Marjan Nouri; Amirsalar Montazer Faraj
Abstract
Drinking water is one of the main factors for health maintenance and sustainable development of communities and its quantity and quality are so important. The aim of present study is random sampling of drinking water in 30 regions of Tehran city during 2 months in summer of 2020 to determine physicochemical ...
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Drinking water is one of the main factors for health maintenance and sustainable development of communities and its quantity and quality are so important. The aim of present study is random sampling of drinking water in 30 regions of Tehran city during 2 months in summer of 2020 to determine physicochemical attributes, microbial quantity and heavy metal levels according to national standard guidelines. Tests such as pH, alkalinity, turbidity, electrical conductivity, chloride, nitrite level, total and thermotolerant coliforms, and also heavy metals (arsenic, copper, zinc and lead), were performed in three replications. The pH (6.50 to 7.81), turbidity (0.011 to 2.983 NUT), chloride level (240.42 to 321.34 mg/L) and nitrate value (7.21 to 20.04 mg/L) were in allowable ranges. The phenolphthalein alkalinity was not found and methyl orange alkalinity was detected in the range of 31.54 to 147.22 (mg/L) in samples. The electrical conductivity (1401.7 to 1972.1 μs/cm) and thermotolerant coliforms were found higher than allowable range in some samples. The range of heavy metals was represented by following trend in Tehran: arsenic (0.85 to 15.90 μg/L), cooper (0.04 to 3.38 mg/L), zinc (0.16 to 3.80 mg/L), lead (0.001 to 0.031 mg/L) and some ranges were not within the national standard guidelines. The present study illustrated that quality of drinking water was in line with World Health Organization, while microbial quantity, electrical conductivity and some impurities (Cu and Pb) were higher than standard in some regions, so more arrangements should consider for increasing of drinking water quality in Tehran.
Robert Ikechukwu Uroko; Obioma Uzoma Njoku
Abstract
This study evaluated the impact of heavy metal contents in vegetables grown in a palm oil mill effluents (POME) irrigated farmland on the biomes and well-being of humans that consume the vegetables. In this study, POME, a soil sample from POME irrigated farmland, and selected vegetables were evaluated. ...
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This study evaluated the impact of heavy metal contents in vegetables grown in a palm oil mill effluents (POME) irrigated farmland on the biomes and well-being of humans that consume the vegetables. In this study, POME, a soil sample from POME irrigated farmland, and selected vegetables were evaluated. The results showed high cadmium (Cd), chromium (Cr), lead (Pb), nickel (Ni),) and arsenic (As) and lower zinc (Zn) and copper (Cu) concentrations in POME relative to their respective permissible limits. The soil irrigated with POME had elevated levels of metals, comparable to the control soil, whereas vegetable growing in POME irrigated farmland contained increased amounts of most of the heavy metals above their respective permissible levels in edible vegetables. The plant concentration factors (PCF) of heavy metals detected in the vegetables were less than one except for V. amygdalina with PCF>1 for cobalt. The pollution load index of Cd, Cr, Cu, Co, and As in the POME soil were above 50, while high enrichment factors were obtained for Cd, Cr, Pd, Co, and arsenic. The geoaccumulation index indicated that the POME soil was strongly contaminated by Zn, Fe, Pb, Mn, Ni and extremely contaminated with Cd, Cr, Zn, Cu, and Co. The metals levels ingested daily from the vegetables were low, comparable totheir respective oral reference doses except for Mn in V. amygdalina and As in most of the vegetables. There was a high target hazard quotient for Mn, and As in most of the vegetables with hazard index (H.I.) >1 in each of the vegetables and increased cancer risk for Cd, Cr, Pb, Ni and As toxicity coupled with very high total cancer risks. These findingsshow that irrigation of farmlands with POME raises the heavy metal levels in vegetables and the risk of heavy metal toxicity.
Zahra Mohebi; Maryam Nazari
Abstract
Disposal of waste products and residuals into the natural water bodies can havefatal consequences for aquatic ecosystems, posing severe threats to naturalhabitats and human health. Natural treatment systems are the most suitabletreatment technologies for various types of wastewaters, which has attracted ...
