Waste Dumps Research Articles

Mercury and lead pollution in rivers in Ghana: geo-accumulation index, contamination factor, and water quality index

Abstract The main environmental problem in Kumasi is water pollution, but little is done about this. Neither water quality nor the degree of heavy metal contamination in Kumasi has been assessed. The degree of mercury and lead pollution in Kumasi was investigated in this study by determining the geo-accumulation index, the contamination factor, and the water quality index (WQI) of mercury and lead in selected rivers in Kumasi. Mercury and lead concentrations were the highest in the Aboabo River, particularly in the Anloga area. This was attributed largely to electronic waste dumping, collection, and processing in the area. The WQI of the rivers indicated that the water was unsuitable for drinking. It is also shown that the water should not be used for crop cultivation or animal rearing, which are among the anthropogenic activities that are both carried out along the rivers, to limit risk to human health.

Estimating Coal Mine Dump Stability from Its Natural Oscillations (Based on Seismic Monitoring at the Kolyvan Anthracite Deposit, Novosibirsk Region)

Abstract —Based on the analysis of the 2017–2021 recordings from the Kharino seismic station (the Altai-Sayan seismic stations network) and the 2002–2019 satellite imagery, the trigger of the July 18, 2020 earth-slide at Elbashinsky waste rock dump of the Kolyvan Anthracite Deposit (Novosibirsk region) has been established. The study of natural oscillations of the mine waste dump allowed estimating its stability and thus contributing to environmental and industrial safety in surface mining of solid minerals.

Effect of Substrate Concentration and Temperature for Bio-Enzyme Production Using Enterococcus faecalis Isolated from Waste Dump Soil in Sokoto Metropolis, Nigeria

The study evaluated the effect of substrate concentration and temperature on the production of amylase enzyme by Enterococcus faecalis from the wastes dump soil Sokoto Metropolis, Nigeria. Five bacteria species were isolated and biochemically characterized which include E. coli, B. subtilis, S. aureus, E. faecalis and P. aeroginosa. The screening of identified bacteria for amylase production was carried out and all bacteria produced a wide halo on a starch agar. E. faecalis produced highest zone of clearance with 70mm,B.subtilis 50mm,S.aureus 34mm, E. coli 29mm,thenB.cereus with the least zone of clearance of 24mm. proximate analysis of the potato peels sample shows that the potatoes peels has high carbohydrate content with value of 75.737 recorded. The effect of substrate concentration was studied at 5g,10g,15g and 20g. The highest amylase production was recorded (20g) with value of 1.218 and 15g with the least absorbance value of 0.973.The effect of temperature were studied at 25˚C, 35˚C, 45˚C, and 55˚C. The temperature of 45˚C has the highest absorbance value of 1.691. While the least was recorded at55˚C with value of 0.970.These shows that temperature and substrate concentration has a vital role to play in the production of microbial enzymes. It’s concluded in this study that waste dump site is a reservoir of important microorganisms and potato peels is a good substrate for enzyme production and therefore can be utilized instead of dumping it for natural degradation.

Assessment of Contamination Potential in Okhla Landfill, New Delhi by using Leachate Pollution Index

Landfill leachate generation from a landfill site is one of the main problems for both developed and developing countries around the world. Leachates liberated from the site contain various organic, inorganic, heavy metals, and sometimes hazardous chemical and organic pollutants, which are the origin of the deterioration of air and water quality in its vicinity. The present attempt was performed to assess seasonal variation of the leachate quality, and also determine three sub-indices of leachate which are LPIorg, LPIin, and LPIhm, and the overall LPI of operational, uncontrolled landfills in South Delhi by using leachate pollution index (LPI). Around twenty-five (25) parameters were analyzed during pre-monsoon, monsoon, and post-monsoon seasons from the collected leachate samples. Out of twenty-five pollutants, COD, BOD, NH4-N, EC, and TDS were found beyond the set standard limit in all seasons. Other pollutants like TKN, TSS, TCB, and Cl were also found in high concentrations. Arsenic (As) concentration was found beyond permissible during post-monsoon. The concentration of lead (Pd) in the pre and post-monsoon season was observed beyond the standard limit. Sub-LPI indices in the pre-monsoon season were observed as LPIorg 82.0, LPIin 40.8, and LPIhm 6.9, and likewise, Sub-LPI in monsoon season were LPIorg 81.4, LPIin 25.5, and LPIhm 5.2 and Sub-LPI post-monsoon season was calculated as LPIorg 90.5, LPIin 30.2 and LPI hm 6.2. Almost in all the seasons, LPIorg i.e. organic pollutants was dominated then followed by LPIin, and LPIhm. The overall LPI value of the study area during the pre-monsoon, monsoon and post-monsoon was 32.5, 28.2 and 32.0, respectively. It was observed that overall LPI (calculated) was maximum during pre-monsoon followed by post-monsoon and monsoon. LPI value was beyond the standard limit, except for LPI hm, which was below the standards. It was recommended that more waste-to-energy plants and decentralized waste segregation units need to be set up, to avoid direct dumping of all mixed waste in the landfill sites.

