Sand Mining Research Articles

Spatial and Temporal Variations of Total Suspended Matter Concentration during the Dry Season in Dongting Lake in the Past 35 Years

Dongting Lake is the second largest freshwater lake in China, located in the middle reaches of the Yangtze River. Since the 21st century, it has faced intensified human activities, particularly the Three Gorges Dam impoundment and sand mining. The water quality of Dongting Lake has significantly changed due to human activities and climate change. Currently, quantitative studies on the spatial–temporal variations of total suspended matter (TSM) during Dongting Lake’s dry season and the human impacts on its concentration are lacking. This study utilizes Landsat-5 TM and Landsat-8 OLI data to estimate the changes in TSM concentration during the dry season from 1986 to 2021, analyzing their spatial–temporal variations and driving mechanisms. By evaluating the atmospheric calibration accuracy and model precision metrics, we select a model based on the ratio of red to green band, achieving an R2 of 0.84, RMSE of 18.94 mg/L, and MRE of 27.32%. Applying this model to the images, we map the distribution of the TSM concentration during the dry season from 1986 to 2021, analyzing its spatial pattern and inter-annual variation, and further investigate the impacts of natural factors and human activities on the TSM concentration. Our results show the following: (1) From 1986 to 2021, the TSM concentration during the dry season ranges from 0 to 200 mg/L of Dongting Lake, with an area-wide average value between 41.61 and 75.44 mg/L. (2) The TSM concentration from 1986 to 2021 is significantly correlated with the water level. Before 2006, it correlates positively, but no significant correlation exists from 2006 onward. (3) From 2006 onward, the mean TSM concentration is notably decreased compared to that before 2006, likely due to the Three Gorges Dam, while our analysis indicates a significant positive correlation between the TSM concentration and sand mining intensity during this period. This study highlights the influence of the Three Gorges Dam and sand mining on the TSM concentration in Dongting Lake during the dry season, providing valuable insights for related research on similar lakes.

Sand mining governance in post-apartheid South Africa: Interlegalities of resource extraction on the Wild Coast

This viewpoint explores the challenge of the intersection of demand for sand, concerns over its exploitation and its governance in South Africa. Mainly drawing on secondary literature review and direct observations, we highlight the irony of the concern about the environmental cost of sand mining, in the midst of poor sand mining governance. The viewpoint argues that the problem in the Wild Coast is the multiple jurisdictions of sand mining governance, ranging from national, provincial and local government legislation, policies and practices, that combine and create confusion. We call for stronger governance locally, and at other scales, including opening up legal mining opportunities, especially in light of current unauthorized sand mining taking place.

Recurrence interval of riverbed sand mining hotspots in the Mekong delta: Potential indications of unsustainable replenishment rates

Rampant and illegal river sand mining in the Vietnamese Mekong Delta (VMD) has led to substantial sediment losses and bank erosion. However, regulation of this issue remains a significant challenge due to insufficient monitoring and enforcement efforts, partly attributed to limited data and technology. To support an improved monitoring system in the VMD, this study investigates the spatiotemporal changes in sand mining hotspots and their underlying drivers. The recurrence intervals of sand mining boats were assessed from 2014 to 2020 using Sentinel-1A, and its association with riverbed incisions were examined from bathymetry field surveys between 2017 and 2020. Our results attest to sand mining intensification from 2015 to 2020, particularly in the upstream section of the VMD, where 70% of the activity was recorded. Not only was there an apparent increase in sand mining hotspots by 32.4%, but most hotspots recorded a recurrence interval of 2 years. This potentially indicates a minimal timeframe of sediment replenishment before the same locations become economically viable for further sand extraction. Additionally, a correlation was detected between sand mining hotspots and significant riverbed incisions, although the lack of spatial overlaps in some regions suggests other upstream influences like bank collapse and river damming. Our study, through the meticulous assessment of sand mining boat movement and river bathymetry data, ultimately sheds light on the potentially unsustainable scale of sand mining activities in the VMD. It aims to support informed decision-making and effective regulations that tackle excessive sand extraction amid the dynamic environmental challenges we face, while offering valuable insights to similar deltas worldwide.

