In 2018, we were approached by the editorial team of the Journal of Marine Science and Engineering (MDPI editorial) to act as guest editors of a Special Issue related to offshore wind energy [...]

The University of Pretoria (UP) and the Council for Scientific and Industrial Research (CSIR), an entity of the Department of Science and Innovation (DSI), signed a Memorandum of Agreement (MoA) on 22 July to collaborate in the area of smart transport, cities and environments. | https://journals.co.za/journal/civeng | hj2021 | Civil Engineering

The editorial team greatly appreciates the reviewers who have dedicated their considerable time and expertise to the journal’s rigorous editorial process over the past 12 months, regardless of whether the papers are finally published or not [...]

The negative effect of high concentration of herbicide in the environment on living species prompted this research. A study of adsorption of paraquat dichloride (PQ) on raw Bambara groundnut shell (RBGNS) was carried out. Adsorption experiments were performed in batch mode to study the effects of some experimental parameters on PQ adsorption properties of the RBGNS powder. The effect of PQ herbicide concentrations (10–60 mg/l), adsorbent dosage (0.2–1.2g), contact time (20–120 min), pH (3–9) and temperature (303–333 K) on the adsorption capacity of these adsorbent was investigated. The adsorption of PQ herbicide was modeled using Langmuir, Freundlich and Temkin isotherms. The highest correlation coefficient (R2) value was obtained from Langmuir model for PQ adsorption on RBGNS as 0.965 thus, chemisorption mechanism. The kinetic and thermodynamic studies revealed that the adsorption processes followed pseudo-second-order kinetics and were exothermic and feasible in nature.

The corrosion performance of carbon steel in acidic medium with different concentration of synthesized organic compounds namely: 2-Phenylpyrimido[1,2-a] benzimidazol-4(1H)-one (PPBI), was investigated by Potentiodynamic Polarization Curves (PPC) and Electrochemical Impedance Spectroscopy (EIS)  measurements. The obtained results reveal that (PPBI) performs excellently as good corrosion inhibitor for carbon steel in 1.0 M HCl. Polarization curves studies indicated that (PPBI) behaves as mixed-type inhibitor. The calculated inhibition efficiencies from two experiments measurements show the same evolution. Also,  the  inhibition  efficiency  was  found  to increase  with increase of the inhibitor concentrations to reach 86 % at 10-3 M of (PPBI) due to the adsorption of the inhibitor molecule on  the  electrode  surface. Impedance measurements spectra exhibit one capacitive and valid the inhibitive ability confirming that this inhibitor inhibits the corrosion in 1 M HCl through adsorption process following Langmuir adsorption isotherm.

Reactivation of spent FCC catalyst for its application in the adsorption of heavy metals from wastewater was investigated in this research. The most effective reactivation route of spent FCC catalyst was oxidation of spent FCC catalyst using H2O2 at oxidant-to-catalyst ratio of 16 ml/g, contact time of 60 minutes and a temperature of 90oC, followed by treatment with  CH3COOH solution at acid-to-catalyst ratio of 20 ml/g, 75 minutes contact time and at a temperature of 50oC. The reactivation process was monitored using the Scanning Electron Microscope Energy Dispersive X-ray (SEM-EDX), X-ray fluorescence (XRF) and X-ray diffraction (XRD). The result showed significant decreases in impurities of coke and metal, and the crystallinity of the treated spent FCC catalyst was much greater than that of the spent FCC catalyst.