An eco-friendly approach of biodiesel production from tannery fleshing wastes by crude neutral protease enzyme

A new approach for extracting fat from tannery fleshing wastes (TFW) was established by hydrolyzing in water using a crude neutral protease enzyme. The bacterial strain for protease preparation was isolated from the waste dumping site of Institute of Leather Engineering and Technology of the University of Dhaka. The crude enzyme thus obtained was found highly active at 55 °C and pH 8.0, with a substrate concentration of 2%. Several reaction parameters, such as enzyme concentration, hydrolysis temperature and duration, were optimized using response surface methodology (RSM). The detailed analysis data by RSM showed 31.33% enzyme to dry weight of fleshing, 2.874 h of hydrolysis, and at 65.23 °C temperature to be the optimum for maximum theoretical fat yield of 38.46%. The laboratory experiments under optimum conditions resulted 34.9% fat yield with an error of 10.17%. The fleshing fat was transesterified in methanol into biodiesel using a recyclable magnetic nano catalyst with a 98% conversion and glycerol as a byproduct. The FT-IR spectroscopic results demonstrated an absorption of CO stretching at 1740 cm−1 for α, β-unsaturated esters in the biodiesel and its fatty acid ethyl ester. The 1H-NMR spectroscopy revealed a singlet peak of methoxy protons at 3.65 ppm and a triplet at 2.26–2.30 ppm for α-CH2 protons that confirmed the presence of unsaturated fatty acids with a carbonyl hydrogen double bond peak at 2.00–2.01 ppm. The GC-MS data of the biodiesel comprises of ethyl E−11-hexa-decanoate, ethyl myristate, palmitate, stearate, and decanoate. The results of various fuel parameters of the biodiesel were measured and compared with standard biodiesel EN14214 which revealed that it has comparable fuel properties to the standard. The higher calorific value (38.5 MJ kg−1) and flash point (152 °C) of the biodiesel than the standard, indicating its high potential and ease of storage stability than standard biodiesel.

Selenite bioreduction with concomitant green synthesis of selenium nanoparticles by a selenite resistant EPS and siderophore producing terrestrial bacterium.

Environmental bacterial isolates play a very important role in bioremediation of metals and toxic metalloids. A bacterial strain with high selenite (SeO32-) tolerance and reducing capability was isolated from electronic waste dump site in Banaras Hindu University, Varanasi, India. Based on 16S rRNA sequencing and BLAST search, this bacterial isolate was identified as Bacillus paramycoides and designated as strain MF-14. It tolerated Sodium selenite up to 110 mM when grown aerobically in LB broth and reduced selenite into elemental selenium (Se0) significantly within 24h with concomitant biosynthesis of selenium nanoparticles as clearly revealed by brick red precipitate and specific surface plasmon resonance peak at 210nm using UV-Visible spectrophotometer. Scanning electron microscopy (SEM) analysis of this bacterial strain exposed to 1mM and 5 mM selenite also demonstrated morphological alterations as cell enlargement due to accumulation and bioprecipitation of elemental selenium (Se0). The FTIR analysis clearly demonstrated that functional groups present on the surface of biogenic selenium nanoparticles (SeNPs) play a significant role in the stabilization and capping of SeNPs. Furthermore, these SeNPs were characterized using spectroscopic analysis involving Dynamic light scattering, zeta potential, XPS, FTIR, XRD and Raman spectroscopy which clearly revealed particle size 10-700nm, amorphous nature, stability as well as it's oxidation state. The biochemical studies have demonstrated that membrane bound reductase enzyme may be responsible for significant reduction of selenite into elemental selenium. Therefore, we may employ Bacillus paramycoides strain MF-14 successfully for bioremediation of selenite contaminated environmental sites with concomitant green synthesis of SeNPs.

