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Studies on removal of Zinc and Chromium from aqueous solutions using water Hyacinth 全文
2015
Swarnalatha, K. | Radhakrishnan, Bindhu
Phytoremediation is an eco-friendly method for removal of pollutants, which can be relied upon as a sustainable technology, if implemented under optimum conditions of plant growth. The effectiveness of water hyacinth, a topical weed, for the removal of Zinc (Zn) and Chromium (Cr) ions from aqueous solutions has been presented in this article. The potential of this plant in removing metals by phytoremediation was explored under various environmental factors such as pH, salinity, metal concentrations, available nutrients, and so on. The efficiency of metal removal was observed by varying the different parameters. It was found that the maximum removal of metals occurred at a neutral pH, low amount of salinity, lower metal ion concentrations, and lack of nutrients. The stress induced in a plant by metal absorption was visible from the health and growth pattern of the plants. The stress on water hyacinth due to metals was also assessed, by observing the changes in its chlorophyll and protein content.
显示更多 [+] 显示较少 [-]Comparison of the environmental indicators of phosphorus efficiency and the balance between saffron and wheat production systems in the Qaenat region, Iran 全文
2015
Yaeghoubi, Fatemeh | Jami Al-Ahmadi, Majid | Bakhshi, Mohammad Reza | Sayyari-Zahan, Mohammad Hassan
Improving the resource use efficiency in agro- ecosystems is an importantfactor for reducing environmental pollution. To evaluate phosphorus (P) efficiency andbalance indicators, research was conducted in wheat and saffron production systems inthe Qaenat region (South Khorasan Province, Iran) during 2011 and 2012, based on themethod of the Organization for Economic Co-operation and Development (OECD). Therequired information about wheat and saffron cultivation was collected via questionnairesand the required coefficients were obtained from various literatures. The results showedthat the phosphorus efficiency and balance indicators were significantly different betweendistinct districts only in the case of wheat crops. The highest P efficiencies of wheat andsaffron farms were 7.21% and 2.93%, respectively. Additionally, P efficiency andbalance indicators showed a significant difference between both crops in some districts,so that wheat had higher P efficiency than saffron, which was mainly because of thedifferent amounts of animal manure applied to these crops. There was no significantdifference between the different ages of saffron farms for P efficiency and balance.Furthermore, there was a significant negative correlation between P efficiency andbalance indicators. It would appear that there are many opportunities for improving theefficiency of P and to prevent environmental pollution through the optimization ofmanagement decisions.
显示更多 [+] 显示较少 [-]Spatial–Temporal Monitoring of Ecotonal Belt Using Landscape Ecological Indices in the Central Elburz Region: Remote Sensing and GIS Analysis 全文
2015
Yavari, Ahmad Reza | Jafari, Hamid Reza | Hashemi, Seyyed Mahmood
Iran has mountainous landscapes and half of its surface is occupied by highlands. Moreover, Iran is an arid country and deserts are located at lower altitudes. Most metropolitan areas are positioned in mid-altitudes between mountain and desert. Cities grow upwardly toward the highlands under pressures of urbanization and desertification. Foothill ecotones are a zone between upland mountains and midland plains. Upwardly sprawl of urban centers has transformed the structures and functions of these ecologically strategic belts. In this article, we analyzed the transformational trend of the ecotonal zone in the southern slopes of the central Elburz (Tehran-Karaj urban region). Landsat 7 ETM+ (2000) and 8 OLI (2013) are used to monitor spatial and temporal variability of landscape metrics. The land covers are grouped into four classes: vegetation cover, open space, built area, and water body. Seven landscape metrics are used including: NP, CAP, MPS, AW-MPS, MNND, PARA, and TE. Our results indicate that NP, AW-MPS, TE, and PARA increased whereas CAP and MPS decreased. These results are a sign of the fragmentation process across the ecotonal strip.
显示更多 [+] 显示较少 [-]Speciation of four heavy metals in agricultural soils around DraaLasfarmine area in Marrakech (Morocco) 全文
2015
Yassir, Barkouch | Alain, Pineau
This study was carried out to 1. determine spatial variations of heavy metal deposition in agricultural soils of two rural communities (OuledBouAicha and Tazakourte) of about 5790 ha in a mining area near Marrakech city in Morocco; 2. to assess the extent of metallic pollution generated by the mining activity and; 3. to identify the key mechanism responsible for this contamination and its relation to mining activity. Soil pollution assessment was carried out on one hand by measurement of the total metal concentration and on the other hand by studying four heavy metals speciation of the studied soils. The chemical forms of four heavy metals in soils around DraaLasfar mine were studied by determining soil Cd, Cu, Pb and Zn species using standard solvent extraction and Atomic Absorption Spectrophotometric techniques. The chemical pools of the metals indicated that the metals were distributed into six fractions with most of them residing in the non-residual fractions thus suggesting how readily the metals are released into the environment. Considering that the metals occur in the most available forms, we suggested that it is most likely that the metals must have been derived from anthropogenic sources especially from the mining activity in the studied region.
