Removal of Lead and Chromium (VI) metals from Water in the Batch System Using Activated Gamma Alumina

Increased water pollution has become an important environmental problem due to the discharge of urban and industrial wastewater into water resources that contain heavy metals and other pollutants. Therefore, the aim of this study was to investigate the effectiveness of Activated Gamma Alumina (AGA) in the removal of lead and chromium (VI) from water, for the synthesis of which, aluminum hydrate has been used. Aluminum hydrate was exposed to 700 °C and converted to gamma alumina. The effect of variables such as pH, contact time, adsorbent dose and initial concentration of pollutants that are effective in removing lead (II) and chromium (VI) also investigated. The maximum removal efficiency of lead and chromium (VI) removal was obtained by Activated Gamma Alumina at a dose of 1 g/L, pH equivalent of 8 for lead and equivalent of 3 for chromium (VI), initial lead and chromium (VI) concentration 20 mg/L and contact time 60 min. Also, the study of absorption isotherm and kinetic model showed that the data of the elimination process are correlated with Langmuir model (Lead: R2 = 0.9805 and Chromium: R2 =0.9865) and kinetic of the pseudo-second-order models (Lead R2=0.9914 and Chromium R2=0.9536). The maximum adsorption capacity for lead and chromium (VI) obtained 27.78 and 30.77 mg/g, respectively. According to the results obtained in this study, the AGA adsorbent has a high ability to remove lead and chromium (VI) and can be recommended as a cheap adsorbent for the filtration of lead and chromium contaminated backwater

Hybrid Nano-filtration and Micro-filtration Pilot Processes for the Removal of Chromium from Water

Heavy metal hexavalent chromium is known as a highly toxic compound and based on World Health Organization standards in concentrations greater than 50 micrograms per liter would lead to diseases such as allergic reactions, skin cancer, lung cancer, damage to the kidneys and liver, and also changes in the shape of the DNA genetic. The aim of this study was to evaluate the performance of the hybrid system of nano-filtration and micro-filtration processes to remove hexavalent chromium from water. Pilot implementation of 1 and 5 micron filters, sand filters, activated carbon filters, and NF (NF 90-400) was built. The effects of various parameters such as pH, pressure, concentration of chromium, concentration of sulfate and total dissolved solids (TDS) were studied on the removal of hexavalent chromium from drinking water. Pressure was changed from 0.1 to 0.4 MPa, pH was set in the range of 2 to10, the concentration of hexavalent chromium was in the range of 100 to 400 micrograms per liter and the concentration of sulfate oral solution was changed between 40 and 500 milligrams per liter. The results showed that the efficiency of chromium removal increased as pH was increased. The removal of chromium dropped when the pressure was increased from 0.1 to 0.4 MPa. In addition, a decreasing trend was observed in removal efficiency by increasing the concentration of chrome and sulfate. Optimal levels of hexavalent chromium concentration was 100 micrograms per liter. For pressure, pH, and sulfate concentration the optimal levels were 0.1 Mpa, 10 and 40 milligrams per liter, respectively. In general, pilot and experimental results showed that the system provided the ability to remove chromium in drinking water (tap water and distilled water) at a rate of 99%

Risk assessment of mercury and lead in fish species from Iranian international wetlands