Chemical Hydrological Features and Water Quality Evaluation of Phewa Lake of Pokhara Valley Gandaki Province of Nepal

This study was conducted to investigate the hydrochemical characteristics and water quality of Phewa lake Pokhara. Water samples were collected and major hydrochemical features were analyzed viz., Transparency, pH, electrical conductivity (EC), total dissolved solids (TDS), total alkalinity (TA), total hardness(TH), dissolved oxygen (DO), microbial analysis (MA), nitrate (NO3¯), phosphate (PO43¯), ammonia(NH3), sulfate (SO42¯), chloride(Cl¯), iron(Fe2+/Fe3+), phosphorus (P) and dissolved solids (DS). The obtained values of the hydrochemical characteristic of lake water have been compared with the world health organization (WHO). The presence of phosphate concentration and the hardness in Phewa lake is higher than the WHO value indicating the problem of rapid eutrophication. This indicates that Phewa lake water has more magnesium and calcium soluble salt. Thus, the rapid eutrophication and higher concentration of organic matter could be a serious problem for lake sustainability. Various types of natural and anthropogenic activities like agricultural runoff, urbanization, discharge of domestic sewage, solid waste dump, and industrial effluent are the major problem for lake sustainability.

Physicochemical characteristics of soil and water in electronic waste dump site, Alaba Lagos, Nigeria

Determination of physicochemical characteristics of soil and water adjoining dumpsites is important to ascertain the fitness of drinkable water and their public health implications. Following the paucity of information on this area of study, physicochemical characteristics of water and soil in electronic waste dump site, Alaba, Lagos, Nigeria. Six samples from the dumpsite made up of three soil and water respectively were collected and extracted using USEPA methods. One soil and water sample far from the dumpsite served as control. Physicochemical parameters of water and soil samples were determined using standard methods. Results show that pH of the water samples ranged from 4.81 to 7.30. SW1 had highest pH (slightly alkaline) while SW3 had lowest pH and was acidic. The electrical conductivity of SW1, SW2 and SW3 ranged from 61 µS to 1421 µS respectively. Water temperature was between 29.53 and 29.57oC. Total dissolved solid of the water ranged from 32.33 to 722 mg/L. Sulphate ranged from 238 mg/L to 314 mg/L. Phosphate ranged from 41.92 to 60 mg/L. Dissolved oxygen ranged from 0.93 to 2.4 mg/L. Similarly, soil pH ranged from 6.57 to 7.44. Soil temperature ranged from 28.43 to 30.7. Soil organic carbon ranged from 13.75% to 20.25% while the soil organic matter ranged from 17.88% to 26.32%. Soil particle distribution ranged from 58.56 – 87.52% sand, 3.22 – 13.79% clay and 8.84 – 27.65% slit. Some physicochemical characteristics of soil and water in sampled location did not follow the WHO standard. This study has informed the state of water available for consumption as well as the state of soil contamination. Proper care is required to checkmate this location to avoid future contaminations.

Determination of Nickel in Selected Surface Waters of the Bonaberi Industrial Zone, Douala IV Council, Littoral Cameroon

