Environmental life cycle assessment of different types of the municipal wastewater pipeline network

With the onset of social life, humans have considered waste disposal as essential, and they have been able to repel it through brick and clay channels. Checking sewage pipes for energy consumption and a longer lifetime than other sewage system components is important. Climate change and exploitation of industrial resources have made environmental impacts, which are important factors in decision making. The purpose of this study was to introduce the most suitable type of sewage pipe considering environmental protection. Therefore, we applied the environmental life cycle assessment (LCA) method, using Sima Pro 8.2.3 software for the one-kilometer length of concrete pipes (300 mm in diameter), Polyvinyl chloride (PVC), and polyethylene (PE) (315 mm in diameter). Also, the BEES method and sensitivity analysis were used to validate the results. The comparison between three types of municipal wastewater pipes indicated that PE pipes are a more environmentally friendly option than PVC, and concrete pipes in pipe recycling, reducing extraction from untapped resources, and inefficient extraction of resources. Electricity, diesel fuel, and sulfate resistance cement consumption for concrete production are the most pollution elements in the LCA of concrete pipes. Usage of PVC granular, sanitary landfill of PVC pipes, and using hydraulic drill in LCA of PVC pipes are the most elements of generating pollution. The usage of PE granules, PE pipes landfilling, hydraulic excavator, and electricity consumption in the LCA of the PE pipes are the greatest polluting parameters.     

Investigating the quantitative and qualitative status of effluent in the wastewater treatment plant in Iran Central Iron Ore

The aim of present study was to investigate the quality of the produced effluent from different units of the Iran Central Iron Ore in Bafq city and comparison of effluent with the standards. This study presents the physicochemical and biological parameters data of effluent of three Sequencing batch reactors (SBR) with a capacity of 160 m³?d^?1. Most common parameters include pH, total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), biochemical oxygen demand (BOD₅), chemical oxygen demand (COD), heavy metals, and total coliforms and fecal coliforms as biological indicators. Then, for each SBR system, the average of each parameter was determined, and results were compared with the standard recommended by the Iranian Environmental Protection Agency. Based on the results, some of the parameters, including BOD₅, COD, and TSS in the wastewater treatment plant (WWTP) effluent, are higher than the permitted amount for discharge to the surface water. Considering the BOD₅, COD, and TSS concentration in WWTPs, the treated wastewater is only suitable for agricultural and irrigation use. Therefore, wastewater produced by Iran Central Iron Ore Co. will need additional treatment to achieve standard quality of water before discharge in surface water and adsorbent well.     

Salinity modulates biochemical and histopathological changes caused by silver nanoparticles in juvenile Persian sturgeon (Acipenser persicus)

Environmental Science and Pollution Research - The objective of this study was to evaluate the effect of salinity on the acute and sub-chronic toxicity of silver nanoparticles (AgNPs) in Persian...     

Heavy metal contamination in feathers of Western Reef Heron (Egretta gularis) and Siberian gull (Larus heuglini) from Hara biosphere reserve of Southern Iran

The main objectives of article were monitor the metal concentrations of cadmium, lead, copper, zinc, cobalt, and iron, in the feather of shorebirds species, Western Reef Heron (Egretta gularis) and Siberian Gull (Larus heuglini) from Hara Biosphere Reserve of Southern Iran; and identify any relationships between species. Assaying heavy metals by using Shimadzu AA 680 flame atomic absorption spectrophotometer, the results were given as micrograms per gram dry weight. The concentrations of heavy metal were found to follow the order of iron>zinc>copper>lead>cadmium>cobalt for E. gularis and of iron>zinc>lead>copper>cadmium>cobalt for L. heuglini. Also, they showed that the cadmium, copper, and cobalt concentrations were higher in females than in the males, while the lead concentration for E. gularis and L. heuglini was higher in males. The cadmium concentration means they were measured as1.16 and 1.37 μg/g for E. gularis and L. heuglini, respectively, whereas the lead concentration means 7.04 and 5.48 μg/g for E. gularis and L. heuglini, respectively. The concentrations of nonessential trace elements in E. gularis and L. heuglini were generally comparable to values reported in other studies. The average levels of lead we observed in these birds were greater than 5 μg/g dry weight in the feather that is known to be associated with adverse behavioral or reproductive effects. Data analysis showed that there was a positive correlation between copper and zinc (P?相似文献   

