Major Water Research Articles

Influence of Nano Urea on Growth Yield and Nutrient Uptake of Blackgram

Background: There is no doubt that the enormous increase in global food production is a direct result of greater use of inorganic fertilizers. However, a number of research studies indicate that the rising use of conventional fertilizers has resulted in major environmental risks, including soil and water body contamination. Nanotechnology and nano-fertilizers have recently been used in agriculture to create healthier solutions. Therefore, there is a pressing need to improve the N availability for plants, while reducing its harmful effects to the soil and environment. Methods: Keeping this point of view, the pot culture experiment was carried out to study the “Impact of nano-urea (Liquid) on blackgram (VBN 8) (Vigna mungo L.) Productivity” with an objective of study the influence of Nano-Urea on growth and yield attributes of Blackgram. The experiment was conducted at Vanavarayar Institute of Agriculture, Pollachi during the Kharif (June-September) season of 2022 and 2023. The treatment includes application of various level of nano urea (1.25 litres ha-1) as foliar spray and soil application along with recommended dose of P and K in comparison with RDF and control (without any nutrient). The treatments were replicated three times in a completely randomized block design. Result: Among the different treatment combination, application of nano-urea (Liquid) 1.25 litres ha-1 as Foliar Spray (FS) (IFFCO) + P and K RDF (T2) resulted in higher pod weight (4.1 and 6.2 g plant-1) and seed weight (3.2 and 3.6 g plant-1) in 2022 and 2023, respectively. Application of nano-urea (Liquid) 1.25 litres ha-1 as Foliar Spray (FS) + PandK RDF responded equally with RDF + Urea 1% foliar spray on better growth and development of blackgram. At the critical juncture, adequate nitrogen from nano-urea would have ensured a steady supply of nitrogen, stimulating meristematic activity and cell elongation in plants and improving the crop performance.

Climate change driven land use evolution and soil heavy metal release effects in lakes on the Qinghai Tibet Plateau.

In recent decades, global warming has intensified hydrological cycles, raising concerns about the impacts of climate change on hydrological processes, water quality, and water resources across various temporal and spatial scales. These changes significantly affect water resource management and environmental protection policies and may also influence the ecological health and socio-economic well-being of lake regions. Qinghai Lake, the largest inland lake and a major water source reservoir in China, plays a crucial role in the ecological security of the Qinghai-Tibet Plateau. However, in recent years, with the ongoing development of the economy and society throughout the province, there has been an increase in algal blooms in the nearshore area of Qinghai Lake, with the affected area expanding annually. There is currently no clear consensus on the causes of eutrophication in lakes, and comprehensive, in-depth research on how different land use types-critical to the material migration and transformation processes of natural water bodies-affects water quality and ecological security, as well as the interactions between nutrients and heavy metals, is lacking. Therefore, it is essential to monitor and understand the effects of climate change on lakes and to develop adaptive strategies to mitigate and respond to these impacts amidst rapid economic and social development. The lake environmental pollution early warning system developed in this study provides a scientific research paradigm for lake water pollution control and offers valuable data support for policymakers in formulating ecological protection and development strategies.

Comprehensive insights into the occurrence characteristics of dissolved organic matter and its indication for heavy metals in drinking water sources

ABSTRACT Dissolved organic matter (DOM) plays a crucial role in various aquatic environments, while comprehensive insights into DOM and its relations with heavy metals in drinking water sources are still lacking. Here, we choose the drinking water sources of Anhui province (China) as a typical case, exploring the occurrence of DOM and its relationship with heavy metals in 159 major drinking water sources. Results indicate the occurrence levels of DOM and three identified fluorescent components in the surface water (rivers, lakes, reservoirs) are significantly higher than that in the groundwater, while there was no significant difference in the occurrence levels of the chromophoric dissolved organic matter (CDOM) among the drinking water sources. Significant correlations between the DOM and heavy metals indicate that DOM could be used as a promising indicator for evaluating the occurrence and environmental behavior of some heavy metals in drinking water sources.