Environmental Impact of River Bank Erosion on Stream Morphology: A Study of the Mini Piti Stream, Obio-Akpor, Nigeria

This study was designed to assess the impact of river bank erosion on the environment and the channel morphology for the Mini-Piti stream in Obio-Akpor local government area of Rivers State, Nigeria. This study determined the depth variations from width measurements due to bank erosion activities and the impact of indiscriminate waste dumps on the river channel. Physical water quality parameters of temperature, turbidity, transparency and TSS were determined using standard methods. The stream was divided into three stations; upstream 2.5km, midstream 2.5km, and downstream with intervals of 1km measured to differentiate each station as 5 samples were obtained per station at intervals of 0.5km apart. The flow velocity and discharge were estimated as the average depth recorded upstream being DS 0.9m, WS 1.4m, Midstream DS 1.3m, WS 1.7m, and Downstream = DS 1.5m WS 1.7m. The maximum width of 11m and minimum of 0.1m were recorded though natives confirmed that the stream is closing up unless maintenance dredging to expand the depth and width, the loss of this channel cannot exceed 20 years. The field observation and the impacts of precipitation and storm water from the built area of midstream were very intensive whose action increased the water level above its channel capacity and eroded the bank. From t-test analysis, there were significant seasonal variations in the depth for the measured widths for the upstream T (8) =2.1, p= 0.036 and the midstream, T (8) =2.36, p=0.023. Similarly using the one-ANOVA, a significant variation in the depths of five locations during the dry season downstream F (4, 60) = 2.79, p= .03 was recorded. The Tukey’s HSD post hoc test showed the locations have no significantly high depths for the studied widths sizes (p<0.01 and p<0.05). A one-way ANOVA revealed a significant variation in the depths of five locations during the wet season upstream F (4, 60) = 5.966, p= .000. The Tukey’s HSD post hoc test showed the locations have significantly high depths for the studied widths sizes (p<0.01 and p<0.05) at locations L2:L4 at Q=5.53 (p=0.00216, L2:L5 at Q= 4.72 (p=0.1214), L3:L4 at Q=4.90 (p=0.00841) and L3:L5 at Q=4.10 (p=0.0403). The studied physical parameters were all above WHO permissible standards and there were no significant variations between dry and wet seasons (38% turbidity midstream, TSS-33%, 31% and 30.6% variation upstream, midstream and downstream respectively) as well as spatial changes. The collapsed sediments and waste dumped at the bank of the stream were transported downstream due to reduced velocity and coarser sediments trapped at the stream bed causing shallow depth while the suspended fine sediment on the water column reduced the clarity of the stream resulting in adverse flooding over 20 years now. The research revealed that bank erosion has significant impact on water quality due to poor transparency and geometry of stream by the alterations of the channel depth and width, flow rate, scouring and deposition of sediments in the stream. The need for regulatory agencies to control anthropogenic inputs and enhance bank erosion prevention programmes cannot be over-emphasized. The monitoring of indiscriminate urbanization programmes to limit excess scouring activities by National Inland Waterways Authority (NIWA) is very essential to reduce excessive sand mining.

Assessing Carbon Capture and Carbonation in Recycled Concrete Aggregates: A Holistic Life Cycle Assessment Perspective with Simulation at Industrial Scale

