Mine Reclamation Research Articles

Management Gaps in the Implementation of Legislation Regulating Derelict and Ownerless Mines in South Africa

Little attention has been paid to the rehabilitation of derelict and ownerless mines in South Africa after their lifespan. This paper aims to explore management gaps in legislation that have resulted in the non-rehabilitation of derelict and ownerless mines in South Africa. There is growing evidence that supports the distressing effects of mining on people living around these mines in the North West Province. This paper was motivated by the current socio-economic status quo of old mining towns, the influx of illegal miners (Zama Zamas), severe environmental damages, and the violence associated with derelict mines. Underpinning this research was an ecosystem approach and integrated resources management principles, which formed the foundation for the decision-making process.The researcher used a mixed-method approach and employed convergent techniques. A semi-structured instrument was used to collect data from 200 respondents. The results indicated that there is a dire need for community-based consultative processes, and an absence of clear guidelines for derelict and ownerless mines to pressure mine management to adhere to rehabilitation standards. Moreover, the mining charter is ambiguous regarding policy implementation, budgetary allocation, and duration of the rehabilitation of these mines. The paper concluded that management challenges associated with derelict mines can be reduced if all stakeholders follow the guidelines as outlined in the environmental legislative framework (NEMA) of South Africa while being open to innovations in line with international best practices. It also contributes towards the development of guidelines for the management and implementation of legislation related to derelict and ownerless mines in South Africa from a philosophical, theoretical, and policy perspective.

Realization of Integrated Regional Ecological Management Based on Ecosystem Service Supply and Demand Flow Networks: An Example from a Dominant Mineral Resources Development Area

Understanding the flow processes and pattern optimization of ecosystem services (ESs) supply and demand is crucial for integrated regional ecological management. However, the understanding of the flow process of ESs at the 1 km grid scale is still limited, especially in areas dominated by mineral resource development. The landscape in these areas has undergone significant changes due to mining activities. It is urgent to construct a regional management model that integrates the flow of ecosystem services and mine restoration. This study developed a framework that links ecosystem service flows (ESFs) and ecological security patterns (ESP) based on multi-source ecological monitoring data, constructed an ES supply-demand flow network through the flow properties, and determined the sequence and optimization strategies for mine rehabilitation to achieve integrated regional management. The results show that, except for food production (FP), other services were in surplus overall, mostly in synergistic relationships, but the spatial distribution of their supply and demand was not coordinated. Surplus areas were located mainly in the eastern woodlands, and deficit areas were located in the northwestern production agglomeration centers, suggesting that areas of supply-demand imbalance can be mitigated through ecological integration. Among these, water yield (WY) had a small number of sources and sinks and is limited in area range. Habitat quality (HQ) sources and sinks had the largest area coverage and the highest number. The distribution of ESF corridors, influenced by factors such as the number of sources and sinks, flow characteristics, and spatial resistance, varied significantly. HQ exhibited a more uniform distribution range, while WY had a longer average length of flow path. Overlaying ecological and mining factors, we identified ecological strategic spots, important supply areas, beneficiary areas, and mine priority restoration areas to further optimize the overall layout and rationally allocate the intrinsic structure of the patches based on ES supply and demand.

Metal-tolerant microbial succession mediated by mining reclamation improves network stress resistance

Metal-tolerant microbial succession mediated by mining reclamation improves network stress resistance

Circular economy strategies in sedimentary phosphate mine reclamation: Development of technosol from phosphate waste rock