The aim of this study is determination of mercury concentration in the muscle, intestine, gonad and kidney of Rutilus rutilus, Hemiculter Leucisculus (Anzali wetland), and Alosa Caspia Caspia (Caspian Sea), and mercury and lead concentrations in the muscle of Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Schizocypris altidorsalis, and Schizothorax zardunyi (Hamun wetlands). The results of this study were compared with global standards. As well as in this multispecies monitoring, health risk assessment of consumers by EPA/WHO instructions has been done. The concentrations of mercury were below the limits for fish proposed by United Nations Food and Agriculture Organization (FAO), World Health Organization (WHO), US Food and Drug Administration (FDA) and US Environmental Protection Agency (EPA), and European Union (EU). Lead concentrations in Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix was under the scope proposed by FAO, WHO, FDA, Turkish Acceptable Limits (TAL), United Kingdom Ministry of Agriculture Fisheries and Food (UK MAFF) and National Health and Medical Research Council (NHMRS), but lead concentration in Schizocypris altidorsalis, and Schizothorax zardunyi were higher than WHO and TAL. Health risk assessment of consumers from the intake of metal contaminated (mercury and lead) was evaluated by using Hazard Quotient (HQ) calculations. The human health hazard Quotient (index) showed that the cumulative risk greatly increases with increasing fish consumption rate, thus yielding an alarming concern for the consumer’s health. • The results of the present study aimed to provide data from Caspian Sea, Anzali wetland, and Hamoon wetland as indicators of natural and anthropogenic impacts on aquatic ecosystem as well as to evaluate the human hazard index associated with fish consumption. • The results show that for mercury, the Maximum Allowable Fish Consumption Rate (Meals/Month) is related to Hemiculter Leucisculus. • The results for lead concentration indicate that there is no HQ value > 1, indicating that humans would not experience any significant health risk if they only consume metals from these species of fish from the hamun wetland. Keywords: Risk assessment, Heavy metals, Anzali wetland, Caspian Sea, Hamun wetland

Study of Mercury Pollution in Water, Sediments, and Fish from Hamoon International Wetland

Contaminant levels in fish are of particular importance because of the potential health risks they pose to human consumers. The presnet study was designed and implemented to determine mercury concentrations in water, sediments, and fish from Hamoon wetland against international standards. For this purpose, the LECO, AMA 254, ASTM Standard D-6722 was used to determine mean Hg concentrations in the muscles of Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Schizocypris altidorsalis, and Schizothorax zardunyi as 0.14, 0.28, 0.15, 0.15, 0.34, and 0.36 mg/kg, respectively, and 0.21, 0.32, 0.22, 0.23, 0.36 and 0.41 mg/kg in their kidneys. Water mercury concentrations at three stations were determined to be 0.06, 0.07, and 0.08 mg/kg while they were 0.39, 0.44, and 0.48 mg/kg in the sediments. Laboratory analysis results showed significant differences in mercury concentrations between fish kidney and muscle (

An Investigation into the Relationship between the Spiritual Tendencies and the Quality of Life among the Students of Shahed University

The main purpose of the study is to evaluate the spiritual tendencies and the quality of life among the students of Shahed University. In other words, the main question of the study is whether the spiritual tendencies increase or decrease, the quality of life is changed or not. This study is applied the survey methodology. The sample size is 359 students (147 boys and 212 girls) from Shahed University. They who were selected by random stratified sampling were analyzed with the help of questionnaires of spiritual tendencies and World Health Organization Quality Of Life (WHOQOL). The obtained results from Pearson correlation coefficient showed that with increasing the spiritual tendencies, the level of students' quality of life increases. In addition, with increasing the spiritual tendencies in dimensions of spiritual beliefs, sense of spirituality, spiritual self-actualization, and spiritual behaviors, the level of quality of life increases. Meanwhile, the results showed that with increasing the spiritual tendencies and their four dimensions, the level of quality of life increases in terms of mental, environmental, and social dimensions

Baseline heavy metals in plant species from some industrial and rural areas: Carcinogenic and non-carcinogenic risk assessment