Assessment of regional background values of bottom deposits at water bodies as their monitoring basis

Microelements Hg, Cd, Zn, Pb, Cu, Cr, Co, Ni, Fe, Mn, As are the most hazardous contaminants for water bodies. The study of bottom deposits in water reservoirs permits the authors us to reveal the endangered sites and determine the contamination sources. The estimation of the bottom sediment contamination by the above-listed microelements is given for a number of the Upper Volga regions, from the Upper Volga lakes to the Ivan’kovskoe water reservoir on the basis of comparing them with the background values for the deposits in the Upper Volga lakes. The results of bottom deposit contamination study have been assessed according to igeo-classes, i. e., the sorbing fraction (0.020 mm) contamination. The comparative analysis of the background microelement values is performed for the Upper Volga water bodies and the values adopted in Europe. The changes of these background values for the latest 20 years are assessed. As a result, it has been found out that for each major water system and for each geographical region, it is necessary to determine the regional background values of their own and to update data recurrently according to a common procedure. The results obtained permit the authors to conclude that despite numerous contamination sources, the technogenic load at the studied objects cannot be considered hazardous.

Nutrient loading as a key cause of short- and long-term anthropogenic ecological degradation of the Salton Sea

The Salton Sea (SS), California’s largest inland lake at 816 square kilometers, formed in 1905 from a levee breach in an area historically characterized by natural wet-dry cycles as Lake Cahuilla. Despite more than a century of untreated agricultural drainage inputs, there has not been a systematic assessment of nutrient loading, cycling, and associated ecological impacts at this iconic waterbody. The lake is now experiencing unprecedented degradation, particularly following the 2003 Quantification Settlement Agreement—the largest agricultural-to-urban water transfer in the United States. Combined with high evaporation rates, reduced inflows have led to rapid lake shrinkage, with current maximum depths of only 10 m. Here we report distinct temporal and spatial patterns for nutrient dynamics at the SS for two decades spanning the period before and after major water transfer agreement. While external nutrient loading remains relatively consistent year-round, internal cycling varies seasonally. Winter exhibits high total phosphates and nitrate levels due to reduced primary productivity, with lower ammonium concentrations from increased oxygenation. Summer conditions shift to decreased phosphate and nitrate levels from enhanced primary production, sustained partly by internal phosphorus release from sediments during anoxic periods. Although N:P molar ratios can exceed 50:1 to 100:1 (far above the Redfield ratio of 16:1), phosphorus consistently remains at hypereutrophic levels (> 0.05 mg/L) challenging previous assumptions of phosphorus limitation. Post-2020 data show disrupted stratification patterns. Despite higher oxygen levels in bottom waters compared to 2004–2009, overall water column oxygenation has declined, reflecting altered hydrodynamics in the shallowing lake. These changes have intensified environmental challenges stemming from cultural eutrophication including harmful algal blooms, threatening both ecosystem and public health. Effective remediation will require significant reduction in external nutrient loading through constructed wetlands and/or treatment facilities at tributary mouths to reduce the lake’s overall nutrient inventory over time.

Simulation of Spatial and Temporal Patterns of Suitable Wintering Habitat for Hooded Crane (Grus monacha) Under Climate and Land Use Change Scenarios