显示更多 [+] 显示较少 [-]Isolation and molecular characterization of bacteria to heavy metals isolated from soil samples in Bokaro Coal Mines, India 全文
2015
Gandhi, Vikram | Priya, Anshu | Priya, Suman | Daiya, Vivek | Kesari, Jitendra | Prakash, Krishna | Kumar Jha, Amrit | Kumar, Kundan | Kumar, Nitish
In recent years, environmental pollution by coal mining is a long-established human activity affecting all levels of life with various environmental impacts by generating heavy metals. The presence of heavy metals even in trace amount is toxic and detrimental to all living organisms. The coal mine area in Bokaro is one of the “Toxic Hotspot” in India. Bacteria have evolved uptake and efflux mechanisms to adapt in heavy metals contaminated environments and thus represent a potential source for bioremediation processes. In the present study, we isolated and characterized eight heavy metal resistant bacteria (NK-1 to 8) from soil sample in Bokaro coal mines, India. Isolates were selected based on high level of heavy metal resistance and its biochemical characterization. The following bacteria were identified based on 16S rRNA gene sequencing Enterobacter ludwigii (KM029957; NK-1), Klebsiella pneumonia (KM029958; NK-2), Enterobacter ludwigii (KM029959; NK-3), Enterobacter ludwigii (KM029960; NK-4), Klebsiella oxytoca (KM029961; NK-5), Enterobacter cloacae (KM029962; NK-6), Acinetobacter gyllenbergii (KM029963; NK-7), Enterobacter cloacae (KM029964; NK-8). A high degree of metal resistance associated with multiple antibiotic resistances was also detected in the selected isolate which was confirmed by the presence of plasmid. These isolates can further be used for bioremediation of heavy metals from contaminated site.
显示更多 [+] 显示较少 [-]Effect of a thermal power plant waste fly ash on leguminous and non-leguminous leafy vegetables in extracting maximum benefits from P and K fertilization 全文
2015
Inam, Akhtar | Sahay, Seema
Although the Indian population is largely vegetarian, not much attention has been given to the cultivation of vegetables, as compared to other crops like cereals, pulses and oil seeds. Therefore, the present study was conducted on two leafy vegetables, spinach (Spanacia oleracea L.) and methi (Trigonella foenum graecum L.) commonly grown in Aligarh, as the two popular vegetables of Indian diet. The study was conducted for two successive years and during the first year, phosphorus and fly ash interactions with a uniform dose of nitrogen and potassium on both vegetables was observed. During the second year, while keeping nitrogen and phosphorus uniform, potassium and fly ash combinations were studied again with both vegetables, to determine the optimum dose of inorganic fertilizers and fly ash combination. It was observed that fly ash applied at the rate of 15 t ha-1 along with N40P15K20, proved optimum for spinach while in the case of methi, N20P30K40 + FA10 was sufficient. Therefore, both vegetables can safely be grown with 10 to 15 t ha-1 of fly ash and a comparatively lower quantity of NPK.
显示更多 [+] 显示较少 [-]Radioactivity analysis in underground drinking water sources in Niger State University of Nigeria 全文
2015
Njinga, Raymond | Ibrahim, Viva | Ishoryiyi, Ibiale
The activity concentration of gross alpha and gross beta particles in four samples of borehole drinking water consumed in Ibrahim Badamasi Babangida University (IBBU), Lapai, Niger State-Nigeria was measured, using a portable single channel gas free proportional counter (MPC2000B-DP) detector. This study focused on cancer related problems and the bio-data of the environment was discussed as well as the radiological effect of the water on consumers. Higher concentration of alpha and beta were observed in Hostel block A (DD) with values of 0.085 0.024 and 11.229 0.901 BqL-1, respectively. However, lower concentration of alpha and beta particles were observed in the Faculty of Management Science (AA) with values of 0.006 0.005 and 0.001 0.276 BqL-1, respectively. Out of the four sampling sites studied, only the Faculty of Management Science fall below the guideline levels of gross alpha (0.5 BqL-1) and gross beta (1.0 BqL-1) in drinking water, established by the World Health Organization. These results show that, consumption of groundwater from the other three major borehole sources, may pose significant radiological health hazards to the population.