This paper provides the first quantitative information on accumulation of cadmium, lead, and arsenic in the soil, leaf, and root of wheat (Triticum aestivum L.), corn (Zea Maize), and tomato (Solanum lycopersicum) in the downstream agricultural lands of an industrial area and agricultural lands of a rural area, Razavi Khorasan province, Iran. The results showed that there is a significant difference among the cadmium concentrations in the soil, root and leaf/seed in various plants (p = 0.00 for wheat and corn and p = 0.0004 for tomato). There was no significant difference between the lead concentrations in the soil, root and leaf/seed in the case of wheat (p > 0.05), but there was a significant difference for other plants. Furthermore, statistical analysis was done on arsenic concentrations of soil, root and leaf/seed in the wheat, tomato, and corn. In the case of rural area, the results showed significant difference between the cadmium and lead concentrations of soil, root and leaf/seed in the wheat and tomato. In this area, statistical analysis was done on the arsenic concentrations of soil, root and leaf/seed in wheat, tomato, and corn (p = 0.00 for wheat, p = 0.00 for tomato, and p > 0.05 for corn). The heavy metals concentrations in some parts of the plants in the industrial area were above the standards. The concentrations of cadmium, lead, and arsenic for soil were below the limits proposed by WHO, EPA, and EU. In this study, the Total Hazard Quotient (THQ) through consumption of wheat was less than 1, indicating no significant potential health risk associated with the consumption of wheat from the areas. The cancer risk of arsenic from wheat consumption was as 255 × 10−6 and 0.00 in the industrial and rural areas, respectively. • Atomic absorption spectrophotometer (AAS) equipped with graphite furnace was used for heavy metal analysis. • The general results revealed that the levels of Cd, Pb, and As in the industrial area were higher than the rural area. • The cancer risk of arsenic in wheat for the industrial area is greater than 1 × 10−6, which is unacceptable. Keywords: Heavy metals, Plant species, Industrial area, Rrural area, Risk assessmen

Measurement and modeling of particulate matter concentrations: Applying spatial analysis and regression techniques to assess air quality

This paper presented the levels of PM2.5 and PM10 in different stations at the city of Sabzevar, Iran. Furthermore, this study was an attempt to evaluate spatial interpolation methods for determining the PM2.5 and PM10 concentrations in the city of Sabzevar. Particulate matters were measured by Haz-Dust EPAM at 48 stations. Then, four interpolating models, including Radial Basis Functions (RBF), Inverse Distance Weighting (IDW), Ordinary Kriging (OK), and Universal Kriging (UK) were used to investigate the status of air pollution in the city. Root Mean Square Error (RMSE), Mean Absolute Error (MAE) and Mean Absolute Percentage Error (MAPE) were employed to compare the four models. The results showed that the PM2.5 concentrations in the stations were between 10 and 500 μg/m3. Furthermore, the PM10 concentrations for all of 48 stations ranged from 20 to 1500 μg/m3. The concentrations obtained for the period of nine months were greater than the standard limits. There was difference in the values of MAPE, RMSE, MBE, and MAE. The results indicated that the MAPE in IDW method was lower than other methods: (41.05 for PM2.5 and 25.89 for PM10). The best interpolation method for the particulate matter (PM2.5 and PM10) seemed to be IDW method. • The PM10 and PM2.5 concentration measurements were performed in the period of warm and risky in terms of particulate matter at 2016. • Concentrations of PM2.5 and PM10 were measured by a monitoring device, environmental dust model Haz-Dust EPAM 5000. • Interpolation is used to convert data from observation points to continuous fields to compare spatial patterns sampled by these measurements with spatial patterns of other spatial entities

Highly Efficient Computationally Derived Novel Metagenome α-Amylase With Robust Stability Under Extreme Denaturing Conditions