In the context of global warming and intensified human activities, the loss and fragmentation of species habitats have been exacerbated. In order to clarify the trends in the current and future suitable wintering areas for hooded cranes (Grus monacha), the MaxEnt model was applied to predict the distribution patterns and trends of hooded cranes based on 94 occurrence records and 23 environmental variables during the wintering periods from 2015 to 2024. The results indicated the following. (1) The elevation (Elev, 43.7%), distance to major water (DW, 39.5%), minimum temperature of the coldest month (Bio6, 9.7%), and precipitation of the wettest month (Bio13, 2.6%) were dominant factors influencing the wintering distribution of hooded cranes. (2) Under current climate and land use scenarios, highly suitable areas for hooded cranes in China cover approximately 1.274 × 105 km2, primarily located in inland lakes such as Dongting Lake, Liangzi Lake, Poyang Lake, Shengjin Lake, and Caizi Lake in the middle and lower reaches of the Yangtze River, as well as in coastal wetlands such as Chongming East Beach, Shandong Peninsula, Bohai Bay, and Liaodong Peninsula. (3) Under future climate and land use scenarios, the suitable habitat areas (high and moderate suitability) for hooded cranes are projected to contract substantially in the middle and lower reaches of the Yangtze River and expand slightly in the areas of Shandong Peninsula, Bohai Bay, and Liaodong Peninsula. Under the SSP126 (low emissions), SSP245 (medium emissions), and SSP585 (high emissions) scenarios, the average area reduction percentages were 29.1%, 28.8%, and 31.6%, respectively. (4) The increases in Bio6 and water areas in northern China were the main reasons for the shift of the wintering distribution centroid for hooded cranes toward northeastern China. The minor expansion of suitable habitat in the north covers mainly cultivated land, and this singular foraging habitat could intensify both intraspecific and interspecific competition among waterbirds, thus exacerbating the survival risks for hooded cranes. To more effectively protect the wintering population of hooded cranes in China, the restoration of natural habitats and population monitoring in the middle and lower reaches of the Yangtze River should be strengthened. Additionally, nature reserves or protected areas should be established in the northern expansion regions.

Valorization of textile waste for removal of Cadmium from contaminated water

AbstractThe rapid development in agriculture and industrial sectors has raised some serious global issues like heavy metals pollution of water resources. Cadmium (Cd) is amongst the major water pollutants worldwide. In this study, two novel sorbents were prepared by using post-consumer textile waste (PCTW). The waste denim fabric was recycled with environmentally friendly H2O2 and Ozone through oxidation under alkaline conditions to produce several functional groups at the surface (named as ODF@H202 and ODF@03 respectively) that could trap the heavy metal cations from contaminated water. The functionalized fabric sorbents were characterized by Fourier transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-Ray (EDX) that revealed the presence of carboxylic acid, hydroxyl, and amine functional groups on their surfaces. The sorption isotherm, sorption kinetics and sorption thermodynamics were carried out to unravel the sorption process mechanism. The ODF@H202 sorbent was proved more effective by giving maximum adsorption capacity of (238.09 mg g−1) compared to Ozone treatment (175.44 mg g−1) for Cd2+ and achieved within just 20 min for both sorbents. Pseudo 2nd order and Langmuir models confirmed the chemosorption as dominant mechanism for the monolayer sorption of Cd2+ ions onto ODF@H202 and ODF@03. The sorption thermodynamic revealed the sorption process as endothermic and spontaneous in nature. The results showed that both ODF@H202 and ODF@03 sorbents have an efficient potential for sorbing Cd from contaminated water. Furthermore, both ODF@H202 and ODF@03 sorbents were also tested in a regeneration study to investigate the reuse of these sorbents, and we achieved marvelous results. Both sorbents gave up to 90% of the sorption capacity even after 10 recycles. Conclusively, both sorbents can have their implications for the preparation of filters that can be used for the treatment of wastewater. This study has practical significance by tackling the two environmental problems i.e. heavy metal pollution and denim waste.

Diversity of Lignicolous Freshwater Fungi from Yuanjiang River in Yunnan (China), with the Description of Four New Species.

Yuanjiang River (Red River) is one of the six major water systems in Yunnan Province, which originates from western Yunnan Province. This river system features numerous tributaries, complex terrain, and abundant natural resources. During the investigation on the diversity of lignicolous freshwater fungi in the Yuanjiang River, nine species were collected and identified, five belonging to Dothideomycetes and four to Sordariomycetes. Based on morphology and multigene phylogenetic analyses, four species, namely, Aquadictyospora aquatica, Dictyosporium fluminicola, Myrmecridium submersum, and Neomyrmecridium fusiforme, are described as new species. Dictyocheirospora aquadulcis is reported as a new national record, and Myrmecridium hydei is reported as a new habitat record. Dictyocheirospora rotunda, Halobyssothecium aquifusiforme, and Pseudohalonectria lutea were known earlier from freshwater habitats, but we described them in detail in this paper. This study contributes significantly to the understanding of the diversity of lignicolous freshwater fungi in southwestern China.