Proper management of mine waste plays a crucial role in minimizing environmental impacts. One potential solution to tackle this problem involves transforming mine waste rock into soil to facilitate the process of mine restoration. The aim of this study was to assess the mineralogical, chemical, and physical characteristics of technosol derived from phosphate mine waste dumps. Following this evaluation, a novel rehabilitation strategy was proposed. For this purpose, a total of 32 samples were systematically collected across a 4 ha area of technosols, which had been established in accordance with the waste rock soil rehabilitation strategy involving geomorphic reshaping. According to the findings, phosphate mining left the soil with a sandy texture, resulting in a degraded soil structure with severely unfavorable crop growth conditions, notably poor stability, and low water retention. The chemistry of the studied soils was characterized by the dominance of CaO (29.02 wt%± 1.01) > SiO2 (27.61 wt% ± 0.61) > P2O5 (11.34 wt% ± 0.23) > MgO (5.97 wt%±0.16). Mineralogically, the samples were mainly formed by quartz, dolomite, calcite, apatite, and clay minerals. The prevalence of dolomite played a significant role in enhancing the accessibility of Mg as an essential nutrient and the occurrence of apatite in the soil resulted in the presence of P2O5. However, the abundance of Ca was linked to three major minerals: calcite, apatite, and dolomite. X-ray fluorescence analyses demonstrated that the concentrations of Fe2O3, K2O, and SO3 did not exceed 2 wt%.Organic matter, represented by SOC <0.2% and N < 0.02%, demonstrated an extraordinary deficiency in the study area. The analysis of element bioavailability confirmed that the soil was rich in Ca (10383,26 mg/kg), Mg (278,47 mg/kg), Zn (12,82 mg/kg), and Cu (3,7 mg/kg) but deficient in other essential nutrients such as P, K, S, Mn, and Fe. Our research results provide a set of recommendations aimed at enhancing existing mine rehabilitation practices applicable to both pre- and post-rehabilitation phases, leveraging automated mineralogy and circular economy principles. Notably, we propose a rehabilitation strategy to be implemented prior to the geomorphic reshaping phase, which is intended to reduce costs and efforts associated with soil reconstitution.

Impact of red mud on soil properties and revegetation species growth in bauxite mining land reclamation

Bauxite mining, a key aluminum production process, can cause environmental degradation, soil erosion, and biodiversity loss. Reclamation measures like reforestation and water management can restore balance. Red mud, a by-product of alumina production, can enhance soil fertility and plant growth in post-bauxite mining reclamation areas. Its alkalinity and mineral composition reduce reliance on synthetic fertilizers, promoting sustainable soil management and addressing environmental challenges. This study aimed to examine the impact of red mud on soil characteristics and the growth of plants in areas during bauxite mining land reclamation. This study was conducted in the post-reclamation area of bauxite mining in West Kalimantan. The experiment involved two treatments: red mud application and a species of revegetation plant. Plant species consist of the plants Embeng, Forest Guana, Johar, and Rambutan. The study used a randomized block design with 24 experimental units. The parameters measured in the study included pH, organic carbon, nitrogen, phosphorus, exchangeable cations, cation exchange capacity, and base saturation, while growth parameters included a high percentage of plant growth and percentages of increased stem diameter. The findings showed that adding red mud to the planting hole increased soil pH and base saturation, improved nutrient availability, and enhanced plant growth in the areas post-mining bauxite at PT Antam, UBPB West Kalimantan. The Embeng Plant is highly regarded as a suitable plant species for re-vegetating areas after bauxite mining.

Research on the Expression of Naturalistic Style in the Landscape Design of Xuzhou Abandoned Mine Park

In recent years, more and more mines have been left idle, and the formed mine wasteland has become a visual pollution of the urban landscape, and the study of landscape design of mine parks has become a focal topic. To address this issue, the sample of this study was selected from Xuzhou Anran Mountain Quarry Abandoned Quarry, to enhance the ecological environment and landscape value of the site through the sample's naturalistic style design and performance. The goal of the study is to explore the innovative design and performance of naturalistic style in the landscape of Xuzhou abandoned quarry park. Methods of this study: observation forms, questionnaires and interview forms, relevant cases and other research methods were used to analyse the overview of mine transformation in China, the landscape characteristics, ecological status and problems of Xuzhou mine wasteland. The design strategy of naturalistic style in the landscape of Xuzhou mine park is proposed.The results of the study show that (1) mine rehabilitation. China's big cities have more mine rehabilitation, and the proportion of cases in small cities is relatively small. (2) Characteristic aspects. Abandoned mines in Xuzhou are characterised by serious ecological damage and chaotic and dilapidated site landscapes. (3) Design strategy. It should be carried out from the ecological restoration and management of the site environment, the aesthetic expression of naturalistic landscape, and the use of natural elements and natural materials. In addition, through the in-depth analysis of the sample landscape design, the originally desolate abandoned mine was transformed into a naturalistic style landscape space, adopting ecological and cultural strategies. The results of the study contribute to the ecological and economic development of the region, and also provide theoretical and practical guidance for the rehabilitation of other mines in China.

