Soil Bodies Research Articles

Effects of Molybdenum Fertilizer Combined with Bacillus subtilis Strain on the Growth of Chinese Cabbage and the Content of Nitrate in Soil

With increasing nitrogen application in soil, the problem of nitrate accumulation in soil and vegetable bodies has become increasingly serious. In this study, Bacillus subtilis (B. subtilis) Strain11 was isolated and studied for its effects in combination with Molybdenum (Mo) on the growth of Chinese cabbage and soil nitrate content. The results showed that the strain effectively increased the growth, height, and moisture content of Chinese cabbage by 27% and 2.5%, respectively, compared to the control. Mo application alone reduced soil nitrate accumulation and increased root length, height, chlorophyll content, and moisture content of Chinese cabbage, with an optimal rate of 0.8–1.2 mg/kg soil. The application of Mo fertilizer in combination with the Bacillus strain was the most effective in increasing plant height and root length of Chinese cabbage, which were 1.49 times and 1.68 times that of the control, respectively. The proportion of dry matter, the average fresh weight, and the dry weight under this treatment were 9.01%, 5.83 g/plant, and 0.53 g/plant, respectively, higher than the rest. At harvest, the highest ammonium-nitrogen content in this treatment group was 8.56 mg/kg, and the soil nitrate reduction reached 40.68%. In conclusion, Mo fertilizer at a rate of 0.8 mg Mo/kg soil, in combination with B. subtilis Strain11, was recommended for the remediation of nitrate-contaminated soils.

PFAS Degradation Techniques – A Road towards Alleviating Organic Pollution

PFAS are commonly found pollutants in soil and water bodies. Of all the PFAS that are found, PFOA and PFOS are the most hazardous ones. The review focuses upon Adsorption, Sonochemical Degradation, Photocatalysts, and Bio-remediation as techniques for the removal and degradation of PFA.

Bioremediation strategies of palm oil mill effluent and landfill leachate using microalgae cultivation: An approach contributing towards environmental sustainability

Palm oil mill effluent (POME) is defined as the wastewater that contains high concentrations of organics, nutrients and oil and grease generated from the production process of palm oil. Therefore, proper discharge and management of POME is important to avoid deleterious impact on the environment. In fact, solid waste generation is a precursor for its disposal issues as most of the solid waste generated in developing nations is dumped into landfills. This has led to the threat posed by the generation of landfill leachate (LL). LL is a complex dark coloured liquid consisting of organic matter, inorganic substances, trace elements and xenobiotics. Hence, it is essential to effectively treat the landfill leachate before discharging it to avoid contamination of soil, surface & groundwater bodies. Conventional treatment methods comprises of physical, biological and chemical treatment, however, microalgal-based treatment could also be incorporated. Furthermore, with the benefits offered by microalgae in valorisation, the application of microalgae in POME and leachate treatment as well as biofuel production, is considerably viable. This paper provides an acumen of the microalgae-based treatment of POME and LL, integrated with biofuel production in a systematic and critical manner. The pollutants assimilation from wastewater and CO2 biosequestration are discussed for environmental protection. Cultivation systems for wastewater treatment with simultaneous biomass production and its valorisation, are summarised. The study aims to provide insight to industrial stakeholders on economically viable and environmentally sustainable treatment of wastewaters using microalgae, and eventually contributing to the circular bioeconomy and environmental sustainability.