Aims: To assess the source and level of Nickel in selected surface waters and its impact on the community of the Bonaberi industrial zone.
 Study Design: Cross-sectional study design that involved semi-quantitative and qualitative data collection method.
 Place and Duration of Study: This study was carried out in the area of Bonaberi industrial zone, Douala IV district between February 2019 to August 2020.
 Methodology: 25 Different surface water samples were collected from 5 sampling sites. Water samples were collected in polyethylene bottles previously washed with deionized water and rinsed with sample to be collected from different sites and acidified with 5 ml concentrated nitric acid. The contents of the metal were analyzed using Colorimetric merck microquant procedure. Two way ANOVA test and a P-value (<0.05) was considered significant.
 Results: Spring Water had a significant concentration of nickel in the various sites (0.06 mg/L), industrial waste (0.05 mg/L), River (0.04 mg/L), Well (0.03 mg/L), Tap waters (0.02 mg/L).
 Conclusion: Nickel is one of the most toxic naturally occurring metal(s) that is very dangerous to environmental sustainability when present in high concentrations. The study justifies the need to ascertain the long-term effects of Nickel contaminant(s) at waste dumping sites. Strengthening waste management systems and water quality monitoring should be implemented in the watersheds to minimize the health effects and deterioration of the aquatic ecosystem. Adequate measures should be taken to educate the community on heavy metals pollution on surface water and their effects to health and environment.

The times they are a-changing. Reconsidering the occupation history and character of a 3rd millennium BCE settlement in the Lower Rhine Area

A re-analysis of soil micromorphology samples and radiocarbon dates was undertaken at the Middle to Late Neolithic settlement of N11, Hazerswoude-Rijndijk, in the Netherlands. The site, located on crevasse deposits of the river Rhine, was previously dated between 3200 and 2500 BCE. Our re-analysis allows us to place the occupation firmly in the 3rd millennium BCE, which holds implications for our understanding of a pivotal transformation process in Northwest European prehistory. At the same time, it presents us a very informative picture of domestic activities including both the remains of combustion next to a dwelling structure, dating to the first phase of occupation, and the dumping of organic waste with varying degrees of intensity throughout the whole habitation period. Finally, we have shown that a combined approach of archaeological soil micromorphology and a critical analysis of radiocarbon dating, can strengthen interpretations of site chronology and characterising socio-cultural processes.

Hydrochemistry and groundwater quality assessment around solid waste landfill sites in peri-urban Jaipur, NW India.

Jaipur, the capital city of Rajasthan State in northwestern India, is one of the fastest-growing urban centers in the country. The city and the region around it have documented a substantial drop in the water table due to the over-abstraction of groundwater resources to cater to the increasing water demands of the growing population. Consequently, the entire Jaipurdistrict has been categorized as a "dark zone," prohibiting any further groundwater development activity. Besides its dwindling availability, water quality is also a matter of concern. In places, the water is geogenically contaminated and unsuitable for drinking purposes due to high levels of undesired elements in groundwater, such as high fluoride in the southern part and high chloride in the southwestern part of the district. Groundwater contamination can also occur through several anthropogenic factors, such as industrialization and excessive use of insecticides and pesticides. Water pollution through sewage disposal in open land-fill sites is also an important factor, especially in the growing urban centers. In this study, the water quality evaluation around three landfill sites in the Jaipur district, namely Mathura Das Pura and Langadiyawas (east of the city) and Sewapura (northwest of the city), was carried out. The cation-anion analysis of 45 groundwater samples collected around these sites reveals a wide variation in the abundance of constituent parameters. In a majority of cases, most of the parameters are within acceptable limits prescribed by the national and international agencies (Bureau of Indian Standards and World Health Organization). The fluoride content is more than the prescribed limit of 1.5mg/l in several cases. This could be an intrinsic property of deeper aquifers. The majority of Mathura Das Pura and Langadiyawas samples classify as Na + K - CO3 + HCO3 to Mg - CO3 + HCO3 types in the Piper classification scheme, while a small proportion shows mixed water type characteristics, i.e., with no dominant parameter. Most of the samples have heavy metal abundances within the permissible limits while slightly elevated Cd and Pb levels were observed in some samples. A positive correlation between these two metals can be attributed to a common pollutant, possibly sourced from solid waste. The percent pollution index of Sewapura samples shows lower pollution levels (PPI < 40%) and a dominant chemical weathering trend while the majority of Mathura Das Pura-Langdiyawas samples show a high pollution effect (PPI 40 to 80%). In general, the chemical parameters of Sewapura (relatively new landfill site) samples define a more coherent group while water quality parameters in Mathura Das Pura and Langdiyawas (old landfill sites) samples show a wide variation, unsystematic distribution, and significantly higher than prescribed values for most of the hydrochemical parameters. The study shows that some of the water quality issues may be geogenic, while municipal waste dumping and leachate infiltration have adversely affected the groundwater quality.