Do Water Pollutant Reduction Projects Promote or Limit Carbon Reduction? Evidence from Building a Beautiful China

The total control of major water pollutants (TCMWP) is a critical strategy for improving water quality in China, with the added benefit of yielding climate-related advantages. This study uses the emission factor method to quantify the reductions in pollutants and carbon emissions resulting from China’s implementation of TCMWP. A synergy scale for pollution and carbon reduction was constructed to assess the co-benefits of reducing the Chemical Oxygen Demand (COD) and ammonium nitrogen (NH4+-N) and carbon dioxide (CO2) emissions. Furthermore, to account for regional variations in energy structure regulation strategies, whether aggressive or unified, we developed Pollutant Synergistic Carbon Reduction Pathways at the Regional (R.PSCRP) model framework level to evaluate the carbon emission reduction potential of TCMWP during the “14th Five-Year Plan” period. The study revealed that China’s unified TCMWP employs different but highly effective combinations of emission reduction paths across different regions. Notably, new renovations and expansions of wastewater treatment facilities (NRE-WWTFS) and pipeline network construction and renovation (CR-PNK) together accounted for 89.3% of the total emission reduction. The construction of key water pollutant reduction projects plays a significant role in reducing carbon emissions at the district level compared to direct discharge practices. Additionally, indirect emissions resulting from TCMWP implementation account for approximately 50% of the total carbon reduction achieved. By aligning either harmonized or independent energy adjustment targets, regions were able to achieve substantial pollution and carbon reduction benefits, ranging from 7.5 to 8 million tons of CO2-equivalent.

Problems of Monitoring Surface Waters in the Dnipro Basin

In Ukraine, the qualitative state of surface waters is unsatisfactory, especially in major water accumulation facilities of national importance, such as the Dnipro reservoirs. This situation necessitates changes in the state monitoring mission and regulatory policies in water use. Particular public importance lies in the objective assessment of the ecological and hydrological state of Ukraine's water bodies and waters, especially under the conditions of ecological-economic and military aggression, with respect to water bodies of national significance, such as the Dnipro reservoirs, primarily the Kremenchuk Reservoir. The study employs scientific methods of systemic analysis, including GIS analysis, generalization, and systematization, while considering synergistic approaches in the development of structural-logical schemes for monitoring systems in hydrology using the abduction method. The necessity of correlation analysis and the integration of surface water and soil monitoring systems has been investigated. For example, soil contamination with free nitrogen has led to a tenfold increase in nitrate concentrations in well water in the Poltava region over recent years. The analysis revealed insufficient observation points for surface water and a lack of systematic soil contamination surveys. It was demonstrated that monitoring of the Kremenchuk Reservoir should encompass not only the water quality of the reservoir itself but also the water-bearing streams, tributaries, and parts of the basin forming the reservoir, in accordance with the proposed structural-logical schemes. It was identified that only 0.1% of the 35 billion UAH allocated over the past 12 years to the Dnipro River rehabilitation program was spent on water monitoring, while water rental payments account for only 20% of state and municipal water management expenditures. A structural-logical scheme for the development of hydro-ecological monitoring of the water environment in part of the Dnipro basin has been proposed. Structural-logical schemes for the development of a spatial monitoring framework for the integral system of the Kremenchuk Reservoir's components have been suggested. The need to establish an information-analytical center for state water monitoring in Ukraine has been identified.

