scholarly journals Evaluation of Aerogel Spheres Derived from Salix psammophila in Removal of Heavy Metal Ions in Aqueous Solution

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 61
Author(s):  
Yuan Zhong ◽  
Yuhong An ◽  
Kebing Wang ◽  
Wanqi Zhang ◽  
Zichu Hu ◽  
...  

Heavy metal wastewater treatment is a huge problem facing human beings, and the application degree of Salix psammophila resources produced by flat stubble is low. Therefore, it is very important to develop high-value products of Salix psammophila resources and apply them in the removal heavy metal from effluent. In this work, we extracted the cellulose from Salix psammophila, and cellulose nanofibers (CNFs) were prepared through TEMPO oxidation/ultrasound. The aerogel spheres derived from Salix psammophila (ASSP) were prepared with the hanging drop method. The experimental results showed that the Cu(II) adsorption capacity of the ASSP composite (267.64 mg/g) doped with TOCNF was significantly higher than that of pure cellulose aerogel spheres (52.75 mg/g). The presence of carboxyl and hydroxyl groups in ASSP enhanced the adsorption capacity of heavy metals. ASSP is an excellent heavy metal adsorbent, and its maximum adsorption values for Cu(II), Mn(II), and Zn(II) were found to be 272.69, 253.25, and 143.00 mg/g, respectively. The abandoned sand shrub resource of SP was used to adsorb heavy metals from effluent, which provides an important reference value for the development of forestry in this sandy area and will have a great application potential in the fields of the adsorption of heavy metals in soil and antibiotics in water.

Author(s):  
Agustina Onyebuchi Ijeomah ◽  
Rebecca Ngoholve Vesuwe ◽  
Bitrus Pam

Vegetables growing in mining areas have become a serious food safety concern because of the high levels of heavy metals always associated with mining. In this study, water used for irrigation, soil, cabbage, green pepper and green beans grown in tin mine areas of Heipang District, Barkin-Ladi LGA of Plateau State were analyzed for lead, cadmium and zinc, using Atomic Absorption Spectrophotometer (AAS). The concentrations of the heavy metals in water, soil, vegetables were all in the order Pb, >> Cd > Zn. In the vegetables, the order was: Pb → cabbage > green beans > green pepper; Cd → green beans > cabbage > green pepper; Zn → cabbage > green pepper = green beans. The transfer factors for all the metals (heavy metal in plant / heavy metal in soil) ranged from 0.95 to 1.48. There were high levels of Pb and Cd in all the vegetables, which may be attributed to the metals in the water used for irrigation. Whilst the concentration of Zn in all the samples were lower than recommended limits, the levels of Pb and Cd in the water, soil and vegetables were higher than the WHO/FEPA standard recommended limits reported for vegetables. The Cd concentrations of the vegetables also exceeded the tolerance thresholds for animals and human beings and therefore consumption of vegetable from the area would endanger the health of the population.


2011 ◽  
Vol 138-139 ◽  
pp. 1149-1155 ◽  
Author(s):  
Yi Dong Guan ◽  
Ye Hong Du ◽  
Zhen Dong Li ◽  
An Cheng Luo

This paper reports the concentration of heavy metals (Cr, Cu, Zn, Cd and Pb) in the soils and rices surrounding the abandoned rural waste dumping sites in Ningbo. Igeo (geoaccumulation index) was calculated to assess the contamination degree of heavy metals in soils. The mean contents of Cr, Cu, Cd, Zn and Pb of soils were 33.3, 24.1, 1.5, 118.9 and 45.6 mg/(kg DW) (dry weight), respectively. All of them were much higher than that of the reference value (i.e. CK), but there were no coherent trend of the metal contents within 1-120m distance from the dumping site. Igeo of heavy metals reveals the order of Cd>Cu>Cr>Pb>Zn, and the contamination assessment of soils using Igeo indicate the moderate Cd pollution, while the soils were unpolluted-moderately overall by Cr, Cu, Zn as well as Pb. The heavy metal contents in root, stem & leaf and rice grains were all remarkable higher than that of the CK at 20-120 m distances, and the heavy metal contents in root were evidently much higher than other plant parts, while those in rice grain were lowest, indicating the great bioaccumulation trend of heavy metals. Although the metal contents in the rice grain were within the legislation limit, its bioaccumulation trend of heavy metals was remarkable, whose contents were 4.38-fold for Cr, 1.76-fold for Cu, 1.28-fold for Zn, 2.67-fold for Cd and 3.03-fold for Pb higher than that of reference value, respectively. Finally, we proposed a decentralized in-situ restoration approach for the dumping sites.