Impact of the natural temperature regime of the upper layers of Earth on efficiency of a hydrothermal heat pump system


 
 
 This article focuses on current issues of alternative geothermal heating development, by using low-potential thermal energy of upper aquifers by heat pumping technology. This type of heat supply is sustainable, does not require fossil fuel consumption and does not pollute the environment. In recent years, heat pumping technologies have become common. A lot of heating systems are implemented, using low potential energy in the air, open bodies of water or soil. Although, now, the heat of groundwater in upper aquifers is a more efficient and reliable source of energy for heat pumps. It was tested in this study. The purpose of this study is to impact assessment of the heat regime of the ground upper layers on efficiency of operation of heat pumping units, using groundwater of near-surface horizons. The factors founded, which form the natural heat mode within the studied area, also the correlation established between temperature changes in the horizon and the operation of the heat pump unit, based on the experimental heat pump unit, established by the Institute of Renewable Energy of the National Academy the Sciences of Ukraine. The article presents an experimental hydrothermal heat pump system developed and constructed at the Institute of Renewable Energy of the National Academy of Sciences of Ukraine, which consists of a heat pump and two wells through which water circulation from the underground horizon to the heat pump. The study describes the characteristics of measuring equipment installed on a hydrothermal heat pump system and described developed an interactive scheduling system based on the software product ESM (Engineering Systems Manager) using the programming language FBD (Function Block Diagram | Continuous Function Chart). This software product was used to create the visual system and archival data system that were obtained in the course of this work. The benefits of this study are that the experimental installation uses the thermal energy of groundwater of the Poltava-Kharkov aquifer as the primary energy source. The interval of the productive horizon is 32-57 m. The groundwater level in the horizon is set at about 40 m. In addition, the air temperature between the pipe space of the observation well and the groundwater temperature in the aquifer are monitored. The duration of regime observations was six months, the frequency of measurements – 5-15 seconds. The monitoring results indicate that despite the fact that the productive horizon is at a depth that significantly exceeds the usual depth of the neutral layer for the territory of Ukraine, the for- mation temperature is not stable and its amplitude is 2 oC. According to the authors, the increase in the depth of the surface of constant annual temperatures may be due to local features of the studied area, namely: increasing the absorption surface of solar radiation due to terrain, the presence of lateral heat inflow, the presence of water-saturated layers in the upper part. Consequently, based on the analysis of geological and hydrogeological conditions of the site, as well as technological processes occurring in the installation, the main factors that form the natural temperature of the upper layers of the earth are identified. As a result, the percentage of energy efficiency drop of the installation is calculated depending on the decrease in the temperature of the natural heat carrier in the aquifer. It is established that it is necessary to conduct additional research to assess the environmental impact of the use of aquifers for energy purposes and to ensure the optimal mode of operation of aquifers, which would be as close as possible to their natural regime.
 
 

Effect of biologically active substances on hematological status of cows

Industry development has a technogenic impact on the environment, thereby posing a threat to health and welfare of farm animals. As a result, toxic substances accumulate in soil, water, feed, and have a long period of decomposition. At the same time, changes in the metabolic profile occur in animals, leading to a decrease in their resistance to viral and bacterial infections. The search for new means and methods to stop the development of pathological conditions and create conditions for the resistance of cows to technogenic stress seems to be relevant. In this regard, the purpose was to study the effect of аminoseleferon-B on hematological parameters and protein metabolism of cows with immune deficiency under technogenic load caused by the chemical industry producing mineral fertilizers in Voronezh region. During monitoring soil and water bodies near this object, an excess of the maximum permissible concentrations for heavy metal content was established. The studies were carried out in industrial livestock complex on 20 highly productive dairy cows with a secondary immunodeficiency state, located in the zone of exposure to chemical emissions into the atmosphere. Control and experimental groups of animals were formed. Experimental cows were injected with аminoseleferon-B. It was revealed that the presence of cows in conditions of technogenic impact on the environment leads to decrease in total protein, change in blood fractional composition, which negatively affects physiological processes in the body. Insufficient levels of and -globulin fractions in cow blood indicate inhibition of natural resistance factors. A negative reaction of animal organism associated with exposure to toxins is indicated by significant increase in the level of -globulins in blood. It was found that аminoseleferon-B had a corrective effect on blood morphological parameters and protein metabolism, significantly increasing number of erythrocytes, leukocytes, hemoglobin, lymphocytes, monocytes, total protein, -globulins, -globulins and reducing content of neutrophils, eosinophils, -globulins to normal levels. Thus, аminoseleferon-B contributed to increase in natural resistance, adaptation to adverse environmental factors and stimulation of metabolic processes in cows.