Mapping annual dynamics of surface mining disturbances in the northeastern Tibetan Plateau using Landsat imagery and LandTrendr algorithm.

The exploitation and utilization of coal resources have significantly contributed to global energy security. However, this mining activity has inflicted considerable damage on the ecological environment, particularly on the Tibetan Plateau, where the impact on ecosystems may be even more detrimental. The implementation of high-intensity mining activities leads to rapid changes in land cover/land use. Consequently, it is essential to accurately and effectively monitor mining disturbances. In this study, we propose an approach to capture surface mining disturbances using spatial-temporal rules and time series stacks of Landsat data. First, a time series of annual mining disturbance probability was generated based on Landsat temporal-spectral metrics and random forest. Second, the Landsat-based detection of Trends in Disturbance and Recovery (LandTrendr) algorithm was employed to segment the time series and detect breakpoints. Finally, mining disturbances were captured by further restricting the output of LandTrendr based on spatial-temporal rules of mining disturbances. This approach was applied and evaluated in the Muli mining area of the northeastern Tibetan Plateau, which experienced large-scale and rapid mining disturbances from 2004 to 2014, and identified a disturbed mining area of 43.62 km2. The mining sites have been reclaimed after mining, and all reclamation work was done after 2016, with a total reclaimed area of 22.28 km2. The validation results indicated that the overall accuracy of mining disturbance and reclamation mapping ranges from 0.7333 to 0.8667, and the F1 scores for mining disturbances and reclamation range from 0.7551 to 0.8723. This study provides a reliable framework for monitoring mining disturbances and reclamation in surface mines, promising to be useful in realizing disturbance monitoring in surface mines for a wide range of mineral types.

Research on the Expression of Naturalistic Style in the Landscape Design of Xuzhou Abandoned Mine Park

In recent years, more and more mines have been left idle, and the formed mine wasteland has become a visual pollution of the urban landscape, and the study of landscape design of mine parks has become a focal topic. To address this issue, the sample of this study was selected from Xuzhou Anran Mountain Quarry Abandoned Quarry, to enhance the ecological environment and landscape value of the site through the sample's naturalistic style design and performance. The goal of the study is to explore the innovative design and performance of naturalistic style in the landscape of Xuzhou abandoned quarry park. Methods of this study: observation forms, questionnaires and interview forms, relevant cases and other research methods were used to analyse the overview of mine transformation in China, the landscape characteristics, ecological status and problems of Xuzhou mine wasteland. The design strategy of naturalistic style in the landscape of Xuzhou mine park is proposed.The results of the study show that (1) mine rehabilitation. China's big cities have more mine rehabilitation, and the proportion of cases in small cities is relatively small. (2) Characteristic aspects. Abandoned mines in Xuzhou are characterised by serious ecological damage and chaotic and dilapidated site landscapes. (3) Design strategy. It should be carried out from the ecological restoration and management of the site environment, the aesthetic expression of naturalistic landscape, and the use of natural elements and natural materials. In addition, through the in-depth analysis of the sample landscape design, the originally desolate abandoned mine was transformed into a naturalistic style landscape space, adopting ecological and cultural strategies. The results of the study contribute to the ecological and economic development of the region, and also provide theoretical and practical guidance for the rehabilitation of other mines in China.

