Challenges and opportunities for low-carbon remediation in the Niger Delta: Towards sustainable environmental management

Functional microbiome and phytoremediation enhance soil diesel degradation via enzyme activity

This study investigates the enhancement of diesel degradation in contaminated soil through the synergistic effects of functional microbiomes and phytoremediation, emphasizing increased enzyme activity. The approach integrates a hydrogen-producing microbiome (HMb) with phytoremediation techniques. Observations revealed changes in soil conditions, including increases in moisture levels from 12.5% to 20% and a shift in pH from 6.9 to an alkaline range of 8.0-8.5 due to the treatment. Organic matter content also improved, supporting microbial activity. These modifications were closely monitored to evaluate their impact on microbial growth and enzyme activity. The findings showed that total petroleum hydrocarbons (TPH) in diesel-contaminated soil decreased by 78.1% using the combined HMb and phytoremediation method. This decrease was markedly higher than the 30.4% achieved through water drenching and the 30.9% with HMb alone. Central to this success were Clostridium sp. and Sporolactobacillus sp., which played essential roles in hydrocarbon degradation. Improved soil conditions supported an increase in microbial populations, with bacterial counts peaking at 6.0 x 1011 by day 4, enhancing degradation. Additionally, Bermuda grass survival rates increased to 35% by day 35. In the HMb and planting combination, amylase activity peaked at 100% by day 10, significantly aiding degradation, although it later decreased to 1% by day 35. This research presents a robust strategy for diesel-contaminated soil remediation, highlighting significant advancements in microbial growth and degradation efficiency.

Quantitative sustainability assessment for in-situ electrical resistance heating coupled with steam enhanced extraction: An effective approach for the development of green remediation technologies

There is a lack of quantitative methodology for the sustainability assessment based on field data in the process of innovative technology development for groundwater remediation. This study developed a quantitative assessment framework, a model based on the life cycle assessment integrated with best management practices (LCA-BMPs), to evaluate the environmental, economic, and social sustainability of in-situ electrical resistance heating coupled with steam enhanced extraction (ERH-SEE), an innovative technology being demonstrated in the field. The results indicated that ERH-SEE offered better environmental sustainability performance compared to ERH only, with a reduction in carbon emissions by 52.6 %. ERH-SEE also significantly reduces human toxicity, resource consumption, and ecosystem impacts under the same remediation scenarios. The further assessment indicated that if taking the renewable energy share in energy structure in different countries into consideration, higher shares of renewable energy used in energy supplies can substantially reduce the environmental footprint of the studied scenarios. The economic sustainability assessment results showed that ERH-SEE was more sustainable than ERH only, as it reduces direct economic costs by 35.7 % and provides higher levels of worker employment. Regarding the social sustainability, ERH-SEE involved more complex operational procedures and presented more health risk exposure scenarios compared to ERH only, resulting in slightly more pronounced worker safety issues. Based on the final normalized results, the overall sustainability results of ERH-SEE and ERH only were 78.4 and 61.5, respectively, demonstrating that the sustainability performance of ERH-SEE was better than ERH only. It can be concluded that the application of ERH-SEE in groundwater remediation where significant heterogeneities occur in subsurface can increase the sustainability in developing countries, due to the lower percentage in renewable electricity in the energy supply. This study provided new insights into the technology development for the remediation of soil and groundwater contamination.

Recycled waste substrates: A systematic review

The growing interest in utilizing recycled waste substrates (RWS) in ecosystem services and environmental remediation aligns with the "waste to wealth" concept and the Sustainable Development Goals (SDGs). Despite the promising potential of RWS, research gaps remain due to a lack of comprehensive reviews on their production and applications. This systematic review attempts to synthesize and critically assess the scientific footprint of RWS through robust methodology and thorough investigation. Characterization of scientific literature, network analysis, and systematic review were conducted on articles indexed in the Web of Science and Scopus databases. Quantitative and qualitative analyses were performed on 140 articles selected by the rigorous article screening process executed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. The findings map the scientific literature and research themes in RWS. Around 66 % of studies in RWS used a multiple research approach, primarily experiments with case studies. Key research topics identified include (A) Technical domains - types of wastes and recycling techniques in RWS production and parameters influencing the substrate quality; (B) Application domains: environmental remediation of soil and agriculture and horticulture. The use of RWS in urban green infrastructure, particularly for green roofs and vegetative walls, and the potential for LCA studies on RWS production and applications emerge as promising areas for future research. This systematic review also presents a conceptual framework model (CFM) on RWS research, encapsulating the state-of-the-art themes, risks, limitations and constraints, and future research avenues.