The next generation of soil and water bodies heavy metals prediction and detection: New expert system based Edge Cloud Server and Federated Learning technology

Heavy metals (HMs) in soil and water bodies greatly threaten human health. The wide separation of HMs urges the necessity to develop an expert system for HMs prediction and detection. In the current perspective, several propositions are discussed to design an innovative intelligence system for HMs prediction and detection in soil and water bodies. The intelligence system incorporates the Edge Cloud Server (ECS) data center, an innovative deep learning predictive model and the Federated Learning (FL) technology. The ECS data center is based on satellite sensing sources under human expertise ruling and HMs in-situ measurement. The FL system comprises a machine learning (ML) technique that trains an algorithm across multiple decentralized edge servers holding local data samples without exchanging them or breaching data privacy. The expected outcomes of the intelligence system are to quantify the soil and water bodies' HMs, develop new modified HMs pollution contamination indices and provide decision-makers and environmental experts with an appropriate vision of soil, surface water, and crop health.

Biochar from Cyperus alternifolius Linn.: from a waste of phytoremediation processing to efficient depolluting agent.

Phytoremediation is one of the most powerful and viable solutions for developing countries to clean the soil and water bodies from metallic pollutants. Cyperus alternifolius Linn. (CAL), a tropical wetland plant, has been widely researched for removing harmful contaminants due to its hyperaccumulation ability. However, the waste biomass of phytoremediation processing may risk secondary environmental pollution. Thus, the preparation and application of biochar from metal-contaminated plants can be considered a new approach. In a 60-day experiment, CAL plants were irrigated with different concentrations of Zn(II) (200, 700, 1200, 1700, and 2200mg·L-1), and then the plants were converted into biochar via the pyrolysis process. The characteristics of biochar including of surface composition and morphology, phase formation, and optical property were analyzed. The biochar enriched with Zn(II) at 1200mg·L-1 had a bandgap value of 3.17eV and consisted of carbon microparticles intermingled with ZnO and SiO2 nanoparticles. Furthermore, the adsorption and photocatalysis of the biochar were studied in the discolouration of methylene blue (MB), as a test reaction, with the maximum MB removal capacities of 55.2mg·g-1. Such results will serve as the basis for new research aiming at the potential for reusing metal-contaminated plants to produce efficient depolluting biochar.

Sustainable industrial ecology and environmental analysis: A case of melamine etherified resin fibres

Increasing global plastic consumption and its related plastic waste have become a major concern in the world. Achieving sustainable development in the plastics industry requires a systematic insight into all the relevant life cycle phases of plastic products and their environmental impacts. This paper utilises the concepts of industrial ecology and the circular economy to evaluate the three key aspects of thermoset plastic materials and their overall life cycle comprehensively: i) Sustainable production, ii) Recycling to obtain secondary products, and iii) End-of-life behaviour. For all three aspects, their environmental impacts are evaluated additionally using the conceptual Life Cycle Assessment (LCA) approach. The industrial ecology approach, together with LCA is performed on a case study of melamine etherified resin (MER) fibre, which is a high value-added thermoset plastic, difficult to recycle, and, at the end-of-life, potentially emits hazardous compounds. The potential to sustainably produce MER fibre exclusively from renewable and waste sources is explored, closing the loop on the manufacturing and disposal phases. The hydrothermal decomposition of MER fibres into valuable compounds is investigated as a recycling technology. Regarding the end-of-life, a systematic assessment is conducted of the environmental impacts of discharging such material into soil and water bodies. Cleaner production of MER fibres shows the potential to reduce greenhouse gas footprint up to 67%, while analysis of sustainable recycling and disposal highlights important environmental hotspots.

