Integrated Assessment of Microplastic Distribution, Polymer Characterization, and Combined Toxicity with Petroleum Hydrocarbons in an Oil Spill–Prone Marine Ecosystem of the Niger Delta

materials, these are QA/QC processes in practice by the laboratory to ensure equipment are optimized before research study. 3.6.3 Data and Result Review All data generated during from the study are tabulated in a results template, reviewed to ensure completion of required analysis and consistence in sample identification to ensure no error occur in reporting of data. Data Analysis Data analysis is essential for interpreting the results of this study and drawing meaningful conclusions regarding microplastic distribution, polymer types, hydrocarbon contamination, and their combined effects on aquatic organisms (Hair et al., 2019). Descriptive statistics, including mean, standard deviation, and frequency distributions, were calculated for all physicochemical parameters, microplastic abundance, polymer types, and hydrocarbon concentrations to provide an overview of central tendencies and variability. Graphical tools such as bar charts, pie charts, and scatter plots were used to visualize spatial patterns and identify potential outliers across sampling stations. Analysis of variance was IIARD International Journal of Geography & Environmental Management employed to test for statistically significant differences in microplastic and hydrocarbon levels among upstream, midstream, and downstream sites of the Okulu Aleto River (Montgomery, 2017). Where significant differences (p < 0.05) were detected, post-hoc comparisons using Tukey’s HSD were conducted to determine which sampling locations differed significantly (Kutner et al., 2005). Additionally, the data were compared with international and local environmental standards, such as those of the World Health Organization and the National Environmental Standards and Regulations Enforcement Agency , to assess the extent of contamination and potential ecological risks. All computational and statistical analyses, including both descriptive and inferential techniques, were carried out using Microsoft Excel and SPSS Statistics, providing a robust framework to address the study objectives and evaluate the interactions between microplastics and petroleum hydrocarbons in the river ecosystem. 3 Results This section presents the findings from the quantitative analysis of microplastics and polycyclic aromatic hydrocarbons in the Okulu Aleto River. Results from water and sediment samples across three strategic sampling sites Upstream (control), Midstream (industrial discharge zone), and Downstream (post-industrial runoff area) Table 3.1 Concentration of Microplastics and PAHs across sampling sites Sampling Site MPs in Water (particles/L) MPs in Sediment (particles/kg) Total PAHs in Water (?g/L) Total PAHs in Sediment (mg/kg) Upstream 4.5 12 0.12 0.45 Midstream 15.3 435 1.34 3.78 Downstream 10.2 298 0.89 2.31 IIARD International Journal of Geography & Environmental Management Table 3.2 Physiochemical Parameters and PAH Data of all water Samples S/N Parameters NUPRC Limit Indorama control 1 surf water Indorama control 2 surf water Indorama Effluent surf water Indorama Upstream surf water Indorama Midstream surf water Indorama Down stream surf water Indorama Composite surf water Units ( Mg/L) 1 pH 6.5-8.5 6.75 7.31 6.41 6.65 6.27 6.39 6.6 2 Temperature(0C) N/A 27.2 27.2 27.2 27.2 27.3 27.3 27.4 3 Electrical Conductivity(?s/cm) 946 950 6330 8900 15440 17070 13740 4 Total Dissolve solids(mg/l) 47.3 47.5 316.5 445 772 853.5 687 5 Dissolve Oxygen (DO) (mg/l) 2.33 2.52 1.79 2.11 1.64 2.34 1.17 6 BiochemicalOxygenDemandmg/l 0.11 0.11 0.99 0.44 0.28 0.86 0.13 7 Chemical Oxygen Demand mg/l 224 352 256 352 192 288 320 8 Salinity 10.6 10.4 8110 9790 9910 10.2 10090 9 PAH 10 Naphthalene <0.01 <0.01 0.04 0.03 0.02 0.02 0.01 11 Acenaphthylene <0.01 <0.01 0.05 0.03 0.02 0.02 0.01 12 Acenaphthene <0.01 <0.01 0.04 0.03 0.02 0.01 0.01 13 Fluorene <0.01 <0.01 0.04 0.03 0.02 0.02 0.01 14 Anthracene <0.01 <0.01 0.05 0.04 0.03 0.02 