α-Amylases are among the very critical enzymes used for different industrial purposes. Most α-amylases cannot accomplish the requirement of industrial conditions and easily lose their activity in harsh environments. In this study, a novel α-amylase named PersiAmy1 has been identified through the multistage in silico screening pipeline from the rumen metagenomic data. The long-term storage of PersiAmy1 in low and high temperatures demonstrated 82.13 and 71.01% activities after 36 days of incubation at 4 and 50°C, respectively. The stable α-amylase retained 61.09% of its activity after 180 min of incubation at 90°C and was highly stable in a broad pH range, showing 60.48 and 86.05% activities at pH 4.0 and pH 9.0 after 180 min of incubation, respectively. Also, the enzyme could resist the high-salinity condition and demonstrated 88.81% activity in the presence of 5 M NaCl. PersiAmy1 showed more than 74% activity in the presence of various metal ions. The addition of the detergents, surfactants, and organic solvents did not affect the α-amylase activity considerably. Substrate spectrum analysis showed that PersiAmy1 could act on a wide array of substrates. PersiAmy1 showed high stability in inhibitors and superb activity in downstream conditions, thus useful in detergent and baking industries. Investigating the applicability in detergent formulation, PersiAmy1 showed more than 69% activity after incubation with commercial detergents at different temperatures (30–50°C) and retained more than 56% activity after incubation with commercial detergents for 3 h at 10°C. Furthermore, the results of the wash performance analysis exhibited a good stain removal at 10°C. The power of PersiAmy1 in the bread industry revealed soft, chewable crumbs with improved volume and porosity compared with control. This study highlights the intense power of robust novel PersiAmy1 as a functional bio-additive in many industrial applications

Efficient bioconversion of lignocellulosic waste by a novel computationally screened hyperthermostable enzyme from a specialized microbiota

A large amount of lignocellulosic waste is generated every day in the world, and their accumulation in the agroecosystems, integration in soil compositions, or incineration for energy production has severe environmental pollution effects. Using enzymes as biocatalysts for the biodegradation of lignocellulosic materials, especially in harsh processing conditions, is a practical step towards green energy and environmental biosafety. Hence, the current study focuses on enzyme computationally screened from camel rumen metagenomics data as specialized microbiota that have the capacity to degrade lignocellulosic-rich and recalcitrant materials. The novel hyperthermostable xylanase named PersiXyn10 with the performance at extreme conditions was proper activity within a broad temperature (30-100 ℃) and pH range (4.0-11.0) but showed the maximum xylanolytic activity in severe alkaline and temperature conditions, pH 8.0 and temperature 90 ℃. Also, the enzyme had highly resistant to metals, surfactants, and organic solvents in optimal conditions. The introduced xylanase had unique properties in terms of thermal stability by maintaining over 82% of its activity after 15 days of incubation at 90 ℃. Considering the crucial role of hyperthermostable xylanases in the paper industry, the PersiXyn10 was subjected to biodegradation of paper pulp. The proper performance of hyperthermostable PersiXyn10 on the paper pulp was confirmed by structural analysis (SEM and FTIR) and produced 31.64 g/L of reducing sugar after 144 h hydrolysis. These results proved the applicability of the hyperthermostable xylanase in biobleaching and saccharification of lignocellulosic biomass for declining the environmental hazards

Taguchi optimization approach for Pb(II) and Hg(II) removal from aqueous solutions using modified mesoporous carbon

Using the Taguchi method, this study presents a systematic optimization approach for removal of lead (Pb) and mercury (Hg) by a nanostructure, zinc oxide-modified mesoporous carbon CMK-3 denoted as Zn-OCMK-3. CMK-3 was synthesized by using SBA-15 and then oxidized by nitric acid. The zinc oxide was loaded to the modified CMK-3 by the equilibrium adsorption of Zn(II) ions from aqueous solution followed by calcination to convert zinc nitrate to zinc oxide. The CMK-3 had porous structure and high specific surface area which can accommodate zinc oxide in a spreading manner, the zinc oxide connects to the carbon surface via oxygen atoms. The controllable factors such as agitation time, initial concentration, temperature, dose and pH of solution have been optimized. Under optimum conditions, the pollutant removal efficiency (PRE) was 97.25% for Pb(II) and 99% for Hg(II). The percentage contribution of each controllable factor was also determined. The initial concentration of pollutant is the most influential factor, and its value of percentage contribution is up to 31% and 43% for Pb and Hg, respectively. Our results show that the Zn-OCMK-3 is an effective nanoadsorbent for lead and mercury pollution remediation. Langmuir and Freundlich adsorption isotherms were used to model the equilibrium adsorption data for Pb(II) and Hg(II)