Therkelsenfry0182
However, fouling occurs with lower rates in FBMBR. The growing rate of transmembrane pressure (TMP) in aerobic condition is 1.7mBar/day in CMBR, while it reduces to 1.2mBar/day for FBMBR in solid retention time (SRT) of 75 days and OLR of 0.58 and 0.71 kgCOD/m3d. In anoxic condition with SRT of 100 days and OLR of 1.55 kgCOD/m3d, the TMP in FBMBR is 59 % of CMBR. In addition, total nitrogen (TN) removal is between 12 % (aerobic) and 27 % (anoxic) in CMBR, while it is between 25 % (aerobic) and 49 % (anoxic) in FBMBR. Total phosphorous (TP) removal also ranges between 50 and 66 % in CMBR, while it is between 51 and 86 % in FBMBR. Consequently, using hybrid systems of FBMBR can reduce membrane fouling rate and improve nutrient removal efficiency in comparison with CMBR. This approach can reinforce the biological treatment efficiency and preserve permeate quality in higher OLRs or in lower DO level.Less attention had been paid to cell toxicity of the various synthesis methods of nanoparticles, this study investigated the effect of the calcination temperature(CT) on the crystallization of SiO2 nanoparticles(NPs), cell proliferation(CP), and cellular uptake(CU) in MRC-5. In this study, parameters were adjusted as CT(70-1000 °C), calcination time(2, 12, and 24 h), and catalyst feed rate(0.01, 0.05, and 0.1 mL.min1). CP was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) test after a 24-h exposure. The CU was achieved using ICP-MS. Results were analyzed using MATLAB2018. Results revealed that the size of synthesized particles was lower than 50 nm and, the XRD peak varied from 21 to 30° during the increase in CT. FTIR spectra confirmed the existence of Si-O and Si-Cl bonds. The maximum level of crystallization was at 1000 °C. CP decreased with the rise in the concentration of NPs(p
The online version contains supplementary material available at 10.1007/s40201-021-00663-4.
The online version contains supplementary material available at 10.1007/s40201-021-00663-4.In this study, numerical simulations of the movement and emissions dispersion of two pollutants (sulfur dioxide(SO2) and carbon dioxide(CO2)) into the atmospheric boundary layer were considered under natural atmospheric conditions. To test the numerical algorithm and to select the optimal turbulent model, the test problem was solved numerically. The obtained computational data were compared with measurement data and values from the computation of other authors and the SST k-omega model illustrated the closest values to the data from the experiment, this is achieved by modifying the boundary condition for turbulent kinetic energy. The tested computational algorithm was used to characterize the emissions process of two pollutants from two chimneys of the Ekibastuz SDPP and the distribution of CO2 and SO2 in the air flow field in natural air condition. For this task, four various velocity variations were considered, as well as several various thermal variations (temperature inversion, constant temperature and decreasing temperature by the height). Isoprenaline From the obtained computational results, it should be noticed that different environmental temperature conditions extremely impact the distribution of pollutants CO2 and SO2 in the atmospheric surface layer, so at constant temperature conditions, the species for all velocity variations have nearly identical species profile.2-4 Dichlorophenoxy acetic acid is most publicly applied from chlorinated phenoxy acids herbicides. In this research, central composite design for optimization of photo-Elecro/persulfate/nZVI process to degradation and mineralization of this herbicide in aqueous solution to environment protection was applied. The initial pH (2-4), persulfate anion concentration (0.25-0.5 mg/L), direct electrical (0.5-1 A), herbicide concentration (50-100 mg/l), nZVI dose (0.05-1 mg/L), and reaction time (50-100 mg/l) are independent variables optimized. Also, the synergist effect, COD and TOC removal, the effect of radical scavengers, and by-products were investigated. The fitting of the model, suggested a quadratic model (R2 = 0.9926). F-value and P value of ANOVA were 719.81 and 0.0001 respectivelty. After optimizing the PEP/nZVI process, the proposed optimal conditions was pH = 3.4, persulfate concentration equal to 0.49 mg/l, in 1 A direct current, nZVI dose equal to 0.1 mg/l, in 50.05 mg/l herbicide concentration as an initial concentration, in 80 min reaction time. The theoretical and actual removal was evaluated 91.99% and 92%, respectively. In the optimum condition, 45.4% synergist effect indicated. 78.3% and 66.5% of initial COD and TOC were decreased. 39.02% of Cl ion was released form 2,4-D structure. The presence of radical scavengers have an adverse impact on the performance of process. The highest amount of radical scavenging was in methanol, tert-butyl alcohol and bicarbonate ions at concentrations at 50 mM/l. The kinetic data was fitted via pseudo-first-order reaction (R2 = 0.99).The direct and indirect oxidation process lead to formation of several organic by-products which were confirmed by GC-MS analysis.The use of granite stones as building materials in homes or offices can result in the residents' long-term whole-body exposure to gamma radiation. Although the whole-body annual dose has been investigated in the literature, it is obvious that different human organs receive different equivalent dose due to different position respect to the walls and floor covered by granite stones. In this paper, the effect of distance from the walls and floor of a room on the equivalent dose is investigated by using MCNPX code. An "ORNL" phantom is simulated in three situations; standing (P1), sleeping one meter above the floor (P2) and sleeping on the floor (P3) and the equivalent dose in different organs is calculated. Excess lifetime cancer risk (ELCR) is calculated in the whole of the body for these three positions. By the results, the value of ELCR in the third position is more than the average world value (2.9 × 10-4). The results show the importance of considering body position in dose determination, especially in some organs such as the brain and eyes which are close to the granite stones in certain positions such as sleeping.The removal efficiency of the pharmaceutical drug Mebeverine Hydrochloride (MEB) from solutions by an activated carbon (AC) prepared from dates stems was investigated in the present research work. The surface properties of the activated carbon were investigated by elementary analysis, BET surface area, SEM, FTIR and pHpzc. The operating parameters effect on the MEB adsorption efficiency was investigated by using batch experiments. The adsorption isotherms study indicated that the experimental data were well described by Freundlich and DR isotherms, with the maximum adsorption capacity (qmax) of 4105 mg/g. This result suggests the multilayer adsorption of MEB on the activated carbon.
