Pyrolysis is a promising thermochemical conversion process that transforms biomass into biochar, a carbon-rich solid material, in an oxygen-limited environment. This study focuses on the utilization of rice byproducts, namely rice straw and rice husk as feedstock for biochar production through low-temperature pyrolysis. The aim is to explore the potential of these biochars as cost-effective adsorbents for removing metal contaminants from aqueous solutions, with a particular emphasis on Pb(II) removal. Physicochemical properties of the biochars produced at a low temperature of 300 °C were thoroughly investigated, including surface morphology and their adsorption capacity for Pb(II). Remarkably, the rice straw biochar (RSB) produced at 300 °C exhibited exceptional Pb(II) adsorption capacity, with a value of 390.10±0.30 mg/g, and demonstrated a high Pb(II) removal efficiency of 96.10±0.30% when modified with 30% w/w H2O2. A crucial aspect of this study lies in the evaluation of the cost-effectiveness of the biochar production process, particularly when compared to commercially available adsorbents. By demonstrating the potential of rice byproduct-derived biochar as an efficient Pb(II) biosorbent in aqueous environments, this work not only provides new insights into the preparation of biochar using low-temperature pyrolysis but also offers a viable and economical solution for metal-contaminated water treatment. The findings of this research contribute to the field of sustainable waste utilization and highlight the significant potential of rice byproduct-based biochar as an environmentally friendly adsorbent for heavy metal removal.

Pesticide application has increased globally with increasing demand for food, and modernized Agriculture as a result of an explosion in the world’s population growth, especially in developing nations in Africa, Asia, and South America. However, pesticides have helped to improve productivity, protect the nutritive integrity of food crops, and ensure year-round food supplies worldwide. The production and consumption of pesticides persisted from one decade to another until the ecosystem started to suffer from its adverse effects on the environment and human health. Previous investigations revealed that pesticides found entry into the human food chain. In response to these problems, researchers all over the world have conducted several kinds of research on pesticide applications, and their residual contamination in food. This review crosses from the past to present researches on the usage of pesticides, their accumulation in food, and possible methods of their reduction as highlighted by researchers over many years. There is a need for continuous monitoring of pesticide residue profile in soil, crop produce, and animal products in developing countries so that it will not exceed maximum residue limits (MRLs).

Bioremediation has become a trending and developing field in environmental restoration through the use of micro-organisms to utilize and reduced the concentration and toxicity of various chemical pollutants. This study is on bioremediation of hydrocarbon-polluted soils using some agricultural wastes. Ninety (90) plastic buckets were filled with 4kg each of the composite soil. The soil contained in the plastic buckets was spiked with 250ml crude oil, except in the unpolluted plastic buckets (0%) crude oil. The agro-wastes (plantain stem sap, bush mango peels, and fruited pumpkin husk powder) in single and combined forms were applied after 14 days soil pollution. The amendments were applied as follows: Pristine control (0% agro-wastes), crude-oil control (0% agro-wastes), 150g, 250g, and 350g of the agro-wastes. Soil samples were collected at 90 days for soil microbial counts and the total hydrocarbon content of the soil. Data collected were subjected to 2-way ANOVA. The result showed that the microbial population in the crude-oil polluted soil amended with different agricultural wastes significantly increased (p<0.05) the total heterotrophic and crude oil utilizing bacterial and fungal counts in the soils and the increase in microbial population result in a significant reduction in total hydrocarbon content (THC) of the soils. The reduction in the THC of the soil was treatment dependent. It is, therefore concluded that based on the efficiency of these agro-wastes in enhancing microbial degradation, further studies should be carried out on the enzyme activities and production of bio-surfactant from the wastes to shorten the degradation time.