Determination of mercury and arsenic levels in fish caught in the Beheshtabad River,Chaharmahal and Bakhtiari Province,Iran

Mercury and arsenic pollution has been recognized as a potential environmental and public health problem for over 40 years. The major source of exposure to mercury for humans is the ingestion of fish. This study was conducted with the aim of determining the levels of mercury and arsenic in the muscles of four fish species caught in the Beheshtabad River and comparing the results with the maximum tolerance levels for mercury and arsenic. The samples of 90 fish were used for the determination of both the metals by graphite furnace atomic absorption spectrometry. The results showed that the concentrations ranged from 1.5 to 3.8 µg kg^?1 for mercury and from 35 to 70 µg kg^?1 for arsenic, with means of 2.7 ± 0.5 and 57 ± 12 µg kg^?1, respectively. Both mean levels were lower than the threshold limits acceptable by WHO standards.     

Heavy metals assessment and identification of their sources in agricultural soils of Southern Tehran, Iran

A detailed investigation was conducted to evaluate heavy metal sources and their spatial distribution in agricultural fields in the south of Tehran using statistics, geostatistics, and a geographic information system. The content of Cd, Cu, Co, Pb, Zn, Cr, and Ni were determined in 106 samples. The results showed that the primary inputs of Cr, Co, and Ni were due to pedogenic factors, while the inputs of Zn, Pb, and Cu were due to anthropogenic sources. Cd was associated with distinct sources, such as agricultural and industrial pollution. Ordinary kriging was carried out to map the spatial patters of heavy metals, and disjunctive kriging was used to quantify the probability of heavy metal concentrations higher than their recommended threshold values. The results show that Cd, Cu, Ni, and Zn exhibit pollution risk in the study area. The sources of the high pollution levels evaluated were related to the use of urban and industrial wastewater and agricultural practices. These results are useful for the development of proper management strategies for remediation practices in the polluted area.     

Experimental and DFT insights into nitrogen and sulfur co-doped carbon nanotubes for effective desulfurization of liquid phases: Equilibrium & kinetic study

• Synthesis of NS-CNTS is used in a high desulfurization performance. • Synthesizing NS-CNT is considered as a novel adsorbent from low-cost precursors. • A high sulfur removal capacity for NS-CNT is attained compared with recent works. Herein, nitrogen and sulfur co-doped carbon nanotubes (NS-CNT) adsorbents were synthesized via the chemical vapor deposition technique at 1000°C by employing the camphor, urea and sulfur trioxide pyridine. In this study, desulfurization of two types of mercaptans (dibenzothiophene (DBT) and tertiary butyl mercaptan (TBM) as nonlinear and linear forms of mercaptan) was studied. In this regard, a maximum capacity of NS-CNT was obtained as 106.9 and 79.4 mg/g and also the removal efficiencies of 98.6% and 88.3% were achieved after 4 h at 298K and 0.9 g of NS-CNT for DBT and TBM, respectively. Characterization of the NS-CNTs was carried out through exploiting scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and elemental analysis (CHN). The isotherm equilibrium data could be ascribed to the Freundlich nonlinear regression form and the kinetic data was fitted by nonlinear form of the pseudo second order model. The negative values of ΔS⁰, ΔH⁰ and ΔG⁰ specify that the adsorption of both types of mercaptans was a natural exothermic process with a reduced entropy. Maintenance of more than 96% of the adsorption capacity even after nine cycles suggest the NS-CNT as a superior adsorbent for mercaptans removal in the industry. Density functional theory (DFT) calculations were also performed to peruse the effects of S/N co-doping and carbon monovacancy defects in CNTs toward the adsorption of DBT and TBM.