A geochemical evaluation was performed to determine the occurrences of many heavy metals as well as their natural activities, in the southeast-Baghdad.  For this purpose, seventeen subsurface soil samples from the cited location were collected at a depth of 50-100 cm. Samples collection included many types of land uses such as open space, roadside, green land, industrial and commercial samples. The samples were characterized systematically using XRF and gamma-ray spectrometry with NaI (Tl) scintillation detector. The total average concentrations of heavy metals Ag, Sn, Sb, I, Hf, W, Th and U in the soil were 1.94, 3.13, 3.01, 2.82, 1.70, 72,5.66 and 0.85 ppm respectively. Heavy metals Sn, I and W appeared with high concentrations among the others as shown in total average, compared with the standard. The enrichment with Sn elements strictly appeared in green and commercial lands with an average 3.63 ppm, whereas I and W concentrated in industrial land 3.0 and 0.95 ppm respectively, indicating anthropogenic rather than autogenic. It was asserted that the observed elements can be used as pollution indicators to discover the state of the contamination. The EF values of the soils in some sites displayed enrichment with Sb and moderate with Ag reflected mild enrichment (EF > 2), confirming their level of pollution by the hazardous heavy metals. The contents of 238U, 232Th and 40K in the samples varied from 34.64-48.54, 47.22-67.73, and 323.27-585.11 Bq/kg, respectively. The mean activities of 238U, 232Th and 40K in the dry weight samples were correspondingly 41.25, 56.89, and 424.12 Bq/kg, which were higher than the global averages of 35, 30 and 400 Bq/kg, respectively. The radium equivalent levels in all samples were much lower than the global average (370 Bq/kg). In addition, all external and internal hazard indices were within the recommended limit. The average dose rate and gamma index levels were greater than the global average value.

Substrates play a major role to filter, adsorb, sediment, flocculate, precipitate, and exchange ions. In CW (Constructed wetland), selecting substrate or bed materials is not difficult, as locally accessible, cost-effective, and environment-friendly materials can be used based on size, hydraulic conductivity, texture, porosity, etc. CW substrates undergo a multitude of purification processes, including physical filtration and sedimentation, sorption, ion exchange and microbial degradation, precipitation, and bio-immobilization in the substrate, in addition to uptake and metabolism by macrophytes. With constructed wetlands, treatment facilities with well-defined substrates, vegetation species, and flow patterns can be built with greater control than with natural systems. This report details investigations of some of the locally available substrates that all fit the requirements. Based on analysis of parameters which are pH, water absorption capacity, hydraulic conductivity, porosity, surface area, bulk density, particle size distribution, D10 particle diameter, D60 uniformity coefficient, permeability and specific gravity, a comparison of four materials is presented in this paper. The study found that the construction waste materials evaluated showed satisfactory physical properties for use as filler media in constructed wetlands for wastewater treatment.

Improper management of wet waste in cities located in temperate, humid regions with abundant rainfall leads to the production and spread of leachate across ecosystems. This not only pollutes soil and surface water but also contributes to the emission of greenhouse gases, negatively impacting both ecosystem and human health. Effective waste management can transform these wastes into valuable products, such as fertilizer and biogas, while also preventing environmental damage. In this study, we focus on a region with moderate weather conditions, which offers the potential for efficient waste management at a reasonable cost. By evaluating various technologies and methods, as well as considering global implementation approaches, anaerobic digestion emerges as a more suitable solution for waste management compared to conventional methods like burying and burning. Apart from waste reduction, anaerobic digestion offers several advantages, including reduced greenhouse gas emissions, prevention of soil, air, and water pollution, decreased toxicity and heavy metal contamination, and eradication of pathogenic organisms. Numerous types of digesters have been developed to date, and factors such as geographical location, substrate availability, construction materials, climatic conditions, cost and capital requirements, and energy consumption influence the design of these digesters. In this study, we estimate the design, construction, and management of a small-scale digester for a town with a population of 2000 people. By providing reliable information, this research aims to assist executive officials of towns and villages in establishing such units within their communities, promoting sustainable rural development.

Acid-activated corn husk waste (CHW) was used to investigate the adsorption mechanism of Indigo Carmine (IC) dye from an aqueous solution. The effect of different operating parameters such as pH (1-7), initial IC dye concentration (40-400 mg/L), contact time (5-75 min), and heating temperature (25–200 °C) was measured on the removal of IC dye by the CHW. The maximum uptake of IC dye was observed at an initial pH of 2. The maximum capacity of 13.57 mg/g and the maximum dye removal of 89.01 % in wastewater. The adsorbents were characterized using Fourier Transforms Infrared Spectrophotometry (FTIR), Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analysis, X-ray Fluorescence (XRF), and Thermogravimetry Analysis. The characterization process reveals the differences in adsorbent characteristics before and after the adsorption processes. The Langmuir showed the best fitting (R2 = 0.977) and described multilayer adsorption on diverse surfaces. The pseudo-second-order kinetic model best correlated with the experimental data (R2 = 0.981). Thermodynamics revealed that adsorption was favorable spontaneous and exotherm. The study's results indicated that using CHW as a low-cost adsorbent to treat IC dye was efficient and beneficial to the environment.