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Disposal of waste products and residuals into the natural water bodies can havefatal consequences for aquatic ecosystems, posing severe threats to naturalhabitats and human health. Natural treatment systems are the most suitabletreatment technologies for various types of wastewaters, which has attracted muchattention in recent years. Phytoremediation is a plant-based technique used toeliminate or recover surplus nutrients in contaminated environments. The use ofaquatic plants in wastewater phytoremediation is very efficient due to they have avery significant ability for assimilating and degrading contaminants (e.g., nitrates,phosphates, and heavy metals). Phytoremediation is a relatively new technologythat is considered as an operational, efficient, new, and environmentally friendlytechnology that is still in the early stages of development and optimization. Itsapplication on a large scale is still limited. It should also be noted that a clear visionof this innovation should be taken into account and, accurate data should be madeavailable to the public as it will enhance its efficiency as a manageable solution inthe worldwide. Additionally, phytoremediation has been evaluated as a separatelow-tech and environmentally friendly green option compared to the existingtechnologies. The present study attempts to review the recently published literatureto explain phytoremediation technology and its advantages in purifying water andwastewater.
Mohammad Hesam Falsafi; Mohsen Moghaddas; Jafarsadegh Moghaddas
Abstract
In this study, removal of heavy metals from synthetic wastewater has been investigated using silica aerogel-activated carbon composite. The synthesized adsorbent was characterized by FE-SEM, FTIR and BET techniques. The effect of amine functional groups embedded on the surface of silica aerogel-activated ...
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In this study, removal of heavy metals from synthetic wastewater has been investigated using silica aerogel-activated carbon composite. The synthesized adsorbent was characterized by FE-SEM, FTIR and BET techniques. The effect of amine functional groups embedded on the surface of silica aerogel-activated carbon 0.5 wt. % composite, optimal initial pH of removal of ions, impact of initial concentration of the solution containing heavy metal ions, adsorbent amount and contact time on removal percentage of ions were investigated. The results showed the optimal pH of 8, optimal adsorbent amount of 0.3 g for the removal of cadmium ion and 0.06 g for the removal of lead ion and optimal contact time of 80 min for cadmium and 60 min for lead ions. Adsorption data were investigated using Langmuir and Freundlich isotherms and maximum adsorption capability for cadmium and lead was obtained at 38.16 and 175.44 mg/g adsorbent, respectively.
Sara Habibi
Abstract
Nowadays, reuse of wastewater is widespread to prevail over shortage of water and to fertilize agricultural lands. This study was conducted to investigate effects of wastewater on some chemical and physical properties of soil. For this purpose, two farms were selected. These farms are located in the ...
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Nowadays, reuse of wastewater is widespread to prevail over shortage of water and to fertilize agricultural lands. This study was conducted to investigate effects of wastewater on some chemical and physical properties of soil. For this purpose, two farms were selected. These farms are located in the Ghahremanloo region at Urmia plain, West Azerbaijan province located in northwestern of Iran. There is no exact information regarding total amount of wastewater delivered to these lands, but flooding irrigation employing wastewater was applied during growing season. The farms are irrigated with two treatments, including wastewater treatment and freshwater where the surface irrigation method was utilized to plant corn. Experiment design was conducted as completely randomized blocks. Each experiment was repeated four times for both freshwater and wastewater treatments. Results of this study showed that the use of wastewater results in a significant decrease in soil's electrical conductivity (EC), sodium absorption ratio (SAR), and a substantial increase in calcium carbonate equivalent (CCE) and organic materials (OM) of the soil. Besides, the wastewater decreased density of Cu and increased density of Zn, Mn, and Fe significantly, known as heavy metals of the soil. However, the density of these elements in the soil was below detection limit. Bulk density also showed a significant reduction in wastewater usage. Finally, paired t-test and Mann-Whitney nonparametric tests were implemented to validate data.