Natural radioactivity levels in the eastern coastline of Lake Hawassa sediment samples of Ethiopia’s Sidama Region have been measured. Sediment samples were collected and analyzed using gamma-ray spectrometery (high purity germanium detector) to evaluate the radioisotopes of 238U (214Pb, 214Bi), 232Th (228Ac, 212Pb), and 40K and their ranges of activity concentrations were 11.70 to 29.73 Bq 〖kg〗^(-1), 19.01 to 58.61 Bq 〖kg〗^(-1), and BDL to 827.21 Bq 〖kg〗^(-1) ,with average values of 16.51 ± 1.20 Bq 〖kg〗^(-1) , 28.17 ± 2.27 Bq 〖kg〗^(-1) ,and 673.95 ± 29.92 Bq 〖kg〗^(-1) (dry mass), respectively. The radiological hazard indices average values (radium equivalent (R_eq) (108.69 Bq 〖kg〗^(-1) ); hazard index (H_ex (0.29); excess lifetime cancer risk (ELCR) (0.23 x 〖10〗^(-3) ); absorbed dose rate (D_R) (52.70 nGyh^(-1) ); annual effective dose equivalent (AEDE) (0.07 mSv〖yr〗^(-1)); and annual gonadal dose equivalent (AGDE) (0.38 mSv〖yr〗^(-1)) were also evaluated and compared to the worldwide-recommended values. All results of radiological hazard indices obtained in this study were lower than their worldwide-recommended values were 370 Bq 〖kg〗^(-1), ≤1, 59 nGyh^(-1), 0.07mSv〖yr〗^(-1), 0.29 × 〖10〗^(-3), and 0.3mSv〖yr〗^(-1) of radium equivalent activity, external hazard index, outdoor absorbed dose rate, outdoor annual effective dose equivalent, excess lifetime cancer risk, and annual gonadal dose equivalent, respectively. This suggests the eastern coastline of Lake Hawassa is safe from radioactive risk for aquatic species and various human activities, and appears as essential radiometric baseline information for further environmental monitoring programs.

Radioactive contamination of the earth’s biosphere has always been a source of concern. From the health point of view, radiation exposure and dose delivered to human beings are of prime importance. Certain parts of coastal southwest districts of the state of Kerala in India namely Thiruvananthapuram (Trivandrum), Kollam (Quilon) and Alappuzha (Alleppey) are known high background radiation areas (HBRA) owing to the presence of rich quantities of thorium and uranium. Surface soil samples from these districts' HBRAs and adjoining regions were studied for their primordial radionuclide levels using NaI(Tl) based gamma-ray spectrometry. Specific activities of 226Ra, 232Th and 40K nuclides in soil samples from the whole study area were between 4.7 Bq/kg to 130 Bq/kg, 6.5 Bq/kg to 611 Bq/kg and 101 Bq/kg to 1852 Bq/kg, respectively. Important dosimetric parameters namely radium equivalent activity (Raeq), absorbed gamma dose (D), Indoor and outdoor Annual Effective Dose equivalents (AEDin &amp; AEDout), internal and external hazard indices (Hin &amp; Hex) for gamma exposure, and Excess Lifetime Cancer Risk (ELCR) were also determined to assess probable health effects on human beings residing in these regions. A comparison of average specific radioactivities and average indoor annual effective doses between the HBRA and Normal background Radiation Area (NBRA) is presented. Results show that the neighbouring regions have considerably lower radiation dosimetric parameters.

This research aims to investigate the effect of virtual education during the COVID-19 outbreak on air pollution indicators in Tehran. The study uses quantitative methods, including One-Way ANOVA, to analyze the air pollution indicators before and during the COVID-19 pandemic. Data on air pollution indicators in Tehran from 2018, 2019, and 2020 were collected from Tehran Air Control Company and compared using statistical tests. The year 2019 represents virtual education, while 2018 and 2020 represent face-to-face education. The examined indicators include particulate matters with a diameter less or equal than 2.5μ (PM2.5), SO2, NOX (i.e., NO2 and NO), O3, and CO. The results of variance analysis show significant differences in the PM2.5and NOX indices between virtual and face-to-face training days. Follow-up tests by Toki and Scheffé indicate that in 2019, when education was fully virtual, the levels of these pollutants were lower compared to 2018 and 2020. However, there were no significant differences in the SO2, O3, and CO indices during the days of virtual education compared to the years before and after. This suggests that virtual education during the COVID-19 outbreak contributed to pollution reduction by reducing traffic to educational organizations and its indirect effects.