Water Quality Assessment using Selected Macroinvertebrate Based Indices and Water Quality Index of Sungai Air Hitam Selangor

A study was conducted from July to December 2022 at Sungai Air Hitam, a small tributary of the Selangor River located within the Tanjung Karang Sub-basin in Malaysia (coordinates: 3° 24' 27" N, 101° 25' 54" E to 3° 28' 14" N, 101° 26' 59" E). This confluence is situated near three major downstream water treatment plants. The study assessed six water quality parameters—pH, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), ammonia (NH3), and suspended solids (SS)—to calculate the Water Quality Index (WQI). Macroinvertebrates were sampled simultaneously using the dipping net method to obtain biotic indices for further evaluation of water quality. The results indicated that the WQI classified Sungai Air Hitam as Class III, with scores ranging from 56.9 to 64.6, suggesting the river is suitable for water supply and fisheries. However, the Biological Monitoring Working Party (BMWP) index categorized the water quality as poor, with scores between 30 and 42. Similarly, the Average Score Per Taxon (ASPT) ranged from 3.25 to 5.25, indicating pollution or environmental impact, while the Family Biotic Index (FBI) further classified the river as having poor to very poor water quality, with scores between 6.57 and 8.11. Overall, the study suggests that Sungai Air Hitam has experienced some degree of ecological degradation. These findings emphasize the need for continuous monitoring and remediation efforts to preserve and restore water quality.

The evolution patterns and driving factors of urban domestic water pollution utilizing China’s two national pollution source surveys

Characteristics of domestic water pollution are of significant practical importance for implementing targeted urban wastewater treatment strategies. The pollutant source census in China serves as a fundamental undertaking in the study of pollution sources, providing crucial data for the analysis of pollution from domestic sources. This study employs pollution coefficients derived from China's two national pollution source surveys, integrating spatial autocorrelation and center-of-gravity shift analysis methods to investigate the national-scale spatial evolution characteristics of major urban domestic water pollutants, including BOD, TN, TP, and Oils. Furthermore, the impact of urbanization processes in population, economic, social, and spatial dimensions on urban domestic water pollution sources is explored using the multi-scale geographically weighted regression (MGWR) method. The results show that: (1) Urban domestic water pollution exhibits an east-high and west-low distribution pattern, with EHL being the primary region of pollution generation. Compared to 2007, the western region experienced a faster increase in BOD (30% increase), while the eastern region showed a sharper decline in TN (45% decrease) by 2017. (2) The results of spatial autocorrelation show that high-value clusters of urban domestic water pollution are located in the eastern China and around Chongqing, while low-value clusters are extensively distributed in the western region, indicating significant spatial heterogeneity in water pollution. (2) Based on center-of-gravity analysis, pollution displays a discernible migration trend from the northeast to the southwest, with the center located near the border of Henan and Hubei provinces, within the latitudinal and longitudinal range of 32°N–32.79°N and 113.09°E–113.85°E. The migration distances, ranked in descending order, are as follows: Oils (72.23 km) > BOD (65.59 km) > TN (63.9 km) > TP (22.73 km). (3) Significant differences are observed in the effects and spatial regions influenced by urbanization factors across different dimensions. Population and social urbanization exhibit pollution-increasing effects, whereas economic and spatial urbanization demonstrate pollution-reducing effects. These results will deepen our understanding of the spatial differentiation patterns of urban domestic source pollution, providing theoretical guidance for alleviating the pressure of urban pollution management. In addition, this article is an in-depth study of the first two pollution source surveys, which can lay a research foundation for future investigation work.

Genetic diversity and distribution of Karenia in the eastern coastal seas of China and implications for the trends in Karenia blooms under global environmental changes

Species of Karenia G. Hansen & Moestrup gen. nov. frequently contribute to intense harmful algal blooms on a global scale, resulting in detrimental effects on fisheries, aquatic ecosystems, and human health. Over the past two decades, there has been noticeable increase in the reporting of Karenia blooms, with outbreaks attributed to newly recorded species, sometimes with multiple causative species. This trend highlights an insufficient understanding of species diversity and geographical distribution of Karenia and related key environment drivers under global environmental change. In this study, we employed a tailored barcode for genus Karenia combined with high-throughput sequencing to examine the species diversity and geographical dispersion of Karenia, as well as their relationships with environment factors in the eastern Chinese coastal seas (ECCS) in spring and autumn. Our findings revealed an unprecedented presence of both described and unrecorded Karenia species in the ECCS. K. mikimotoi was predominantly observed in the cold waters of the ECCS north of 35°N in autumn and the major waters of the ECCS in spring, while various Karenia species tend to co-inhabit in the warmer waters of autumn in the East China Sea. Sea temperatures were significantly correlated to the distribution patterns of Karenia species in the ECCS. In contrast, concentrations of inorganic nitrogen and phosphorus were not identified as major correlates to Karenia distribution. In light of the findings of this study and the understanding that Karenia species exhibit strong mixotrophic capabilities, it is suggested that ocean warming and increased coastal eutrophication, particularly the rise of dissolved and particulate organic substances, may contribute to the proliferation of Karenia blooms associated with undocumented species and/or multiple causative species.

