The removal of toxic metals from wastewaters by biosorption, based on the metal-binding capacities of various biological materials,
has received much interest. However, the success of this approach depends on economic feasibility, which can be obtained by
optimization of the environmental conditions. This paper evaluates, for the first time, the use of low-cost biosorbent (date
stones (DS) and palm-tree waste (PTW)) to eliminate Cu(II) from aqueous solutions. The effect of some parameters on copper
biosorption has been studied using date stones and palm-tree waste as solid sorbents. Results show that the highest percentage
of copper adsorption was obtained for the smallest size of the sorbent particles. The biosorption process was found to occur
rapidly, i.e. the maximum sorption capacity was reached within 20 min. The process involved pseudo-second-order kinetics with
an activation energy value within the normal range considered for processes, where a physical interaction between the sorbate
and the sorbent solid predominated. The thermodynamic parameters of the copper ions uptake onto the solid sorbents indicated
that, the process was endothermic and proceeds spontaneously from the date stones. However, the thermodynamic studies of the
adsorption of copper on palm-tree waste indicated that the process was exothermic and proceeds spontaneously. 相似文献
Environmental Geochemistry and Health - This study describes spatiotemporal patterns from October 2015 to September 2016 for PM2.5 mass and carbon measurements in rural (Kosmarra), urban (Raipur),... 相似文献
Environmental Science and Pollution Research - Human papillomavirus (HPV) is a well-known sexually transmitted disorder globally. Human papillomavirus (HPV) is the 3rd most common cancer that... 相似文献
In this study, nano-sized cellulose modified with lactic acid (MW-Ce-LA) was prepared with the assistant of microwave then used for the adsorption of Cu2+ from real samples. This modified cellulose was characterized by means of FTIR, TEM, XRD, and elemental analysis. ICP-OES was used for determination of Cu2+. The effect of pH, adsorption times, temperature, sorbent dose, and initial adsorbate concentration were studied to detect the ideal adsorption condition. Langmuir model proved to be the best to fit the adsorption isotherm experiments with maximum adsorption capacity of 90.3 mg g?1 Cu2+. Calculated thermodynamic parameters (ΔG° and ΔH°) for adsorption of Cu2+ on MW-Ce-LA suggested exothermic and nonspontaneous character of the adsorption process. The reusability tests indicated regeneration of the prepared adsorbent simply using 1 mol L?1 of HCl. The examined method was used effectively to preconcentrate Cu2+ from water, blood, and food samples.
Environmental Science and Pollution Research - This study examines the association between air pollution and economic growth based on the idea of environment Kuznets curve (EKC) hypothesis which... 相似文献
Decamethylcyclopentasiloxane (D5) is a cyclic volatile methyl siloxane (cVMS) commonly found in commercially available products. D5 is expected to enter the terrestrial environment through the deposit of biosolids from sewage treatment plants onto agricultural fields for nutrient enrichment. Little to no information currently exists as to the risks of D5 to the terrestrial environment. In order to evaluate the potential risk to terrestrial organisms, the toxicity of a D5 contaminated biosolid in an agricultural soil was assessed with a battery of standardized soil toxicity tests.D5 was spiked into a surrogate biosolid and then mixed with a sandy loam soil to create test concentrations ranging from 0 to 4074 mg kg−1. Plant (Hordeum vulgare (barley) and Trifolium pratense (red clover)) and soil invertebrates (Eisenia andrei (earthworm) and Folsomia candida (springtail)) toxicity tests were completed to assess for lethal and sub-lethal effects. Plant testing evaluated the effects on seedling emergence, shoot and root length, and shoot and root dry mass. Invertebrate test endpoints included adult lethality, juvenile production, and individual juvenile dry mass (earthworms only). Soil samples were collected over time to confirm test concentrations and evaluate the loss of chemical over the duration of a test. The toxicity of the D5 was species and endpoint dependent, such that no significant adverse effects were observed for T. pratense or E. andrei test endpoints, however, toxicity was observed for H. vulgare plant growth and F. candida survival and reproduction. Chemical losses of up to 50% were observed throughout the tests, most significantly at high concentrations. 相似文献
