scholarly journals Photocatalytic Heavy Metal Detoxification from Water Systems

Author(s):  
P.S. Kumar

Heavy metals are one of the greatest elevating threat to mankind and other living organisms and it is released into the environment due to increasing dumpsites, transports, and industrial sectors. The industrial wastewater containing heavy metal ions easily enters into the food chain through the air, water, and soil; it results in bioaccumulation and biomagnifications of metal ions in human beings. It causes severe chronic health disorders affecting the nervous system, circulatory system, digestive system and other sensitive organs of the human body. Many conventional techniques such as adsorption, coagulation, flocculation, electrochemical treatment, and biological treatment are used for the reduction of heavy metal ions in the aqueous system. The photocatalysis method is one of the emerging effective ways for eliminating the toxic metal ions from the aqueous solution. This chapter elaborates the principle, mechanism and various methods utilized in the photocatalytic reduction of heavy metal ions from the wastewater.

2017 ◽  
Vol 14 (1) ◽  
pp. 15
Author(s):  
M.B. Nicodemus Ujih ◽  
Mohammad Isa Mohamadin ◽  
Milla-Armila Asli ◽  
Bebe Norlita Mohammed

Heavy metal ions contamination has become more serious which is caused by the releasing of toxic water from industrial area and landfill that are very harmful to all living organism especially human and can even cause death if contaminated in small amount of heavy metal concentration. Currently, peoples are using classic method namely electrochemical treatment, chemical oxidation/reduction, chemical precipitation and reverse osmosis to eliminate the metal ions from toxic water. Unfortunately, these methods are costly and not environmentally friendly as compared to bioadsorption method, where agricultural waste is used as biosorbent to remove heavy metals. Two types of agricultural waste used in this research namely oil palm mesocarp fiber (Elaesis guineensis sp.) (OPMF) and mangrove bark (Rhizophora apiculate sp.) (MB) biomass. Through chemical treatment, the removal efficiency was found to improve. The removal efficiency is examined based on four specification namely dosage, of biosorbent to adsorb four types of metals ion explicitly nickel, lead, copper, and chromium. The research has found that the removal efficiency of MB was lower than OPMF; whereas, the multiple metals ions removal efficiency decreased in the order of Pb2+ > Cu2+ > Ni2+ > Cr2+.


2021 ◽  
Vol 904 (1) ◽  
pp. 012009
Author(s):  
A W Abd Byty ◽  
M A Gharbi ◽  
A H Assaf

Abstract Toxic metal pollutants in groundwater should be identified to prevent future health risks. In this paper, the presence of heavy metals in groundwater in the western region of Iraq was investigated. The heavy metals concentrations, including Ni2+, Co2+, Zn2+, Pb2+, Cr3+, Cd2+, As3+ and Hg2+ were explored in twenty selected aquifers near Rutba City and the results were presented as spatial distribution maps. Findings indicate that contamination with the investigated heavy metal ions possesses a serious threat to the study area’s groundwater quality when compared to WHO and IEPA guideline values. Thus, a new approach to remove or adsorb heavy metal ions can be developed for large-scale production and the safe use of these aquifers water. Results revealed that the highest concentrations in mg/L1 of 2.312 in w19, 1.098 in w2, 5.78 in w17, 0.292 in w9, 3.349 in w5, 0.32 in w13, 0.074 in w11 and 5.622 in w1 for Zn2+, Cr3+, As3+, Pb2+, Ni2+, Co2+, Cd2+ and Hg2+ were recorded, respectively.


2016 ◽  
Vol 52 (13) ◽  
pp. 2831-2834 ◽  
Author(s):  
Anindita Chakraborty ◽  
Sohini Bhattacharyya ◽  
Arpan Hazra ◽  
Ashta Chandra Ghosh ◽  
Tapas Kumar Maji

An anionic MOF shows the potential to capture toxic metal ions from water and the CuII@AMOF hybrid obtained through post-synthetic metalation is used as a Lewis acid catalyst.