(Invited) Photocatalytic and Photoelectrochemical Systems for Nitrogen Cycles

The chemical transformation of N species plays important roles in the global environmental systems and their interconversion involves key compounds such as nitrate, nitrite, and nitric oxide, which are major water and air pollutants. The photocatalytic and photoelectrocatalytic processes have been applied to denitrification, de-NOx, and nitrogen fixation reactions but the successful performance is limited. The direct conversion of nitrogenous pollutants to dinitrogen and dinitrogen to ammonia without using chemical reductants is an ideal solution but difficult to be realized. Here we introduce various engineered photo(electro)catalytic systems that selectively interconvert among NO3 −, NO2 − ,NO, NH4 +, and N2. Firstly, a ternary composite photocatalyst composed of TiO2, bimetals, and reduced graphene oxide (rGO) is developed and tested for chemical reductant-free solar denitrification. Direct transformation of nitrate to N2 occurs via using in-situ H2 generated from water splitting with achieving near 100% conversion and selectivity to N2 under both anoxic and oxic conditions. Secondly, a PEC system that converts NO to nitrate and ammonium on an anode and a cathode simultaneously is described. Finally, the direct NO conversion to N2 and O2 is successfully demonstrated by developing oxygen-deficient titania as a photocatalyst working under visible light.

The Influence of Local Climatic Factors and Water Vapor Transport from North Atlantic Ocean on Winter Snow-Cover Variation on Western Kunlun Mountains and Eastern Pamir Plateau

Snow cover days (SCD) have increased significantly in winter on the Western Kunlun Mountains and Eastern Pamir Plateau (hereafter referred to as KMPP for short), however the causes have not been well understood so far. Here, we use remote sensing data to analyze the abnormal increase in SCD on the KMPP and explore its causes from the perspective of the local factors and water vapor transport caused by sea surface temperatures (SST) warming. We discover that the winter SCD on the KMPP increased significantly at a rate of 4.75 days/decade (significant at the 0.01 level) during 1989–2020, while there has been a significant decrease on the Tibetan Plateau (TP), with a rate of −1.50 days/decade (significant at the 0.1 level). Based on ERA5, GPCP, GHCN, and station data, we find that, in contrast to the significant warming observed on the TP, temperature changes on the KMPP are negligible, while precipitation is increasing, differing from the decreasing precipitation trend observed on the TP. The differences in local temperature and precipitation changes cause different variations in SCD between the KMPP and the TP. The increase in SCD on the KMPP is primarily driven by increased precipitation (over 97% contribution), with minimal impact from the more or less unchanged temperature. In contrast, the decline in SCD on the TP results from decreased precipitation and significantly increased temperature. Furthermore, we found that changes in SCD on the KMPP are significantly correlated with SST in the northern North Atlantic Ocean. Based on the correlation vector, the anomaly field in the high/low SCD years of water vapor transport, and the FLEXPART model, we show that the northern North Atlantic Ocean is one of the major water vapor sources affecting the SCD on the KMPP. The warming SST in the northern North Atlantic Ocean enhances water vapor transport to the KMPP in winter, leading to an abnormal increase in the SCD that differs from the overall trend on the TP. The findings are conductive to further understand the peculiarity of winter precipitation and SCD on the KMPP, and the “Western Kunlun Mountains Oddity” in mountain glacial change.

