Reduction of sludge formed during a coagulation treatment of Ridomil Gold by means of non-thermal quenched plasma pre-treatment

Chemical coagulation and adsorption, despite many drawbacks, are actually the main techniques used for the removal of pollutants from aqueous solution; however, these techniques are becoming ineffective due to the exponential increase in the amount and complexity of discharged pollutants; thus, the sludge treatment process became a more complex challenge. The present study focuses on the way to reduce the quantity of sludge formed during the removal of Ridomil Gold, a widely used pesticide-fungicide in agriculture. Results revealed that pre-treatment of initial waste solution by the gliding arc (Glidarc), a source of non-thermal plasma, leads to a significant reduction of the sludge formed during the coagulation treatment. For a 20-min pre-treated effluent Glidarc followed by chemical coagulation, there was a reduction in the volume of sludge formed in the order of 90 and 80% for alum and ferric sulfate coagulants respectively without reducing the performance of pesticide removal. Therefore, there is a positive synergism between treatment by chemical coagulation and plasma treatment. These results suggest that the Glidarc can be an effective solution for the reduction of sludge obtained during treatment by coagulation.     

Thermal treatment of plasma-synthesized goethite improves Fenton-like degradation of orange II dye

Various iron oxides are used for Fenton reactions to degrade organic pollutants. The degradation efficiency may be improved by transforming an iron oxide phase to another. Here, we report on the transformation of goethite into hematite by thermal treatment at 400 °C. The products were analyzed by X-ray diffractometry, Raman spectroscopy, scanning electron microscopy and N₂-physisorption. The catalytic activities were measured for orange II bleaching at initial concentration of 25 mg L^?1, pH 3, catalyst concentration of 0.2 g L^?1; 5 mM H₂O₂, 30 °C. Results show that the synthesized goethite was successfully transformed into hematite, and the specific surface area of the material increased from 134 to 163 m² g^?1. The bleaching efficiency of the orange II dye reached 100 % for the hematite product, versus 78 % for goethite. Therefore, a moderate thermal treatment of a plasma-synthesized goethite improves the catalytic oxidation of organic pollutants.     

PM2.5 concentration declining saves health expenditure in China

● Monthly hospitalization expenses are sensitive to increases in PM_2.5 exposure. ● The increased PM_2.5 causes patients with CHD and LRI to stay longer in the hospital. ● The impact of PM_2.5 on total expenses for stroke is greater in southern China. ● Males may be more sensitive to air pollution than females. Air pollution has been a severe issue in China. Exposure to PM_2.5 has adverse health effects and causes economic losses. This study investigated the economic impact of exposure to PM_2.5 pollution using monthly city-level data covering 88.5 million urban employees in 2016 and 2017. This study mainly focused on three expenditure indicators to measure the economic impact considering lower respiratory infections (LRIs), coronary heart disease (CHD), and stroke. The results show that a 10 µg/m³ increase in PM_2.5 would cause total monthly expenses of LRIs, CHD, and stroke to increase by 0.226%, 0.237%, and 0.374%, respectively. We also found that LRI, CHD, and stroke hospital admissions increased significantly by 10%, 8.42%, and 5.64%, respectively. Furthermore, the total hospital stays of LRIs, CHDs, and strokes increased by 2.49%, 2. 51%, and 1.64%, respectively. Our findings also suggest heterogeneous impacts of PM_2.5 exposures by sex and across regions, but no statistical evidence shows significant differences between the older and younger adult subgroups. Our results provide several policy implications for reducing unequal public health expenditures in overpolluted countries.     

Evaluation of an integrative masters program in occupational health at the Tel Aviv University Medical School

Tel Aviv University conducts the Master's program in occupational health in Israel. The program is composed from three different disciplines: occupational physicians, industrial hygienists and psychosocial workers. The aim of the program was to train graduate academic professionals for the developing occupational health system in Israel. The program is a two year study, opens every second year and accommodates about thirty students per class. After the second class, comprehensive assessment was conducted by the Unit of Medical Education. The evaluation was done by means of personal interview of class leaders, teachers and students, using structured questionnaires. A similar evaluation was again conducted after graduation of the fourth class in 1993. Three aims of the assessment were defined: to learn about the students' and teachers' expectations of the course, the level of integration achieved between the occupational health professionals in the three disciplines; and to evaluate the employment status of the graduates upon completion of the course. Following the first evaluation, changes were implemented in the methods of student selection for the program. A new entering examination was constructed to ensure a common basic knowledge of the potential students in the three disciplines. Changes were also made in the curriculum regarding teaching hours and subjects. A major problem at that time was that most of the graduates could not find positions in the field, because of low awareness for occupational health in Israel. In the second evaluation done in 1993 a higher level of satisfaction of students and teachers from the program was noted. The average level of the accepted students was higher compared with those accepted earlier. Better and deeper integration between the three disciplines of studies was appreciated. More graduates of the program found jobs in the area of occupational health and there is a higher level of awareness of employers and high regards to the course.     

Net Ecosystem Production of Boreal Larch Ecosystems on the Yenisei Transect

The study was carried out in the Turukhansk Research Station of Yenisei Transect (65^°46^′N, 89^°25^′E). Larch (Larix gmelinii (Rupr.) Rupr.) is the dominant overstory tree species. The research has been conducted on four permanent test plots in same-age mature (110-year old) and overmature (380-year old) post-fire larch stands of green moss and lichen groups of forest type. Carbon cycle parameters were assessed based on a biometric method. Quantitative analysis of carbon pools and fluxes shows that net ecosystem production of north taiga larch stands averages 32% of net primary production. Sink of atmospheric CO₂ makes 1.22 and 0.74 t C ha^{− 1} year^{− 1} for mature and overmature green moss larch stands, and 0.65 and 0.35 t C ha^{− 1} year^{− 1} for lichen type. Net carbon sink in the tree layer make up 9% of net primary production carbon, ground vegetation – 15%, and dead plant residues accumulation – 8% of atmospheric carbon uptake via photosynthesis.     

Biodegradation and mineral weathering controls on bulk electrical conductivity in a shallow hydrocarbon contaminated aquifer

Geochemical and stable carbon isotope data from closely spaced vertical intervals in a hydrocarbon-impacted aquifer were used to assess the relationship between biodegradation, mineral weathering, and enhanced bulk conductivity zones. The results show that depth zones of enhanced bulk conductivity in the contaminated aquifer had higher total dissolved solids (TDS) compared to background groundwater. The higher TDS in contaminated groundwater were due to elevated ion concentrations from enhanced mineral weathering. Depth intervals with higher concentrations of major cations overlapped with zones with higher total petroleum hydrocarbons, which were the same zones where reduction of nitrate, iron, manganese, sulfate, and methanogenesis was occurring. Hence, the zones of higher bulk conductivity may be explained by mineral weathering related to hydrocarbon biodegradation. Our results suggest that biodegradation of hydrocarbons may impart changes to the aquifer geochemistry that can be indirectly observed using geophysical techniques. We therefore argue for inclusion of geophysical investigations as part of natural attenuation assessment programs.