Photovoltaic Solar Farms Site Selection through “Policy Constraints–Construction Suitability”: A Case Study of Qilian County, Qinghai

The scientific selection of photovoltaic (PV) sites is essential for achieving sustainable development of renewable energy and ensuring regional ecological security. In western China, extensive land resources coexist with a fragile ecological environment. To this end, we propose a PV siting framework based on policy restrictions and construction suitability. This paper evaluated the PV construction suitability index (CSI) from four dimensions of topography, climate, location, and ecology and proposed typical “PV+” models. Then, Qilian County was selected as a case study. The results showed the following: (1) In Qilian, 59.97% (8333.18 km2) of the area is unsuitable for development due to policy restrictions, leaving 40.03% (5563.02 km2) available for PV construction. (2) The most suitable areas are approximately in the western and southern areas, where there is a lot in common with the reported PV sites under construction. (3) Three distinct PV development models are proposed according to policy guidelines and local circumstances, including the PV + pastoralism model, PV + mine rehabilitation model, and PV + hydropower model. The results can be used to determine the suitable areas for solar PV farms and the appropriate development model, as well as promote the sustainable development of renewable energy.

Strategies for Sustainable Mine Reclamation: Case Study of the Meghahatuburu Iron Ore Mine

ABSTRACT The demand for raw materials is increasing rapidly, leading to higher production targets for mining industries. Currently, largescale opencast mining operations are causing extensive damage to forest areas, agricultural land, and various habitats for humans and animals. Despite these negative impacts, mining plays a crucial role in our national economy, serving as the second backbone of the country after agriculture. Given the inevitability of mining operations, it is essential to carry them out in a sustainable manner, minimizing or even eliminating environmental harm. This study focuses on the challenges associated with iron ore mining and emphasizes the significance of ecological restoration and land reclamation in mitigating environmental consequences. The focus of this research work is the implementation of a comprehensive procedural approach to achieve sustainable mine reclamation in an easy way. The primary objective is to restore the biodiversity of the Saranda Forest ecosystem. To accomplish this, a three-tier plantation model was adopted, involving the strategic planting of 2,664 trees and 3,136 herbs/shrubs in 1.5 hector degraded backfilled area. This initiative aims to rehabilitate the degraded land that has been adversely affected by mining activities.

Sustainability Analysis of Mine Rehabilitation Using Native Plants: A Case Study of the Qinling Mountains

Sustainability Analysis of Mine Rehabilitation Using Native Plants: A Case Study of the Qinling Mountains

Rheological performance regulation of solidified soil slurry for mine reclamation: Superplasticizer selection and structural characterization based on in-situ techniques

This paper focuses on the low cement content characteristic of soil slurry materials for mine reclamation, investigating the effects of three types of superplasticizers (polyester-based polycarboxylate (PCE), sodium lignosulfonate (SLS), and naphthalene-based (PNS)) on the flow properties of freshly mixed solidified soil slurry. It proposes a method combining shear rheology and micro-rheology experiments to complete the selection of superplasticizers. The rheological properties of the freshly mixed slurry were compared at different dosages of superplasticizers and various resting times. The results indicate that PCE at 0.4 % dosage exhibits the best dispersion effect in the solidified soil slurry. In-situ ATR FTIR, in-situ low-field NMR, and ζ-potential tests confirmed that PCE can effectively delay the solidification process of the soil slurry to maintain its fluidity. At a PCE dosage of 0.4 %, the spatial hindrance between slurry particles is reduced, increasing the proportion of “free water” in the solidified soil, with the ζ-potential not being the main factor affecting the rheological properties of the soil slurry. This study provides a theoretical foundation and solutions for regulating the early fluidity of solidified soil slurry materials used in the land reclamation of coal gangue in the Northwest mining areas of China.