Co-over expression of Ascorbate Glutathione pathway enzymes improve mercury tolerance in tomato

The genetic modification of plants for the removal of inorganic pollutants from contaminated soil and water bodies is an emerging area for addressing environmental concerns. This approach is based on the ability of plants to take up and accumulate heavy metals, with efficiency being dependent on the underlying mechanisms of heavy metal accumulation and tolerance. A robust antioxidant pathway is determinantal for heavy metal uptake and accumulation and, therefore, in this study, we evaluated the transgenic tomato plants installed with Ascorbate Glutathione (ASA-GSH) pathway genes for uptake, accumulation, and response to mercury (Hg). We observed that ASA-GSH overexpressing lines were resilient to Hg stress as they displayed higher photosynthetic activity and increased photosynthetic gas exchange parameters with a concomitant decrease in ion leakage under Hg stress. Additionally, transgenic lines accumulated high osmolytes and showed enhanced activity of antioxidant enzymes. Moreover, the results of SEM and confocal microscopy confirmed least damage to plant tissue in ASA-GSH overexpressing lines compared to wild-type under Hg-stress which was further supported by Atomic absorption study that revealed a significant decline in Hg accumulation in the leaves of transgenic lines compared to wild-type under stress conditions. In conclusion, pyramiding of ASA-GSH pathway genes in tomato plants is an efficient approach for the development of Hg-resistant tomato plants and the reclamation of Hg-contaminated sites.

Mechanism of Casing String Curvature Due to Displacement of Surface Strata

One of the main problems of well operation is the risk of uncontrolled leakage of hydrocarbons into the environment. This problem is especially relevant for the long-term operation of wells. The idea for this study was inspired by a real industrial problem that the authors of the article were involved in solving. At several operating gas wells, an abnormal slope of the production tree occurred, which raised the question of the safety of their further operation. An analysis of known studies and current regulatory documents did not allow us to assess the safety of using a gas well based on the measured kinematic parameters of production tree deviations. A mathematical model for the deformation of a package of casing strings when the surface layer of the rock is displaced is developed in the article. A boundary value problem is formulated for differential equations of pipe bending on an elastic foundation. Based on the results of solving this problem, an unambiguous relationship was established between the maximum bending stress in the surface pipe and the angle of inclination of the production tree. The quantitative characteristics of the connection depend on the geometric and mechanical properties of the pipes and on the thickness and mechanical parameters of the formations. It was established that the existing inclination of the production tree can be achieved due to the beginning of the plastic bending of the surface pipe under the slickenside, which does not exclude the exhaustion of the safety margin of the surface pipe and indicates the possible operation of the casing string in a pre-emergency state. In general, the obtained results develop analytical approaches to assessing the behavior of underground structures of a production well in unstable soil bodies.

Effect of Corn Stalk Biochar on the Evolution of Water Evaporation and Cracking of Soil

The evolution of water evaporation and cracking of soil affected by corn stalk biochar is experimentally investigated. Water evaporates from the soil surface, causing shrinkage in soil body and forming cracks, which significantly lead to crop nutrient loss, groundwater pollution, and land salinization. Biochar is a recyclable natural material widely used in improving the water retention and suppression of cracking of soils. Free desiccation tests were conducted with adding the biochar contents of 0%, 4%, and 8%. The variation of water evaporation amount and the development of cracking were recorded and disposed. The results show that the evaporation process can be changed due to the addition of biochar contents. The evaporation rate can be divided into three phases of a constant rapid evaporation phase, a fluctuated evaporation phase, and a residual evaporation phase. A sudden increase at around 30% of moisture content in evaporation rate indicated that the crack began to develop and extend greatly, which increased the evaporation surface area. The residual moisture contents of soils with biochar contents of 4% and 8% increased by 105.56% and 88.38% than those of soil without biochar, respectively. The crack ratio reduced by 32.39% and 15.31% with the addition of biochar contents of 4% and 8%, respectively. A three-level crack was observed during evaporation process, where a second and third crack developed less with the addition of biochars. The corn stalk biochar improves the integrity of soil bodies and increases the connection of soil particles for more water storing between the biochar particles and soil particles. It can be concluded that corn stalk biochars are able to delay the evaporation and cracking developing in cohesive soils, which may be beneficial for crops in dry area.