Effect of reclamation years on soil physical, chemical, bacterial, and fungal community compositions in an open‐pit coal mine dump in grassland area of Inner Mongolia, China

AbstractUnderstanding the process of changes in substrate physical, chemical, and biological properties is critical for vegetation ecosystem reconstruction of open‐pit coal mining dumps. However, the relationships of soil chemical, biological, bacterial, and fungal characteristics in open‐pit coal mining dumps in grassland area are still unclear. The purpose of this study is to understand the changes and relationships of soil physic‐chemical, bacterial, and fungal properties under the reclamation time series of open‐pit coal mining dumps. Soil samples were collected from the waste dump reclaimed after 2, 5, 10, and 15 years in Shengli West No. 2 open pit coal mine in Inner Mongolia, China, and the surrounding natural grassland was set as a control at 0–10 cm and 10–20 cm. Soil pH, electrical conductivity (EC), soil organic matter (SOM), nutrient properties, bacterial, and fungal community structures were measured in the waste dump reclaimed after 2, 5, 10, and 15 years. The results showed that soil pH was decreased at 0–20 cm in the waste dump while SOM was increased by 1.2 times in 0–10 cm reclaimed after 15 years than that after 2 years. Soil EC was decreased by 55.5% and 58.3%, respectively, in 0–10 cm and 10–20 cm, respectively, after 10 years than that after 2 years. Soil available nitrogen, available phosphorus, and available potassium were 97.8%, 13.2%, and 60.9% lower after 15 years' reclamation than those in control. The acid phosphatase in 0–10 cm and 10–20 cm was increased by 2.2 and 2.1 times, respectively, after 15 years compared with that after 2 years. Alkaline phosphatase was decreased by 16.8% reclaimed after 15 years than that after 2 years in 10–20 cm soil. The Shannon diversity index of fungi was increased by 42.0% and 43.8%, respectively, in 0–10 cm and 10–20 cm, in the waste dump reclaimed after 15 years than that after 2 years. Soil organic matter was positively correlated with soil urease activity. Soil pH, EC, and texture had different effects on bacterial and fungal communities. Therefore, appropriate measurements should be applied to the reclamation dumps to help the soil properties of reclamation areas to recover to the natural grassland.

Characterization of high-performance concrete using limestone powder and supplementary fillers in binary and ternary blends under different curing regimes

Although the dumping of waste generated by industries in the environment poses a hazard, it is feasible to use waste and unused materials to manufacture high-performance concrete. By recycling these wastes in binary and ternary blends, sustainable and durable concrete mixtures can be created, resulting in the development of sustainable concrete structures. Therefore, a research project was undertaken to develop high-performance concrete (HPC) using available supplementary and waste materials, such as fly ash (FA), silica fume (SF), Quartz filler (QF), and limestone powder (LSP), as partial replacements for cement in binary and ternary blends under various curing conditions. Different percentages (5, 8, 10, 15, 20%) of the supplementary materials were mixed in binary and ternary combinations to determine the optimal dosage for high-performance concrete. The fresh and hardened properties of the concrete were evaluated using various tests, including slump, compressive strength, rapid chloride ion permeability, porosity, and drying shrinkage tests. The prepared concrete specimens were tested using various concentrations of binder replacement in binary, ternary, and quaternary combinations. The results showed that incorporating quartz filler as a partial replacement of cement up to 8% yielded positive results regarding mechanical properties. However, all mixtures containing different dosages of SF, QF, FA, and LSP demonstrated significant improvement in durability-related properties under normal and high-temperature curing conditions. Interestingly, the porosity of mixtures incorporating fly ash and LSP showed a slight increase compared to identical specimens under normal curing conditions. Moreover, the drying shrinkage behavior of ultrafine fillers (QF, SF, LSP, FA) indicated that their incorporation led to an increase in the shrinkage of high-performance mixtures under normal and high-temperature curing conditions. Binary and ternary blends incorporating QF, LSP, and SF showed an increase of around 5–8% in shrinkage under high-temperature curing compared to identical specimens under normal curing conditions. Therefore, it can be concluded that QF, LSP, SF, and FA can be efficiently used to produce high-performance cementitious composites, leading to sustainable concrete material.