Yield Performance of Pangasius sutchi with Carps in Farm Ponds of Dakshina Kannada, Karnataka, India

Farm ponds are the major water storage facilities available for the farming community and majority of the farming community face scarcity of water during the summer months. Dakshina Kannada being the coastal district, majority of the population is dependent on marine fisheries for fish nutrition. Pangasius sutchi is an omnivore and bottom feeder, feeding on variety of plant and animal protein (Philippe 1998). Composite fish culture of carps with Pangasius sutchi using farm ponds was carried for three years in various parts of the district, Pangasius sutchi under composite fish culture with carps exhibited better growth with a mean growth of 0.948+0.33, 0.961 +0.20 and 0.901+0.16 kg during 2019-20, 2020-21 and 2021-22 respectively. Pangasius sutchi and Catla performed better in terms of growth in farm ponds under the composite culture system giving more benefits to the farmer. The total yield varied with a minimum of 68.45 qtl/ ha in 2020- 21 and a maximum of 72.69 qtl/ha during 2019- 20.

Rayleigh wave-based monitoring of mortar coating and concrete core cracking on prestressed concrete cylinder pipe under external pressure using piezoelectric lead zirconate titanate

Prestressed concrete cylinder pipe (PCCP) is a critical type of pressure pipe widely used in major water conveyance projects worldwide. As essential components of a PCCP, the mortar coating and concrete core are directly linked to its operational safety. This study employed piezoelectric lead zirconate titanate (PZT) devices as transducers to generate excitation vibrations and measure the resulting Rayleigh waves, thereby providing a means to detect cracking in and monitor the health of the mortar coating and concrete core of a prototype 1400 mm inner-diameter PCCP under external pressure. First, a theoretical analysis was conducted to define the propagation laws of Rayleigh waves. Next, a finite element analysis was undertaken to identify the tensile regions of the PCCP mortar coating and concrete core when under external pressure applied along the length of the PCCP and thereby establish the locations for the PZT devices. Experiments were subsequently conducted by incrementally increasing the external pressure load from 0 to 700 kN while monitoring the cracking in the mortar coating and concrete core using sinusoidal excitation signals with frequencies of 5, 10, and 20 kHz. The voltage amplitudes measured at each external pressure load were analysed, confirming the Rayleigh wave propagation laws and revealing that the change in the measured voltage amplitude curve aligned with the experimental observations, thereby validating the proposed measurement method. Finally, the relative percentage deviation of amplitude (RPDA) and relative percentage deviation of energy (RPDE) damage indices were established based on the voltage measurements to further evaluate the damage state of the mortar coating and concrete core. The RPDA measured at an excitation frequency of 20 kHz was best for detecting cracks in the PCCP mortar coating, whereas the RPDA and RPDE measured at excitation frequencies of 20 and 10 kHz, respectively, were best for monitoring concrete core cracking.

Leaf growth in third dimension: a perspective of leaf thickness from genetic regulation to ecophysiology.

Leaf thickness, the leaf growth in the third dimension as quantified by the distance between the adaxial and abaxial surface, is an indispensable aspect of leaf development. The fitness of a plant is strongly influenced by leaf thickness via modulation of major physiological processes, including photosynthesis and water use efficiency. The cellular basis of leaf thickness by alterations in either cell size or the number of cell layers is envisaged using Arabidopsis leaf thickness mutants, such as angustifolia (an) and rotundifolia (rot). Environmental factors coordinate with endogenous signaling mechanisms to exhibit leaf thickness plasticity. Plants growing in different ecological and environmental regimes show different leaf thickness attributes. However, genetic and molecular understandings of leaf thickness regulation remain largely limited. In this review, we highlight how cellular growth is transposed to fine-tune the leaf thickness via the integration of potential cues and molecular players. We further discuss the physiological significance of leaf thickness plasticity to the environmental cues that might serve as ecological adaptation enabling the plants to withstand future climatic conditions. Taken together, we seek to bridge the genetics and molecular biology of leaf thickness to its physiological significance so that leaf thickness can be systemically targeted in crop improvement programs.