Uncovering the impacts of LUCC on ecological connectivity in suburban open-pit mining concentration areas: A pattern collection of changing relationships between ecological resistance and ecological network elements

The suburban open-pit mining concentration area couples two human activities, urban sprawl and open-pit mining, while destruction of surface vegetation and ecological restoration coexist. This has also resulted in complex land use shifts that significantly affect regional ecological connectivity. However, the impact of such complex Land use/land cover changes (LUCC) on ecological connectivity in this region is not well understood Therefore, this study takes the suburban open-pit mining concentration area of Jinan City as a case study and uses Land use/land cover (LULC) data from the years 2000, 2010, and 2020 to simulate the spatio-temporal evolution of ecological networks (ENs). Subsequently, a pattern collection of changing relationships was proposed that relate changes in ecological resistance to changes in EN elements, addressing the dynamic transmission process from "spatial field" to "spatial structure entity". Based on this approach, GeoDetector is employed to reveal the response extent of EN elements to LUCC. The results indicate: (1) In the past 20 years, the area of construction land has increased by 100 %, while mining land has increased by 69 %. This significant increase in LUCC has led to a notable enhancement in ecological resistance in the study area, driving the generation of 20 % more ecological pinch points and barriers. Additionally, it has resulted in a twofold increase in both the number and length of level 1 ecological corridors. (2) The dominant status and structure of grassland, agriculture land, and woodland remain relatively stable; however, the interflow among them has caused approximately 25 % of the ecological corridors to undergo changes such as disappearance and path alteration. (3) The implementation of ecological protection and restoration has led to a continuous increase in the area of ecological sources, particularly with the mining rehabilitation increasing by 32.7 times compared to 2000, thereby driving gradual improvement in 25 % of the ecological network elements. (4) Although the quantity and length of ecological corridors in the study area remain relatively stable, evaluation results indicate that its spatial structure is gradually deteriorating, with ecological connectivity decreasing by 7.7 %. This study highlights the importance of restoration of ecological processes in sub-urban open-pit mining concentration areas. The study results can provide a scientific basis for ecological restoration and sustainable development in resource-based cities.

PERHITUNGAN EMISI GAS RUMAH KACA DALAM KAWASAN PERTAMBANGAN

Carbon emissions are one of the components of greenhouse gas (GHG) emissions in the form of carbon dioxide (CO2) which mainly comes from the use of fossil fuels and various human activities. Based on fossil fuel and industrial emissions data, in 2022 Indonesia ranked as the 6th largest carbon emitting country in the world after China, the United States, India, Russia and Japan, with 728.88 million tons of CO2e total emissions. The Ministry of Industry reported that total GHG emissions from Indonesia's industrial sector reached 238.1 million tons of CO2e in 2022. In the mining industry, GHG emissions originate from deforestation, energy use, processing, and refining, with non-renewable energy use being the largest emitter. GHG emissions from primary mineral and metal production contribute approximately 10% of global GHG emissions related to energy. Each mining industry may have varying primary sources of GHG emissions depending on the type of mine and the final product. Mining industries, as one of the major emitters, must conduct GHG inventories to understand emission sources and develop effective reduction strategies. GHG inventory activities are conducted based on guidelines provided by the Ministry of Environment and Forestry's National Greenhouse Gas Inventory Management Handbook (2012), Book II Volumes 1-4. Efforts to reduce GHG emissions can be undertaken through planting plants that have high carbon absorption and storage capabilities in mine reclamation activities, as well as using New and Renewable Energy (NRE) as an alternative to replace fossil energy.

