Total Aluminum Research Articles

Fiber morphological characteristics of bamboo Ferrocalamus strictus culms from different geographical distribution regions

The fiber index including fiber length, width, wall thickness and lumen diameter of Ferrocalamus strictus culms (1, 2, and ≥ 3 years) from Jinping, Mojiang and Lvchun counties of Yunnan Province was determined and the elemental content of the soil was also determined to analyze the fiber characteristics. The average relative fiber index measured for F. strictus culms were fiber length (1.30 mm), width (21.57 μm), slenderness ratio (60.79 μm), wall thickness (4.21 μm), lumen diameter (7.22 μm), and runkel ratio (1.22 μm), which belonged to the range of middle and long fibers. The fiber length increased with the culm age. The proportion of long fiber increased while short fibers decreased along with culm maturing. The fiber morphology did not show a specific trend with the culm height. Fiber length reached the maximum in the bottom portions of the culms. There is a correlation between fiber morphology and soil elements, the content of organic matter, total potassium, total sulfur, total aluminum, total zinc, total iron, total boron, alkali-hydrolyzed nitrogen and available silicon in the soil affects fiber morphology. The content of organic matter, total boron and alkali-hydrolyzed nitrogen in the soil from Mojiang County was largest. Comparatively, the culm fiber in Mojiang County had the best fiber index performance for utilization, since the greatest proportion of medium and long fibers and the optimal distribution of fiber length frequency was obtained from the culms in Mojiang County. This study can provide a theoretical basis for large-scale bamboo forest cultivation and the development and utilization of bamboo culm fiber.

Optimizing surface water quality parameters in monitoring networks in a developing sub-tropical region with high anthropogenic pressure (São Paulo State Brazil).

Efficient water quality monitoring is a central aspect of water resources management, especially in developing countries, where water quality is under high anthropogenic pressure and resources for monitoring are usually limited. Here, we evaluated an alternative to optimize water quality parameters (WQPs) in the water quality monitoring network (WQMN) of the most populous state in Brazil (São Paulo State). We focused on the monitoring goal of identifying water quality temporal trends, selecting WQPs with high statistical explanatory power and those that were particularly sensitive to natural and anthropogenic perturbations. We considered 12 initial WQPs (dissolved copper, total zinc, total lead, total chromium, total mercury, total nickel, total cadmium, total iron, total manganese, total aluminum, total copper, and surfactant) with data from 2004 to 2018 for 56 monitoring sites distributed across four major watersheds with contrasting land uses in the state. We performed principal component analysis, followed by objective criteria to refine WQPs recommendation for the WQMN. Our results indicated the opportunity of reducing at least one parameter from the initial set of WQPs in all watersheds. Total iron, total manganese, and total aluminum were the most relevant initial WQPs, since their maintenance in monitoring were indicated in all the analyzed cases. Natural watershed conditions (e.g., geomorphology and water geochemistry) potentially governed their concentrations in surface water. On the other hand, total mercury, total chromium, and dissolved copper had the maintenance indicated in only one watershed, especially due to concentrations consistently below the respective limits of quantification (LoQs). Future investigations can complement our recommendations for these parameters, since changes in LoQs could throw another light on water quality spatial and temporal variations and the need for reference areas for assessing baseline conditions can also be relevant. Moreover, we argue that depending on the monitoring goals of the WQMN, additional sampling of biota and sediments could be useful as many of the studied WQPs' bioconcentrate. Our results illustrated an alternative approach towards adaptive monitoring in São Paulo state in accordance with the intended monitoring goal (i.e., water quality temporal trends), converging with the more flexible monitoring adopted in well-structured networks worldwide. While we did not cover other monitoring goals in our study (as the control of illegal discharge of effluents or industrial spills, for example), we expect our methodology can contribute to establishing technical guidelines for reviewing the existing WQMNs in Brazil and other developing countries with similar challenges.