This work explores a life cycle assessment (LCA) concerning carbon capture and carbonation of recycled concrete aggregates (RCA), addressing the growing challenges posed by increased carbon emissions in power generation and ecological concerns tied to construction waste. We propose an integrated solution involving the capture of low-concentration carbon dioxide (CO2) from natural gas combined cycle (NGCC) power plants through aqueous ammonia absorption and sequestration by mineralization of RCA. The cradle-to-gate LCA focuses on an industrial-scale scenario for capturing 200 kilotonnes of CO2 annually, with functional unit per tonne of carbonated RCA output. The findings reveal a net positive carbon abatement of 21.42 kg CO2 eq., with heat production and electricity consumption being the major contributors to global warming potential (GWP). Within the spectrum of environmental impact categories under study, Marine Aquatic Ecotoxicity Potential (MAETP) exhibits a significant impact, primarily influenced by sulfur production. Human Toxicity Potential (HTP) follows as the second-worst contributor, with 96.80% of its impact attributed to heat and sulfur production. Subsequently, Acidification Potential (AP) follows, arising from sulfur and sulfuric acid production. Sensitivity analysis and Monte Carlo simulation introduce a ±20% standard deviation to electricity and thermal energy consumption. Scenario analysis demonstrates a net carbon-positive abatement potential of 286.66 kg CO2 eq. per tonne of CO2 input. Employing carbon mineralization for CO2 capture not only reduces emissions but also repurposes waste materials, providing a comprehensive and sustainable solution for effective CO2 management, contributing to reduced sand mining, and offering cost advantages through the production of carbonated RCA.

Synthesis of Alpha Ferrous Oxalate Dihydrate from Ferrotitaniferous Mineral Sands via Hot Pressurized Aqueous Oxalic Acid: Kinetics and Characterization

Ferrous oxalate dihydrate is a versatile organic mineral with applications across fields. However, little is known about the feasibility of its synthesis directly from iron-bearing minerals using binary subcritical water (sCW) systems and its associated kinetics. In this study, the sCW+oxalic acid system at either 115 °C or 135 °C was investigated as a reaction medium for ferrous oxalate dihydrate (α-FeC2O4∙2H2O) synthesis, starting from ferrotitaniferous sands. The kinetics of the synthesis reaction were studied, and the physicochemical characterization of the as-synthetized ferrous oxalates was performed. Overall, the sCW synthesis was temperature-dependent, following second-order reaction kinetics according to the proposed precipitation pathway. A high reaction rate constant, significantly high yields (up to 89%), and reduced reaction times (2–8 h) were evident at 135 °C. The as-synthetized product corresponded to the monoclinic α-FeC2O4∙2H2O, showed relatively high specific surface areas (from 31.9 to 33.7 m2∙g−1), and exhibited band gap energies within the visible light range (~2.77 eV). These results suggest that α-FeC2O4∙2H2O can be synthesized using an organic dicarboxylic acid and iron-rich, widely available, low-cost mineral precursors. In addition, the as-prepared α-FeC2O4∙2H2O could be further optimized and tested for catalytic and visible light photocatalytic applications.

Impact of diverse material precursors on microstructure and ionic conductivity Li0.33La0.56TiO3 solid-state electrolyte properties

The development of rechargeable lithium-ion batteries (LIBs) with solid-state electrolyte (SSE) is gaining attention in recent years. Among various SSE materials, lithium lanthanum titanate (LLTO) has emerged as a promising candidate due to its high ionic conductivity and excellent chemical stability. This study aims to synthesis and investigate the potential of Indonesian locally source lanthanum oxide compared to commercial lanthanum oxide for use as an SSE material. LLTO powders were synthesized via the solid-state reaction method. The local LLTO pellet achieved an impressive relative density of 99 %, slightly higher than the commercial LLTO at 97 %. This high relative density enhances ionic conductivity. The local LLTO sample achieved the highest ionic conductivity of 2.68×10−5 S/cm at 100°C and 1.15×10−5 S/cm at room temperature, nearly double that of commercial LLTO measuring approximately 8.40×10−6 S/cm at 100°C and around 4.57×10−6 S/cm at room temperature. The research findings indicate that lanthanum oxalate sourced from waste generated during monazite sand mining operations in the Bangka Belitung region of Indonesia, exhibits potential as a material for lithium-ion-conducting electrolytes in all-solid-state batteries.

