scholarly journals Low cost nanoparticles derived from nitrogen fertilizer industry waste for the remediation of copper contaminated soil and water

2020 ◽  
Vol 25 (6) ◽  
pp. 930-937 ◽  
Author(s):  
Elsayed Elkhatib ◽  
Mohamed Moharem ◽  
Ayman Mahmoud

The goal of this study was to produce a novel nano-scale material from nitrogen fertilizer industry byproduct (nNFIB) and assess its capability to remediate Cu contaminated wastewater and soil. The novel nNFIB was produced using planetary mono mill and characterized. Equilibrium and kinetics studies of Cu sorption by nNFIB were performed in batch system. The effects of a variety of factors, including pH, coexisting ions and adsorption time on Cu adsorption were investigated. Furthermore, Cu sequestration mechanism onto nNFIB was investigated using sequential extraction technique and Fourier transform infrared (FTIR) spectra before and after nNFIB adsorption. The Cu sorption equilibrium and kinetics data were successfully described by Langmuir and first-order models, respectively. The calculated maximum Cu(II) adsorption capacity (qmax) of nNFIB (100 mg g−1) was four times higher than qmax of bulk NFIB. Copper removal by nNFIB was quite fast (around 86%) in the first 5 min and gradually slowed down until achieved 100% removal at equilibrium time. The FTIR spectra and Cu fractionation data in biosolid-amended soil demonstrated that Cu sequestration in contaminated water and soil is strongly related to CaCO3 of nNFIB. The overall findings show the potential use of nNFIB as a best management practice for Cu removal from wastewater and Cu stabilization in contaminated biosolid-amended soils.

2021 ◽  
pp. 104687812110326
Author(s):  
Adeel Arif ◽  
Amber Arif ◽  
Kimberly Anne Fasciglione ◽  
Farrukh Nadeem Jafri

Abstract: Background Locations concentrated with High School (HS) students tend to have lower out-of-hospital cardiac arrest (OHCA) survival rates. Mobile applications (apps) have the capability to augment cardiopulmonary resuscitation (CPR) skill retention as a low-cost, accessible training method. Methods An iterative process to develop an app to reinforce CPR skills emphasizing hand placement, compression rate, real-time feedback, and recurring tips is described. The app was tested on HS students to measure its impact on quality and comfort of CPR using Likert surveys and skills assessments before and after one month of usage. CPR Score and compression rate were measured using the Laerdal™ Little Anne Manikin QCPR software. Results Fourteen HS students participated in a prospective observational study. It was found that the use of the developed app was associated with improved CPR performance (80.43% v. 87.86%, p=0.01-0.02, 95% CI=2.20-12.66) after one month. Additionally, improvements were demonstrated in compression rate accuracy (21.43% v. 64.29%, p=0.041, 95% CI=0.132-0.725), increased comfort performing CPR (3.86 v. 4.79, p<0.001, 95% CI =0.99-1.00) and comfort performing CPR on strangers (2.71 v. 4.42, p<0.001, 95% CI=1.24-2.19). In addition, for every time the app was used, CPR performance increased by 0.5668% (p=0.0182). Conclusion Findings suggest that mobile apps may have promising implications as augmentative tools for CPR curriculums.


Landslides ◽  
2021 ◽  
Author(s):  
Lorenzo Brezzi ◽  
Alberto Bisson ◽  
Davide Pasa ◽  
Simonetta Cola

AbstractA large number of landslides occur in North-Eastern Italy during every rainy period due to the particular hydrogeological conditions of this area. Even if there are no casualties, the economic losses are often significant, and municipalities frequently do not have sufficient financial resources to repair the damage and stabilize all the unstable slopes. In this regard, the research for more economically sustainable solutions is a crucial challenge. Floating composite anchors are an innovative and low-cost technique set up for slope stabilization: it consists in the use of passive sub-horizontal reinforcements, obtained by coupling a traditional self-drilling bar with some tendons cemented inside it. This work concerns the application of this technique according to the observational method described within the Italian and European technical codes and mainly recommended for the design of geotechnical works, especially when performed in highly uncertain site conditions. The observational method prescribes designing an intervention and, at the same time, using a monitoring system in order to correct and adapt the project during realization of the works on the basis of new data acquired while on site. The case study is the landslide of Cischele, a medium landslide which occurred in 2010 after an exceptional heavy rainy period. In 2015, some floating composite anchors were installed to slow down the movement, even if, due to a limited budget, they were not enough to ensure the complete stabilization of the slope. Thanks to a monitoring system installed in the meantime, it is now possible to have a comparison between the site conditions before and after the intervention. This allows the evaluation of benefits achieved with the reinforcements and, at the same time, the assessment of additional improvements. Two stabilization scenarios are studied through an FE model: the first includes the stabilization system built in 2015, while the second evaluates a new solution proposed to further increase the slope stability.


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