Impact of Landfill Leachate on Groundwater Quality and Health Risk Assessment in Mohammedia Prefecture, Morocco

Several studies have been conducted to identify the potential impact of landfills on groundwater resources. This study evaluates the impact of landfills on groundwater resources in Mohammedia prefecture, Morocco. The groundwater was analysed from 2015 to 2022. The groundwater quality was evaluated based on electrical conductivity, pH, biological oxygen demand, chemical oxygen demand, total Kjeldahl nitrogen, phosphate, suspended solids, dissolved oxygen, ammonia, and total hydrocarbon, aluminium, iron, cadmium, chromium, copper, iron-nickel, zing, and mercury. The assessment was based on the water quality index, leachate pollution index, non-carcinogenic risk assessment, and carcinogenic risk assessment. A leachate pollution index <5 indicates that it poses a severe risk to groundwater resources. The non-carcinogenic risk HQ was determined to be <1, which infers no potential risk. The carcinogenic risk index value of 10-4 indicated that it is within the threshold of acceptable limit. The current study concludes that leachate from the analysed landfills does not infiltrate the groundwater resources of Mohammedia prefecture. However, the leachate pollution, even though it varies, is increasing over time. This is validated by the fact that the landfill is protected with a membrane covering the ground, which inhibits any possible infiltration of soil or water resources. Hence, this study calls for continuous monitoring of groundwater resources in the region. Future studies are required to investigate the groundwater in Mohammedia prefecture in terms of emerging pollutants to identify any potential risk.

Modeling Aluminum Stocks and Flows in China until 2050 Using a Bottom-Up Approach: Business-As-Usual Scenario Analysis

Aluminum metal is used in a wide range of applications such as construction, transportation, power, and aerospace. Previous studies have mainly used a top-down approach to explore future aluminum stocks and flows in China. In this study, we developed a dynamic material flow analysis model using a bottom-up approach to simulate aluminum flows and stocks in China until 2050, based on current government and sector policies. The results show that China’s aluminum stocks will be nearly saturated by 2050, with a total and per capita of 591 million tons (Mt) and 449 kg/per, respectively. The domestic demand for aluminum will grow until 2030 and will remain relatively stable thereafter at around 28–30 Mt. Construction and transport are the two sectors with the highest demand for aluminum, accounting for over 60% of the total aluminum demand. The domestic aluminum scrap will increase almost sevenfold, from 2.7 Mt to 20.0 Mt between 2020 and 2050. However, even assuming a 90% recycling rate, secondary aluminum will at best meet around 70% of demand by 2050. To realize sustainable development in China’s aluminum industry, extending the life of aluminum products and increasing aluminum scrap recycling are sensible measures.

Dominant host phase of mercury within the sediments of the East China Sea inner shelf: Implications for mercury inputs

Mercury (Hg) concentrations normalized to their dominant hosts have been widely used to identify geological events such as massive volcanic eruptions. However, the modern Hg cycle has significantly changed, and the implications of host-normalized Hg concentrations for the Hg dynamics in contemporary coastal environments (e.g., sources, delivery mechanisms, and Hg fluxes) remain poorly understood. In this study, 66 surface sediment samples from the continental shelf of the East China Sea (ECS) were analyzed, and the total organic carbon (TOC), aluminum (Al), total sulfur (TS), and Hg concentrations were determined. Our results support that organic matter predominantly hosts Hg in these sediments. Factors such as the Hg source and abundances of organic fractions influence Hg distributions, with notable enrichment in the Changjiang River estuary and the inner shelf of the ECS, especially near the mud depocenter located off the Oujiang River estuary. The oxic to suboxic redox state and the lack of significant sulfide accumulation in surface sediments suggest that sulfides are not the primary Hg hosts. The Hg/TOC ratios, ranging from 3.0 to 169.6 (ppb/%), are particularly high in the Changjiang River estuary and exhibit an exponential correlation with the Hg accumulation rates (Hg-AR). These findings suggest that the host-normalized Hg concentration could serve as a valuable tool for assessing Hg dynamics where the accumulation rates are uncertain.

