Developing water treatment technologies in removing heavy metals from wastewater: A review

Author(s):  
Tawfik A. Saleh ◽  
Mujahid Mustaqeem ◽  
Mazen Khaled
Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1094
Author(s):  
Emily S. Bailey ◽  
Nikki Beetsch ◽  
Douglas A. Wait ◽  
Hemali H. Oza ◽  
Nirmala Ronnie ◽  
...  

It is estimated that 780 million people do not have access to improved drinking water sources and approximately 2 billion people use fecally contaminated drinking water. Effective point-of-use water treatment systems (POU) can provide water with sufficiently reduced concentrations of pathogenic enteric microorganisms to not pose significant health risks to consumers. Household water treatment (HWT) systems utilize various technologies that physically remove and/or inactivate pathogens. A limited number of governmental and other institutional entities have developed testing protocols to evaluate the performance of POU water treatment systems. Such testing protocols are essential to documenting effective performance because inferior and ineffective POU treatment technologies are thought to be in widespread use. This critical review examines specific practices, procedures and specification of widely available POU system evaluation protocols. Testing protocols should provide standardized and detailed instructions yet be sufficiently flexible to deal with different treatment technologies, test microbe priorities and choices, testing facility capabilities and public health needs. Appropriate infectivity or culture assays should be used to quantify test enteric bacteria, viruses and protozoan parasites, or other appropriate surrogates or substitutes for them, although processes based on physical removal can be tested by methods that detect microbes as particles. Recommendations include further research of stock microbe production and handling methods to consistently yield test microbes in a realistic state of aggregation and, in the case of bacteria, appropriately physiologically stressed. Bacterial quantification methods should address the phenomenon of bacterial injury and repair in order to maximally recover those that are culturable and potentially infectious. It is only with harmonized national and international testing protocols and performance targets that independent and unbiased testing can be done to assure consumers that POU treatment technologies are able to produce water of high microbial quality and low health risk.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Eric N. Guyes ◽  
Amit N. Shocron ◽  
Yinke Chen ◽  
Charles E. Diesendruck ◽  
Matthew E. Suss

AbstractEmerging water purification applications often require tunable and ion-selective technologies. For example, when treating water for direct use in irrigation, often monovalent Na+ must be removed preferentially over divalent minerals, such as Ca2+, to reduce both ionic conductivity and sodium adsorption ratio (SAR). Conventional membrane-based water treatment technologies are either largely non-selective or not dynamically tunable. Capacitive deionization (CDI) is an emerging membraneless technology that employs inexpensive and widely available activated carbon electrodes as the active element. We here show that a CDI cell leveraging sulfonated cathodes can deliver long-lasting, tunable monovalent ion selectivity. For feedwaters containing Na+ and Ca2+, our cell achieves a Na+/Ca2+ separation factor of up to 1.6. To demonstrate the cell longevity, we show that monovalent selectivity is retained over 1000 charge–discharge cycles, the highest cycle life achieved for a membraneless CDI cell with porous carbon electrodes to our knowledge, while requiring an energy consumption of ~0.38 kWh/m3 of treated water. Furthermore, we show substantial and simultaneous reductions of ionic conductivity and SAR, such as from 1.75 to 0.69 mS/cm and 19.8 to 13.3, respectively, demonstrating the potential of such a system towards single-step water treatment of brackish and wastewaters for direct use in irrigation.


2016 ◽  
Vol 20 (2) ◽  
pp. 104-110 ◽  
Author(s):  
Eunyoung Jang ◽  
Seongpil Jeong ◽  
Eunhyea Chung

Author(s):  
Ekemena Oghenovoh Oseghe ◽  
Azeez Olayiwola Idris ◽  
Usisipho Feleni ◽  
Bhekie Brilliance Mamba ◽  
Titus Alfred Makudali Msagati

Author(s):  
Chu Dai ◽  
Xike Tian ◽  
Chao Yang ◽  
Yulun Nie ◽  
Yanxin Wang

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Prashant Agarwal ◽  
Ritika Gupta ◽  
Neeraj Agarwal

Rapid industrialization, economic development, and population overgrowth are the major reasons responsible for the release of organic and inorganic substances into the environment, further leading to environmental pollution and contamination of water. Nowadays, it is truism that wastewater treatment has raised concern worldwide and is the need of the hour. Therefore, it is necessary to conserve sustainable energy and adopt advanced wastewater treatment technologies. Microalgae culture is gaining tremendous attention as it provides a combined benefit of treating wastewater as a growth medium and algae biomass production which can be used for several livestock purposes. Microalgae are ubiquitous and extremely diverse microorganisms which can accumulate toxic contaminants and heavy metals from wastewater, making them superior contender to become a powerful nanofactory. Furthermore, they are versatile, relatively convenient, and easy to handle, along with various other advantages such as synthesis can be performed at low temperature with greater energy efficiency, less toxicity, and low risk to the environment. Comparing with other organisms such as fungi, yeast, and bacteria, microalgae are equally important organisms in the synthesis of nanoparticles; therefore, the study of algae-mediated biosynthesis of nanometals can be taken towards a newer branch and it has been termed as phytonanotechnology. Here, an overview of recent advances in wastewater treatment processes through an amalgamation of nanoparticles and microalgae is provided.


Desalination ◽  
2008 ◽  
Vol 223 (1-3) ◽  
pp. 487-493 ◽  
Author(s):  
Antonia Ketsetzi ◽  
Aggeliki Stathoulopoulou ◽  
Konstantinos D. Demadis

2013 ◽  
Vol 2 (1) ◽  
pp. 150 ◽  
Author(s):  
Jamil Rima ◽  
Karine Assaker

<p>In this study, B-Cyclodextrinn polymerized with beetroot fibers (Bio-polymer), was prepared and applied to the removal of organic and inorganic contaminants from wastewater. An investigation into the use of cross-linked cyclodextrin polyurethanes copolymerised with beetroot fibers as adsorbents for organic pollutants and heavy metals has yielded very useful results which may have an impact in future water treatment applications.</p> The Biopolymer was tested in water contaminated by dyes, polycyclic aromatic hydrocarbons (PAH) and heavy metals. The effectiveness to eliminate dyes such as methylene blue and Rhodamine B with concentrations around 100 ppm was more than 99%, while the pyrene,which was chosen as an example among PAHs, showed a potential of elimination exceeding the 97% for solutions of 10 ppm. Also, heavy metals, such as Lead, Zn, and Cu, were tested and showed an efficacy exceeding the 99.8%. The results indicated that the biopolymer developed in this study has the potential to be a promising material for the removal of mixed pollutants from industrial wastewater or from contaminated groundwater.


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