The present study aims at determining the geotechnical properties of the tailings and the natural bed at Iran Mineral Processing Company, Sites 1 and 5. It qualitatively studies the subsurface layers of the company’s tailings storage site. After drilling different boreholes and conducting in-situ tests, it has made laboratory analyses in the form of field exploration to determine the geotechnical parameters of the extracted samples. Results from the analyses show the permeability coefficient of the subsurface layer of Site No. 1 and 5 to be very small, in the range of 10-7 cm/sec. Considering the conformity of permeability coefficient, percentage of fine grains (98% to 99%), plasticity index (28.5-29.5), and clay content of different layers of Sites 1 and 5 (68%-80%), based on the compacted clay liner criteria, it can be concluded that by nature, the subsurface layers of the mentioned sites are sealed with no need for any compacted clay liner. The tailings for storage Site 5 are fine-grained (80-88<75mm), basically in ML range according to USCS system, with a permeability coefficient of about 10-6 cm/sec. Therefore, the tailings themselves act as a relatively primary sealing layer against the infiltration of hazardous leachates into the natural bed. The method, used in the process of site selection of tailings storage facilities (TSF), can cut the construction time as well as the expenditures, thus reducing the production costs in the long run.

In order to ensure radiation monitoring and protection, investigation and assessment of radiological risks that may be associated with the consumption of packaged table waters commonly consumed in Ogbomoso and Ilorin metropolis, Nigeria, was carried out. The measurements were carried out using a ‘3 x 3’ inch lead-shielded NaI (Tl) detector coupled through coaxial cable to a multichannel analyser. The measured activity concentrations of the natural radionuclides in the packaged drinking water sample are mostly within the recommended limits. The estimated mean Annual Effective Dose was found to be within the acceptable limits of 1 mSv/y for the general populace except for the infants which is slightly higher for some of the samples. The estimated Excess Lifetime Cancer Risk were found to be lower than the world average value of 0.2 x 10-3 in only two of the selected packaged drinking water. This implies the possibility of developing cancer over a lifetime considering seventy years as the average life span is considerably high.

Atmospheric models today represent all significant aerosol components. Atmospheric aerosols play an important role in the air, globally through their action on the Earth's radiation balance and locally through their effects on health in heavily polluted areas, they vary considerably in their properties that affect the way they absorb and disperse radiation, and they can thus have a cooling or warming effect, they impact on the formation and life of clouds is one example. Among the main sectors of activity releasing emissions of PM10 (fine particles with a diameter of less than 10 µm) and a diameter of less than 2.5 µm (PM2.5) is the industrial sector, in particular the extraction industry of building materials. The aerosols emitted by this type of industry are composed mainly of a mixture of dust, sulphates, carbon black and nitrates, is clearly perceptible in many continental regions of the northern hemisphere. Improvements in in situ, satellite and surface measurements are needed. However, the mechanisms by which aerosols interact with the environment are extremely complex and still poorly understood. This study is based on satellite atmospheric models to have spatiotemporal variability of concentrations of fine particles smaller than 10 µm in diameter (PM10) and smaller than 2.5 µm in diameter (PM2.5) at the level of the western Rif part of Morocco, home to a large number of extraction quarries and thus offering a high-resolution particle capture system (PM10 and PM2.5).

Atmospheric aerosols are very crucial from air pollution and health perspective as well as for regional and global climate. This paper attempts to summarize the aerosol loading and their properties such as Aerosol Optical Depth (AOD), Single Scattering Albedo (SSA), Angstrom exponent, and Radiative forcing, over India. All the above mentioned parameters have shown significant variability with change in the site and season. From various studies it was observed that AOD is relatively higher over Northern part of India as compared to Southern and Eastern part. Generally, lower values of SSA were observed over all sites during winter and post-monsoon seasons which indicates the dominance of absorbing type aerosol during these seasons. Also the ARF within atmosphere showed comparatively higher values during November-December and lower value during August and September all over the India. The current state of knowledge about aerosol sources, interactions and their effects on environment is limited because of its complexity. Therefore, more focused research in needed to understand the aerosol’s role in climatic phenomenon.