Remote sensing of artisanal and small-scale mining: A review of scalable mapping approaches

Artisanal and small-scale mining (ASM) significantly influences the socio-economic development of many low-to-middle-income countries, albeit sometimes at the expense of environmental and human health. Characterized by its labor-intensive extraction from confined (<5 ha) or peripheral mineral reserves, congregated ASM practices can rival the spatial footprint of industrial mines. The unregulated and informal nature of many ASM activities presents monitoring challenges that remote sensing (RS) methods aim to address. While local-scale ASM mapping has seen success, scaling these methods to regional or global levels remains unclear. We review literature on mapping ASM to determine: (1) if studies represent the global distribution and diversity of ASM activities, (2) how ASM's unique characteristics influence the choice of RS methods, and (3) which RS approaches are the most accurate and cost-effective. We found current studies disproportionately focused on ASM regions in Africa, which highlights the need to extend the research to other regions with unique ASM characteristics, such as coal and sand mining in India and China. The selection of RS approaches is heavily influenced by local ASM contexts, the scale of analysis, and resource constraints such as funding for high-resolution imagery and validation data availability. We argue that accurate regional-scale ASM mapping (>100,000 km2) requires innovative combinations of data and methods to overcome data management and storage challenges. Local community participation, including miners, is vital for on-ground mapping and monitoring capacity. We outline a research agenda needed to develop a range of approaches for mapping and monitoring ASM in under-studied regions. By synthesizing effective methods, we provide a foundation for generating accurate and comprehensive spatial data, addressing the issues of inaccurate and incomplete data that global ASM platforms aim to resolve. This spatial data can guide policymakers, NGOs, and businesses in making informed decisions and targeted interventions to improve ASM sector safety, sustainability, and efficiency. Leveraging cloud-based geoprocessing platforms, with regularly updated global satellite image archives, combined with crowd-sourced on-ground information offers a potential solution for sustained regional-scale monitoring.

Simulation-Based Integration of Thermal Drying of Fluid Fine Tailings for Tailings Management and Freshwater Conservation in Oil Sands Mining

Simulation-Based Integration of Thermal Drying of Fluid Fine Tailings for Tailings Management and Freshwater Conservation in Oil Sands Mining

Electrodeposition of calcareous cement from seawater in marine silica sands

The erosion of marine sediments is a pressing issue for coastal areas worldwide. Established methods to mitigate coastal erosion fail to provide lasting and sustainable solutions to protect marine ecosystems. Here we demonstrate the application of mild electrical stimulations to precipitate calcareous mineral binders from seawater in the pores of marine soils via electrodeposition, an alternative approach to mitigating coastal erosion. Results of electrochemical laboratory experiments unveil that the polymorphs, precipitation sites, intrusion mechanisms, and effects of electrodeposited minerals in marine sands vary as a function of the magnitude and duration of applied voltage, soil relative density, and electrolyte ionic concentration. Surprisingly, in addition to the precipitation of calcium carbonate and magnesium hydroxide, the formation of hydromagnesite is also observed due to electrically driven fluctuations in the local pH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${pH}$$\\end{document}. These electrodeposits lead to enhanced mechanical and hydraulic properties of the marine sands, indicating that electrodeposition routes could be developed to reinforce marine soils in coastal areas that more closely mimic natural systems.

Tinjauan Hukum Pidana Islam Terhadap Penambangan Pasir Ilegal Untuk Bahan Pembangunan Proyek Di Pasaman Barat

The sand mining activities taking place in West Pasaman, specifically in the Paku River area, Kinali Nagari, Kinali District, are unauthorized or illegal mining activities carried out by several parties. The consequences of this mining have led to environmental damage, prompting local residents to report the matter to the West Pasaman District Police for legal action. This study aims to examine Islamic criminal law related to illegal sand mining used for construction projects in West Pasaman. The method used in this research is empirical juridical research using primary and secondary data. Factors that contribute to illegal sand mining in the Paku River area, Kinali Nagari, Kinali District, West Pasaman Regency include economic needs, demand for building materials, lack of supervision and legal socialization on mining, and the difficulty of obtaining people's mining licenses (IPR) or special mining business permits (IUPK). The results of the study show that illegal mining is regulated under Law No. 3 of 2020, specifically in Articles 158 to 164. Unauthorized sand mining is regulated in Articles 158 to 164 of Law No. 4 of 2009. From the perspective of Islamic criminal law, illegal sand mining that causes environmental damage is considered a prohibited act (jarimah), as explained in Surah Al-Baqarah 205, which emphasizes that humans have a responsibility to manage and utilize natural resources wisely to achieve prosperity and to protect the environment in all contexts.

