The effect of TiO2 nanoparticles on bacterial growth: the effect of particle size and their structure - a systematic review.

One of the widely used microbiological methods to determine the toxicity of chemicals, catalysts, and other types of materials is the minimum inhibitory concentration (MIC) test. The present study aims to investigate the influence of composition of composite materials based on TiO2 and their particle size as well as bacterial type and shape based on the MIC values reported in the literature. The results show that among the 36 articles selected, most of the studies used Escherichia coli (E. coli) (26) and Staphylococcus aureus (S. aureus) (19) bacteria to determine MIC values. This study revealed that the MIC in values below 70 µg ml-1 for S. aureus was lower than that for E. coli bacteria (below 200 µg ml-1). Importantly, MIC value decreased from 60.6 to 7.66 µg ml-1 with decrease in the size of nanoparticles. It follows from the increased surface area for smaller-sized particles, thus increased interaction with bacteria during MIC test.

Correction to: Environmental impact assessment of a steel industry development plan using combined method involving Leopold matrix and RIAM.

[This corrects the article DOI: 10.1007/s40201-021-00752-4.].

Synthesis of new composite based on TiO2 immobilized in glass fibers for photo-catalytic degradation of chlorobenzene in aqueous solutions.

In this study photo-catalytic degradation of chlorobenzene from aqueous solutions using CQD decorated Fe-doped TiO2 immobilized in Glass Fibers (GF) was investigated. Characteristics of the synthesized photo-catalyst were determined by EF-SEM, EDX, BET, XRD, FTIR, and DRS analysis. Additionally, DRS analysis demonstrated adding CQD to the TiO2-Fe reduced its band gap energy from 2.96 eV to 2.91eV, while that was 3.10 eV for undoped TiO2. Among that three photo-catalysts, GF/CQD(4.5 wt%) decorated Fe-TiO2 composite had performance nearly 100.0%, when pH was 5 and low concentration of chlorobenzene. In addition, GF/CQD(4.5 wt%) decorated Fe-TiO2 composite show it could be well applied for five times and with a little reduction on the performance. Also, no detectable Fe found to be released from the composite. Minimum inhibitory concentration (MIC) for E. coli bacteria was 12.2 mg L-1 of chlorobenzene residual. Our findings show the catalyst was successful for chlorobenzene removal in the wastewater effluent. In conclusion, present hybrid composite could successfully and safely remove chlorobenzene from synthetic aqueous solution.

Dispersion of NO2 and SO2 pollutants in the rolling industry with AERMOD model: a case study to assess human health risk.

Steel and rolling industry are the most important industries polluting the environment. Therefore, aim of this study is to make an emission model for SO2 and NO2 pollutants released from the rolling industry of Sepid-Farab Kavir Steel (SKS) complex using the AERMOD model and health risk assessment. Sampling pollutants released from SKS complex was performed in January 2017 at 10 different sites. Distribution of these pollutants was investigated by AERMOD model, domain site of AERMOD was designed for area around the factory with a radius of 30 km, and also SO2 and NO2 modeling was performed for both natural gas and liquid fuel. Human health risk assessment was also studied. The results of this study demonstrated the emission of SO2 and NO2 from this complex is less than the maximum allowable, when used natural gas as the main fuel. The hourly concentration of SO2 reached about 324 µg/m3, which in higher than the standard value for 1 h. Considering the findings, the urban gas is considered as a clean source in terms of furnace air output and the concentration of emitted pollutants. Also, it has no side effects on workers' health.

Environmental impact assessment of a steel industry development plan using combined method involving Leopold matrix and RIAM.

The present study was conducted to determine positive and negative impacts of Sepid-Farab Kavir steel (SKS) complex development plan and to propose suitable managerial strategies by a combined method involving Leopold matrix and Rapid Impact Assessment matrix (RIAM). The SKS complex is located in Aran-Bidgol city, Isfahan, Iran. Two scenarios of project implementation and project cancellation were formulated for SKS complex development plan, which has two sub-phases: construction and operation Using Leopold and RIAM matrices, the direct and indirect impacts of the project on the study area was investigated. The impact analysis for project cancellation scenario showed that the obtained scores of construction and operation phases were -119 and -52, respectively. Also, for project implementation scenario, the obtained scores of construction and operation phases were + 302 and + 382, respectively. The number of positive impacts in the implementation and cancellation scenarios were 354 and 48, respectively, and the number of negative impacts in implementation and cancellation scenarios were 270 and 127, respectively. Also, comparison of positive and negative impacts frequency in the two scenarios, and in the two sub-phases, in RIAM indicated the project implementation will have positive impacts in social-cultural and economic-operational aspects compared to option of prevention, especially in operation phase. The results of environmental impact assessment of the mentioned project indicated the superiority of positive impacts over the negative ones.

Photo-catalytic degradation of bisphenol-a from aqueous solutions using GF/Fe-TiO2-CQD hybrid composite.