This study focuses on the use of a new synthesized compound namely 2-(4-(3-phenyl-4,5-dihydro-1H-pyrazol-5-yl)phenoxy)acetic acid (PYR-3) as an efficient sustainable inhibitor for the corrosion of mild steel in 1 M HCl solution.For this purpose, the current assessment was conducted using a range of experimental and theoretical techniques such as weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic‎polarization (PDP), DFT computations and molecular dynamic (MD) simulations.The experimental results revealed that the studied compound give a maximum inhibition efficiency of 87 % and the inhibition ability increased with raising of the inhibitor concentrations. Further, this inhibitor effectively reduced the corrosion rate of MS which is afforded by the adsorption of this compound onto the MS surface obeyed the Langmuir adsorption isotherm via physico-chemical adsorption. The adsorption parameters such as adsorption equilibrium constant (Kads) and free energy of adsorption (ΔG0ads) were calculated and discussed. To provide further insight into theinteraction’s mechanism between our synthesized compound with the iron surface in an acidic medium, computational calculations such as DFT and MD simulations could beof interesting. Overall, the obtained results from theoretical point of view correlate well with the electrochemical parameters.

A waste to energy approach in pollution controls is highly desirable to create a green and sustainable environment. Microbial Fuel Cell (MFC), which converts organic to electricity via the help of microorganism is one of the examplatory approach of waste to energy concept. Here we tried to find out the influence of MFC technology to the degradation of Total Petroleum Hydrocarbon (TPH) on contaminated sediment. The research used completely randomized design with three treatments and three replications which were control, single-chamber MFC and dual-chamber MFC observed for twenty days. The result showed that the TPH content degraded around 10.26%, 46.15 and 25.64% for control, single-chamber MFC and dual-chamber MFC treatments, respectively. The electricity production for single-chamber treatments was 184.36 mV, 179.59 mA/m2 and 50.57 W/m2 and for dual-chamber MFC was 57.58 mV, 62.51 mA/m2 and 5.76 W/m2. According to annova analysis at 5% significance rate, it could be concluded that the use of MFC technology had shown a significant effect to TPH degradation on contaminated sediment.

In Madaoua Department-Niger, market gardeners have adopted peasant practices of using pesticides that can pollute the soil. The objective of this study is to quantify pesticide residues in the soils of these market garden sites in order to highlight their level of pollution. Sixteen (16) composite soil samples, including five (5) in Galma, six (6) in Madaoua and five (5) in Sabon Guida were taken in the first twenty centimeters using an auger. The extraction and analysis of pesticide residues were carried out by the QuEChERS method. Residues of twenty-seven (27) pesticides belonging to eight (8) chemical families were quantified in soils at average concentrations ranging from 3.6 to 678 µg.kg-1. According to the maximum residue limits (MRLs) of pesticides fixed in the soil in the Netherlands, Canada, the United States and India, 44.44% of the quantified residues have average concentrations, which are 1.01 to 2194 times higher than MRLs in soils. Pesticides with average concentrations above their MRLs are: DDT (84.2-238 µg.kg-1), aldrin (9.6-20 µg.kg-1), dieldrin (3.6-5.67 µg.kg-1), alpha-endosulfan (126.4-227.7 µg.kg-1), beta-endosulfan (59.4-113.8 µg.kg-1), heptachlor (40.6-146.8 µg. kg-1), lindane (34.8-109.7 µg.kg-1), dicofol (54-86.8 µg.kg-1), chlorpyrifos methyl (164.8-278.6 µg.kg-1), pyrimifos methyl (144.4-277.2 µg.kg-1), profenofos (53.6-94.2 µg.kg-1) and malathion (193.4-304.5 µg.kg-1). The very high concentrations of lindane are worrying. Indeed, they exceed its MRL by 696 to 2194 times (0.05 µg.kg-1). Some pesticides such as DDT, aldrin, dieldrin, endosulfan, and lindane are even banned according to Annex III of the Rotterdam Convention for health or environmental reasons.  This study therefore revealed soil pollution by pesticide residues from the market garden sites investigated

In this work, the electroanalytical action VO(OH) – poly(naphthoquinones) in the determination of peroxycompounds has been theoretically analyzed. The redox pair V(III) – V(V) is involved in this case. The analysis of the correspondent bivariant mathematical model confirms the efficiency of the VO(OH) – Poly(naphthoquinone) composite in the peroxide compounds determination. The linear dependence between current and concentration is observed in the wide range of parameter values. On the other hand, the oscillatory behavior is only possible due to the DEL influences of the electrochemical stage.