The characteristics of municipal solid waste (MSW) play a key role in many aspects of waste disposal facilities and landfills. Because most of a landfill is made up of MSW, the overall stability of the landfill slopes are governed by the strength parameters and physical properties of the MSW. These parameters are also important in interactions involving the waste body and the landfill structures: cover liner, leachate and gas collection systems. On the other hand, the composition of the waste, which affects the geotechnical behavior of the MSW, is dependent on a variety of factors such as climate, disposal technology, the culture and habits of the local community. It is therefore essential that the design and stability evaluations of landfills in each region be performed based on the local conditions and the geotechnical characteristic of the MSW. The Bandeirantes Landfill, BL, in São Paulo and the Metropolitan Center Landfill, MCL, in Salvador, are among the biggest landfills in Brazil. These two disposal facilities have been used for the development of research involving waste mechanics in recent years. Considerable work has been made in the laboratory and in the field to evaluate parameters such as water and organic contents, composition, permeability, and shear strength. This paper shows and analyzes the results of tests performed on these two landfills. The authors believe that these results could be a good reference for certain aspects and geotechnical properties of MSW materials in countries with similar conditions. 相似文献
Selected toxic metals (Zn, Pb, Cu, Cr, Co, Cd, Ni and Mn) were determined by atomic absorption spectrophotometry in 55 samples of bronchial washouts obtained from patients with respiratory ailments. These subjects either worked or lived in industrial locations which have mineral-based industries such as steel plants, thermal power plants, cement plants, limestone mines and iron ore mines. Half of the samples analysed were from the plant workers and the other half from the non-workers living in the respective industrial areas. Samples from subjects living outside the industrial areas were also collected and analysed. The highest occurrence of toxic metals was found in the subjects living in the steel plant area. The occurrence was of the order: steel plant > thermal power plant > cement plant > iron ore mines > limestone mines > non industrial areas. Plant workers showed a higher presence of metals in their respiratory tracts compared to the non-workers in each industrial area. Higher depositions were noticed in areas of coal-fired industries compared to non-coal-fired industries. Zn, Cu and Pb were more likely to reach the respiratory tracts. The occurrences were found to increase with the age of the subjects. A slightly higher susceptibility to bronchial contamination was noticed in females.To whom correspondence should be addressed. 相似文献
Environmental Science and Pollution Research - Heavy metals are a heterogeneous group of metals that can cause detrimental biological disruptions in vultures. Heavy metals play a threatening role... 相似文献
Plants coupled with endophytic bacteria hold great potential for the remediation of polluted environment. The colonization patterns and activity of inoculated endophytes in rhizosphere and endosphere of host plant are among the primary factors that may influence the phytoremediation process. However, these colonization patterns and metabolic activity of the inoculated endophytes are in turn controlled by none other than the host plant itself. The present study aims to determine such an interaction specifically for plant-endophyte systems remediating crude oil-contaminated soil. A consortium (AP) of two oil-degrading endophytic bacteria (Acinetobacter sp. strain BRSI56 and Pseudomonas aeruginosa strain BRRI54) was inoculated to two grasses, Brachiaria mutica and Leptochloa fusca, vegetated in crude oil-contaminated soil. Colonization patterns and metabolic activity of the endophytes were monitored in the rhizosphere and endosphere of the plants. Bacterial augmentation enhanced plant growth and crude oil degradation. Maximum crude oil degradation (78 %) was achieved with B. mutica plants inoculated with AP consortium. This degradation was significantly higher than those treatments, where plants and bacteria were used individually or L. fusca and endophytes were used in combination. Moreover, colonization and metabolic activity of the endophytes were higher in the rhizosphere and endosphere of B. mutica than L. fusca. The plant species affected not only colonization pattern and biofilm formation of the inoculated bacteria in the rhizosphere and endosphere of the host plant but also affected the expression of alkane hydroxylase gene, alkB. Hence, the investigation revealed that plant species can affect colonization patterns and metabolic activity of inoculated endophytic bacteria and ultimately the phytoremediation process. 相似文献