Screening, characterization and optimization of potential dichlorodiphenyl trichloroethane (DDT) degrading fungi

Dichlorodiphenyltrichloroethane is an organo-chlorine insecticide used for malaria and agricultural pest control, but it is the most persistent pollutant, endangering both human and environmental health. The primary aim of the research is to screen, characterize, and assess putative fungi that degrade DDT for mycoremediation. Samples of soil and wastewater were gathered from Addis Ababa, Koka, and Ziway. Fungi were isolated and purified using potato dextrose media. Matrix-Assisted Laser Desorption, Ionization, and Flight Duration The technique of mass spectrometry was employed to identify fungi. It was found that the finally selected isolate, AS1, was Aspergillus niger. Based on growth factor optimization at DDT concentrations (0, 3500, and 7000 ppm), temperatures (25, 30, and 35 °C), and pH levels (4, 7, and 10), the potential DDT-tolerant fungal isolates were investigated. A Box-Behnken experimental design was used to analyze and optimize fungal biomass and sporulation. The highest biomass (0.981 ± 0.22 g) and spore count (5.60 ± 0.32 log/mL) of A. niger were found through optimization assessment, and this fungus was chosen as a potential DDT-degrader. For DDT degradation investigations by A. niger in DDT-amended liquid media, gas chromatograph-electron capture detector technology was employed. DDT and its main metabolites, DDE and DDD, were eliminated from both media to the tune of 96-99 % at initial DDT concentrations of 1750, 3500, 5250, and 7000 ppm. In conclusion, it is a promising candidate for detoxifying and/or removing DDT and its breakdown products from contaminated environments.

Unearthing Earth's secrets: Exploring the environmental legacy of contaminants in soil, water, and sediments

The Earth's history is documented in human civilizations, soil layers, river movement, and quiet sediments throughout millennia. This investigation explores the significant legacy of environmental toxins in these key planet components. Understanding how ancient activity shaped the terrain is crucial as mankind faces environmental issues. This interdisciplinary study uses environmental science, archaeology, and geology to uncover Earth's mysteries. It illuminates the dynamic processes that have built our globe by studying pollutants and soil, water, and sediments. This research follows human actions, both intentional and unintentional, from ancient civilizations through contemporary industrialization and their far-reaching effects. Environmental destiny examines how contaminants affect ecosystems and human health. This study of past contamination helps solve modern problems including pollution cleanup, sustainable land management, and water conservation. This review studies reminds us that our previous activities still affect the ecosystem in a society facing rapid urbanisation and industrialization. It emphasises the importance of environmental stewardship and provides a framework for making educated choices to reduce toxins in soil, water, and sediments. Discovery of Earth's secrets is not only a historical curiosity; it's a necessary step towards a sustainable and peaceful cohabitation with our home planet.

Socio-economic baseline for oil-impacted communities in Ogoniland: towards a restoration framework in Niger Delta, Nigeria

This study documents the socio-economic baselines in selected oil-impacted communities prior to the commencement of the Ogoni clean-up and restoration project. Adopting mixed approach consisting of semi-structured interviews, focus group discussions (FGDs), key informant interviews (KIIs), and household surveys, we surveyed the pre-remediation socio-economic conditions in the Ogoniland communities between July 2018 and March 2019. Results indicated that almost all respondents (99.6%) agreed that the smell of petroleum products or crude oil was evident in the air they breathed even as there were visible black particles (soot) in the respondents' nostrils, on their clothes, and in water. The respondents described the ambient air as smoky and choked with an offensive smell. The household waters were smelly, brownish, or oily, and most respondents (76%) cannot afford to treat their water. Forty-two percent of the respondents who relied on fishing and farming for a living sought for alternative means of subsistence and acknowledged that oil pollution caused stunted growth and low crop yield. The majority of respondents (91%) reported falling fish catches, while the fish caught smell and taste of oil, lowering their market value and posing a potential health risk to consumers. It is evident that oil pollution has impacted the socio-ecological values and sustainable livelihood in Ogoniland. This study provides baseline data for monitoring post-remediation socio-economic improvements in Ogoniland. It also highlights areas of urgent intervention to improve livelihood, and access to basic amenities (e.g., potable drinking water), waste management infrastructure, and statutory policy changes for sustainable development in Ogoniland.

Inclusive Environmental Decision-making in a Developing Nation: Insights from the Ogoni Remediation Project, Niger Delta, Nigeria

Greater involvement of women is globally believed to enhance environmental management outcomes. Despite being disproportionately affected by environmental degradation primarily caused by oil spills in the Niger Delta region of Nigeria, women in the region are often excluded in environmental decision-making processes. Women involved in farming and fishing face increased vulnerability to contaminated land, food insecurity and conflicts driven by environmental degradation. Using a mixed approach, women, lawmakers, policymakers, regulators, civil society organizations, environmental management practitioners, and government agents responsible for environmental remediation were engaged through interviews, focus group discussions and questionnaires to examine women's inclusion in environmental decision-making and governance in the Ogoni contaminated land remediation project in the Niger Delta region of Nigeria. The results indicate that lack of trust and confidence in drivers of the environmental decision-making process could affect women's participation and involvement in environmental management. Although cultural beliefs and practices impede the participation of women in the region, their actual participation does not independently translate into inclusion in environmental decision-making due to limited capacity, confidence and trust in the process. Creating platforms for capacity building, developing gender policy, adapting appropriate communication strategies, initiating women networks and strengthening social cohesion could enhance women involvement in environmental decision-making in regions with similar cultural context to the Niger Delta region.