In this photocatalytic study, removal of bisphenol-A from aqueous solution was studied using the GF/Fe-TiO2-CQD composite. Due to its health and environmental effects, this compound should be disposed of sources that are mainly industrial wastewater. The phis-chemical properties of the composite were determined by traditional analyzes of EF-SEM, EDX, BET, XRD, FTIR and DRS. In this study, different ratios of CQD in the composite (1.5, 4.5 and 7.5 wt%), pH, and bisphenol-A concentration as variable parameters were investigated. All analyzes, EF-SEM, EDX, BET, XRD, FTIR, show that the GF/Fe-TiO2-CQD composite is well coated on glass fibers (GF) and all the elements in the catalyst are present. On the other hand, DRS analysis showed that CQD reduces the band gap of Fe-TiO2 from 2.96 eV to 2.91 eV, it was 3.10 eV for TiO2. Among different catalysts, GF/Fe-TiO2-CQD4.5wt% has the best performance. The results showed that for GF/Fe-TiO2-CQD4.5wt%, optimum for the process was at pH = 6 in low concentration of bisphenol-A. The first order model for the photocatalytic degradation process were well studied. In addition, GF/Fe-TiO2-CQD4.5wt% showed that it can be used many times with a minimal reduction in performance. As a result, the GF/Fe-TiO2-CQD4.5wt% composite can successfully remove bisphenol-A form in synthetic aqueous solution. However, it is necessary to further studies to applied that for real water source in water and wastewater treatment plants.

Assessment of COVID-19 control strategies in a steel industry using a SWOT matrix.

According to the health regulations, industrial environments due to the gathering of people are considered as one of the highest-risk places during the COVID-19 pandemic. Thus, planning with regard to health concerns can decisively help in infection control and continuity of businesses during the pandemic. The aim of this study was to evaluate the COVID-19 control management measures in the Sepid-farab Kavir Steel Complex (SKS complex) located in Isfahan province (Iran) using strengths, weaknesses, opportunities, and threats (SWOT) matrix. After a literature review and field surveys, all weak, strong, threatening, and opportunity points were collected and were listed using the internal factor evaluation (IFE) and external factor evaluation (EFE) matrices and then were prioritized and weighted. Next, given the sum of scores of IFE and EFE, the SWOT matrix was constructed, the disease prevention and control strategies in the complex was determined, and finally, experts proposed corrective measures to improve the current situation. The results of the IFE matrix (IFE) analysis showed that in terms of corona control, there are more weaknesses than strengths within the company (the score of this matrix was 201.12). Also the score of 165 on the EFE matrix indicated that external threats were predominant, compared to external opportunities of company. SWOT analysis showed that despite some external problems and challenges, the existence of a favorable internal decision-making system had an important role in developing appropriate health strategies and implementing effective prevention measures in SKS complex against the COVID-19.

Selecting the best stabilization/solidification method for the treatment of oil-contaminated soils using simple and applied best-worst multi-criteria decision-making method.

Oil-contaminated soils resulted from drilling activities can cause significant damages to the environment, especially for living organisms. Treatment and management of these soils are the necessity for environmental protection. The present study investigates the field study of seven oil-contaminated soils treated by different stabilization/solidification (S/S) methods, and the selection of the best treated site and treatment method. In this study, first, the ratios of consumed binders to the contaminated soils (w/w) and the treatment times for each unit of treated soils were evaluated. The ratios of consumed binders to the contaminated soils were between 6 and 10% and the treatment times for each unit of treated soils were between 4.1 and 18.5 min/m3. Physicochemical characteristics of treated soils were also determined. Although S/S methods didn't change the water content of treated soils, they increased the porosity of soils. Unexpectedly, the cement-based S/S methods didn't increase the pH of the treated soils. The highest and the lowest leaching of petroleum hydrocarbons was belonging to S/S using diatomaceous earth (DE) and the combination of Portland cement, sodium silicate and DE (CS-DE), respectively. The best acid neutralization capacity was obtained for soils treated using the combination of Portland cement and sodium silicate (CS). Based on the best-worst multi-criteria decision-making method (BWM-MCDM), the soils treated using CS-DE was select as the best. The BWM-MCDM can be used as an effective tool for the selection of the best alternative in all areas of environmental decontamination.

Removal of methylene blue from aqueous solution by Artist's Bracket fungi: kinetic and equilibrium studies.

In this study, adsorption of methylene blue (MB) dye onto Artist's Bracket (AB) fungi was investigated in aqueous solution. Fourier transform infrared and scanning electron microscopy were used to investigate surface characteristic of AB fungi. Influence of operational parameters such as pH, contact time, biosorbent dosage, dye concentration, inorganic salts and temperature was studied on dye removal efficiency. With the increase of pH from 3 to 9, removal efficiency increased from 74.0% to 90.4%. Also, it reduced from 99.8% to 81.8% with increasing initial MB concentration from 25 mg L(-1) to 100 mg L(-1), whereas it increased from 54.7% to 98.7% and from 98.5% to 99.9% with increasing biosorbent dosage from 0.5 g L(-1) to 2 g L(-1) and with increasing temperature from 25 °C to 50 °C, respectively. Isotherm studies have shown adsorption of MB dye over the AB fungi had a better coefficient of determination (R(2)) of 0.98 for Langmuir isotherm. In addition, the maximum monolayer adsorption capacity (qm) was 100 mg g(-1). Also, the MB dye adsorption process followed pseudo-second-order kinetic. In general, AB fungi particles can be favorable for removal of MB dye from dye aqueous solution with natural pH and high temperature.