Abstract: Hospital wastewater in Ghana is frequently treated using waste stabilization ponds (WSPs); however, their treatment efficiency and reuse potential remain poorly characterized. This study conducted a six-month assessment of the Cape Coast Teaching Hospital WSP using an integrated framework that combined physicochemical, microbial, hydrochemical, and heavy metal analyses with predictive modeling and reuse suitability indices. The system achieved notable reductions in suspended solids (54.5%) and heavy metals, including Pb (0.001 mg/L) and Cr (0.002 mg/L), which complied with WHO (2006) discharge standards. Fecal coliform concentrations decreased by 21.7%, yet remained above acceptable thresholds for direct reuse. In contrast, salinity and nutrient levels accumulated, with electrical conductivity reaching 1565 μS/cm, ammonia rising to 59.4 mg/L, and nitrate and phosphate concentrations indicating elevated eutrophication risk. Corrosivity indices (LSI −98; RSI >200) suggested strong potential for metal corrosion, while sodium hazard (SAR up to 155.9) and Kelly’s ratio (>9) rendered the effluent unsuitable for irrigation without dilution or tertiary treatment. This study introduces a novel integrated framework that combines pollutant attenuation assessment with reuse potential analysis, offering a comprehensive approach rarely applied in hospital-based waste stabilization pond systems. The findings demonstrate that, although the effluent contains nutrients beneficial for crops, its high salinity and sodium hazard necessitate controlled reuse strategies and post-treatment interventions to prevent soil degradation, thereby informing sustainable wastewater management and reuse planning.

Keywords: Hospital wastewater, Waste stabilization ponds, Predictive modelling, Effluent reuse, Corrosion indices, tropical wastewater treatment

Abstract: Ground settlement is a major issue in geotechnical engineering since it may cause significant structural damage and financial losses. The study evaluates ground settlement at Wassa Agona in the Western Region of Ghana using field investigation, laboratory testing and numerical methods. Five trial pits were investigated, from which soil samples were obtained for geotechnical characterisation and settlement assessment. Detailed data were gathered through fieldwork and laboratory testing, which provided the basis for empirical analysis and numerical modelling using Settle3D and Plaxis 3D software. The numerical settlement analysis was conducted under a foundation pressure of 125 kN/m² at 1.0 m embedment depth. Results from the laboratory and field tests revealed that the soil is mainly silt-dominated with low plasticity and specific gravity values indicating quartz-rich mineralogical setting. Oedometer consolidation test results indicated primary consolidation settlement values of 21.3 mm, 20.9 mm and 19.5 mm for Pit 1-Layer 3, Pit 2-Layer 3 and Pit 5-Layer 3, respectively. Settle3D predicted maximum staged settlement values of 34.1 mm, 30.4 mm and 36.1 mm, while Plaxis 3D predicted 10-year downward displacement values of 0.77 mm, 0.71 mm and 0.52 mm for the same pits, respectively. The results show that Settle3D is more responsive to one-dimensional compressibility and staged consolidation settlement, while Plaxis 3D provides a complementary three-dimensional finite element check on relative vertical displacement. The findings indicate that settlement serviceability checks should be included in foundation design at Wassa Agona, particularly where predicted staged settlements exceed acceptable limits.

Keywords: Ground settlement, Consolidation settlement, Oedometer Test, Numerical modelling, Tropical soils

Abstract: Uncontrolled landfilling remains the main method for municipal solid waste disposal in Ghana, despite its potential to generate highly contaminated leachate that can degrade soil and water resources. This study characterized leachate from three major uncontrolled landfills in Breman Asikuma, Agona Swedru, and Cape Coast in Ghana’s Central Region, and assessed their pollution potential using the Leachate Pollution Index (LPI). Composite leachate samples were collected monthly over 6 months and analysed for physicochemical, microbiological, and heavy metal parameters according to Standard Methods. Pearson correlation and principal component analyses (PCA) were used to identify relationships among contaminants and infer their possible sources. Most parameters measured such as electrical conductivity, total dissolved solids, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), ammonium nitrogen (NH4–N), chloride, total coliform bacteria, and various heavy metals exceeded Ghana Environmental Protection Agency and WHO guidelines for wastewater discharge. The BOD5/COD ratios (0.14–0.35) and alkaline pH levels indicated that the landfills were mostly in the methanogenic stage of stabilisation. Overall LPI values ranged from 10.00 to 16.00, which are significantly above the safe threshold for inland water discharge, indicating high pollution potential. Organic components, especially COD, BOD5, and total coliform bacteria, along with inorganic pollutants like chloride, NH4–N, and total dissolved solids, contributed most to the overall LPI. Although heavy metals contributed less to the index, they remain environmentally significant due to their persistence and toxicity. Multivariate analyses showed strong associations among contaminants, suggesting common human-related sources stemming from municipal, household, and industrial waste. These findings demonstrate that uncontrolled landfills in the Central Region are major sources of environmental pollution and highlight the urgent need for comprehensive leachate management that combines biological treatment with advanced membrane-based physicochemical technologies to protect groundwater resources and public health.

Keywords: Leachate, uncontrolled landfills, Leachate Pollution Index, Central Region, Ghana

Abstract: This study investigates the geotechnical and geochemical properties of artisanal mine waste originating from Ayanfuri, central Ghana, to rigorously assess its potential for reuse as a sustainable construction material. Artisanal and Small-Scale Mining (ASM) is a significant economic activity in the region, but it generates vast, uncontained volumes of tailings that represent a considerable long-term environmental liability and pose public health risks. The urgent need for efficient use of these mine wastes necessitates a comprehensive material characterisation study. Samples were systematically collected from five distinct disposal pits and subjected to a suite of laboratory analyses. Geotechnical tests included particle size distribution, specific gravity (SG), and constant-head permeability, which are crucial for determining structural viability and mechanical behaviour. Geochemical analyses measured pH, major soluble anions (chloride and sulphate), and total concentrations of heavy metals, including mercury (Hg) and arsenic (As). The results indicate that the waste is predominantly sand-sized, with coefficients of uniformity and curvature confirming it is a relatively well-graded material, suggesting high compaction potential. High SG values (2.64 to 2.69) reflect dense aggregates, and high permeability rates (0.30 to 0.46 cm/s) indicate excellent drainage characteristics. Geochemical tests showed a neutral to slightly acidic pH (6.06 to 6.53) and low chloride (<20 mg/kg) and sulphate (<80 mg/kg) levels within permissible limits. Crucially, however, concentrations of the toxic heavy metals, particularly arsenic (peaking above 180 mg/kg) and mercury, were found to be highly elevated in several samples. The study finds that, while the geotechnical properties are highly favourable for construction, the extensive arsenic and mercury contamination presents an unacceptable environmental risk, rendering the material unsuitable for direct reuse unless substantial stabilization and immobilization treatment is implemented.

Keywords: Artisanal Mine Waste, Geotechnical and Geochemical Properties, Arsenic and Mercury Contamination