scholarly journals Peptide-Based Gel in Environmental Remediation: Removal of Toxic Organic Dyes and Hazardous Pb2+ and Cd2+ Ions from Wastewater and Oil Spill Recovery

Langmuir ◽  
2020 ◽  
Vol 36 (43) ◽  
pp. 12942-12953 ◽  
Author(s):  
Biplab Mondal ◽  
Dipayan Bairagi ◽  
Nibedita Nandi ◽  
Biswanath Hansda ◽  
Krishna Sundar Das ◽  
...  
2021 ◽  
Vol 1035 ◽  
pp. 1043-1049
Author(s):  
Di Xiang ◽  
Chang Long Shao

A simple route has been developed for the synthesis of Ag2O/ZnO heterostructures and the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and photoluminescence (PL) spectroscopy analysis. Considering the porous structure of Ag2O/ZnO, the photocatalytic degradation for the organic dyes, such as eosin red (ER), methyl orange (MO), methylene blue (MB) and rhodamine B (RhB), under visible light irradiation was investigated in detail. Noticeably, Ag2O/ZnO just took 40 min to degrade 96 % MB. The rate of degradation using the Ag2O/ZnO heterostructures was 2.3 times faster than that of the bare porous ZnO nanospheres under visible light irradiation due to that the recombination of the photogenerated charge was inhibited greatly in the p-type Ag2O and n-type ZnO semiconductor. So the Ag2O/ZnO heterostuctures showed the potential application on environmental remediation.


2012 ◽  
Vol 90 (10) ◽  
pp. 858-864 ◽  
Author(s):  
Jizhuang Wang ◽  
Changhua An ◽  
Meiyu Zhang ◽  
Chuan Qin ◽  
Xijuan Ming ◽  
...  

The performance of a photocatalytic reaction is mainly determined by the quality of the photocatalyst. For real applications, significantly enhancing the stability and activity of the photocatalysts still remains a challenge for materials scientists and chemists. In this paper, we have achieved a highly efficient plasmonic AgCl–Ag nanophotocatalyst via photochemical conversion of AgCl nanocubes. Compared with reported photocatalysts, the as-achieved nanophotocatalyst exhibits superior activity, long-term stability, and wide applicability in the decomposition of organic dye pollutants. For example, only 30 s is needed to bleach methyl orange molecules assisted by AgCl–Ag nanoparticles. Furthermore, the catalyst can be reused up to 50 times without significant loss of activity. A possible mechanism was discussed and the specified photocatalytic reactions verified that both O2•– and OH• radicals were the main active species in decomposing pollutants. The excellent performance of the present photocatalyst suggests promising applications in environmental remediation, clean energy creation, and solar cells.


2015 ◽  
Vol 39 (6) ◽  
pp. 4624-4630 ◽  
Author(s):  
Osmando F. Lopes ◽  
Vagner R. de Mendonça ◽  
Ahmad Umar ◽  
Mohinder S. Chuahan ◽  
Ramesh Kumar ◽  
...  

ZnSn(OH)6 cubes as potential material for the efficient photodegradation of organic dyes with high chemical stability.


2021 ◽  
Vol 55 (3-4) ◽  
pp. 365-373
Author(s):  
MOHAMED EL-SAKHAWY ◽  
AHMED SALAMA ◽  
AHMED K. EL-ZIATY ◽  
HAZEM HASSAN

"Photo-catalytic degradation of organic dyes in aquatic environments under visible light irradiation affords an efficient and economic technique for environmental remediation. TEMPO-oxidized cellulose nanofibers/zinc oxide nanocomposite (TEMPO-CNF/ZnO) was prepared through oxidation of cellulose pulp, followed by zinc oxide precipitation in the presence of oxidized fibers. TEMPO-CNF/ZnO was characterized by different techniques. The degradation rate of methylene blue (MB) by TEMPO-CNF/ZnO was gradually increased with increasing pH and the degradation reached 86% within 340 minutes at pH 7. The kinetic study showed that the pseudo-first-order kinetic best fitted the photo-catalytic process. A mechanism was proposed for the degradation of MB using TEMPO-CNF/ZnO under visible light irradiation. TEMPO-CNF/ZnO showed high antibacterial activity against S. aureus and E. coli. Thus, the TEMPO-CNF/ZnO nanocomposite has been demonstrated to be an effective photo-catalytic material for degrading MB under visible light irradiation."


Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1570 ◽  
Author(s):  
Laura Riva ◽  
Nadia Pastori ◽  
Alice Panozzo ◽  
Manuela Antonelli ◽  
Carlo Punta

Nanostructured materials have been recently proposed in the field of environmental remediation. The use of nanomaterials as building blocks for the design of nano-porous micro-dimensional systems is particularly promising since it can overcome the (eco-)toxicological risks associated with the use of nano-sized technologies. Following this approach, we report here the application of a nanostructured cellulose-based material as sorbent for effective removal of organic dyes from water. It consists of a micro- and nano-porous sponge-like system derived by thermal cross-linking among (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (TEMPO)-oxidized cellulose nanofibers (TOCNF), branched polyethylenimine 25 kDa (bPEI), and citric acid (CA). The sorbent efficiency was tested for four different organic dyes commonly used for fabric printing (Naphthol Blue Black, Orange II Sodium Salt, Brilliant Blue R, Cibacron Brilliant Yellow), by conducting both thermodynamic and kinetic studies. The material performance was compared with that of an activated carbon, commonly used for this application, in order to highlight the potentialities and limits of this biomass-based new material. The possibility of regeneration and reuse of the sorbent was also investigated.


Author(s):  
Miguel A´ngel Alema´n ◽  
Ramiro Bermeo ◽  
Andre´s Mendiza´bal ◽  
Wong Loon

On February 25, 2009, OCP Ecuador S.A. faced its first incident; an oil spill consisting of 11,700 barrels of heavy crude oil in an area of high biodiversity in eastern Ecuador. An earth movement caused stress in the pipeline causing its breakage. The temporarily impacted area covered 30 hectares of soil and gravel along 180 kilometers of three rivers that form the high watershed of the Amazon River; these rivers are the Santa Rosa, Quijos and the Coca. During the emergency, while workers rallied to contain the spill and clean the affected area, other workers took safety precautions regarding the health of the inhabitants of the area. Consequently, 1,258 residents from the Gonzalo Pizarro and Orellana cantons received medical assistance in order to rule out patients with pathologies related to the oil spill. OCP executed a joint effort with the Emergency Operations Committee (COE) stationed in Coca in order to supply water for the citizens that reside in the affected area. OCP responded to the requirements claimed by residents, all of which were approved by the COE. Communities affected by the event participated in cleaning efforts through the creation of temporary jobs for them. OCP strictly adhered to the regulations passed by the Ministry of the Environment and those of internationally accepted best practices for these types of events. The media and the citizenry were kept continuously abreast of developments. In addition, all corresponding works and reliability tests were performed on March 4 in order to restart pumping activities. On September 30th, 2009, and following a rigorous process of cleaning and remediation (L&Rr—in Spanish) activities, all tasks were completed in all affected areas prior to an inspection and a walking tour of the area performed by governmental authorities, community members and independent observers. For the collective benefit of affected communities, the environment and OCP, local authorities and international auditors recognized the model established during the event. OCP created a taskforce charged with the execution of the Environmental Remediation Program (PRA—in Spanish) and environmental authorities prepared and approved this program. The Environmental Remediation Taskforce (UPRA) covered the following aspects related to the incident: legal, environmental, cleaning and remediation technical aspects, as well as social, environmental, financial, insurance, internal and external communication aspects, along with a rigorous oversight of contractors. The model implemented is the first of its kind deployed in Ecuador. National and international regulations in force validated the methodology used to remediate the soil, riverbanks and surface water contaminated with the oil caused by the incident. The application of this methodology, aptly deployed in response to the distress situation present at the various affected areas, allowed a reduction in a short period, of the total hydrocarbon concentrations established in the environmental standard, to equal or lower values than those previously indicated for sensitive ecosystems. OCP developed and implemented a technical, environmental and economic matrix that allowed the Company to choose and justify the remediation methods used in affected areas.


Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3810
Author(s):  
Mohammad Ilyas Khan ◽  
Mohammed Khaloufa Almesfer ◽  
Abubakr Elkhaleefa ◽  
Ihab Shigidi ◽  
Mohammed Zubair Shamim ◽  
...  

Proper treatment and disposal of industrial pollutants of all kinds are a global issue that presents significant techno-economical challenges. The presence of pollutants such as heavy metal ions (HMIs) and organic dyes (ODs) in wastewater is considered a significant problem owing to their carcinogenic and toxic nature. Additionally, industrial gaseous pollutants (GPs) are considered to be harmful to human health and may cause various environmental issues such as global warming, acid rain, smog and air pollution, etc. Conductive polymer-based nanomaterials have gained significant interest in recent years, compared with ceramics and metal-based nanomaterials. The objective of this review is to provide detailed insights into different conductive polymers (CPs) and their nanocomposites that are used as adsorbents for environmental remediation applications. The dominant types of CPs that are being used as adsorbent materials include polyaniline (PANI), polypyrrole (Ppy), and polythiophene (PTh). The various adsorption mechanisms proposed for the removal of ODs, HMIs, and other GPs by the different CPs are presented, together with their maximum adsorption capacities, experimental conditions, adsorption, and kinetic models reported.


TAPPI Journal ◽  
2017 ◽  
Vol 16 (09) ◽  
pp. 507-513
Author(s):  
PRAVEEN KUMAR YEGYA RAMAN, ◽  
AKSHAY JAIN ◽  
SESHADRI RAMKUMAR

Oil spill is a threat to the ecosystem, and there is a need for the development of highly efficient oil sorbents for environmental remediation. In this study, four different types of polypropylene fibers were evaluated for their oil absorbency and desorption characteristics. These fibers varied in their fineness and structural characteristics, i.e., hollow or solid. A modified ASTM methodology was used in the study to better represent the oil sorption capacity of a sorbent. To the best of our knowledge, this is the first study to present the effect of fiber fineness and structure on the oil desorption behavior of polypropylene fibers. Results showed that finer fibers had higher oil sorption capacity (g/g) than the coarser fibers. There was no statistical difference in the rate of desorption among the solid fibers; however, the hollow fiber had a statistically higher rate of desorption than the solid fibers.


Pollutants ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 234-252
Author(s):  
Karina García-Villacís ◽  
Luis Ramos-Guerrero ◽  
José Luis Canga ◽  
Daniel Hidalgo-Lasso ◽  
Paul Vargas-Jentzsch

Past petroleum-extraction activities in Ecuador have contaminated its Amazon region. To assess the environmental impact attributed to remediation activities regarding the cleanup of these oil spills, two scenarios were studied according to Life Cycle Analysis methodology: (1) No-action, which means to leave the contamination in place without any further action and (2) Environmental remediation, where the environmental-load attributed to the remediation of the representative oil spill was studied. Results indicated that the no-action scenario presented a higher environmental impact for 12 out of the 16 environmental categories evaluated (climate change, ozone depletion, human toxicity non-cancer effects, particulate matter, ionizing radiation human health, ionizing radiation ecosystem, photochemical ozone formation, acidification, terrestrial eutrophication, marine eutrophication, freshwater ecotoxicity, mineral, fossil and renewable resource depletion). Moreover, the no-action scenario presented a global weighted score of contamination of 5.45 points, while the remediation scenario got a score of 3.3 points, which means that the remediation decreased by 39% of the global environmental impact due to the remediation activity applied, showing the positive influence of environmental remediation to mitigate the effects attributed to the presence of pollution sources associated to the petroleum industry in the Ecuadorian Amazon region.


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