Pollution characteristics and risk assessment of heavy metals in the soil of a construction waste landfill site

Heavy metals found in construction waste can enter soil and water bodies through surface runoff and leachate, where they represent an environmental hazard. In this study, we investigate the pollution characteristics and ecological risks of eight heavy metals (Cd, Cr, Cu, Mn, Ni, Pb, Zn, and As) in the soils of an unofficial construction waste landfill site in Beijing, China. The results indicate that long-term disposal of construction waste in the dry riverbed can reduce the pH value of the soil, increase the soil organic carbon content, and affect the total amount and distribution of heavy metals. Moreover, the landfill site pollutes the external soil environment, with Cd, Zn, Pb, and Cu as the characteristic pollutants. According to the Nemerow comprehensive pollution index and potential ecological risk assessment, heavy metal pollution decreases in the following order: internal soil > bottom soil > boundary soil. Cd, Zn, Pb, and Cu pollution is higher in the internal region, with single heavy-metal pollution indexes (Pi) of 1.41, 1.65, 1.26, and 1.28, respectively. Conversely, the Pi for Cr is higher in boundary and bottom soils (1.91 and 1.94, respectively). Risk assessment codes indicate that Cd and Mn pose the greatest environmental risk (31.9% and 17.8%, respectively) as they have the highest effective content, bioavailability, and mobility. Thus, environmental monitoring is a necessity for these metals.

Zinc Essentiality, Toxicity, and Its Bacterial Bioremediation: A Comprehensive Insight.

Zinc (Zn) is one of the most abundantly found heavy metals in the Earth’s crust and is reported to be an essential trace metal required for the growth of living beings, with it being a cofactor of major proteins, and mediating the regulation of several immunomodulatory functions. However, its essentiality also runs parallel to its toxicity, which is induced through various anthropogenic sources, constant exposure to polluted sites, and other natural phenomena. The bioavailability of Zn is attributable to various vegetables, beef, and dairy products, which are a good source of Zn for safe consumption by humans. However, conditions of Zn toxicity can also occur through the overdosage of Zn supplements, which is increasing at an alarming rate attributing to lack of awareness. Though Zn toxicity in humans is a treatable and non-life-threatening condition, several symptoms cause distress to human activities and lifestyle, including fever, breathing difficulty, nausea, chest pain, and cough. In the environment, Zn is generally found in soil and water bodies, where it is introduced through the action of weathering, and release of industrial effluents, respectively. Excessive levels of Zn in these sources can alter soil and aquatic microbial diversity, and can thus affect the bioavailability and absorption of other metals as well. Several Gram-positive and -negative species, such as Bacillus sp., Staphylococcus sp., Streptococcus sp., and Escherichia coli, Pseudomonas sp., Klebsiella sp., and Enterobacter sp., respectively, have been reported to be promising agents of Zn bioremediation. This review intends to present an overview of Zn and its properties, uses, bioavailability, toxicity, as well as the major mechanisms involved in its bioremediation from polluted soil and wastewaters.