0.01 15 Phenanthrene <0.01 <0.01 0.06 0.05 0.03 0.02 0.01 16 Fluoranthene <0.01 <0.01 0.04 0.03 0.02 0.02 0.01 IIARD International Journal of Geography & Environmental Management Table 3.3: Petrochemical Microplastic Count Sample Film Nurdles Fibres Pellets Fragments Filament Indorama Control 1 surface water 2 Indorama Control 2 surface Water 10 Indorama Effluent surface water 6 Indorama Upstream surface Water 1 5 Indorama Midstream surface water 1 1 6 Indorama Downstream surface water 2 9 Indorama Composite Surface water 1 3 7 1 Indorama control 1 sediment 2 13 Indorama control 2 sediment 4 3 16 Indorama effluent Sediment 1 3 15 Indorama Upstream Sediment 1 7 Indorama Midstream Sediment 1 2 5 10 Indorama Downstream sediment 4 1 1 12 Indorama Composite Sediment 3 2 8 Crabs 1 1 3 Fish 4 5 Prawns 4 2 2 Downstream Plate 1: Fragments in downstream IIARD International Journal of Geography & Environmental Management Midstream Plate 2: Fragments in midstream Upstream Plate 3: Fragments in upstream IIARD International Journal of Geography & Environmental Management 4.1.1.2 Indorama Sediment Fragments Pellets Plate 4: Fragments and Pellets Plate 5: Fibres, fragments, nurdles IIARD International Journal of Geography & Environmental Management Indorama Upstream Fragments Nurdles IIARD International Journal of Geography & Environmental Management Plate 6: Fragment and Nurdles Indorama Sed Midstream Fibres fragments Plate 7: Fibres and Fragments Film fibres Plate 8: Film and Fibres IIARD International Journal of Geography & Environmental Management Indorama Control 1 Plate 9: Fragments of microplastics FTIR Analysis for Microplastics Figure 3.1: Spatial Distribution of Concentration from FTIR analysis for Microplastics from Indorama Upstream Water 0 200 400 600 800 1000 1200 1400 1600 1800 Butyl-Warco Cellulose Filter Paper 99.7% hydrolyzed Granular Polyvinyl alcohol Aramid Woven Fabric Bisphenol A epoxy cured with polypropylene... Buna-N Carboxyl Polyacrylamide Powder Cellulose Powder Chlorobutyl-1051 Polycorp Chlorobutyl-1051Polycorp Chlorobutyl-536 Blai Copolymer Powder Ethylene Propylene G12 Neoprene Mosites Rubber Granular Zein, Hydroxyethyl cellulose Powder Hypalon Durodyne Hypalon Unaflex Methyl vinylether_maleic acid copolymer 50_50 Neoprene Neoprene Hose-sleeve CLEANED - Branham Nylon 6 (3) T Poly Trimethyl hexamethylene... Nylon 6_6 Polyhexamethylene adipamide Pellets Poly(2-hydroxyethylmethacrylate) Granular Polyvinylpyrolidone Powder Vinyl chloride_vinylacetate_hydroxylpropyl... Conc. Micrplastic IIARD International Journal of Geography & Environmental Management Figure 3.2: Spatial Distribution of Concentration from FTIR analysis for Microplastics from Indorama Midstream Water Figure 3.3: Spatial Distribution of Concentration from FTIR analysis for Microplastics from Indorama Downstream Water 0 100 200 300 400 500 600 700 800 Neoprene Branham Nylon Film Aluminum trihydrate... Bisphenol A epoxy cured with... Carboxyl Polyacrylamide Cellulose Filter Paper Chlorinated Polyisoprene Chlorobutyl-536 Blair Countertop hard, grey... Granular Polyacrylamide Hypalon methacrylate) Approx Natural Latex Rubber Nitrile-Bunan Branham Nylon 6_6 Polyhexamethylene... Poly(2-hydroxyethyl Polyimide Film Sodium Alginic acid, salt powder Conc. Microplastic 0 500 1000 98% hydrolyzed Granular Polyvinyl alcohol Aramid Woven Fabric Bisphenol A epoxy paint, cured Carboxyl Polyacrylamide Cellulose Paper Filter Chlorobutyl Chlorobutyl-Polycorp Ethylene Propylene Granular Poly(2-hydroxyethylmethacrylate) Hypalon Klockner Moeller 74 Natural Latex Rubber Neoprene Hose-sleeve CLEANED Nitro cellulose paper Nylon 6_6 Polyhexamethylene adipamide... Poly (butyleneterephthalate) Pellets Polyhexamethyleneterephthalamide Powder. TiO2 pigment Zein Granular Conc. Microplastic IIARD International Journal of Geography & Environmental Management 4. Discussion The results presented in Table 3.1: Concentration of Microplastics and PAHs across Sampling Sites indicate a clear spatial variation in microplastic (MP) and polycyclic aromatic hydrocarbon contamination al