Experimental and numerical investigation on the crashworthiness performance of double hat‐section Al‐CFRP beam subjected to quasi‐static bending test

AbstractNowadays, hybrid structures, which combine low‐density composites with low‐cost thin‐walled metals, have shown great effect in enhancing the performance of automotive body structures, especially the energy absorber components. This study focuses on the experimental and numerical investigation of the bending energy absorption behavior of CFRP/aluminum hybrid double hat‐section beams used in the side part of the car body. In the experimental section, two types of double hat‐section beams were fabricated: aluminum and Al/CFRP. These beams were then subjected to quasi‐static three‐point bending tests. The results demonstrated that the hybrid beam exhibited superior energy absorption capabilities compared to the single beam. Subsequently, a finite element model was developed using LS‐Dyna software and was validated by comparing the experimental and numerical load–displacement results. In‐depth numerical analyses were conducted to investigate the influence of various design parameters, including CFRP‐reinforcement configuration, numbers of CFRP layers, CFRP ply‐angle, CFRP reinforced length, and aluminum/CFRP mass, on crashworthiness indicators. The numerical findings indicate that the hybrid beam with , ply‐angles exhibited better crash force efficiency (CFE) and specific energy absorption (SEA) compared to other ply‐angles, respectively. Furthermore, increasing the number of CFRP layers within the total beam's mass improved its energy absorption capacity. It was also revealed that the CFRP length on the upper and lower hats could be considered as 42.5% of the total aluminum beam length, as opposed to the full CFRP length, providing enhanced energy absorption capabilities.Highlights Bending behavior of the Al and Al/CFRP double hat section beams. Effects of variable thickness and identical mass on the double hat section beam. Effects of variable ply angle and number of CFRP layers on the hybrid beams. Discrete effect of CFRP reinforcement configurations and inner CFRP lengths.

Effect of Aluminum Concentration in Water on Its Toxicity and Bioaccumulation in Zooplankton (Chaoborus and Chironomus) and Carp (Cyprinus carpio L.) Roe.

An attempt to evaluate aluminum toxicity to living organisms was undertaken in the study. A laboratory experiment was conducted to determine aluminum bioaccumulation and toxicity in Chironomus and Chaoborus larvae and in Cyprinus carpio L. roe depending on aluminum concentration in water reflecting natural chemical composition. Water was examined for temperature, pH, electrical conductivity, dissolved oxygen, color, nitrate nitrogen, nitrite nitrogen, sulfates by spectrophotometric method; total hardness and chlorides by titration method; and calcium, magnesium, sodium by flame atomic absorption spectrometry, total aluminum by electrothermal atomic absorption spectrometry. Determination of aluminum levels in water, roe, and zooplankton was carried out after mineralization using electrothermal atomic absorption spectrometry. Aluminum bioaccumulation factor in roe was determined with respect to concentration in water. Moreover, acute toxicity (LC50) was calculated. In the roe experiment, aluminum concentration in water at the end of the experiment was 0.0635-0.1283 mgAl∙dm-3. The lowest values were noted for the control sample and the highest for water with 0.03 mgAl∙dm-3 aluminum content. The final aluminum level in roe was, like in water, the highest in roe treated with 0.03 mgAl∙dm-3 (18.95 mgAl∙kg-1), and the lowest in roe treated with 3.00 mgAl∙dm-3 (6.96 mgAl∙kg-1). Aluminum bioaccumulation in roe was the strongest in the control. Survival rate ranged from 2.00 to 97.00%, which shows higher sensitivity of roe to aluminum concentration. LC50 value for Chaoborus was 0.6464 mgAl⋅dm-3, and for Chironomus 0.2076 mgAl⋅dm-3 indicating that Chironomus is more sensitive to aluminum toxic effects. Concentration of 3.0 mgAl∙dm-3 caused the highest mortality. Aluminum in both species at each concentration reached the highest levels after one day (24h), 254.58mg⋅kg-1 for Chaoborus and 3107mg⋅kg-1 for Chironomus. After another day, aluminum levels decreased. This demonstrated the differential accumulation of aluminum depending on the species, which predisposes Chironomus as a better indicator organism. This type of research is important from the point of view of aquaculture, which is a targeted activity with a high degree of economic importance, but is also important for aquatic organisms living in natural conditions. Fish reproduction takes place in both types of waters, so all these reservoirs regardless of their source of destination should be inspected.

