Dye Contaminated Waste Water Treatment through Metal-Organic Frameworks (MOFs) based Materials

The high tendency of water to get polluted is due to the extensive usability among all the resources. Amongst all the anthropogenic pollutants, a variety of synthetic non-biodegradable dyestuff are...

Mixed or Contaminated Waste Plastic Recycling through Microwave - Assisted Pyrolysis

A single type of thermoplastic polymer is easily recycled through a mechanical process, but this way can’t be followed in the presence of mixed or contaminated plastic. In this case, one of the main followed solutions is a thermochemical process and among them, microwave-assisted pyrolysis is one of the emerging technologies. This chapter offers an update of the microwave-assisted pyrolysis of mixed or contaminated waste plastic as a very promising example of chemical recycling. Furthermore, some unpublished results in this field will be reported such as the pyrolysis of waste lead containing polyethylene coming from end cycle batteries or the pyrolysis of waste polypropylene from facemasks used for covid protection. Finally, some examples of pilot plants will be described and commented as well as several industrial cooperations.

Estimation of COVID-19 waste generation and composition in Vietnam for pandemic management

Despite its initial success in COVID-19 pandemic control, Vietnam faces a growing risk of outbreaks as new infection waves driven by the highly contagious Delta variant surge in the region. In the context of preparedness through waste management, this study estimated the rate and quantity of generation and the composition of COVID-19 waste in Vietnam from the supply of resources and equipment. Over a year under COVID, 1486 t of COVID-19 waste was produced from the treatment of isolated COVID-19 patients (4.64 kg bed−1 day−1), quarantine in medical facilities (3.86 kg bed−1 day−1), centralised quarantine (46.43 g bed−1 day−1), testing (50 g test−1) and vaccination (10.46 g shot−1). Plastic dominated the waste at 76.7%, followed by paper. The additional management of waste from households with persons under quarantine is likely to reduce infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) – contaminated waste. Thorough assessment is recommended for the establishment of regional collaboration to secure COVID-19 waste treatment capacity. These findings will support COVID-19 waste planning in Vietnam in association with pandemic scenarios and could be used as a reference by other developing countries for pandemic control.

Isolation and Screening of Antagonistic Actinomycetes for Potential Application in The Control of Pathogenic Bacteria in Contaminated Waste

Purpose Organic wastes for agricultural use represents a real agronomic interest but also a risk for public and animal health. Actinomycetes present a potential source of bioactive compounds with multiple applications. Methods Among the 88 isolates of actinomycetes obtained from different samples, we selected a strain identified, thanks to macro- and microscopic characters, as Streptomyces sp. SCM21. This strain showed these potentialities to produce antibacterial metabolites against the pathogenic bacteria tested (S. aureus, B. cereus and S. enteritidis) when cultivated in liquid and solid fermentation. Solid-state fermentation was conducted using sewage sludge as substrate. Results This is the first time that sewage sludge has been used to produce antibacterial metabolites by a strain of actinomycetes in solid-state fermentation. In addition, solid-state fermentation moistened with distilled water gave better antibacterial activity with good sporulation of Streptomyces sp. CSM21. Conclusion The product of solid-state fermentation can be used in the management of contaminated waste to control pathogenic bacteria.

Removal of Cesium from Radioactive Waste Liquids Using Geomaterials

In this study, we investigated the removal of Cs from aqueous solutions using geomaterials. Adsorption was chosen as an effective method to develop for the removal of Cs from radioactive waste liquids. Geomaterials, including fly ash and slag as raw materials, were prepared as adsorbents using an alkali activator. The materials were characterized by X-ray diffraction (XRD); scanning electron microscopy with energy dispersive spectrometer (SEM-EDS); and BET surface area, pore volume, and pore size analysis. The effects of various parameters, such as pH, contact time, and adsorbent dosage on the adsorption of the Cs were studied. The partition coefficient (PC) as well as the adsorption capacity were evaluated to assess the true performance of the adsorbent in this work. The fly ash-based geomaterials showed a maximum Cs adsorption capacity of 89.32 mg·g−1 and a high PC of 31.02 mg·g−1·mM−1 for the Cs under our experimental conditions. From this work, this method can be regarded being practical for use as a potential adsorbent for treating Cs in wastewater. Furthermore, the immobilization of Cs in geomaterials was explored from a chemical perspective. In conclusion, fly ash-based geomaterials may be a promising option for the treatment and disposal of nuclear-contaminated waste.

Preparation of lignin-based mesoporous biochar nano- and microparticles, and their adsorption properties for hexavalent chromium

The removal performance and mechanism of Cr(VI) from aqueous solution was studied for a novel micro-nano particle kraft lignin biochar (BC) pyrolyzed at 400 to 700 °C. The physicochemical properties of BC were determined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and N2 adsorption-desorption isotherms. The results illustrated that the BC had irregular micro- and nanoparticles with abundant pore structure and high BET surface area (111.1 m2/g). The FT-IR results showed that the lower pyrolysis temperature resulted in more oxygen-containing functional groups. The Cr(VI) adsorption capacity decreased with the pyrolysis temperature increasing from 400 to 700 °C, and the maximum percentage removal of Cr(VI) for BC obtained at 400 °C was 100% at pH 2, which suggested that the removal efficiency was mainly dependent on functional groups. Kinetic analysis demonstrated that Cr(VI) adsorption on BC fit well to the pseudo-second-order kinetic model. The adsorption data was well fitted with the Langmuir isotherm models, and the maximum adsorption capacity was 37.2 mg/g at 298K. The BC could be reused twice with Cr(VI) removal of 63.91% and was suitable for Cr(VI) contaminated waste-water treatment.