显示更多 [+] 显示较少 [-]Residual archives on organochlorine insecticides in the core sediment of a tropical estuary, India 全文
2015
P.S., Akhil | H, Sujatha
A comprehensive evaluation of the residual levels of Organochlorine insecticides (OCIs) in the sediment cores of Cochin Estuarine System (CES) is highlighted in this research article. It assessed the distribution pattern and impact of these xenobiotics in this environmental niche. Fifteen persistent organochlorine compounds (OCs) were quantitatively analysed in the six sediment core samples collected from specific sites of CES, during November 2009. Among these contaminants, residual levels of HCH, Cyclodienes and DDT were the dominant entities. According to the sediment quality guidelines (SQGs), the higher concentration of these persistent toxicants found in the CES was enough to pose ecological risk to the bottom dwelling consumers. This study provides a better understanding of these trace organics in the environment and could develop more effective strategies for protecting this vulnerable ecosystem from further pollution. Further, sediment screening bioassays can also be conducted for both sediment quality evaluation and identification of existing potent toxicants.
显示更多 [+] 显示较少 [-]Assessment and control of VOCs emitted from gas stations in Tehran, Iran 全文
2015
Eisaei, Hamid Reza | Ahmadi Dehrashid, Seyed Shaho | Khani, Mohammad Reza | Hashemi, Seyed Mukhtar
In this research, gasoline vapours including Benzene, Toluene, Xylene (BTX) and Total Volatile Organic Compounds (TVOCs) emitted from vent pipes of underground storage tanks (USTs) were measured at six gas stations in Tehran. Thereafter, gas station No. 29 was selected as a pilot station and equipped with a vapour control system. The vapours were measured during the summer of 2013 and winter of 2014 in two states, before and at the time of gasoline discharge from a petrol tanker to the UST. The results reveal that the average of BTX and TVOCs are 161.22, 200.81, 229 and 647.01 ppm, respectively, higher than the World Health Organisation (WHO) guidelines. The average of TVOCs and BTX in the situation in which the control system is inactive at the pilot station, are 259.13, 55.9, 73.03 and 96.88 ppm, respectively. After activating the control system at the pilot station, the VOCs were reduced by 0.01 ppm. Almost 99.99% control was obtained for this system and 87% of the people living around the pilot station were satisfied and no longer had any complaints about the bad odour of VOCs. It can be concluded that gasoline discharge from the petrol tanker to UST, is the main reason behind the overproduction of VOCs in Tehran's gas stations (P<0.001). So, the most important element is to reduce VOCs at Tehran's gas stations by installing a vapour control systems in all the stations and activating the systems at the time of gasoline discharge.
显示更多 [+] 显示较少 [-]Driving patterns as a contributing factor to light-duty vehicular emission in the Kumasi metropolis 全文
2015
Owusu- Boateng, Godfred | Nabena, Francis
Exhaust emissions contribute greatly to air pollution, the social cost of which may occur as danger to human health, attracting huge medical expenses, causing absenteeism and hence loss of productivity. These are incentives to reduce exhaust emissions to the barest minimum. Two major cities in Ghana, Accra and Kumasi, are struck by vehicular traffic jams especially during rush-hours and are grappling with the situation perceived to be worsened by driving pattern, a travel-related characteristic with a tendency to increase vehicular emission and hence, atmospheric pollution. Driving patterns were studied in the Kumasi Metropolis using questionnaires purposively administered to drivers who visited the Driver and Vehicles Licensing Authority. Parameters were analyzed with SPSS. Results indicate that drivers plied highway (90.0%), feeder (6.7%) and urban (3.3%) roads. Drivers (90%) had no knowledge of how driving patterns contribute to emissions, effect of idle and hot emissions and hot-and-cold starts dynamics. This could explain the failure of drivers to allow vehicle engines to stabilize for over 5 min and also to put off engines when stuck in traffic. Drivers changed speed as often as 4 times/km due to vehicle congestion and intermittent traffic lights, intersections and roundabouts. This may explain the difficulty in maintaining constant speed; thereby compelling drivers to exhibit frequent gear-changing behaviours as well as unstable and inconsistent speed profiles, as the commonest driving patterns. Such characteristics potentially increase energy consumption, emission level and abatement cost significantly and therefore, call for intensified educational programmes aimed at curbing this environmental peril.
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