Estimation of Gas Emissions using the LandGEM Model from the Landfill of Baft County, Kerman, Iran.

Over time, waste buried in landfills produces greenhouse gases (GHG) such as methane (CH4) and carbon dioxide (CO2). It is essential to know and investigate the type and amount of production of these gases from landfills as well as their effects, considering the environment's vulnerability to GHG. In the present study, the gases released from the landfill of Baft county were estimated using the landfill gas emissions model (LandGEM). CH4 production rate (k) and potential CH4 generation capacity (Lo) considering the semi-arid area for Baft county were considered 0.05 year-1 and 170 m3/Mg, respectively. According to the results, in 2054, an amount of 18703819 Mg/year of waste enters the landfill of Baft county. The emissions of landfill gases (LFG), including total landfill gas, CH4, and CO2, remained relatively constant between 2004 and 2044, followed by a period of increasing emissions until 2054. However, from that point onward, there was a decline in gas emissions that continued until 2144. In 2054, the estimated emissions for total landfill gas, CH4, CO2, and non-methane organic compounds (NMOC) are projected to be 3.043E + 05, 8.128E + 04, 2.230E + 05, and 3.493E + 03 Mg/year, respectively. Similarly, in 2144, the estimated emissions for total landfill gas, CH4, CO2, and NMOCs are projected to be 3.380E+03, 9.029E+02, 2.477E+03, and 3.881E+01 Mg/year, respectively. The potential to generate 18.25 MWh/year of electricity exists for the Baft county landfill in 2054. The study showed that a significant amount of CH4 and CO2 gases would be discharged into the atmosphere from the landfill site of Baft county, which can be recycled to help produce energy and improve air quality.

Non-carcinogenic and cumulative risk assessment of exposure of kitchen workers in restaurants and local residents in the vicinity of polycyclic aromatic hydrocarbons.

Polycyclic aromatic hydrocarbons (PAHs) are often formed when organic substances do not burn completely. This study evaluates the non-carcinogenic and cumulative risks associated with PAHs levels by testing blood and urine samples in kitchen workers and residents near restaurants in Shiraz, Iran. Metabolites of PAH in the urine samples as well as clinical parameters in the blood samples were measured. The non-carcinogenic and cumulative risk assessments from exposure of the study groups to PAH metabolites were also evaluated. The highest average concentrations of PAH metabolites were related to kitchen workers (2126.7 ng/g creatinine (ng/g cr)). The metabolites of 1-Hydroxypyrene (1-OHP) and 9-Phenanthrene (9-OHPhe) had the highest and lowest mean concentrations, respectively. A direct correlation was observed between the levels of PAH metabolites with malondialdehyde (MDA) and total antioxidation capacity (TAC) levels (p < 0.05). Hazard Index (HIi) was obtained less than one (HIi < 1), indicating low-risk negative health impacts on the target groups. Nevertheless, conducting more studies to determine the health status of these people is quite evident.

Direct red 81 adsorption on iron filings from aqueous solutions; kinetic and isotherm studies.

Direct Red 81 (DR-81) dye with a very high water solubility is widely used in many industries particularly textile industries. This study aimed to evaluate the practicability of using iron filings for the adsorption of DR-81 dye from the aqueous solutions. The effects of pH, adsorbent dose, initial DR-81 dye concentration, and adsorption time on adsorption process were also evaluated. The maximum of adsorption efficiency of DR-81 dye achieved in the optimum pH: 3, adsorbent dose: 2.5 g/L, contact time: 30 min, and initial dye concentration: 50 mg/L. The dye adsorption efficiency is increased by increasing the adsorbent dose and adsorption time. The kinetic and isotherm studies indicated that the adsorption process obeys a pseudo-first-order and Langmuir isotherm models. The experimental studies indicated that iron filings had the potential to act as an alternative adsorbent to remove the DR-81 dye from an aqueous solution.