The total particle mass concentration, size distribution, pH form, polycyclic aromatic hydrocarbons (PAHs) value, the concentration of total Benzo[a]pyrene Toxic Equivalence (BaPTE) and water-soluble organic carbon (WSOC) of smoke particles from the rubber sheets processing sewage sludge biochar burning were studied. In this work, the temperature was measured at 500 mm above the fire base by using K-type thermocouples and a continuously data logger. The result showed that the measured temperature value increased when decreasing the biochar moisture content. The highest average total smoke particle mass concentration values at the initial burning time was found to be 17.53 to 35.27 mg/m3 and then it was persistently reduced until the 60th minute, when the burning was stopped. The pH of biochar's smoke particles was higher than it was before combustion. The total smoke particle mass concentration, the mass median aerodynamic diameter (MMAD) and PAHs values decreased with increasing burning period and decreased the biochar moisture content. The largest BaPTE emission was observed at the highest moisture content, which was within the range of the greatest particle mass (less than 0.43 micron) in an initial combustion period. This value was about 60% that of a given the total value of BaPTE concentration. Meanwhile, the amount of PAHs, the BaPTE concentration and WSOC were depended on the smoke particle number, moisture content and combustion period.

The biodegradation rates of single-use blended bioplastic packaging nylon, nylon 6, and cellulose polymer were assessed in aquatic environments in an attempt to identify real biodegradable bioplastics (RBB). The natural biodegradation rates of the test samples in freshwater and marine water were assessed by respirometric method following the procedure of the American Standard Testing and Materials. The experimental design was arranged thrice in a completely randomized design of 2x4x3. The physicochemical parameters were obtained using the standard methods while the rates of biodegradation were obtained by titration method. Data obtained were analyzed using descriptive statistical method. At the end of 120 days, there were steady increase in the rates of biodegradation of cellulose and bioplastic samples across the fourth month in both freshwater and marine water. However, the rate of biodegradation in marine water were higher than in freshwater following the trend cellulose in marine (342 %) > cellulose in freshwater (259%) > bioplastics packaging nylon in marine (193%) > bioplastics packaging nylon in freshwater (175%). For nylon 6, the rate (-14) of retardation in the biodegradation process in Nylon 6 soaked in marine water is greater than that of Nylon 6 soaked in freshwater (-13). Consequently, nylon 6 was recalcitrant to biodegradation both in freshwater and marine water. The study concluded that the blended bioplastic packaging nylon is a real biodegradable bioplastic and could be suggested as a feasible and environmentally-friendly option to replace traditional plastics in the society.

River basins perform the crucial role of providing water resources, especially in arid regions. Due to the nature of interconnection, human interventions and natural events will cause cumulative impacts on the downstream parts of river basins. The aim of this research is to identify and evaluate the impacts of interventions and changes occurring in the upstream of the Tigris-Euphrates River Basin on the downstream parts and provide strategies to reduce and control those effects. To achieve this purpose, multi-scaled investigation of the changes and dynamics of the land cover was performed and the causes and consequences of these changes were investigated using the Driving force-Pressure-Sate-Impact-Response (DPSIR) framework. The results displayed an increase in the area of artificial lakes and agricultural lands and a decline in the area of rangelands and natural wetlands, especially in the downstream of the basin. The state of the ecosystem was under the influence of Driving forces such as population and industrial growth and political competitions of the littoral states, which led to pressure on the limited water resources and development of water management and control projects. The overall trends of changes in the state of the environment had created impacts on the ecosystem and communities that required urgent responses from the riparian countries. Finally, to foster water cooperation instead of non-constructive completions in this region, a framework was developed with an emphasis on creating a union of riparian countries and using their scientific potentials to provide effective and impartial solutions.

People’s growing anxiety, and fear of the issue of a large number of mobile phone towers, as well as the lack of studies dealing with this issue at the level of the country in general, and the governorate in particular. All these reasons led to the issue of non-ionizing rays given off by mobile telephone masts on the table of worries about how this radioactivity will affect people's health. Non-ionized radiation emissions were measured by taking 280 readings for the three frequency packets 900, 1800, and 1840 MHz, which are sequential-Global System Mobile (GSM), of 20 cell phone towers in the Al-Amara, the city center of Misan prefecture. Four readings were collected for each frequency, with the highest value for overlap between electromagnetic field and frequency being chosen. A selective Radiation Meter (SRM-3006) was the device used in this study. It was found that the amount of non-ionizing radiation emitted by the towers taken in the study, and for the frequencies (900, 1800, and 1840 MHz) was, in a successive manner (309 × 10-8, 7 ×10-8, and 1109×10-7 MHz). Thus, the measured values of radiation were less than the surveyed limit (4×10-1 μW/cm2) provided for by the law of Iraq’s Determinants for Non-ionized Radiation Emissions (IDNREs).

In recent years, increasing in energy demand and the importance of using energy with minimum green- house gas emission (GHG) leads researchers to study about renewable energy resources such as biomasses. Biomasses can be converted to biofuels by applying the appropriate technologies. In this study, a hybrid group fuzzy multi-criteria decision making (MCDM) approach based on step-wise weight assessment ratio analysis (SWARA), technique for order preference by similarity to ideal Solution (TOPSIS), additive ratio assessment (ARAS), weighted aggregated sum product assessment (WASPAS) and simple additive weighting (SAW) in the fuzzy environment is applied to rank biomasses in the case of Hormozgan province in Iran, because of being a coastal area and the access to different types of first, second and third generation resources of biofuel. After ranking these resources by mentioned methods, two aggregated multi-criteria decision making (MCDM) methods (mean rank method and Copeland method) are employed to prioritize these biomasses.  Results of mean rank show that municipal solid wastes (MSW), fish wastes and microalgae have the minimum average rank, respectively and the results of Copeland method show that MSW, fish wastes and microalgae have the maximum (wins-loses), respectively. So, these biomasses are the most suitable ones in biofuel production in this province.

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.