Soil erodibility results of revegetation using bitti plant at various ages reclamation of quarry a lime stone mine at Pt Semen Tonasa, Pangkep District, South Sulawesi

Background: Limestone mine reclamation carried out by PT Semen Tonasa is carried out periodically as an effort to restore land conditions in a sustainable manner. The reclamation was carried out in the form of revegetation using endemic plants, namely the bitti plant (Vitex cofassus R.) which grows a lot in the southern part of Sulawesi. This study aims to determine the erodibility of the soil in limestone mine reclamation land planted with bitti plants. Methods: The method used is the survey method by determining the location of soil samples using the purposive sampling method based on the reclamation age planted with bitti plants in 2019, 2015 and 2010 and determining the erodibility value using the formula according to Wischmerier and Smith (1978). Parameters used included soil texture, soil structure, organic matter, soil permeability, soil pH, and soil unit weight. Findings: The results of this study indicate that the erodibility of the soil in the limestone mine reclamation land planted with bitti plants is classified as high due to the high dust content which is influenced by the parent material. The results of this study indicate that the erodibility value of the land reclamation in 2019 was classified as moderately low to moderately high, the land reclamation in 2015 was classified as moderate to moderately high, and the land reclamation in 2010 was classified as moderate to high. Conclusion: The factor affecting the erodibility of the soil in the reclamation area is the M value (percentage of very fine silt and sand). Novelty/Originality of this Study: The novelty of this study lies in the examination of soil erodibility changes over different reclamation ages in a limestone mine using endemic bitti plants. This research highlights the unique relationship between reclamation age and soil properties, contributing valuable insights into effective land reclamation practices in tropical karst environments.

Visiting mine reclamation: How field experience shapes perceptions of mining.

Recognizing the prevailing negative public opinion on mining, it is important to understand how firsthand encounters with mining activities might influence these perceptions. This study investigates how field trips to open pit coal mines and their reclamation sites in the Czech Republic affected the attitudes of 148 university students toward mining and mine reclamation. Using pre and post trip questionnaires, we observed significant changes: Students became less neutral about mining, saw it as a temporary disruptive activity, expressed reduced concern for social conflicts in mining areas, and showed increased support for the ecological restoration of post mining sites. These findings underscore the transformative impact of direct engagement with mine reclamation activities on shaping attitudes. Understanding these effects offers promise for positively shifting public perceptions of mining practices, emphasizing the potential for constructive changes in attitudes through field experiences with reclamation efforts in the Global North.

Quantifying mine waste rock physical weathering rate and processes for improved geomorphic post-mining landforms

Erodibility of landform surfaces depends on several factors and numerical methods are needed to predict erosion and landform evolution particularly for post-mining landscapes. Surface armouring caused by immobile coarse particles tends to reduce the erosion potential of landform surfaces significantly. However, the breakdown of such material through weathering could destabilise this armour and lead to high erosion rates. Hence, the surface erodibility of newly constructed landforms (here we focus on post-mining landforms) can rapidly change over a few years to decades. At present, it is difficult to predict with certainty the rate, or in some cases the dominant processes and pathways, of soil erodibility and soil production over post-mining landscape design lifetimes (typically 100–1000 years). To improve our understandings of soil evolution and its relationship to soil erosion, data is needed to determine the rate at which fine transportable material is produced from the weathering of larger, non-transportable particles, the resultant fragment size distribution together, and how that distribution evolves over time.Here, laboratory weathering experiments were conducted for four different materials from a single coal mine in the Bowen Basin, Queensland, Australia. Wetting and drying cycles were found to rapidly weather all materials. After 32 wet and dry cycles, all materials had a less coarse particle size distribution than at the start. Heating and cooling had no measurable influence on weathering. Due to the rapid reduction of particle sizes caused by high weathering rates, the materials examined would not provide surface armour capability. A new mathematical methodology was developed to determine the weathering parameters for an existing numerical model based on the weathering mechanism and particle size-dependent weathering rate. Although the materials were collected from the same geographical location, they undergo weathering through different mechanisms and rates. Size dependent weathering rate analysis showed that most samples have high weathering rates for large particles and lower weathering rates for smaller particles. The methods used here are simple and inexpensive and can be easily employed to assess mine rehabilitation materials' weathering and armour potential.

