Journal of Environmental Health Science and Engineering

In order to obtain basic design criteria for anaerobic digestion of a mixture of poultry manure and wheat straw, the effects of different temperatures and organic loading rates on the biogas yield and methane contents were evaluated. Since poultry manure is a poor substrate, in term of the availability of the nutrients, external supplementation of carbon has to be regularly performed, in order to achieve a stable and efficient process. The complete-mix, pilot-scale digester with working volume of 70 L was used. The digestion operated at 25°C, 30°C and 35°C with organic loading rates of 1.0, 2.0, 2.5, 3.0, 3.5 and 4.0 kg Volatile solid/m3d and a HRT of 15 days. At a temperature of 35°C, the methane yield was increased by 43% compared to 25°C. Anaerobic co-digestion appeared feasible with a loading rate of 3.0 kg VS/m3d at 35°C. At this state, the specific methane yield was calculated about 0.12 m3/kg VS with a methane content of 53–70.2% in the biogas. The volatile solid (VS) removal was 72%. As a result of volatile fatty acid accumulation and decrease in pH, when the loading rate was less than 1 or greater than 4 kg VS/m3d, the process was inhibited or overloaded, respectively. Both the lower and higher loading rates resulted in a decline in the methane yield.

To investigate the interaction of zinc oxide nanoparticles (ZnO NPs) with fly ash soil (FAS) for the reduction of metals from FAS by Parthenium hysterophorus were studied. The average accumulation of metals by P. hysterophorus stem were Fe 79.6%; Zn 88.5%; Cu 67.5%; Pb 93.6%; Ni 43.5% and Hg 39.4% at 5.5 g ZnO NP. The concentration of ZnO NP at 1.5 g did not affect the metals accumulation, however at 5.5 g ZnO NP showed highest metal reduction was 96.7% and at 10.5–15.5 g ZnO NP of 19.8%. The metal reduction rate was Rmax for Fe 16.4; Zn 21.1; Pb 41.9; Hg 19.1 was higher than Ni 6.4 and Cu 11.3 from the FAS at 5.5 g ZnO NP whereas, the reduction rate of Pb showed highest. With doses of 5.5 g ZnO NP the biomass increased upto 78%; the metal reduced upto 98.7% with the share of 100% ZnO NP from FAS. Further investigation with phytotoxicity the plant reactive oxygen species (ROS) production were affected due was mainly due to the recovery of metals from FAS (R2 = 0.99).

It has been proven that exposure to bioaerosols is associated with several health effects, such as pulmonary diseases and allergies. The present cross-sectional study was aimed to investigate fungal contamination in indoor air and on the surfaces of four traditional baths in Shiraz, Iran, one of the most historical cities in the world. Samples were taken from indoor air, using a microbial air sampler, as well as the surfaces of the shower, hallway, and dressing rooms of studied baths for 3 months. Totally 180 samples, including 45 air and 135 surfaces samples, were collected from studied baths. The concentrations of fungi collected from the air of studied baths were ranged from 22.6 to 34.6 CFU/m3. Besides, the levels of fungi collected from the surface samples of studied baths were ranged from 21.2 to 60 CFU/m2. The highest and lowest fungi species detected both in air and surfaces samples of the studied baths were Penicillium spp. and Mucor spp. respectively. Although the levels of fungi in the studied baths were lower than the levels recommended by the World Health Organization, some environmental health measures such as washing and disinfecting surfaces and tools after each working shift and periodic inspections are recommended ensuring the safety of costumers who are visiting such places.

Highly purified chitosan was generally preferred for heavy metal (HM) removal and the preparation parameters varied largely without any agreement. This study investigated to the influences of chitin with different purities on the HM removal of corresponding chitosan. Sea shrimp waste was used as raw materials and Pb2+ was used as target HM. The results of orthogonal experimental analysis showed that only acid concentration played an important role in the deproteinization and demineralization processes of the chitin preparation under HCl, H2SO4 and CH3COOH treatment. Ca-bearing minerals (CBM) but not free –NH2 group of chitosan played a major role in the removal of Pb2+ from solution. Partly purified chitosan mainly removed Pb2+ by precipitation and then biosorption. The dissociation of Ca2+ from CBM elevated pH value of Pb2+ solution which benefited to precipitation and the formation of NH2-Pb2+. Partly purified chitosan prepared from HCl and CH3COOH treated chitin showed 720–753 mg/g of Pb2+ adsorption at the initial pH value of 6.0; however, highly purified chitosan prepared from HCl treated chitin showed only 45–160 mg/g. Chitosan prepared from H2SO4 treated chitin showed 720–752 mg/g of Pb2+ adsorption. This research found the unexplored information for the industrial application of chitosan with minimum cost but the highest HM removal efficiency.

