Treatment of synthetic textile wastewater containing dye mixtures with microcosms

The aim was to assess the ability of microcosms (laboratory-scale shallow ponds) as a post polishing stage for the remediation of artificial textile wastewater comprising two commercial dyes (basic red 46 (BR46) and reactive blue 198 (RB198)) as a mixture. The objectives were to evaluate the impact of Lemna minor L. (common duckweed) on the water quality outflows; the elimination of dye mixtures, organic matter, and nutrients; and the impact of synthetic textile wastewater comprising dye mixtures on the L. minor plant growth. Three mixtures were prepared providing a total dye concentration of 10 mg/l. Findings showed that the planted simulated ponds possess a significant (p < 0.05) potential for improving the outflow characteristics and eliminate dyes, ammonium-nitrogen (NH4-N), and nitrate-nitrogen (NO3-N) in all mixtures compared with the corresponding unplanted ponds. The removal of mixed dyes in planted ponds was mainly due to phyto-transformation and adsorption of BR46 with complete aromatic amine mineralisation. For ponds containing 2 mg/l of RB198 and 8 mg/l of BR46, removals were around 53%, which was significantly higher than those for other mixtures: 5 mg/l of RB198 and 5 mg/l of BR46 and 8 mg/l of RB198 and 2 mg/l of BR46 achieved only 41 and 26% removals, respectively. Dye mixtures stopped the growth of L. minor, and the presence of artificial wastewater reduced their development

British journal of ophthalmology : BJO

https://works.swarthmore.edu/alum-books/5660/thumbnail.jp

Bioelectrical impedance measurements in patients with gastrointestinal disease: validation of the spectrum approach and a comparison of different methods for screening for nutritional depletion

Bioelectrical impedance measurements in patients with gastrointestinal disease: validation of the spectrum approach and a comparison of different methods for screening for nutritional depletion. Cox-Reijven PL, van Kreel B, Soeters PB. Department of Dietetics, University Hospital Maastricht, P Debyelaan 25, PO Box 5800, 6202 AZ Maastricht, Netherlands. [email protected] BACKGROUND: Bioelectrical impedance spectroscopy (BIS) may be of value in identifying patients with nutritional depletion. OBJECTIVE: The primary aim of the study was to assess the validity of BIS in patients with gastrointestinal disease. The secondary aim was to compare different screening methods for identifying nutritionally depleted patients. DESIGN: In 70 patients with gastrointestinal disease, BIS measurements were performed and fluid compartments were calculated from extrapolated resistance (R) values of extracellular (R(ECW)) and intracellular (R(ICW)) water based on mixture equations. Results were compared with total body water and ECW, which were measured by dilution methods. Patients were classified as depleted if their actual fat-free mass (FFM) was <90% of their ideal FFM (iFFM). Different screening approaches for depletion were compared: the impedance vector method and the resistance index (RI) in relation to iFFM (RI/iFFM). RESULTS: Total body water and ICW were largely underestimated (4 L) in the not-depleted patients but not in the depleted patients. In both groups, ECW was slightly overestimated (0.6-0.7 L). The critical frequency was 60% higher and the membrane capacitance was 40% lower in the depleted than in the not-depleted patients. The impedance vector method failed to identify depleted patients, whereas the proposed ratio at R(50) (R measured at 50 kHz) and R(inf) (R at infinite frequency) resulted in comparable sensitivity (86%) and specificity (73-80%). CONCLUSIONS: BIS measures of body fluids are influenced by the presence of depletion, probably because of alterations in the electric properties of the body at the cellular level. However, for screening purposes, the use of the ratio (L(2)/R)/iFFM at R(50) and R(inf) may be of valu