Assessing levels of selected heavy metals with other pollutants in soil and water resources in Nandom District in the semi-arid northwestern Ghana.

This study assessed heavy metal contaminations of soils in cultivated fields (or farms) and water samples from rivers, boreholes, and dug-out wells in Nandom District in semi-arid northwestern Ghana. Other parameters of water from the three sources were also measured and then compared to the permissible limits in the literature. The results showed that soils in farms across the study communities significantly (P ≤ 0.05) had higher levels of chromium (Cr = 0.456 ± 0.132 mgkg-1), iron (Fe = 214.8 ± 1.52 mgkg-1), lead (Pb = 0.854 ± 0.03 mgkg-1), nickel (Ni = 2.813 ± 0.4 mgkg-1), and arsenic (As = 1.753 ± 0.42 mgkg-1) when compared to permissible limits set by World Health Organization (WHO) and Food and Agricultural Organization (FAO) for food crops. Water from the study sites significantly (P ≤ 0.0001) had lower levels of heavy metals than the permissible limits set by FAO for irrigation of growing crops. Thus, the water sources appear to be safe for irrigation in the study area. Nonetheless, these sources of water in Nandom District had significantly higher levels of total suspended solids, turbidity, and coliforms that were above the maximum limits indicated in the guidelines of WHO and the Government of Ghana for drinking water. Therefore, treatments of water for drinking are required to minimize any potential threats to public health.

Electronic waste control and management in Ghana: A critical assessment of the law, perceptions and practices.

The aim of the study was to assess the impact of Ghana's hazardous and e-waste control and management Act 917 of 2016 on current e-waste management practices and the level of awareness among key stakeholders (general public, repairers, wholesalers/retailers, recyclers and importers of electronic items) in the Greater Accra Region of Ghana. Both quantitative and qualitative data were collected and examined in this study. Results showed a low level (12%) of awareness among stakeholders on the e-waste legislation. Almost 13% of respondents had been educated on e-waste management. Community engagement and the mass media were the main sources of information on e-waste. Significant associations between background information of respondents and awareness level on 'Ghana's Act 917' were observed. Relative to general e-waste issues, only education and stakeholder showed significant associations with e-waste legislation and management. The main e-waste disposal methods adopted by respondents were disposal at dumpsites (22.7%), repair and reuse (21.1%) and reselling (20.1%). Almost 10% of respondents made changes to their e-waste disposal practices over the past 5 years. These changes were mainly due to the economic benefits derived from reselling e-waste (37.6%) and the perceived adverse impacts of e-waste on the environment (23.9%). Overall, there is the need to intensify awareness on 'Ghana's Act 917', especially issues regarding sustainable e-waste management practices.

Sludge management in anaerobic swine lagoons: A review.

Sludge is nutrient and mineral rich residue of anaerobic treatment that is often utilized as a fertilizer. Sludge management is crucial to maintain the function of anaerobic treatment lagoons and ensure efficient nutrient utilization. Intensive livestock production has resulted in accumulation of sludge residue in regions where nutrients are in surplus. This situation adversely impacts the sustainability of livestock production. Alternative uses of sludge needs to be developed and adopted to reduce the negative impacts associated with the nutrients accumulation on farms and nearby crop fields. A thorough understanding of sludge composition is necessary to identify appropriate end use. This review explores swine lagoon sludge (SLS) in relation to its composition, sampling techniques, management approaches, fertilizer value, challenges and opportunities for further development.

Planning methodology for anaerobic digestion systems on animal production facilities under uncertainty.

Anaerobic digestion (AD) reduces GHG emission and facilitates renewable energy generation. The slow rate of adoption of this technology is often attributed to economic and technical considerations. Collaboration of two or more dairy farms into a centralized AD system can improve the process economics through economies of scale. However, uncertainties related to the process parameters and the scope/scale of the collaborative implementation impede its adoption. This study presents techno-economic optimization model as a design aid to determine ideal location, capacity, and participation level (cluster size) that maximize economic return on a cooperative digester. This study employs a probabilistic approach to overcome uncertainty regarding project parameters such as manure biomethane potential (BMP), project capital, and electricity sale price. Two case studies based on dairy production regions in Wisconsin were developed to test the model and demonstrate its capabilities. Herd sizes and spatial distribution in a given region were found to be critical factors in determining the viability of digestion projects in general, and collaborative digestion systems in particular. The number of simulation runs needed to capture the probability of profitable AD facility establishment was less than 1000 for both case studies assessed. Electricity sale price and biomethane potential of feedstock utilized were found to be the most restrictive to the feasibility of AD adoption. Changing the optimization objective function, to adopting maximization, favored the formation of collaborative AD facilities for both case studies evaluated.