by Selvaraju Sivamani  , Rajoo Baskar  and Balasubramanian Lakshmi

Received: 29 April 2021;  Published: 14 September 2021;  doi: 10.21926/rpm.2103037

One of the crucial steps in the enzymatic hydrolysis of biomass is pretreatment. We investigated the applicability of a hybrid pretreatment method, This involved acid treatment followed by alkali before the production of fermentable sugars from cassava stem. The substrate was initially treated with acid (1% oxalic acid at 100 °C for 2 h), followed by treatment with a 10% NaOH–urea mixture (by mixing 5 g each of NaOH and urea in 100 mL of water) at 100 °C for 1 h. A cellulose recovery of 98.55% was obtained with the [...]

by O.A. Kornienko  , S.V. Yushkevych  , A.V. Sameljuk  and O.R. Andrievskaya

Received: 24 May 2021;  Published: 02 September 2021;  doi: 10.21926/rpm.2103036

The phase equilibria and structural transformations in the ternary ZrO2-CeO2-Eu2O3 system at 1500 °C were studied by X-ray diffraction and scanning electron microscopy in the overall concentration range. The system was found to constitute fields of solid solutions based on the tetragonal (T) modification of ZrO2, cubic (C) and monoclinic (B) modifications of Eu2O3, cubic with a fluorite-type structure (F) modifications of CeO2 (ZrO2), and ordered intermediate phase with a pyrochlore-type structure of Eu2Zr2O [...]

by Athanasia Soultana  , Michael Galetakis  , Anthoula Vasiliou  , Konstantinos Komnitsas  and Despina Vamvuka

Received: 11 February 2021;  Published: 17 August 2021;  doi: 10.21926/rpm.2103035

Waste concrete is the most predominant constituent material among construction and demolition waste. Current waste concrete recycling is limited to the use of recycled concrete aggregates as a road-base material and less as aggregates in new concrete mixes. Further, the production of recycled concrete aggregates results in the generation of a high amount of fines, consisting mainly of cement paste particles. Hence, this study aims to produce the cement mortars using the upgraded recycled concrete aggregates (sand g [...]

by Sydney Katras  , Dejian Ma  , Ayman al Dayeh  and David Tipton

Received: 31 March 2021;  Published: 12 August 2021;  doi: 10.21926/rpm.2103034

Bisphenol A (BPA) is a widely used synthetic compound that has been identified as an endocrine disruptor. It has been linked to adverse health effects such as developmental defects, infertility in both men and women, cardiovascular disease, and obesity. There has been increased interest in BPA’s effects on the developing fetus and data has revealed that doses below the presumed safe dose can produce harmful effects. Orthodontic clear aligner therapy is a popular treatment modality that involves the patient we [...]

by Layachi Guelmine  and Hadda Hadjab

Received: 27 March 2021;  Published: 09 August 2021;  doi: 10.21926/rpm.2103033

The present study investigated the effect of reused rubber particles (RRP) on the deicer salt durability of ordinary concrete. Four mixtures were designed, a control concrete (CC) and three other rubber concretes obtained by partial substitution of natural dune sand aggregate with reused rubber particles with 0%, 3%, 6%, and 9% w/w. All studied concretes were subjected to the combined effect of freeze/thaw (56 and 120) cycles with the deicer salt solution of 3% NaCl. The results indicated that RRP improved the deic [...]

by Mônica Batista Leite  and Paulo Roberto Lopes Lima

Received: 07 March 2021;  Published: 28 July 2021;  doi: 10.21926/rpm.2103032

The production of concrete using recycled aggregates, obtained from the processing of construction and demolition waste, is extensively practiced worldwide. However, the effect of simultaneous adding fine recycled aggregate and the recycled coarse aggregate on the mechanical properties of concrete is still unfamiliar. This work aims to evaluate the influence of the water/cement ratio (WC Ratio), the fine recycled aggregate content (%FRA), the coarse recycled aggregate content (%CRA), as well as the interaction betw [...]

by Julia Tourtelot  , Ann Bourgès  and Emmanuel Keita

Received: 09 March 2021;  Published: 26 July 2021;  doi: 10.21926/rpm.2103031

Currently, the largest among the earth excavation sites in Europe are located in the Paris region. The soils excavated from these sites are often considered waste and are not valorized. With an increasing focus on sustainable development, the demand for low-carbon building materials is rising. Although construction using raw earth is a vernacular technique, the diversity in the behavior of the raw earth building materials warrants better control of their mechanical properties. The construction techniques differ dep [...]

by Laila Midhat  , Naaila Ouazzani  , Abdessamed Hejjaj  , Ahmed Ouhammou  and Laila Mandi

Received: 29 December 2020;  Published: 22 July 2021;  doi: 10.21926/rpm.2103030

This study aimed to assess the effectiveness of the phytostabilization ability of the native Moroccan plant Citrullus colocynthis on the neutralization of soil acidity and stabilization of metallic trace elements (MTEs) assisted by marble waste. Mine tailings (MT) collected from an abandoned polymetallic site were mixed with powdered marble (PM) using different mixing ratios (%): (MTPM25), (MTPM50), (MTPM75), and agricultural soil (AS) acting as the control. Seeds of C. colocynthis were selected and planted under g [...]

by Fahriye Yagmur Bütün Buschalsky  and Carsten Mai

Received: 15 March 2021;  Published: 22 July 2021;  doi: 10.21926/rpm.2103029

A thermo-hydrolytic disintegration process qualifies as a promising option for recycling the waste MDF and preserving the fibrous morphology of the recovered lignocellulosic fibre material. This study aims to include a drainage process between the thermo-hydrolytic disintegration and the further utilization of the recovered fibres (RF) obtained using a screw press for removing the disintegration water (DW). In this context, the chemical properties of the RF (pH, nitrogen content, formaldehyde emissions) and the DW [...]

by Lucy V. Fisher  and Andrew R. Barron

Received: 24 February 2021;  Published: 16 July 2021;  doi: 10.21926/rpm.2103028

One of the largest problems facing the steelmaking industry is the high amount of waste currently produced and the low amount of waste that is currently recycled. This study aims to look at the suitability of 3 different samples of basic oxygen steelmaking (BOS) slag as a construction material, in concert with their carbon capture capacity. Characterization by scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma spectroscopy (ICP), X-ray fluorescence (XRF), CO2 adsorption analysis [...]