile dyes (Lanasyn Blue F-L 150, Lanasyn Dark Brown M-GLN, Lanasyn Red M-GA, Nylosan Dark Brown S-MBL, and Nylosan Red N-2RBL) which were not yet studied in literature by high-performance thin-layer chromatography. For SPE of these dyes, four types of Strata cartridges (WAX/NH2, SAX, C18-U and C18-E) were tested. The best results were obtained on Strata WAX/NH2. The dyes were separated on precoated Alugram RP-18W/UV254 plates with the n-butanol-ethyl acetate-5% ammonium hydroxide 4:4:1 (v/v) mobile phase. The densitometric scanning was performed at 550 nm. Linear regression analysis of the calibration data indicated a good linear relationship between the peak area and the dye concentration in the range of 20–60 ng per band. For the HPTLC method, the detection and the quantification limits of the studied dyes were calculated. The obtained detection limits (ng per band) were: 6.6 for Lanasyn Blue F-L 150, 5.90 for Lanasyn Dark Brown M-GLN, 3.38 for Lanasyn Red M-GA, 5.49 for Nylosan Dark Brown S-MBL, and 1.07 for Nylosan Red N-2RBL. The SPE-HPTLC procedure was applied to monitor these textile dyes in the effluent wastewater samples collected from a textile factory from Romania.
Authors:Wu Yanbo, Fu Jie, Zeng Sisi, Sun Peng, and Yan Yingchun
technological properties of pharmaceutical wastewater sludge (volatile matter, ash and fixed carbon), unlike the coal, significant differences in the pyrolysis profiles must be expected. This may have an important influence on pyrolysis efficiency. Studies on TG