The online version contains supplementary material available at 10.1007/s40201-021-00658-1.
The online version contains supplementary material available at 10.1007/s40201-021-00658-1.
The aim of the present study was to investigate the effect of short-term exposure to ambient black carbon (BC) on daily cause-specific mortality, including mortality due to respiratory, cardiovascular, ischemic heart and cerebrovascular diseases in Tehran, Iran.
Daily non-accidental death counts, meteorological data and hourly concentrations of air pollutants from 2014 to 2017 were collected in Tehran. A distributed lag non-linear model was used to assess the association between exposure to BC and daily mortality.
The mean daily BC concentration during the study period was 3.96 ± 1.19µg/m
. The results indicated that BC was significantly associated with cardiovascular, ischemic heart disease, and cerebrovascular mortality, but not with respiratory mortality. In first model, each 10µg/m
increase in at lag 3, lag 4 and lag 5 were associated with cardiovascular mortality in 16-65 year age group with the relative risks (RRs) of 1.17 (95 % CI 1.02-1.33), 1.17 (95 % CI 1.04-1.31) and 1.12 (95 % CI 1.02-1.24), respectively. The highest mortality rate per 10µg/m
increase in exposure was found for ischemic heart diseases with RR of 3.98 (95 % CI 1.04-1.81, lag 01) for 16-65 age group. Cerebrovascular mortality was associated with 10µg/m
increases in non-cumulative exposure with RR of 1.17 (95 % 1.009-1.35, lag 5) in the age group ≥ 65 years. In the second model for a 10µg/m
increase in BC, cardiovascular mortality at specific lag days (5 and 6 days) in the age group ≤ 16 years were associated with RR of 1.34 (95 % CI 1.08-1.66) and 1.35(95 % CI 1.02-1.77), respectively.
This study in Tehran found significant effects of BC exposure on daily mortality for cardiovascular, ischemic heart disease, cerebrovascular disease.
The online version contains supplementary material available at 10.1007/s40201-021-00659-0.
The online version contains supplementary material available at 10.1007/s40201-021-00659-0.The mobile phone is a fast-growing E-waste stream that includes hazardous substances and valuable metals. Smartphone touch screens (SPTS) contain a considerable amount of critical metals, such as indium and strontium that can be recovered from end of life devices as a secondary resource. Bioleaching is an emerging and environmentally friendly method for metal recovery from electronic waste. In the present study, bioleaching was assessed for the extraction of indium and strontium from organic light emitting diode type smartphone touch screens. A statistical approach based on the response surface methodology was successfully applied. The effects of influential variables pH, ferrous sulfate, elemental sulfur, and solid content and their interactions on indium and strontium recovery using adapted Acidithiobacillus ferrooxidans were evaluated. Under optimum conditions (ferrous sulfate 13.0 g/L; solid content; 3.0 g/L; elemental sulfur 5.6 g/L; and initial pH of 1.1), a complete indium extraction was observed, with a concentration in solution of about 200 mg/L indium. As concerns strontium, a 5% extraction efficiency was observed, which, even if quite low, resulted in a relatively high strontium concentration in solution, around 3000 mg/L, due to its high content in the solid (2%). This work opens new perspectives in the application of clean technologies for the extraction of valuable metals, such as indium and strontium from smartphone screens.
Road traffic noise is the most common source of noise in modern cities. The noise indicators used to manage noise do not take into account its temporal structure. However, in cities the traffic flow varies during the day, peaking due to congestion and more fluent periods. In this research we sought to analyze how people (giving answers on a numerical ICBEN scale) perceive noise stimuli with the same L
values but different time structures (more/less noise events, different amplitude envelopes).
31 people with normal hearing took part in an experiment conducted in an anechoic chamber. Participants listened to 18 different noise recordings and rated each of them using the numerical ICBEN scale regarding noise annoyance.
The results showed that only sound level was a statistically significant factor. However, based on people's remarks about noise, we can also say that the more intermittent the noise is, the more negative feelings it evokes in people.
Time structure does not have a significant influence on people's judgments about noise annoyance.
