Zero-wastewater capacitive deionization: selective removal of heavy metal ions in tap water assisted by phosphate ions

2019 ◽  
Vol 6 (11) ◽  
pp. 3225-3231 ◽  
Author(s):  
Xingkang Huang ◽  
Xiaoru Guo ◽  
Qianqian Dong ◽  
Lianjun Liu ◽  
Rebecca Tallon ◽  
...  

Removing trace toxic heavy metals such as Pb2+ completely from drinking water while retaining beneficial ions such as Ca2+ and Mg2+ is important for protecting human health. A novel concept of zero-wastewater CDI is demonstrated to selectively remove lead ions against Ca2+ and Mg2+.

2020 ◽  
Author(s):  
Francis Hamwiinga ◽  
Chisala D. Meki ◽  
Patricia Mubita ◽  
Hikabasa Halwiindi

Abstract Background: One of the factors impeding access to safe water is water pollution. Of particular concern is heavy metal contamination of water bodies. This study was aimed at determining the levels of heavy metals in drinking water sources of Chingola District of Zambia. Methods: A cross sectional study was employed. A total of 60 water samples were collected. Thirsty (30) samples were collected in the dry season in the month of October 2016 and another 30 in the wet season in the months of February and March, 2017. For each season 10 water samples were collected from each of the three water sources. i.e. Tap water, Urban ground water sources and Rural ground water sources. Heavy metal analysis was done using Atomic Absorption Spectrophotometer (AAS).Results: This study revealed that the concentrations of Iron, Manganese, Lead, Nickel and Arsenic were beyond maximum permissible levels in various water sources. Combined averages for both dry and wet seasons were as follows: Iron: 2.3, Copper: 0.63, Cobalt: 0.02, Manganese: 0.36, Lead: 0.04, Zinc:3.2, Nickel: 0.03, Arsenic: 0.05. Chromium and Cadmium were below detection limit in all water samples. The median concentrations of iron, arsenic, copper, manganese in drinking water from the Tap, rural and urban ground water sources were different, and this difference was statistically significant (p<0.05). The median concentrations of arsenic, nickel, manganese and cobalt were different between dry and wet season, and this difference was statistically significant (p<0.05).Conclusions: Sources of heavy metals in water seems to be both natural and from human activities. The concentration of heavy metals in different water sources in this study was found to be above the recommended levels. This calls for improvement in water monitoring to protect the health of the public. Therefore, there is need for continuous monitoring of heavy metals in drinking water sources by regulatory authorities.


2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Hawraz Sami Khalid ◽  
Hoshyar Saadi Ali ◽  
Dhary Almashhadany

The present study was conducted to evaluate the quality of drinking water in randomly selected schools in Erbil city, Kurdistan Region, Iraq. The water quality indices such as the Heavy metal Pollution Index (HPI) and Heavy metal Evaluation Index (HEI) were applied to characterize water quality. Eighteen schools were incorporated and sampled for their water storage tanks available to students. Water samples and sediment samples from tanks floor were analyzed by Inductively Coupled Plasma Optical Emission Spectrometer for the determination of twenty-two metal elements. In drinking water samples, all detected metals did not exceed the permissible limits of the World Health Organization. The results of this study showed that the average values of HPI and HEI for As, Cd, Cr, Cu, Fe, Pb, Mn, Ni, and Zn were 54.442 and 0.221, respectively. According to data of the water quality indices, the schools drinking water quality are good and suitable for drinking in terms of heavy metals. However, sediments samples contained high concentrations of all elements including the toxic heavy metals (As, Cd, Cr, and Pb). Re-suspension of sediments into water column after refilling storage tanks can pose a serious threat to students drinking water from such vessels. It is therefore recommended that proper storage tanks are provided to the schools accompanied by continuous sanitation and hygiene practice to mitigate the corrosion of tanks to avoid health risks of toxic metal


2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Abate Ayele ◽  
Yakob Godebo Godeto

Heavy metals generated mainly through many anthropogenic processes, and some natural processes have been a great environmental challenge and continued to be the concern of many researchers and environmental scientists. This is mainly due to their highest toxicity even at a minimum concentration as they are nonbiodegradable and can persist in the aquatic and terrestrial environments for long periods. Chromium ions, especially hexavalent ions (Cr(VI)) generated through the different industrial process such as tanneries, metallurgical, petroleum, refractory, oil well drilling, electroplating, mining, textile, pulp and paper industries, are among toxic heavy metal ions, which pose toxic effects to human, plants, microorganisms, and aquatic lives. This review work is aimed at biosorption of hexavalent chromium (Cr(VI)) through microbial biomass, mainly bacteria, fungi, and microalgae, factors influencing the biosorption of chromium by microorganisms and the mechanism involved in the remediation process and the functional groups participated in the uptake of toxic Cr(VI) from contaminated environments by biosorbents. The biosorption process is relatively more advantageous over conventional remediation technique as it is rapid, economical, requires minimal preparatory steps, efficient, needs no toxic chemicals, and allows regeneration of biosorbent at the end of the process. Also, the presence of multiple functional groups in microbial cell surfaces and more active binding sites allow easy uptake and binding of a greater number of toxic heavy metal ions from polluted samples. This could be useful in creating new insights into the development and advancement of future technologies for future research on the bioremediation of toxic heavy metals at the industrial scale.


