Identification of perylene in sediments: Occurrence and diagenetic evolution

Perylene and penta-aromatic hydrocarbons were determined in sediments as part of a study that was dedicated to the aquatic ecosystem of Elelenwo Creek (Southern Nigeria) in order to carry out a critical corroboration of occurrence and diagenetic evolution of perylene in the sediments of the creek. The results show that the annual mean levels of Benzo [g, h, i] Perylene ranged from 209.00 – 245.28 μg/kg dry weight at the various stations sampled. Meanwhile, Station 3 recorded the highest mean level of 245.28 μg/kg dry weight. The observed values for total penta-aromatic hydrocarbons were high (787.00 -1154.36μg/kg dry weight) in all the stations sampled. In addition, the highest mean value of 1154.36μg/kg dry weight was again recorded at station 3 for the penta-aromatic hydrocarbons. One origin index or concentration ratio of Ip/Ip+BghiP was also used to evaluate the suitability of the penta-aromatic hydrocarbons as a tracer to distinguish between contaminations arising from different sources. The values for the sampling stations therefore ranged from 0.41 to 0.43. A critical appraisal of the PAH index, consequently, suggested that petroleum combustion is the major penta-aromatic hydrocarbon source in sediments of the creek. The PAH group profile shows that perylene was high in the sediments and would pose apparent effects in fauna. The high concentration of perylene in the sediments was also indicative of an in situ biogenic derivation. Furthermore, a concentration of perylene > 10 % of total penta-aromatic hydrocarbons established a credible diagenetic origin

Physical and mechanical properties of locally fabricated geopolymer-plastic ceiling boards

The 21st century has seen a rise in the demand for building materials, which is not unconnected to the rise in population. The high demand has led to an increase in the price of such commodities as well as a strain on environmental resources and the call for more sustainable, and cost-effective alternatives to replace the conventional materials. In this study, waste glass powder was alkali-activated to produce geopolymer, which was combined with both fine and coarse waste polyethylene terephthalate (PET) pulverized plastics (aggregates). The product was then cured to form the ceiling board. The impact of the employed glass, alkaline solution, aggregate size, and aggregate content in the boards were then investigated. Board J with 92.5% PET particles (Coarse and Fine) and 7.5% Glass Particles gave the best water absorption (16.561%), thickness swelling (3.332%) and density test (0.918 g/cm3) results. It was found that the geopolymer with equal proportions of fine and coarse PET aggregates reduced the material's ability to absorb water and increased its density and swelling thickness. The modulus of rupture and modulus of elasticity of the boards were both enhanced by adding more glass powder and fine PET aggregates. However, it was discovered that the board's mechanical qualities, unlike its physical properties, were not improved by the addition of the geopolymer during manufacture