Effect of alkaline treatment of wooden sawdust for the removal of heavy metals from aquatic environments

2019 ◽  
Vol 155 ◽  
pp. 207-215 ◽  
Author(s):  
Stefan Demcak ◽  
Magdalena Balintova ◽  
Maria Demcakova ◽  
Kornel Csach ◽  
Inga Zinicovscaia ◽  
...  
2018 ◽  
Vol 68 (12) ◽  
pp. 2765-2767 ◽  
Author(s):  
Violeta Monica Radu ◽  
Petra Ionescu ◽  
Elena Diacu ◽  
Alexandru Anton Ivanov

The quality of the aquatic environment was strongly influenced by the development of urbanization, industrialization and population growth, and therefore water pollution, mainly due to the presence of heavy metal, becoming a widespread concern. The objective of this work was to evaluate the possibility to remove heavy metals Cd, Zn, Cr and Ni from wastewater using two aquatic plants, water hyacinth (Eichornia crassipes) and water lettuce (Pistia stratiottes). These plants possess excellent abilities to metabolize and bioaccumulate heavy metals from various polluted aquatic environments. For a period of 30 days, the content of heavy metals from wastewater and aquatic plants samples was monitored weakly and the efficacy of these plants to remove heavy metals was quantified. Heavy metals were determined by atomic absorption spectrophotometry with graphite furnace (GFAAS). The obtained results have shown the efficacy of Eichornia crassipes and Pistia stratiottes to remove metals from the studied wastewater. The bioaccumulation rate of heavy metals in plants was effective until day 24 of the period of 30 days of the experiment, as the plants become inefficient beyond this period. The uptake of heavy metals in the studied aquatic plants depends on the concentration of each heavy metal present in the used wastewater and the exposure time.


Author(s):  
Ankita Negi ◽  
Rajesh Kumar ◽  
Sushil Kumar Joshi ◽  
Arpita Negi ◽  
Bhuvnesh Kumar ◽  
...  

The increasing number of efluents discharged from the source of water (urban, industrial, agricultural etc.), is resulting in a higher concentration of heavy metals in the source. Heavy metals have a density of over 5g/cm3 to the metals. These are toxic, mutagenic, carcinogenic and resistant in watery and non-aquatic environments and impact water and non-water bodies seriously by substituting the basic metals of the same function. The extraction from the wastewater can be done in numerous techniques for example using an ion replacement, membrane filtration, osmosis, etc. This study discusses the adverse effects of heavy metals on the human body, the benefits of biosorption over traditional approaches for removal of heavy metals, the different biosorbents used to extract heavy metals and concerning issues regarding its commercial use, offering a wider viewpoint for the diversity of biosorbents and utilization of biosorption technique. It is evident from the profound literature survey that pH, biosorbent particle size, contact time, initial metal ion concentration, presence of chelating ligands etc. are some factors that affect the rate and extent of biosorption. 


2011 ◽  
Vol 2 (3) ◽  
pp. 1-8 ◽  
Author(s):  
Sasmita Sabat ◽  
◽  
R V Kavitha R V Kavitha ◽  
Shantha S L Shantha S L ◽  
Gopika Nair ◽  
...  

2013 ◽  
Vol 12 (3) ◽  
pp. 239-247

The removal of heavy metals from wastewaters is a matter of paramount importance due to the fact that their high toxicity causes major environmental pollution problems. One of the most efficient, applicable and low cost methods for the removal of toxic metals from aqueous solutions is that of their adsorption on an inorganic adsorbent. In order to achieve high efficiency, it is important to understand the influence of the solution parameters on the extent of the adsorption, as well as the kinetics of the adsorption. In the present work, the adsorption of Cu(II) species onto TiO2 surface was studied. It was found that the adsorption is a rapid process and it is not affected by the value of ionic strength. In addition, it was found that by increasing the pH, the adsorbed amount of Cu2+ ions and the value of the adsorption constant increase, whereas the value of the lateral interaction energy decreases.


2020 ◽  
Vol 57 (2) ◽  
pp. 109-114
Author(s):  
Amirhossein Dolatzadeh khiyavi ◽  
Reza Hajimohammadi ◽  
Hossein Amani ◽  
Hadi Soltani

2018 ◽  
Vol 69 (7) ◽  
pp. 1695-1698
Author(s):  
Marin Rusanescu ◽  
Carmen Otilia Rusanescu ◽  
Gheorghe Voicu ◽  
Mihaela Begea

A calcium bentonite from Orasu Nou deposit (Satu Mare Romania) was used as raw material. We have conducted laboratory experiments to determine the influence of bentonite on the degree of heavy metal retention. It has been observed that the rate of retention increases as the heavy metal concentration decreases. Experimental studies have been carried out on metal retention ( Zn) in bentonite. In this paper, we realized laboratory experiments for determining the influence of metal (Zn) on the growth and development of two types of plants (Pelargonium domesticum and Kalanchoe) and the effect of bentonite on the absorption of pollutants. These flowers were planted in unpolluted soil, in heavy metal polluted soil and in heavy metal polluted soil to which bentonite was added to observe the positive effect of bentonite. It has been noticed that the flowers planted in unpolluted soil and polluted with heavy metals to which bentonite has been added, the flowers have flourished, the leaves are still green and the plants whose soils have been polluted with heavy metals began to dry after 6 days, three weeks have yellowish leaves and flowers have dried. Experiments have demonstrated the essential role of bentonite for the removal of heavy metals polluted soil.


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