Changes in fungal abundance and biochemical properties of soil through a temporal restoration of forests

Changes due to the exploratory management of the soil and cultivated plant species can interfere with the cycling of nutrients vital for soil fertility. This biogeochemical cycling of soil is an interaction of physical, chemical, and biological processes that can be altered by land use change and management. Therefore, the objective of this study was to evaluate soil quality indicators in sand-extraction-degraded areas that had been reforested at different times and compare them to an unrestored area and native forest fragments. The five areas reforested with native Atlantic Forest species were 20, 17, 10, 7, and 5 years old. The fungal abundance, microbial respiration rate, enzyme activity, and C content were evaluated in soil samples collected at a depth of 10 cm. In addition, the total organic carbon, soluble carbon content, total carbohydrates, moisture, organic matter, and pH of these soils were studied. Our results verified a significant improvement in the fertile fraction of these soils due to the action of microorganisms in the different reforestation areas. The longer the reforestation period, the more the soil exhibited similar characteristics to native forests and approached the level of primary forests. The unrestored sand mining degraded soil area had the poorest fungal community and the least biochemical activity, which was less than the fungal abundance and activity of the most recent reforestation. These results suggest that the use of microbial and enzymatic activities as soil quality indicators is a viable approach to assess the impact suffered from past uncontrolled exploitation in areas that are undergoing ecological restoration processes of native forests.

The Impact of Sand Mining on the Environment in Tamedan Village, North Dullah Island District, Tual City

This study aims to determine the impact of sand mining activities on the environment in Tamedan Village, Pulau Dullah Utara District, Tual City. This research method uses a descriptive method with a quantitative and direct field approach. The population in this study was the Tamedan Village community both directly involved in mining and those affected by sand mining. The variables in this study consist of sand mining activities (X) and environmental damage (Y). Data collection techniques in this study were conducted through observation, interviews, filling in questionnaires, and documentation, while for data analyzing data using descriptive statistics and inferential analysis. Bassed on theprocessed data, it is known that the independent variabel (X), namely sand mining activities, has an effect on the dependent variabel (Y) , namely environmental damage, determined based on the significant value in the results the value obtained is 0,001 &lt; 0,05, which means that the variabel X has an effect on the variabel Y. the process of mutual influence, namely sand mining on environmental damage, the higher the number of sand mines, the higher the environmental damage in Tamedan Village, North Dullah Island District Tual City

Precious and Base Metal Minerals in Black Sands of the Egyptian Mediterranean Coast: Mineralogical and Geochemical Attributes

This paper investigates the mineralogical and geochemical characteristics, as well as the possible sources, of gold, silver, platinum group elements (PGE), copper, and lead found in the beach sands along Egypt’s Mediterranean coast. Using scanning electron microscopy and electron probe micro-analysis, this study determines the morphology and micro-chemistry of separated grains to assess their economic potential and how various minerals respond to different transport distances. The analysis reveals that gold grains are of high purity (94.11 to 98.55 wt.%; average 96 wt.% Au) and are alloyed with Ag (1.28–2.32 wt.%) and Cu (0.16–3.15 wt.%). Two types of gold grains were identified, indicating differences in transport distances. Variations in morphology, surface features, inclusion types, rims, and chemistry of the native metals, including gold grains, suggest differences in composition, weathering degree, transport distance, deposit types, and host rocks. The average Ag concentration in gold grains (1.86 wt.%) suggests a link to mesothermal or supergene deposits. Most silver, copper, and lead grains are spherical, with some variations in shape. Silver grains have 71.66–95.34 wt.% Ag (avg. 82.67 wt.%). Copper grains have 92.54–98.42 wt.% Cu (avg. 94.22 wt.%). Lead grains contain 74.22–84.45 wt.% Pb (avg. 79.26 wt.%). The identified platinum group minerals (PGM) belong to the Pt–Fe alloys and sperrylite, both of which are PPGE-bearing minerals. These metals likely originate from the weathering of upstream Nile tributaries surrounded by igneous and metamorphic rocks from Ethiopian and Central African regions, with a minor contribution from the Egyptian Eastern Desert Mountains.