2005 ◽  
Vol 52 (10-11) ◽  
pp. 151-156 ◽  
Author(s):  
J. Mikes ◽  
M. Siglova ◽  
A. Cejkova ◽  
J. Masak ◽  
V. Jirku

Wastewaters from a chemical industry polluted by heavy metal ions represent a hazard for all living organisms. It can mean danger for ecosystems and human health. New methods are sought alternative to traditional chemical and physical processes. Active elimination process of heavy metals ions provided by living cells, their components and extracellular products represents a potential way of separating toxic heavy metals from industrial wastewaters. While the abilities of bacteria to remove metal ions in solution are extensively used, fungi have been recognized as a promising kind of low-cost adsorbents for removal of heavy-metal ions from aqueous waste sources. Yeasts and fungi differ from each other in their constitution and in their abilities to produce variety of extracellular polymeric substances (EPS) with different mechanisms of metal interactions. The accumulation of Cd(2+), Cr(6+), Pb(2+), Ni(2+) and Zn(2+) by yeasts and their EPS was screened at twelve different yeast species in microcultivation system Bioscreen C and in the shaking Erlenmayer's flasks. This results were compared with the production of yeast EPS and the composition of yeast cell walls. The EPS production was measured during the yeast growth and cell wall composition was studied during the cultivations in the shaking flasks. At the end of the process extracellular polymers and their chemical composition were isolated and amount of bound heavy metals was characterized. The variable composition and the amount of the EPS were found at various yeast strains. It was influenced by various compositions of growth medium and also by various concentrations of heavy metals. It is evident, that the amount of bound heavy metals was different. The work reviews the possibilities of usage of various yeast EPS and components of cell walls in the elimination processes of heavy metal ions. Further the structure and properties of yeasts cell wall and EPS were discussed. The finding of mechanisms mentioned above is necessary to identify the functional groups entered in the metals elimination processes.


2012 ◽  
Vol 12 (1) ◽  
pp. 34 ◽  
Author(s):  
Reginawanti Hindersah ◽  
Dedeh Hudaya Arief ◽  
Soetijoso Soemitro ◽  
Lukman Gunarto

The contamination of toxic heavy metal Cadmium (Cd) in soils will be endanger the human health because it ismore available comparing to another toxic heavy metals. One method of Cd-contaminated soil bioremediation isusing exopolysachharide-producing bacteria Azotobacter. Exopolysachharides (EPS) can mobilize Cd through theformation of complex Cd-EPS which sequentially can increase the availability of Cd for plants uptake. A laboratoryexperiment has been done to study the EPS production and the viability of six Azotobacter isolates in the liquidculture containing 0.01, 0.1, and 1 mM CdCl2. The bacteria were cultured in liquid medium with and without CdCl2 for72 hours at room temperature. The EPS production was determined by gravimetric method after precipitationusing acetone and centrifugation at 7000 rpm. The result was that all of Azotobacter isolates produce EPS in thepresence of CdCl2. In the culture with 1 mM CdCl2, the density of Azotobacter sp. isolate BS3, LK5, LKM6 increasedsignificantly, and that of isolate LH16 decreased. No significant effect of CdCl2 on the density of isolate BS2 andLH15. This research suggested that some Azotobacter isolates were relatively resistence to the Cd and could bedeveloped as biological agents in Cd-contaminated soil bioremediation.


RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 86607-86616 ◽  
Author(s):  
Pradyot Koley ◽  
Makoto Sakurai ◽  
Toshiaki Takei ◽  
Masakazu Aono

Facilely fabricated silk protein sericin-mediated hierarchical hydroxyapatite hybrid architectures show excellent adsorption of toxic heavy metal ions of Pb(ii), Cd(ii) and Hg(ii) and a hazardous dye, Congo red (CR), from wastewater.


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...


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Abate Ayele ◽  
Setegn Haile ◽  
Digafe Alemu ◽  
M. Kamaraj

Human and industrial activities produce and discharge wastes containing heavy metals into the water resources making them polluted, threatening human health and the ecosystem. Biosorption, the process of passive cation binding by dead or living biomass, represents a potentially cost-effective way of eliminating toxic heavy metals from industrial wastewater. The abilities of microorganisms to remove metal ions in solution have been extensively studied; in particular, live and dead fungi have been recognized as a promising class of low-cost adsorbents for the removal of heavy metal ions. The biosorption behavior of fungal biomass is getting attention due to its several advantages; hence, it needs to be explored further to take its maximum advantage on wastewater treatment. This review discusses the live and dead fungi characteristics of sorption, factors influencing heavy metal removal, and the biosorption capacities for heavy metal ions removal and also discusses the biosorption mechanisms.


Author(s):  
MdDidarul Islam, Ashiqur Rahaman, Aboni Afrose

This study was based on determining concentration of essential and toxic heavy metal in coconut water available at a local Hazaribagh area in Dhaka, Bangladesh. All essential minerals, if present in the drinking water at high concentration or very low concentration, it has negative actions. In this study, fifteen samples and eight heavy metals were analyzed by Atomic Absorption Spectroscopy (AAS) method which was followed by wet ashing digestion method. The concentration obtained in mg/l were in the range of 0.3 to 1.5, 7.77 to 21.2, 0 to 0.71, 0 to 0.9, 0 to 0.2, 0.9 to 17.3, 0.1 to 0.9, 0 to 0.9 and 0 to 0.7 for Fe, Ni, Cu, Cd, Cr, Zn, Pb and Se respectively. From this data it was concluded that any toxic heavy metals like Cd, Cr, Pb and Ni exceed their toxicity level and some essential nutrients were in low concentration in those samples. 


Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 860
Author(s):  
Konstantinos Simeonidis ◽  
Manassis Mitrakas

Elevated concentrations of heavy metals in drinking water resources and industrial or urban wastewater pose a serious threat to human health and the equilibrium of ecosystems [...]


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