Assessing the Nutrient Status of Soil and Water Bodies in Palayapatti Areas, Thanjavur District of Tamil Nadu (India)

Background: Thanjavur is a cauvery delta zone for paddy growing area of Tamil Nadu. The current study aiming with understanding about chemical properties and nutrient status of soils of selected area and assessing quality of water bodies. Methods: The study was conducted during 2018-19 at Palayappatti and its surrounding villages in Thanjavur district of Tamil Nadu to find out the nutrient status of soil and water. Fifty representative soil samples and ten water samples collected with the objectives of analyzing chemical properties of soil and assessing water quality in Palayapatti and its surrounding villages of Thanjavur district. Result: The collected soil and water samples varied with different chemical and physical properties. Soils were slightly acidic to slightly alkaline, normal EC and low organic carbon, low to medium content of nitrogen, phosphorus and potassium, low to medium content of calcium, magnesium and sulphur. Water samples were slightly acidic to moderately alkaline pH, medium to high salt content, moderate amount of carbonate and bicarbonate content. The soil and water bodies of this land having medium range of nutrients and also improvement is need in water quality.

Concrete Industry, Environment Issue, and Green Concrete: A Review

Concrete is the second most utilized substance around the world behind the water. The aim of this paper is to review the environmental effect of concrete industry. It has been found that the environmental impact of concrete industry is severe in various environmental categories as global warming, depletion of ozone layer, and acidification of soil and water bodies. Moreover, concrete industry affects ecosystems and alters hydrogeological and hydrological systems. Green concrete has become increasingly popular among researchers and academics in recent years, although it is still in its infancy. This article examines the environmental impact of waste materials such as fly ash, silica fume, and slag as partial or complete replacements for cement, and of waste and recycled material as aggregates. It shows that the negative environmental effect of the concrete industry can be minimized by using these waste materials in the concrete production.

Effect of the Ni3TeO6 phase in a Ni2Te3O8/expanded graphite composite on the electrochemical monitoring of metribuzin residue in soil and water samples

Growing food demand and climate change have led to the development of various pest control agents to increase crop yields. Although pesticides help meet the food demand, they cause harm to human health and the environment. Metribuzin (MTBZ) is one of the common herbicides used for controlling weeds. Therefore, monitoring MTBZ residues in soil and water bodies is essential for decreasing risk to the environment and human health. This paper reports a highly selective and sensitive electrochemical sensor electrode based on a Ni3TeO6-phase-integrated Ni2Te3O8/expanded graphite (referred to here as NTO-eGR) composite for the detection of MTBZ. The NTO-eGR composite was prepared by a one-step low-temperature hydrothermal method and characterized by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and electron microscopy techniques. The Ni3TeO6 phase was found to be an active component in the NTO/eGR composite, which exhibited satisfactory analytical performance in MTBZ detection with a sensitivity of 1.454 µA µM−1 cm−2. Moreover, the NTO-eGR electrode exhibited high selectivity to MTBZ even in the presence of a five-fold excess of interfering species in water and soil samples. The studies on practical applicability revealed that NTO-eGR exhibits good reproducibility with a relative standard deviation of 2.67% (n = 5). Moreover, good recoveries of greater than 90% were achieved in the determination of MTBZ in soil and water samples. Hence, the NTO-eGR sensor electrode is highly suitable for the rapid on-site determination of MTBZ.

Protein nanofibrils as versatile and sustainable adsorbents for an effective removal of heavy metals from wastewater: A review

Water is a valuable natural resource, which plays a crucial role in ecological survival as well as economic progress. However, the water quality has deteriorated in recent years as a result of urbanization, industrialization and human activities due to the uncontrolled release of industrial wastes, which can be extremely carcinogenic and non-degradable, in air, water and soil bodies. Such wastes showed the presence of organic and inorganic pollutants in high dosages. Heavy metals are the most obstinate contaminants, and they can be harmful because of having a variety of detrimental consequences to the ecosystem. The existing water treatment methods in many situations may not be sustainable or effective because of their high energy requirements and ecological impacts. In this review, state-of-the-art water treatment methods for the elimination of heavy metals with the help of protein nanofibrils are covered featuring a discussion on the strategies and possibilities of developing protein nanofibrils for the active elimination of heavy metals using kitchen waste as well as residues from the cattle, agriculture, and dairy industries. Further, the emphasis has been given to their environmental sustainability and economical aspects are also discussed.