Impacts of illegal solid waste dumping on the water quality of the Mthatha River

Abstract The world faces problems such as improper waste disposal that have spread to include disposal near water bodies. It is getting difficult to find fresh water everywhere. Given that surface sources provide around one-third of the world's drinking water needs, their contamination exacerbates the issue. This paper aims at evaluating the impacts of solid waste on water quality along the Mthatha River. During the rainy and dry seasons of 2021, Hanna probe instruments were used to assess the physicochemical quality of water before and after identified illegal dump sites. To compare the measured mean values of water quality parameters data were analysed using ANOVA in SPSS version 22. In terms of temperature, dissolved oxygen, pH, nitrite, conductivity, and Escherichia coli, the water quality in the sampling points after the illegal dump sites revealed deterioration, which was more severe in the rainy season and moderate in the dry season. The study's findings suggest that illegal dump sites along water bodies negatively impact the water quality. Diverse research on water pollution shows that declining water quality endangers aquatic species and is unsafe for human consumption. This paper recommends strengthening of laws against improper waste handling, and frequent waste collection to prevent contamination of water bodies.

Ecological restoration of coal mine waste dumps: A case study in Ximing Mine, China

ABSTRACT This study focuses on addressing the issues of spontaneous combustion and slope instability at the coal mine waste (CMW) dump located on the north side of the Yumen River in Ximing Mine, China. We conducted slope restoration and environmental treatment of the CMW dump using shotcrete, deep hole grouting, external soil spray seeding technology with multiple soil fixation measures. The stability of the repaired CMW dump was analysed using LiZheng Slope Stability Analysis Software, and the displacement and stress of high-risk zones were assessed using MIDAS GTS NX Software. Our findings provide valuable insights for slope restoration and evaluation.

Occurrence, spatio-temporal variation and ecological risk assessment of benzotriazole ultraviolet stabilizers (BUVs) in water and sediment of rivers in central India

Occurrence of benzotriazole ultraviolet stabilizers (BUVs) in different environmental matrices has attracted researchers and regulatory agencies worldwide due to its persistency, bioaccumulative and toxic properties. Environmental occurrence of BUVs in Indian freshwater is lacking. The present study analyzed six targeted BUVs in surface water and sediments of three rivers of Central India. BUVs were determined in pre- and post-monsoon seasons to reveal their concentration, spatio-temporal distribution and probable ecological risks. Results indicated that total concentration of BUVs (ƩBUVs) ranged from ND to 42.88 μg/L in water, and ND to 165.26 ng/g in sediments with UV-329 as the predominant BUV in surface water and sediments during pre- and post-monsoon seasons. Surface water samples from Pili River, and sediment of Nag River accounted for maximum BUVs concentration. Partitioning coefficient results confirmed the effective transfer of BUVs from overlaying water to sediments. The observed concentration of BUVs in water and sediments posed low ecological risk to planktons. Untreated municipal discharges and poor waste management practices including dumping of wastes might be the sources of BUVs in water bodies.

Heavy metal pollution of river water and eco-friendly remediation using potent microalgal species

Pollution of rivers is mainly caused by anthropogenic activities such as discharge of effluent from industrial facilities, maintenance of sewage/effluent treatment plants, and dumping of solid waste on river banks. This study dealt with the pollution issues of the Cooum River in the well-known city of Chennai in South India. Water samples from 27 locations were collected and analyzed for 12 elements, including Ba, B, and Al, as well as heavy metals such as Pb, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Cd. The samples showed levels of these elements that exceeded World Health Organization recommendations. Pearson correlation analysis revealed the inter-dependency among elements, and the contribution of each element based on factor loadings showed its percentage contribution compared to others. Water samples from six significant locations were chosen for remediation with three algae: Chlorella vulgaris, Scenedesmus dimorphus, and Phormedium sp. The uptake of pollutants led to the continuous growth of algae during the incubation period of 15 d, effectively removing heavy metals from the river water. The increasing levels of algal counts and the chlorophyll a content confirmed the algal growth during the incubation period, followed by a declining stage after the incubation period. The scanning electron microscopic images of algae before and after the remediation showed no remarkable modification of morphological patterns. This study showed that the uptake of heavy metals using algae is an effective water pollution remediation measure, making the process practicable in the field on a large scale in the near future.