In this work, the amount and physical and chemical characteristics of airborne microplastics (MPs) pollution in dust samples in Sistan, located in the eastern part of Iran, is reported. Sampling stations were selected according to the wind direction and population density. MPs were collected by a static dust sampler and analyzed by optical microscopy and FT-IR spectroscopy. Results showed that the distribution frequency of MPs in residential and non-residential areas was 6 to 11 pieces per 100 g (pcs/100 g) with an average abundance of 9.8 pcs/100 g. Fragmented MPs were approximately consisted 64% of total MPs and their sizes were in the range of 0.9–3.8 mm. Polyethylene (49%), polystyrene (21%) and polyester (18%) were the main MPs presented in the dust samples. It was observed that population density and wind direction were the most important parameters affecting MPs pollution in dust.

A Correction to this paper has been published: https://doi.org/10.1007/s40201-021-00700-2

Recent development in separation technologies has envisioned a green and sustainable future that encouraged energy preservation and waste minimization. The concept of a clean future emphasizes on retrieval and reutilization of valuable products from waste streams to improve the water quality. Membrane-based separations are currently explored as an auspicious substitution over traditional separation processes. The present study is designed to purify water using aluminum and gallium mixed matrix membranes from toxic metals (Lead and Mercury) and dyes (Rhodamine B, and Reactive Blue-4). Facile protocol i.e., immersion precipitation phase inversion method was used for the fabrication of mixed matrix membrane. The aluminium and gallium hybrids act as a filler and create heterogeneity and hydrophilicity within the membrane, affirming better water permeability and mechanical strength. The performance of fabricated mixed matrix membranes is evaluated using a lab-based dead-end membrane filtration unit. The result showed 30–71% rejection of Mercury, 24–65% rejection of Lead, 12–66% rejection of Reactive Blue-4, and 15–80% rejection of Rhodamine B.

The Coronavirus (COVID-19) pandemic has infected more than three million people, with thousands of deaths and millions of people into quarantine. In this research, the authors focus on meteorological and climatic factors on the COVID-19 spread, the main parameters including daily new cases of COVID-19, carbon dioxide (CO2) emission, nitrogen dioxide (NO2), Sulfur dioxide (SO2), PM2.5, Ozone (O3), average temperature, and humidity are examined to understand how different meteorological parameters affect the COVID-19 spread in Canada? The graphical quantitative analysis results indicate that CO2 emissions, air quality, temperature, and humidity have a direct negative relationship with COVID-19 infections. Quantile regression analysis revealed that air quality, Nitrogen, and Ozone significantly induce the COVID-19 spread across Canadian provinces. The findings of this study are contrary to the earlier studies, which argued that weather and climate change significantly increase COVID-19 infections. We suggested that meteorological and climatic factors might be critical to reducing the COVID-19 new cases in Canada based on the findings. This work’s empirical conclusions can provide a guideline for future research and policymaking to stop the COVID-19 spread across Canadian provinces.

Wastewater-based epidemiology (WBE) is considered an innovative and promising tool for estimating community exposure to a wide range of chemical and biological compounds by analyzing wastewater. Despite scholars' interest in WBE studies, there are uncertainties and limitations associated with this approach. This current review focuses on the feasibility of the WBE approach in assessing environmental pollutants, including pesticides, heavy metals, phthalates, bisphenols, and personal care products (PCPs). Limitations and challenges of WBE studies are initially discussed, and then future perspectives, gaps, and recommendations are presented in this review. One of the key limitations of this approach is the selection and identification of appropriate biomarkers in studies. Selecting biomarkers considering the basic requirements of a human exposure biomarker is the most important criterion for validating this new approach. Assessing the stability of biomarkers in wastewater is crucial for reliable comparisons of substance consumption in the population. However, directly analyzing wastewater does not provide a clear picture of biomarker stability. This uncertainty affects the reliability of temporal and spatial comparisons. Various uncertainties also arise from different steps involved in WBE. These uncertainties include sewage sampling, exogenous sources, analytical measurements, back-calculation, and estimation of the population under investigation. Further research is necessary to ensure that measured pollutant levels accurately reflect human excretion. Utilizing data from WBE can support healthcare policy in assessing exposure to environmental pollutants in the general population. Moreover, WBE seems to be a valuable tool for biomarkers that indicate healthy conditions, lifestyle, disease identification, and exposure to pollutants. Although this approach has the potential to serve as a biomonitoring tool in large communities, it is necessary to monitor more metabolites from wastewater to enhance future studies.