Emerging Contaminants in Soil and Water

The global population increase puts tremendous pressure on the already dwindling natural resources such as soil and freshwater. Healthy and productive soils as well as the availability of freshwater resources are critical for agricultural productivity. On the other hand, climate change and variability make the water scarcity problem even worse. Agriculture, being the biggest consumer of fresh water, is expected to be affected significantly. Yet, agriculture is expected to play a significant role in achieving greater food, and fiber needs to meet the growing global population. In addition, soil and water quality are also becoming a bigger threat to soil productivity and freshwater availability. Some portion of nutrients applied to agriculture and urban landscapes end up in runoff and leaching water that feeds streams, rivers, lakes, groundwater, etc. These excess nutrient loadings are causing soil and water quality deterioration, which could have severe impacts on human health, aquatic ecosystems, and environmental sustainability. In addition to nutrient and chemical pollutions, emerging contaminants such as heavy metals are showing an increasing trend in soil and freshwater bodies. These emerging contaminants not only impair soil quality and freshwater sources but could also get into the food chain and affect human and animal health. While growing evidence is becoming available on the increasing threats from emerging contaminants, research and understanding are still limited. This mini-review paper summarizes available research on types of emerging contaminants and their impacts on soil and water quality.

Bioconversion of Keratin Wastes Using Keratinolytic Microorganisms to Generate Value-Added Products.

The management of keratinous wastes generated from different industries is becoming a major concern across the world. In each year, more than a billion tons of keratin waste is released into the environment. Despite some trials that have been performed and utilize this waste into valuable products, still a huge amount of keratin waste from different sources is a less explored biomaterial for making valuable products. This indicates that the huge amount of keratin waste is neither disposed properly nor converted into usable products rather thrown away to the environment that causes environmental pollution. Due to the introduction of this waste associated with different pathogenic organisms into soil and water bodies, human beings and other small and large animals are affected by different diseases. Therefore, there is a need for modern and ecofriendly approaches to dispose and convert this waste into usable products. Hence, the objective of this review is to give a concise overview regarding the degradation of keratin waste by biological approaches using keratinase producing microorganisms. The review also focuses on the practical use of keratinases and the economical importance of bioconverted products of keratinous wastes for different applications. Various researches have been studied about the source, disposal mechanisms, techniques of hydrolysis, potential use, and physical and chemical properties of keratin wastes. However, there is negligible information with regard to the use of keratin wastes as media supplements for the growth of keratinolytic microorganisms and silver retrieval from photographic and used X-ray films. Hence, this review differs from other similar reviews in the literature in that it discusses these neglected concerns.

Effect of lithium on seed germination and plant growth of Amaranthus viridis

Lithium is one of the trace elements essential for the human body. The use of Li-based products has increased tremendously, leading to higher consumption patterns and the generation of lithum-based wastes. A higher concentration of lithium leads to the contamination of soil and water bodies. Lithium enters the food chain through the plant pathway. The food chain becomes contaminated with agricultural products produced on lithium-contaminated soil. Owing to this scenario, the present study is focused on studying the effect of lithium on the germination and growth of Amaranthus viridis. Germination studies were conducted in petri dishes, and the rate germination was 95% at control and 10 ppm. At higher concentrations, the rate of germination was 73% at 50 ppm, 57% at 75 ppm and 41% at 100 ppm. Pot experiments were conducted for 51 days using lithium-amended soil from 10 to 100 ppm. Pot experiments revealed that, at higher concentrations, lithium promoted the length and weight of the plant from 1.122 g/plant in the control to 2.415 g/plant at 100 ppm. The stress tolerance index was calculated for the length and dry weight of the roots and shoots, respectively. High stress tolerance at root and shoot biomass led to an increase in the biomass of the plant, which promoted the accumulation of lithium in plant parts. These results concluded that lithium stimulated plant growth at lower concentrations and increased biomass at higher concentrations, which was confirmed through the calculation of the stress tolerance index.