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Soft drinks are industrial intermediate chemicals found in wastewater and are among the most significant environmental pollutants. Up-flow anaerobic sludge blanket (UASB) reactors are used to treat soft drink wastewater, offering high-volume loading capacity, optimal grain deposition, and the ability to bear impact loads. The use of support materials can enhance biological productivity and expedite the UASB start-up period. In this study, bone powder was utilized as a support material in a UASB reactor to remove contaminants from wastewater. During the 70-day sludge adaptation period, the treatment reactor achieved a 93% reduction in COD, while the control reactor achieved a 65% reduction. Biogas production was higher in the bone powder UASB reactor (1750 mL/d) compared to the control UASB reactor (1100 mL/d), and the bone powder UASB reactor demonstrated greater resistance to shock loading. The improvement in sludge settling, shear strength, and higher biological activity in the bone powder UASB reactor was attributed to the formation of large granular sludge. The size of the granular sludge increased further with the colonization of filamentous bacteria at the irregular levels of bone powder. [ABSTRACT FROM AUTHOR]

Infectious waste disinfection is an essential process in medical waste management that may cause release of some pollutants. In this study, the PAHs concentration at the disinfection was investigated. The change in the release rate of PAHs in two including infectious waste reduction and increasing the segregation ratio was estimated. The results showed that the PAHs concentration was 1172 – 2066 ng/m3. The specific concentration of PAHs was 852 ng/ton of infectious waste in average. The annual emission of the PAHs resulting from infectious waste disinfection is estimated to be 612.6 kg. Reduction of infectious waste caused by redefining infectious waste and increasing the segregation ratio leads to reduction of PAHs concentration by 50%. Increasing the ratio of segregation and redefinition of infectious waste that led to reduced waste loading volume are essential measures that reduce the emissions of pollutants as by-products of disinfection. [ABSTRACT FROM AUTHOR]

In this study, three different reusable photocatalysts containing different amino acids as a source of non-metals, including L-Arginine, L-Proline, and L-Methionine, have been synthesized for the first time. Using a kinetic study and degradation efficiency test, these visible driven photocatalysts were investigated for their photocatalytic activity in removing antibiotics, including metronidazole (MNZ) and cephalexin (CEX). The morphology, structure and optical properties of the fabricated catalysts were characterized by X-ray Powder Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectrometry (EDS)/mapping, Fourier-Transform Infrared Spectroscopy (FTIR), Photoluminescence Spectroscopy (PL) and UV-Vis Diffuse Reflectance Spectroscopy (DRS) analyses. Based on the results of the PL analysis, it was confirmed that doping TiO2 with amino acids containing C, N, and S inhibited the recombination of induced electrons and holes. Among the three catalysts, L-Arginine-TiO2 demonstrated the highest photocatalytic activity for antibiotic degradation, followed by L-Proline-TiO2. According to the response surface methodology (RSM), the optimum operating conditions were a concentration of 50 mg/L MNZ, pH = 4, and catalyst concentration = 1.5 g/L under 90 min of irradiation time. At this condition, 99.9% of MNZ and 81% of TOC were removed. In addition, 97.2% of CEX and 75% TOC were eliminated at the optimum conditions of 1g/L catalyst concentration, 50 mg/L CEX concentration, at neutral pH, and after 120 min irradiation. L-Arginine (1 wt.%)-TiO2 was tested for stability and reusability, and it showed that after five cycles, 10% of its performance had been lost. The role of reactive species in photocatalysis was identified and •OH had the most significant impacts on MNZ and CEX photodegradation. Antibiotic degradation efficiency was adversely affected by the presence of anions and humic acid, but this reduction was not significant for inorganic anions, as only 13% of degradation was lost. [ABSTRACT FROM AUTHOR]

In recent year's climate changes account for extreme droughts, and one of the consequences of the drought is the reduction in groundwater levels. The present study was conducted to evaluate the drought status and its impact on the groundwater resources of Hamadan, Iran. This descriptive study data were collected from Water Affairs departments from 1987 to 2011. The study of the rainfall patterns over the past 25 years shows the large fluctuations in rainfall. The consequence of indiscriminate depletion of underground water resources is creating about 19 sinkholes in the plains. Over the past 50 years, about 320 villages have been uninhabited and the drinking water for 100 villages was supplied by tankers. Digging the illegal wells, uncontrolled exploitation of groundwater that cannot be replenished by recharge, uncontrolled exploitation of groundwater by the Shahid Mofateh power plants, unfavorable spatial and temporal distribution of rainfall, and lack of modern irrigation methods are responsible for the recent drought in Hamadan. [ABSTRACT FROM AUTHOR]