2020 ◽  
Vol 1010 ◽  
pp. 489-494
Author(s):  
Abdul Hafidz Yusoff ◽  
Rosmawani Mohammad ◽  
Mardawani Mohamad ◽  
Ahmad Ziad Sulaiman ◽  
Nurul Akmar Che Zaudin ◽  
...  

Conventional methods to remove heavy metals from polluted water are expensive and not environmentally friendly. Therefore, this study was carried out to investigate the potential of agricultural waste such as pineapple peel (Ananas Cosmos) as low-cost absorbent to remove heavy metals from synthetic polluted water. The results showed that Cd, Cr and Pb were effectively removed by the biosorbent at 12g of pineapple peels in 100 mL solution. The optimum contact time for maximum adsorption was found to be 90 minutes, while the optimum pH for the heavy metal’s adsorption was 9. It was demonstrated that with the increase of adsorbent dosage, the percent of heavy metals removal was also increased due to the increasing adsorption capacity of the adsorbent. In addition, Langmuir model show maximum adsorption capacity of Cd is 1.91 mg/g. As conclusions, our findings show that pineapple peel has potential to remove heavy metal from polluted water.


2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Upoma Mahmud ◽  
Md. Tareq Bin Salam ◽  
Abu Shamim Khan ◽  
Md. Mizanur Rahman

AbstractHigher accumulation of heavy metals in food grains is one of the leading problems for carcinogenic effects in the body. That’s why; scientists have taken this problem as a potential indicator for ensuring safe food. The present study was carried out to assess the ecological risk of heavy metals such as nickel, copper, arsenic, lead, and manganese in agricultural soil and transfer status to rice grain. Soil samples were collected from four agricultural fields at different times in the Dumuria Upazila under Khulna district in Bangladesh. Heavy metal concentration in soil extracts, irrigation water samples, and grain samples was determined by Atomic Absorption Spectrometer. Average metal concentrations in soil were calculated and compared with the reference value in soil. In most cases, heavy metals in agricultural soil (Ni: 61.73–94.52 mg/kg; Cu: 23.33–37.5 mg/kg; As: 7.53–19.63 mg/kg; Pb: 15.17–29.19 mg/kg; Mn: 322.98–478.45 mg/kg) were greater than the reference soil (Ni: 13.08–24.55 mg/kg; Cu: 10.35–13.28 mg/kg; As: 1.87–4.61 mg/kg; Pb: 4.88–8.27 mg/kg; Mn: 52.17–74.3 mg/kg). Overall risk index stated that the examined soils were at moderate risk of contamination. Transfer Factor of arsenic (0.018–0.032 mg/kg) and manganese (0.059–0.155 mg/kg) was higher from soil to rice grain. On the other hand, transfer factor of lead was found negligible that is a good sign of improvement. The findings of the study will be good documentation for planning, risk assessment, and decision-making by environmental managers in this region.


2017 ◽  
Vol 75 (10) ◽  
pp. 2443-2453 ◽  
Author(s):  
Henry H. Mungondori ◽  
Sandile Mtetwa ◽  
Lilian Tichagwa ◽  
David M. Katwire ◽  
Pardon Nyamukamba

The adsorption of a multi-component system of ferrous, chromium, copper, nickel and lead on single, binary and ternary composites was studied. The aim of the study was to investigate whether a ternary composite of clay, peanut husks (PH) and saw-dust (SD) exhibited a higher adsorption capacity than that of a binary system of clay and SD as well as a single component adsorbent of PH alone. The materials were used in their raw state without any chemical modifications. This was done to retain the cost effective aspect of the naturally occurring adsorbents. The adsorption capacities of the ternary composite for the heavy metals Fe2+, Cr3+, Cu2+, Ni2+ and Pb2+ were 41.7 mg/g, 40.0 mg/g, 25.5 mg/g, 41.5 mg/g and 39.0 mg/g, respectively. It was found that the ternary composite exhibited excellent and enhanced adsorption capacity compared with both a binary and single adsorbent for the heavy metals Fe2+, Ni2+ and Cr3+. Characterization of the ternary composites was done using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Kinetic models and adsorption isotherms were also studied. The pseudo second order kinetic model and the Langmuir adsorption isotherm best described the adsorption mechanisms for the ternary composite towards each of the heavy metal ions.


