Overall, laboratory water quality analysis must have stability in their results, especially in laboratories accredited by ISO 17025. Accredited parameters should be strictly reliable. Using control charts to ascertain divergences between results is thus very useful. The present work applied a methodology of analysis of results through control charts to accurately monitor the results for a wastewater treatment plant. The parameters analyzed were pH, BOD5, COD, total suspended solids, and total phosphorus. The stability of the results was analyzed from the control charts and 30 analyses performed in the last 12 months. From the results, it was possible to observe whether the results are stable, according to the rehabilitation factor that cannot exceed WN = 1.00 and the efficiency of removal of pollutants that remained above 70% for all parameters. The method of determining the technological reliability and stability of the treatment station using control charts is an efficient tool for detecting any instability in the results. These results help to monitor the results of the analyses more clearly and thus enable a rapid response to possible disturbances and maintain the quality of the analysis control, as well as determining the accreditation entities.
Nowadays, most of the world’s population lives in urban centres, where air quality levels are not strictly checked; citizens are exposed to air quality levels over the limits of the World Health Organization. The interaction between the issuing and atmospheric sources influences the air quality or level. The local climate conditions (temperature, humidity, winds, rainfall) determine a greater or less dispersion of the pollutants present in the atmosphere. In this sense, this work aimed to build a math modelling prediction to control the air quality around the campus of IPBeja, which is in the vicinity of a car traffic zone. The researchers have been analysing the data from the last months, particle matter (PM10 and PM2.5), and meteorological parameters for prediction using NARX. The results show a considerable increase in particles in occasional periods, reaching average values of 135 μg/m3 for PM10 and 52 μg/m3 for PM2.5. Thus, the monitoring and prediction serve as a warning to perceive these changes and be able to relate them to natural phenomena or issuing sources in specific cases.
This work evaluated caffeine removal in a vertical flow constructed wetland (VFCW), planted with Vetiveria zizanioides. The feeding was continuous (synthetic influent: mineral medium and caffeine) to reduce the concentration variations in the bed. Two influent concentrations (0.75 ± 1.0 mg·L−1 and 1.5 ± 1.0 mg·L−1) were used with a constant hydraulic load (100 ± 10 L·m−2·d−1). Plant growth was monitored weekly, and characterization was carried out to determine the levels of chlorophyll a and b, pigments and carotenoids, and nutrients (nitrogen, phosphorus, magnesium, calcium, sodium and potassium). HPLC-MS was used to determine the caffeine concentration. The caffeine removal efficiency reached averages of 93 ± 1% and 87 ± 1% (retention time: 6.23 ± 0.23 hours). The caffeine contents in the influent did not affect chlorophyll a, total chlorophyll or carotenoids, and an increasing trend throughout the tests was observed. Sodium and potassium contents also showed an increase with higher caffeine concentration. This preliminary study showed that removing caffeine from wastewater using a VFCW is promising. Keywords: wastewater, emergent pollutants, caffeine, vertical flow constructed wetlands, Vetiveria zizanioides
The non-invasive nutritional analysis of feed through images captured by hyperspectral cameras represents an innovative and promising approach in the field of biotechnology. With this technology, it is possible to capture images at multiple wavelengths and identify unique spectral patterns associated with different molecular components, such as total fat and moisture. The technique is particularly valuable in biological environments, enabling a more detailed and comprehensive analysis of the presence and distribution of nutrients. The objective of this work was to perform a nutritional pre-characterization of Hermetia illucens (Black Soldier Fly-BSF) larvae meal, using hyperspectral images in the range of 400–1000 nm, with a spectral resolution of 7 nm and a spatial sampling of 512 pixels, and correlate them to traditional chemical analysis methods. The results were also compared to wheat flour samples. The chemical results of BSF meal indicated 7.2% ± 0.05% (w/w) and 28.15% ± 0.15% (w/w) in moisture and total fat content, respectively. When compared to wheat flour, BSF meal contains less total fat and this difference was clearly identified in the spectra derived from the hyperspectral images, which underscores the efficiency and utility of multispectral cameras to conduct real-time and non-destructive analyses. Furthermore, this analysis can be extended to other components (e.g., protein content), increasing the potential of the technique for feed characterization.
Due to growing concern about air pollution and its harmful effects on the health of the population, especially in regard to sub-micrometric particles, some studies have reported that applying an electric field to particle suspensions can improve filter performance by enhancing the deposition of particles in the filter medium. This can result in better particulate retention, which is particularly important for industrial processes such as cement production. The objective of this study was to investigate the behavior of cement particles with electrostatic charges during cake formation in fabric filters. The particles (with a d50 % of 17 μm) were generated using a dust feeder at a flow rate of 0.083 kg s-1. The fiberglass filter medium was subjected to filtration tests with constant dust concentrations (9-12 g.m-³) and air surface velocities (6 cm.s-1and 10 cm s-1) until the pressure drop reached the maximum value of 400 Pa. The electrostatic precipitator utilized discharge voltages of 0, 4, 10, and 12 kV. The particles were initially passed through the electrostatic precipitator to become charged with voltages of 0, 4, 10, and 12 kV applied. The results indicated a reduction in pressure drop of up to 55 %. The study observed a change in the deposition behavior of particles on the filter medium surface and in the filter cake formation, demonstrating that the electrostatic charge improves air filtration performance, resulting in higher efficiency and cost-effectiveness.