Heavy metals contamination in sediments of Bharalu river, Guwahati, Assam, India: A tributary of river Brahmaputra.

This study aimed to assess heavy metals in the surface sediments of the Bharalu river, India. Metal concentrations ranged from 6.65-54.6 mg/kg for Ni, 25.2-250.0 mg/kg for Zn, 83.3-139.1 mg/kg for Pb, and 11940.0-31250.0 mg/kg for Fe. The level of metal contamination was assessed using sediment quality guidelines, geo-accumulation index (Igeo), enrichment factor (EF), pollution Load Index (PLI),Nemerow's pollution index (PIN), and potential ecological risk index. Pb exceeded the sediment quality guidelines at all sites indicating a potential threat to the river ecosystem. (Igeo) and EF also showed moderate to severe enrichment for Pb. Potential ecological risk (RI) showed low risk in the sediments, and Pb is the major contributor to ecological risk. Overall, pollution indices revealed comparably higher contamination of the sediments in the downstream sites than in the upstream site. PCA and correlation matrix analysis indicated both anthropogenic and natural origins for metals. Among anthropogenic sources, urban discharges and waste dumping could be mainly attributed to metal contamination in the river sediments. These findings may aid in developing future river management methods explicitly aimed at tackling heavy metal pollution to prevent further damage to the river ecosystem.

An Introduction to Nuclear Industrial Archaeology

The legacy of the early days of the Atomic Age consists of many problematic sites worldwide, including radioactive waste dumps, uranium mines, spent fuel reprocessing plants, and defunct processing and enrichment plants. Although nature quickly reclaims abandoned sites, any remaining radioisotopes can pose a threat for millennia to come, long after the benefits gained from nuclear technology have faded. The field of nuclear industrial archaeology specialises in finding and characterising these sites to support local communities and site owners. Where maps and building plans have been lost, nuclear archaeologists deploy state-of-the-art analysis techniques on the ground to unravel the current state of legacy sites, and quantify the remaining radioactive inventories to the standard required by the nation the site is located within. The objectives of nuclear industrial archaeology are varied and site dependent. Whether the objective is to puzzle the forgotten history of activity back together or safeguard and recover dangerous radioactive materials, nuclear industrial archaeology adapts radioanalytical laboratory and site-surveying techniques in order to understand the site and allow scientists to communicate this information to support remediation efforts. This paper discusses current methodologies alongside a case study.

STUDY OF WATER ABSORPTION OF GEOPOLYMER MATERIALS BASED ON IRON ORE ENRICHMENT TAILINGS

As you know, the problem of environmental safety is important in the process of mining and processing of ore and non-metallic minerals. In the process of primary processing of ore minerals, the so-called enrichment tailings or production wastes are formed. The resulting waste accumulates in huge quantities, contributing to changes in the landscape and worsening the hydrogeological and sanitary conditions of the environment. In addition, rainfall and meltwater contribute to the constant leaching of heavy metals from waste dumps, which eventually leads to the pollution of groundwater, rivers and lakes. Therefore, the important ecological task of rational disposal of mining tailings is very relevant around the world. Research aimed at developing and obtaining new materials on the basis of this waste is of the greatest interest. One of such directions is the utilization (immobilization) of mining tailings when obtaining of geopolymer materials, which eliminates the leaching of heavy metals from the volume of the obtained material. Over the past 60 years, millions of tons of enrichment tailings have accumulated at the Dashkesan iron ore deposit, which are waiting to be disposed of. For this reason, the tailings of Dashkesan iron ore enrichment were used as a mineral filler for producing geopolymer material. Mineralogical and chemical compositions of enrichment tailings were studied using X-ray phase and X-ray fluorescence methods. Water absorption of the obtained specimens of geopolymer material was researched in accordance with the known methodology. It was revealed that with the increase of mineral filler content from 60 to 90%wt. the value of water absorption of geopolymer material specimens in the first five minutes of exposure increased from 1 to 10,2%, respectively. With the increase of mineral filler content from 60 to 90%wt. the maximum value of water absorption increases from 2,6 to 10,2%, respectively. Keywords: geopolymer, water absorption, enrichment tailings, iron ore.