Product Characteristics of Sludge Pyrolysis and Adsorption Performance of Metals by Char

The microwave heating system was used for sludge pyrolysis. The raw sludge and KOH-immersed sludge were pyrolyzed and their product characteristics were determined. The research results are advantageous to understand the influence of KOH activation on characteristics of pyrolysis products and the adsorption performance of metals in char. In the case of a high temperature and high KOH dose, most of the lost mass from sludge pyrolysis was converted into gaseous products instead of oil. The heat values of liquid oils were 40.86–41.39 MJ kg−1, which has the potential for use as fuels. The use of a higher KOH dose for sludge pyrolysis is beneficial to the porosity development and generates a mesopore structure. The results from adsorption tests indicate that precipitation could be the dominant adsorption mechanism due to the binding between alkaline anion and carbonate and metal ions with a strong chemical affinity. The high KOH dose sludge adsorbent has a remarkable adsorption performance and can be used as adsorbent for the removal of the studied metals.

Archaeological and Chemical Investigation on Mortars and Bricks from a Necropolis in Braga, Northwest of Portugal

This investigation intends to study and characterize the mortars and bricks from walls and floors used in the funerary nucleus of the archaeological site of Dr. Gonçalo Sampaio Street (Braga, Portugal), associated with the Via XVII necropolis of the Bracara Augusta Roman city. The diversity of the funeral structures and their exceptional state of conservation make this sector of the necropolis an unprecedented case and a reference site in the archaeology of Braga, a determinant for its conservation and musealization. Nineteen mortars samples were analysed by X-ray Fluorescence. The results showed clear chemical composition differences among coating and floor mortars (CFM), masonry mortars (MM) and bricks (B) groups of samples. The chemical affinity between CFM from the V to IV centuries, CFM from the IV to V centuries, MM from brick walls (IV–V centuries), MM from stone walls (V–VII centuries) and B from the IV to V centuries samples were confirmed by statistical analyses. Their composition was distinctly related to the use of different raw materials, according to their chronological context; in mortars, according to their function in the structures; and in some samples, from contamination.

Synthesis Luminescent Plasmonic Silver Nanoparticles and The Chemical Affinity towards sulphur atom in Sulphide and Thiourea molecules: Ab-Initio DFT Study

Three different luminescent silver nanoparticles(AgNPs) were synthesized by simple reduction method with the different mole ratios of L-ascorbic/citrate solution and stabilized with CTAB. The prepared three AgNPs were characterized by UV, fluorescence, FTIR, dynamic light scattering measurements and Scanning Electron Microscopy. The plasmon bands of AgNPs- reddish-brown (RB), green (G) and reddish-green (RG) were centered at 565, 587 and 592 nm, respectively. The highly luminescence emission was observed for AgNPs(G). The size diameters of the prepared AgNPs-G, RG and (RB) were measured by dynamic light scattering (DLS) method at 24.3 nm, 66.28 nm and 103.46 nm, respectively. The electrochemical properties of AgNPs-RG was recorded the oxidative part of AgNPs into Ag+ at +0.23 V and the reduction part of Ag+ into Ag0 was recorded at -0.49 V vs. Ag/AgCl). Cetyl trimethylammonium bromide (CTAB) was stabilized AgNPs(RG) which recorded in infrared and scanning electron microscope measurements. The concentration of thiourea, sodium sulphide was detected by the electrochemical sensitivity of AgNPs(RG)-CTAB. A calibration curve between electrochemical sensitivity of AgNPs-CTAB vs concentration of sulphur molecule. The limit of detection (LOD) was founded 2.10 and 1.90 µmole L-1 of sodium sulphide and thiourea, respectively (R2=0.94, n=3). The computational calculations are used to illustrated the chemical affinity of sulphur atom in sodium sulphide or thiourea towards AgNPs(RG).

Exploring Aromatic Medicinal Compounds for the Treatment of Amyotrophic Lateral Sclerosis

Purpose: Amyotrophic lateral sclerosis (ALS) is a lethal neurodegenerative condition, in which motor neurons start to degenerate due to the accumulation of protein aggregates in the neuron cytoplasm. The formation of aggregates causes neurotoxicity, facilitated by the N-terminal domain (NTD) of the transactive response DNA-binding protein-43 (TDP-43). Therapies used to treat ALS manage secondary symptoms, but do not stop the activity of the rogue NTD domain of TDP-43. Therefore, new drug candidates should be designed to deal efficiently with this disease by inhibiting the domains involved in the development of ALS. This study determined the chemical affinity of aromatic medicinal compounds with NTD. Screening of 1323 medicinal compounds was conducted with PYRX 0.9 software against NTD. Compounds obtained from this analysis were further used to predict absorption, distribution, metabolism, excretion, and toxic (ADMET) properties and their effect on major gene targets of ALS. Results: From 1300 + compounds, acetovanillone showed binding affinity for NTD and had good ADMET and drug likeness attributes. This compound reduced the expression of CXCL2, NOP56, and SOD1 genes implicated in ALS pathogenesis. Conclusion: These results concluded that acetovanillone is a candidate drug for in vitro and clinical studies into the exploitation of drugs within ALS therapeutics.

Integrated Assessment of Affinity to Chemical Fractions and Environmental Pollution with Heavy Metals: A New Approach Based on Sequential Extraction Results

To assess the affinity degree of heavy metals (HMs) to geochemical phases, many indices with several limitations are used. Thus, this study aims to develop a new complex index for assessing contamination level and affinity to chemical fractions in various solid environmental media. For this, a new integrated approach using the chemical affinity index (CAF) is proposed. Comparison of CAF with %F on the literature examples on fractionation of HMs from soils, bottom sediments, atmospheric PM10, and various particle size fractions of road dust proved a less significant role of the residual HMs fraction and a greater contribution of the rest of the chemical fractions in the pollution of all studied environments. This fact is due to the normalization relative to the global geochemical reference standard, calculations of contribution of an individual element to the total pollution by all studied HMs, and contribution of the particular chemical fraction to the total HMs content taken into account in CAF. The CAF index also shows a more significant role in pollution and chemical affinity of mobile and potentially mobile forms of HMs. The strong point of CAF is the stability of the obtained HM series according to the degree of chemical affinity and contamination. Future empirical studies are necessary for the more precise assessment of CAF taking into account the spatial distribution of HMs content, geographic conditions, geochemical factors, the intensity of anthropogenic impact, environmental parameters (temperature, humidity, precipitation, pH value, the content of organic matter, electrical conductivity, particle size distribution, etc.). The combined use of CAF along with other indices allows a more detailed assessment of the strength of HMs binding to chemical phases, which is crucial for understanding the HMs’ fate in the environment.

Chemical affinity assisted H2 isotope separation using Ca-rich onion-peel-derived nanoporous carbon composite

Stable isotopes of hydrogen are a prerequisite for many industrial and scientific applications and require their ready supply at a large scale. Herein, we explore the chemical affinity-assisted separation of...