Noise pollution assessment and management in rare earth mining areas: a case study of Kollam, Kerala, India.

Noise pollution is an unintentional consequence of mining activities, needing rigorous assessment, monitoring, and mitigation techniques to reduce its impact on local residents and ecosystems. The study specifically examines the noise pollution from rare earth mining activities in the Neendakara-Kayamkulam (NK) coastal belt, Kollam, Kerala, India, a region rich in ilmenite, rutile, sillimanite, zircon, and monazite. Despite the known environmental and health impacts of noise pollution, there is limited specific data on its magnitude and sources in this region, as well as a lack of effective mitigation strategies tailored to rare earth mining operations. Studies have indicated that mining operations, such as the movement of heavy mineral sands, considerably elevate noise levels, which have an effect on the environment's quality and public health. This study seeks to fill the gap by geospatial mapping and assessing the noise levels and recommend measures to effectively mitigate noise pollution. Systematic noise measurements were conducted at 48 suitable locations within the NK coastal belt, including residential, commercial, industrial, coastal, and silence zones. The noise levels vary from 49.1dB(A) near a religious place to 82.4dB(A) near the local industry. The study employs geospatial noise mapping and land cover superimposition to implement class-specific mitigation measures for noise pollution in a coastal vicinity mixed land use area, including natural and vegetative barriers, operational scheduling, zoning, and land use planning.

Productivity Analysis of Excavator Heavy Equipment in Sand Mining at PT Mitra Pasir Siliwangi

Heavy equipment, including mining activities, is a crucial resource often required in project work. PT Mitra Pasir Siliwangi in Sintang Regency uses heavy equipment from the excavator to support sand mining operations. This study aims to determine the productivity value of heavy equipment in sand mining activities, specifically the Kobelco SK 130-8 Excavator. The productivity value is obtained from field data collected over seven days and compared with the planned productivity per the company's planning. The study results show that the planned productivity value for the heavy equipment is 91.58 m³/hour, while the actual field productivity value is 65.89 m³/hour. Therefore, it is concluded that using the Kobelco SK 130-8 Excavator for sand mining has a lower field productivity value than the planned productivity. This discrepancy is due to several factors, such as data recording errors in the field and frequently idle equipment (the machine is running but not performing mining activities).

Adsorptive-Photocatalytic Composites of α-Ferrous Oxalate Supported on Activated Carbon for the Removal of Phenol under Visible Irradiation.

Adsorptive-photocatalytic composites based on activated carbon (AC) and α-ferrous oxalate dihydrate (α-FOD) were synthesized by an original two-step method and subsequently used for the removal of phenol from aqueous solutions. To obtain the composites, ferrotitaniferous black mineral sands (0.6FeTiO3·0.4Fe2O3) were first dissolved in an oxalic acid solution at ambient pressure, and further treated under hydrothermal conditions to precipitate α-FOD on the AC surface. The ratio of oxalic acid to the mineral sand precursor was tuned to obtain composites with 8.3 and 42.7 wt.% of α-FOD on the AC surface. These materials were characterized by X-ray powder diffraction, scanning electron microscopy, and the nitrogen adsorption-desorption method. The phenol removal efficiency of the composites was determined during 24 h of adsorption under dark conditions, followed by 24 h of adsorption-photocatalysis under visible light irradiation. AC/α-FOD composites with 8.3 and 42.7 wt.% of α-FOD adsorbed 60% and 51% of phenol in 24 h and reached a 90% and 96% removal efficiency after 12 h of irradiation, respectively. Given its higher photocatalytic response, the 42.7 wt.% α-FOD composite was also tested during successive cycles of adsorption and adsorption-photocatalysis. This composite exhibited a reasonable level of cyclability (~99% removal after four alternated dark/irradiated cycles of 24 h and ~68% removal after three simultaneous adsorption-photocatalysis cycles of 24 h). The promising performance of the as-prepared composites opens several opportunities for their application in the effective removal of organic micropollutants from water.