2018 ◽  
Vol 68 (12) ◽  
pp. 2804-2807
Author(s):  
Mircea Stefan ◽  
Adriana Bors ◽  
Daniela Simina Stefan ◽  
Ionut Alexandru Savu Radu ◽  
Cicerone Marinescu

Sorption of heavy metals on Na-montmorillonite was studied as a function of solution pH and different concentrations of background electrolyte and also a function of added metal ion at constant pH. Equilibrium isotherms have been measured and analyzed using a Langmuir isotherm model. The metal ions were predominantly adsorbed on the permanent charge sites in a easily replaceable state. There was also evident a substantial involvement of the hydroxyl groups on the edges of Na-montmorillonite in specific adsorption of the cations especially at higher pH.


Investigate the possibility of treating wastewater containing heavy metals Zn2+ with activated carbon material prepared from macadamia shell with chemical activating agent H3PO4, showing high efficiency of adsorption of Zn2+. The results of the study showed that activated carbon with H3PO4 activating agent has high adsorption capacity, capable of handling Zn2+ best at pH = 4.5, dosage 1.8 g/L and time is 120 minutes. . The results show similarities with other research results and are capable of treating wastewater containing heavy metals Zn2+.


2019 ◽  
Vol 9 (24) ◽  
pp. 191203 ◽  
Author(s):  
Meena Kapahi ◽  
Sarita Sachdeva

Background. Rapid industrialization and anthropogenic activities such as the unmanaged use of agro-chemicals, fossil fuel burning and dumping of sewage sludge have caused soils and waterways to be severely contaminated with heavy metals. Heavy metals are non-biodegradable and persist in the environment. Hence, remediation is required to avoid heavy metal leaching or mobilization into environmental segments and to facilitate their extraction. Objectives. The present work briefly outlines the environmental occurrence of heavy metals and strategies for using microorganisms for bioremediation processes as reported in the scientific literature. Methods. Databases were searched from different libraries, including Google Scholar, Medline and Scopus. Observations across studies were then compared with the standards for discharge of environmental pollutants. Discussion. Bioremediation employs microorganisms for removing heavy metals. Microorganisms have adopted different mechanisms for bioremediation. These mechanisms are unique in their specific requirements, advantages, and disadvantages, the success of which depends chiefly upon the kind of organisms and the contaminants involved in the process. Conclusions. Heavy metal pollution creates environmental stress for human beings, plants, animals and other organisms. A complete understanding of the process and various alternatives for remediation at different steps is needed to ensure effective and economic processes. Competing interests. The authors declare no competing financial interests.


2020 ◽  
Vol 175 ◽  
pp. 09009
Author(s):  
Tatiana Bauer ◽  
Tatiana Minkina ◽  
Saglara Mandzhieva ◽  
Marina Burachevskaya ◽  
Maria Zharkova

Sorption of heavy metals on solid matrices such as soils is one of the key processes which determine the fate of contaminants in the environment. Knowledge of adsorption behavior of heavy metals using biochar is essential for their application in soil remediation. Using the adsorption method, the possibility of using a wood biochar to detoxify Fluvisols contaminated with heavy metals (for example, copper) was studied. It is shown that the addition of biochar increases the metal adsorption capacity of soil. The results were analysed using the Langmuir and Freindlich isotherm equations. It was concluded that biocar can be applied to immobilize heavy metals in contaminated soils.


2012 ◽  
Vol 549 ◽  
pp. 703-706
Author(s):  
De Yi Zhang ◽  
Jing Wu ◽  
Bai Yi Chen ◽  
He Ming Luo ◽  
Kun Jie Wang ◽  
...  

In this paper, a novel carbon/bentonite composite was prepared using sucrose as carbon source and bentonite as raw material. The characterization results shown that plenty of carbon particles distribute on the surface of the composite, and an abundant of functional groups, such as SO3H, carboxylic and hydroxyl groups, were successfully introduced onto the surface of the prepared composite. The adsorption capacity of the prepared composite for typical heavy metal ions and methylene blue deys also was investigated and compared with activated carbon and bentonite, the results show that the composite shows excellent adsorprion performance for heavy metal ions, and the adsorption capacity for Cu2+and Ni2+ increase by 136% and 591% than natural bentonite, respectSuperscript textively. The prepared composite with excellent adsorption performance could be used as a low-cost alternative to activated carbon for the treatment of heavy metal ions polluted wastewater.


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