Issues of large exposed roof area, poor stability, and significant roof support workload are prevalent in the mining of metal ores with gently inclined thick bodies. In response to these challenges, a downward cemented fill mining method has been proposed to enhance the stability of the surrounding rock and filling body. By integrating SURPAC and FLAC3D software, a three-dimensional numerical model that conforms to the actual geological morphology of the mining area was established. Numerical calculation results indicate that after the first stage of ore body excavation, the surrounding rock settlement mainly occurs in the roof and the hanging wall of the -65m level, with the hanging wall settlement primarily concentrated between the 3rd and 4th vertical exploration lines. The filling body demonstrates a weak compressive stress capacity, leading to a gradual transition of compressive stress to the surrounding rock of the mine stope. As the excavation level increases, the compressive stress on the pillars also increases, forming a compressive stress concentration area at the -65m level. A mixed plastic zone of shear and tension is generated in the roof and hanging wall, while a shear plastic zone is present in the inter-pillar area. The findings of this study offer valuable insights to ensure the safety of mining in gently inclined thick ore bodies.

Emerging as an efficient, cost-effective, and environmentally sound approach, electrochemical treatment methods hold significant promise for sustainable remediation and wastewater treatment. This review elucidates recent progress in electrochemical techniques used for site decontamination and wastewater management. It elucidates the fundamental electrochemical processes, detailing the principles of electrocoagulation, electroflocculation, electrochemical membranes, electrochemical oxidation (EO), and advanced oxidation processes (AOPs). The broad applicability of these methods for contaminant removal, inclusive of heavy metals, organic pollutants, complex organic compounds, and suspended particulate matter, is underscored. Notwithstanding, the adoption of these techniques encounters notable challenges. These involve the heterogeneity of soil conditions, the presence of intricate contaminant mixtures, and the risk of electrode fouling and degradation. Suggestions for overcoming such challenges include refining the comprehension of electrochemical treatment processes in field-scale applications, investigating innovative electrode materials, and developing advanced modeling and simulation tools. This review offers a robust overview of electrochemical treatment strategies for sustainable wastewater management and can guide researchers, engineers, and policymakers towards the successful adoption and implementation of these techniques to meet environmental challenges and foster sustainable water management.

Escalating issues pertaining to the disposal of plastic waste have emerged as an alarming global concern, underscored by the environmental infiltration of fragmented plastic materials into terrestrial, aquatic, and atmospheric systems. This predicament is notably amplified within the African continent, where rudimentary waste management infrastructures exacerbate the situation. This review dissects the prevalence, abundance, and distribution of plastic litter and microplastics within diverse environmental compartments (namely, sediments, water bodies, and biota) across Africa. Detailed analysis of existing research findings highlights concentrations of plastic debris and microplastics, identifying the predominant types of polymers and shapes of particles present. It is observed that most African research endeavours have primarily concentrated on microplastics, albeit macroplastics or plastic litter posing substantial challenges as well. Marine environments have been the predominant focus of these studies, with freshwater ecosystems relatively understudied. The geographical focal points of these research efforts were primarily South Africa, Tunisia, and Nigeria. Conversely, a glaring lack of comprehensive studies addressing plastic pollution within terrestrial and atmospheric systems calls for urgent research attention. Documented evidence of plastic ingestion by diverse aquatic and terrestrial fauna, including insects, fish, birds, molluscs, and arthropods, reaffirms the pervasive nature of the problem within African water bodies. An evaluation of existing literature identifies polyester, polyethylene, and polypropylene as the most common types of plastics present within both freshwater and coastal systems. Unfortunately, a significant proportion of these studies failed to adequately characterize the identified plastics, thus obstructing the identification of potential sources. Consequently, it is imperative that future investigations prioritize polymer identification, which can facilitate the development and implementation of efficacious strategies for mitigating plastic pollution and curtailing environmental leakage of plastics.