Feyisayo Victoria Adams

Petroleum hydrocarbon-contaminated water remains difficult to remediate because crude-oil-derived pollutants are chemically diverse, hydrophobic, and persistent. Herein, a graphene nanoplatelet-integrated polymeric iron phthalocyanine framework (GNP-PFePc) was developed as an interfacial peroxydisulfate (PDS) activator for surface-bound reactive species-mediated degradation of total petroleum hydrocarbons (TPH) in crude-oil-contaminated water. The contaminated-water matrix contained an initial GC-MS-detectable TPH concentration of 11.47 g L⁻¹, dominated by C11-C29 linear and branched aliphatic hydrocarbons. The GNP-PFePc architecture combines polymeric Fe-Nₓ coordination sites with a conductive and hydrophobic graphene nanoplatelet framework, promoting active-site accessibility, hydrocarbon enrichment and localized PDS activation near catalytic interfaces. Under optimized conditions, GNP-PFePc/PDS achieved 89.7% TPH removal within 30 min and 94.9% within 150 min. The apparent pseudo-first-order rate constant calculated over the 150 min reaction interval was 0.0198 min⁻¹, corresponding to 17.2-fold and 5.7-fold enhancements relative to PDS alone and GNP-PFePc alone, respectively. Control and kinetic analyses confirmed that the coupled system outperformed adsorption or direct PDS oxidation alone, supporting an adsorption-assisted interfacial oxidation pathway. Compound-resolved analysis further showed that hydrocarbon degradation was structure-dependent, with different responses across linear, branched, long-chain and halogenated hydrocarbon fractions. Radical-scavenging and surface-probe experiments indicated that SO₄•⁻ and •OH participated in the oxidation process, with strong involvement of surface-bound reactive species generated at the GNP-PFePc/PDS interface. Overall, the results demonstrate that GNP-PFePc provides an effective Fe–Nₓ–C catalytic interface for localized PDS activation and surface-bound reactive species-mediated degradation of petroleum hydrocarbons in crude-oil-contaminated water.

This study was carried out to ascertain the optimum parameters for maximum total acid number (TAN) reduction via catalytic esterification using chicken eggshell ash as catalyst. A central composite design (CCD) was created to optimize TAN reduction by varying temperature and catalyst weight %. The chicken eggshell ash was calcined and reactivated in a furnace at 900 °C for an hour. An oil solution (referred to as synthetic solution) of diesel was adulterated with the organic acid m-toluic which served as a representation for highly acidic oil. Titration using alcoholic potassium hydroxide (KOH) and an indicator (phenolphthalein) was used to deduce the total acid number of the synthetic solution before and after esterification. The optimum parameters for maximum TAN reduction obtained from the model were a temperature of 56.90 °C, a catalyst weight % of 11.45%, and a maximum TAN reduction of approximately 94%. Fourier Transform Infrared (FTIR) Spectroscopy also confirmed that TAN reduction had taken place as the peaks that represent the carbonyl group (C=O stretch at ~1605 cm-1) was reduced significantly.

In this study, therefore, multi-walled carbon nanotubes (MWCNTs) were prepared on account of morphology, particle size and thermal properties of CNTs from high-density polyethylene (HDPE) waste and polypropylene (PP) using pyrolysis in the presence of Fe/Mn/Al catalyst. A comparison between the produced CNTs and commercially available CNTs was conducted to analyse if any deviations exist between both products. It was discovered that The commercial CNTs properties have similarities with the MWCNTs produced from plastic wastes. These materials were found to differ in purity with 1% error. The structures and morphologies of these materials are comparable as they were found to be crystalline and they revealed lattice fringes. They differ by the planes in the structural orientation. The MWCNTs synthesized from plastic wastes showed low thermal stability as opposed to the commercial CNTs.

The world population keeps increasing, and this growth has enormously impacted the environment negatively. Researchers all over the world have continually seeking different ways by which the negative impact of the global increasing population can be minimized including developing new technologies to accommodate the high population. The use of plastic has increased, wastes are taking land spaces, which could be used for other purposes such as building and farming, water bodies are been polluted leading to poor access to portable water, and food shortage has been experienced in many communities. The research presented in this book cut across Machine Design, Technologies of Environmental Engineering and Bioprocessing, Materials and Technologies in Construction, Information and Communication Technologies, and Engineering and Project Management. These researches if implemented would go a long way in providing sustainable and lasting solutions to these challenges.

Some organic pollutants change the color, smell, and other characteristics of water leaving it undesirable for use. However, other organic pollutants do not change the physical properties of the water, yet, they make the water non-useful. This study was carried out to determine the characteristics of petroleum contaminated water and how it can be purified using economical filters for possible reuse in rural areas of the Niger Delta, of Nigeria. The filters were made from rice husk ash, and white clay, as main materials, while calcium carbonate and poly (propylene carbonate) were used as binders and pore former. The water samples were tested for conductivity, turbidity, pH, heavy metals, and total hydrocarbon contents. The results showed a significant decrease in the amount of petroleum/organic pollutants present in the water sample before purification. The filter candle made using poly (propylene carbonate) as a binder was found to be the most efficient in removing organic pollutants, but it was not very effective in the removal of heavy metals and also, the pH of the filtrate became more acidic. Filtrates from other filters, however, had pH in an acceptable range. Dodecanoic acid and hexadecanoic acid were found to be removed from the polluted water using the filters.

Naphthenic acid (NA) is one of the components of heavy crude oil. It is composed of a carboxylic acid functional group attached to a hydrocarbon molecule. Heavy crude oils with high concentration of NA are usually classified as poor quality oil and are sold at cheaper price. The presence of high concentration of naphthenic acid in crude oil often result in limited life span of equipment used in exploration and refining processes due to corrosion. In order to improve the quality of such crude oil and to save cost, it becomes very important to remove NA compounds from it. Researchers, as well as the oil and gas industries, have been working on how to overcome this challenge, and several techniques have been developed for the removal of naphthenic acid from the crude oil. This study thus envisages to present the various recent techniques available for the removal of NA from heavy crude oil. It has been seen that of all the recent physical and chemical methods that are available, catalytic-based methods are effective and their effectiveness depend on the temperature at which the catalyst is calcined as well as the surface area of the catalyst.