Author(s):  

Water factor plays an important role in formation of healthy environment for human beings. Due to unfavorable anthropogenic impact upon environment certain surface and groundwater water supply sources are contaminated with heavy metal compounds. Clints (siliceous rocks) are considered the most promising materials for the natural and waste waters treatment from such ingredients. The paper presents the results of the siliceous rocks’ physical/chemical and operational properties studying. It has been shown that these siliceous rocks satisfy all requirements to filtering materials. Methods of physical/chemical analysis were applied for studying the adsorption processes nature. It was for the first time stated (with methods of potentiometric titration and infra-red spectroscopy) that siliceous rocks included the fixed functional ion-exchange groups in their composition and were subacid cationits. Beside chemical adsorption heavy metal ions interact with siliceous rocks due to the action of their physical nature forces. Physical adsorption contributes the most in the heavy metal compounds up-taking by filtering materials, this is supported by the fact of low values of the process activation energy: from 3 to 8 kJ/gram-molecule. Parameters of the process of heavy metal ions adsorption with siliceous rocks in static and dynamic conditions have been calculated in accordance with the experimental results. Influence of salt content and the liquid phase pH value on the adsorption process has been stated. Optimal conditions for the worked siliceous rocks regeneration have been determined. New data on heavy metals cations adsorption with nuclear filtering materials confirm principal possibility of their use for natural and waste waters treatment.


2017 ◽  
Vol 64 (5) ◽  
pp. 493-502 ◽  
Author(s):  
Thien-Khanh Tran ◽  
Hoang-Jyh Leu ◽  
Kuo-Feng Chiu ◽  
Chiu-Yue Lin

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Pragnesh N. Dave ◽  
Lakhan V. Chopda

In the 21st century water polluted by heavy metal is one of the environment problems. Various methods for removal of the heavy metal ions from the water have extensively been studied. Application of iron oxide nanaparticles based nanomaterials for removal of heavy metals is well-known adsorbents for remediation of water. Due to its important physiochemical property, inexpensive method and easy regeneration in the presence of external magnetic field make them more attractive toward water purification. Surface modification strategy of iron oxide nanoparticles is also used for the remediation of water increases the efficiency of iron oxide for the removal of the heavy metal ions from the aqueous system.


2021 ◽  
Vol 25 (Special) ◽  
pp. 3-88-3-96
Author(s):  
Hibatallah J. Shamkhi ◽  
◽  
Tamara K. Hussein ◽  

Pollution with heavy metal ions lead, zinc and nickel resulting from industrial wastewater for various industries such as electroplating industry, batteries, metal refining mines and other factories which discharge into the environment causing damage and pollution to the environment, living organisms, and the majority of heavy metals carcinogenic due to its high toxicity and its containment of dangerous chemicals. Potential danger to human health in all forms by ingestion, inhalation, or skin contact pose by heavy metals ions such as lead, nickel, zinc, and others. To prevent hazards, they must be removed before disposal by different methods such as ion- exchange, chemical separation, filtration, membrane separation, and adsorption. The purpose of this research is to review different low cost adsorbent materials to remove heavy metal ions lead, zinc and nickel from wastewater.


Author(s):  
Chen Zhao ◽  
Guowei Zhong ◽  
Da-Eun Kim ◽  
Jinxia Liu ◽  
Xinyu Liu

Heavy metal ions released into various water environments have severe impact on both human beings and aqueous environments, and excess amount of lead and aluminum ions pose high risks to human health and could cause life-threatened diseases. The existence of metal ions in drinking water contributes most to the daily intake by humans, and thus it urges to develop a rapid, low-cost and sensitive method for detection of heavy metal ions. In this research, we develop a portable analytical system for metal ion detection in water by combining a powerful gold nanoparticle (AuNP) based colorimetric method with lab-on-a-chip technology. We utilize single-step assays involving surface functionalized AuNPs for colorimetric detection of lead (Pb2+) and aluminum (Al3+) ions in water with low limit of detection (LOD) and high sensitivity. We demonstrate that this portable system provides LODs of 30 ppb for Pb2+ and 89 ppb for Al3+, both comparable to bench-top analytical spectrometers. The system permits metal ion detections in a more economical and convenient fashion, and is particularly useful for water quality monitoring in remote and/or resource-poor settings.


Author(s):  
Jin Li ◽  
Shitao Wang ◽  
Xiaohua Cao ◽  
Huanan Huang ◽  
Dapeng Cao

As one of the most toxic heavy metals to human beings and the environment, how to simultaneously achieve the fluorescent detection and removal of mercury in the wastewater is still...


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