Research on ecological restoration and green reclamation technology of goaf in phosphorus mines

The subsidiary of Yunnan Phosphate Group Co., Ltd., Kunyang Phosphate Mine’s mining area is the subject of study. The mining of open-pit phosphate mines has caused significant damage to the ecological environment. Therefore, carrying out ecological restoration and green reclamation of the ecosystem in the mining area has become the top priority for current development. This article establishes an evaluation system for ecological restoration indicators, selecting four indicators including vegetation coverage, soil and water conservation, restoration of native plants, and Plant Species Diversity Index to assess the effects of ecological restoration and green reclamation of phosphate mines. The techniques of reconstructing soil ecological structure using phosphate tailings substrate and improving acidic soil with soil conditioner and calcium-magnesium phosphate compound fertilizer were applied. A series of other measures were taken, including: drafting scientific ecological restoration plans; employing physical, chemical, and biological methods for ecological restoration and green reclamation; selecting suitable plant species for planting; enhancing planting techniques; and strengthening post-restoration ecological monitoring and regulation. After ecological restoration and green reclamation, the Ecological Remediation Effect Index (EREI) for the years 2020, 2021, and 2022 were 48.40, 87.38, and 93.23 respectively, indicating significant improvement in the ecological environment. Furthermore, the difficulties encountered during the ecological system restoration process of the mine and the future development directions were summarized, providing practical and guiding significance for ecological restoration and green reclamation of abandoned mining areas both domestically and internationally.

Combining Organic and Inorganic Fertilization Enhances Soil Enzyme Activity, the Bacterial Community, and Molecular Ecological Network Complexity in Coal Mine Reclamation Areas

Combined organic and inorganic fertilization can improve soil fertility in coal mine reclamation areas. However, the contribution of the bacterial community (especially its occurrence patterns) to soil physicochemical properties and enzyme activity needs further evaluation. The objective of this research was to clarify the bacterial community diversity, composition, and intraspecific interactions in response to combined organic and inorganic fertilizer application in coal mine reclamation areas in the Loess Hilly Region, China. Maize rhizosphere soil samples were collected under four fertilization regimes (CK, no fertilization control; NPK, compound inorganic fertilizer; M, organic fertilizer; and NPKM, combined organic and inorganic fertilization) in a 10-year field experiment in Gujiao city, Shanxi Province. Bacterial communities were characterized using high-throughput sequencing of the 16S rRNA gene V3–V4 region. A cross-treatment Spearman correlation network was constructed to explore the bacterial co-occurrence patterns. Compared with CK, NPK, M, and NPKM decreased the pH by 0.59%, 2.27%, and 0.12%; increased the soil organic carbon by 11.25%, 11.69%, and 27.05%; and significantly decreased the bacterial Shannon diversity by 3.68%, 0.14%, and 3.54%, respectively. Compared with CK, NPKM significantly increased sucrase, urease, and alkaline phosphatase activities (p &lt; 0.05). Critically, oligotrophic Acidobacteria were significantly more abundant in CK than in the other treatments. Gemmatimonadetes were more abundant in NPK and M, and Actinobacteria, Bacteroidota, and Patescibacteria were more abundant in NPKM. In addition, network analysis revealed that the keystone taxa in the different fertilization treatments belonged to different network modules and were significantly correlated with soil nutrient content and enzyme activity. Simultaneously, the Actinobacteria enriched in NPKM formed specific clusters through strong symbiosis, and there were significant positive correlations among sucrase, urease, and alkaline phosphatase. In summary, long-term combined organic and inorganic fertilization improved maize rhizosphere soil fertility by regulating enzyme activity, bacterial community composition, and bacterial species interactions in coal mine reclamation areas in the Loess Hilly Region.

Batch Operating Limestone Treatment Systems (BOLTS): Greater Efficiency and Cost Savings

Reclamation Highlights: A novel batch operating limestone treatment system was used to treat mine drainage. Batch limestone treatment can decrease necessary limestone volume and overall cost. Treating mine drainage in batches could foster mine reclamation innovation.