Microbiome divergence across four major Indian riverine water ecosystems impacted by anthropogenic contamination: A comparative metagenomic analysis

Rivers are critical ecosystems that support biodiversity and local livelihoods. This study aimed to evaluate the effects of metal contamination and anthropogenic activities on microbial and phage community dynamics within major Indian river ecosystems, focusing on the Ganga, Narmada, Cauvery, and Gomti rivers -using metagenomic techniques, Biolog, and ICP-MS analysis. Significant variations in microbial communities were observed both within each river and across the four systems, influenced by ecological factors like geography and hydrology, as well as anthropogenic pressures. Downstream sites consistently exhibited higher microbial diversity, with prevalence of Acidobacteria, Actinobacteria, Verrucomicrobia, Firmicutes, and Nitrospirae dominating, while Proteobacteria and Bacteroides declined. The Ganga River showed a higher abundance of bacteriophages compared to other rivers, which gradually reduced with the increment of anthropogenic impact. Functional gene analysis revealed correlations between carbon utilization and metal resistance in contaminated sites. ICP-MS analysis indicates elevated chromium and lead levels in downstream sites of all rivers compared to upstream sites. Interestingly, pristine upstream sites in the Ganga had higher trace element levels than those in Narmada and Cauvery, likely due to its Himalayan origin. Both the Ganga and Cauvery rivers contained numerous metal resistance genes. The Alaknanda was identified as the primary source of microbial communities, bacteriophages, trace elements, and heavy metals in the Ganga. These findings offer new insights into anthropogenic influences on river microbial dynamics and highlight the need for targeted monitoring and management strategies to preserve river health.

Adsorption of synthetic cationic dyes from water (experimental, DFT and Monte Carlo studies) and treatment of real industrial wastewater using dextrose compound-modified layered double hydroxide

Dyes are a major water pollutant, and various methods have been employed to address the dye pollution in aqueous solutions. Currently, adsorption using inexpensive, abundant, and eco-friendly adsorbents like anionic clay is one of the simplest and most effective methods. This study aimed to investigate the fabrication of a novel layered double hydroxide modified with dextrose D@Mg1.5Zn0.5Al-LDH composite via co-precipitation route for removing both synthetic Rhodamine B (RhB) and Basic Fuchsin (BF) dyes from aqueous solutions. Various characterization techniques were employed to comprehensively understand the properties of the as-synthesized material, including XRD, FTIR, SEM-EDX, BET surface area analysis and zeta potential. To enhance the adsorption process of both basic dyes, experiments were conducted in a batch reactor to investigate the effects of key parameters such as reaction duration, initial dye concentration, pH, adsorbent dosage, and solution temperature. Cationic dyes uptake was predominantly observed within the first 10mins, reaching equilibrium in approximately 60mins. The D@Mg1.5Zn0.5Al-LDH composite achieved removal efficiencies of 99% for BF dye and 60% for RhB dye at pH 10, which are considerably higher than that of bare Mg1.5Zn0.5Al-LDH. The experimental adsorption data demonstrated excellent agreement with pseudo-second-order kinetics and the Langmuir isotherm. Density functional theory (DFT) calculations and molecular simulations had been employed to elucidate the adsorption mechanism of BF and RhB dyes onto the D@Mg1.5Zn0.5Al-LDH composite. Quantum parameters were calculated to characterize the electron density of the dyes which provided insights into their reaction behavior. Additionally, Monte Carlo simulations were employed to calculate the fluctuation energy, and to determine probability distributions of adsorption energy, and geometry of the small adsorption energy poses for BF/D@Mg1.5Zn0.5Al-LDH and RhB/ D@Mg1.5Zn0.5Al-LDH. These results offer equilibrium statistical conditions that explain the adsorption mechanism behaviors between the D@Mg1.5Zn0.5Al-LDH composite and BF/RhB dyes optimally. Importantly, the theoretical outcomes are in good agreement well with experimental results. Finally, the adsorption process is used to treat real industrial wastewater that mainly contains a mixture of Rhodamine B and Methylene Blue as the cationic dyes. The D@Mg1.5Zn0.5Al-LDH composite has shown good efficiency in the treatment of real industrial wastewater.