Sand Mining Tailings as Supplementary Cementitious Material

Sand mining tailing (ST) is a byproduct of the sand extraction of submerged pits, a process which is carried out to obtain aggregates for civil construction. This tailing consists of fine particles from the pulp washing process, usually disposed of in decantation ponds. The present study proposes ST as a supplementary cementitious material (SCM) for Portland cement concrete, thereby reintegrating this tailing into the production chain. In this sense, ST was characterized, and concretes containing 2% to 14% of cement replacement (%vol) by ST were produced and evaluated. STs showed natural fineness, particles with angular morphology, a significant amount of kaolinite, and 36% amorphous content. ST concretes exhibited a compressive strength of up to 57.9 MPa at 28 days under 7.0% of cement replacement, 38.8% higher than the reference. Consequently, only 5.6 kg/m3 of Portland cement was required to attain 1.0 MPa, representing a 33.6% reduction compared to the reference. The ultrasonic pulse velocities measured in ST concrete with 2.0%, 4.0%, 7.0%, and 14.0% cement replacement were 3.0%, 6.1%, 9.3%, and 6.6% higher than the reference, respectively. These results indicate enhanced mechanical properties, improved matrix uniformity, and superior environmental performance across all SCM levels compared to the reference, with optimal efficiency observed at 7.0% ST content.

Performance of Modified Polymer as a Binder with Qarry Dust and Ballast in the Production of Paving Blocks

The city of Nairobi is in need of pedestrian and cyclist infrastructure as an answer to an increasing reliance on automobiles. Collaborative efforts are underway to reduce congestion, although challenges such as sand mining persist. The utilization of plastic waste and Quarry Dust (QD) may provide a sustainable solution. The proposed study aims to assess the mechanical properties and optimal blend design for the production of paving blocks using a modified polymer and a combination of ballast (B) and QD. The gradation curve constituted a pivotal stage in the research process, as it provided vital information regarding the ratio of B and QD required for the optimal mix design. The study methodically explored the optimal ratio of materials for the production of paving blocks incorporating a modified polymer, QD, and B. It was observed that there were minor reductions in strength under acidic conditions, which suggests that the proposed paving blocks may be suitable for use in a variety of outdoor applications. Additionally, it would be advantageous to investigate innovative solutions for Non-Motorized Transport (NMT) infrastructure.

Penegakan Hukum dalam Penanggulangan Kejahatan Pertambahan Pasir Ilegal

The crime of illegal sand mining is a problem that requires the attention of various parties. The current phenomenon is that illegal mining is rampant among individuals and companies. Based on data from the Central Lampung Police, illegal mining crimes occur every year, while data from Walhi Lampung and the Environmental Service shows that there are still very few mining activities that have IUPs. This shows that illegal mining crime is a problem that must be handled by various elements. The research method used is a Normative Juridical and Empirical Juridical approach. Sources and types of data in research were obtained from field studies with interviews and literature studies. This research was conducted at the Central Lampung Police, lecturers at the Faculty of Law, Unila University, Walhi Lampung, and the Environmental Service. The results of this research describe that the police do not only focus on law enforcement, but also focus on preventative efforts to tackle illegal mining crimes. Even though Law Number 3 of 2020 concerning Mineral and Coal Mining, the Police does not contain the authority of the Police in mining crimes. However, the police as the front guard of law enforcement officials must make countermeasures. This includes pre-emptive efforts to identify potential risks that cause illegal mining to occur. Monitoring efforts are carried out actively and periodically and are routinely used as an effort to detect potential crimes before they develop into real crimes. The preventive approach involves outreach and education activities in areas where there is potential for mining to increase public awareness about the negative impacts of illegal mining crimes. Then the last one is repressive efforts as a form of providing legal certainty