Behavior and Distribution of Free Aluminum Oxides in some Soil Orders in North of Iraq

This study was conducted to investigate the behavior of free aluminium oxides in some soil orders in Iraq. Soil samples were collected from five Pedons for soil orders Entisols, Aridisols, Inceptisols, Vertisols and Mollisols. Total free aluminium oxides (Ald) were extracted by (striate-bicarbonate, sodium dithionite), amorphous aluminium oxides by acid ammonium oxalate and aluminium oxide associated with organic matter by alkaline Sodium pyrophosphate. The results showed that the amorphous aluminium oxides followed the same behavior in the vertical distribution and did not take a homogeneous pattern among the study pedons, noting that the Vertisols and Mollisols had outperformed the rest of the orders when it was observed that the highest values of 1.42 g / kg soil appeared in the horizon Ck1 of the Mollisols order, and that the highest values of the active ratio Alo/Ald also appeared in these two orders, which reflects the effect of the development state of the soil in releasing larger amounts of these oxides. Crystalline aluminium oxides appeared at lower values than the amorphous form in the Vertisols and Mollisols, unlike the Entisols, Aridisols and Inceptisols, in which these values excelled, noting that the values of crystalline oxides were somewhat superior in Vertisols. The aluminium oxide associated with the organic matter was concentrated in the surface horizons of all the study pedons, and the degree of soil development had no effect on that.

Geospatial modelling of soil phosphorus fractions and sorption indicators from heterogeneous landscapes in Ireland

Soil mapping of phosphorus (P) pools at regional scale can be used to inform policy and land management strategies in agri-environmental systems. However, linking an element that is predominantly managed by fertiliser and organic inputs to regional scale geochemistry can be problematic. This study used a geological survey of the northern half of Ireland at ≤4 km2 resolution to map total P (ICP aqua regia), plant available P (Morgan’ P) and Labile P pools (ICP aqua regia and Mehlich-3 P). Spatial modelling was used to map P interactions with total and available aluminium (Al) (ICP aqua regia and Mehlich-3 Al), as predefined sorption indicators. With the aim to develop agri-environmental mapping approaches to link soil P sorption dynamics to geological controls that can assist with regional, catchment and national-scale modelling for policy development.Plant available P concentration showed no spatial continuity in Kriged variogram output and was regulated by fertiliser inputs which mask any underlying geological processes. Subsequently, making this exploration method redundant in highly managed landscapes. Available Al concentrations determined by Mehlich-3 Al (M3-Al) are however regulated by underlying geology. Moreover, they have a significant negative correlation with bioavailable P indices. Areas of high M3 Al concentrations (≥ 702.5 mg kg−1) are dominant in the study area and show mainly low plant available P values (<5 mg l−1), however, potential labile P pools were indicated. Whereas areas of low Al concentrations (≤ 697 mg kg−1) show moderate to high plant available P concentrations. Which could identify areas where P is likely to be more soluble and at greater risk to loss to water. Therefore, using available Al as a sorption indicator can identify regional areas of high P fixation and low soil P retention in soils. Furthermore, using sorption dynamics in geospatial modelling could benefit targeted management approaches.

Fluoride and Aluminium in Tea (Camellia sinensis L.)-Tea Quality Indicators and Risk Factors for Consumers.

In recent years, the quality and sourcing of tea have gained importance in Europe, but information remains scarce. The aim of this study was to determine the concentrations of fluoride (F-) and total aluminium (Al) species in infusions of commercially available teas in Slovenia, and thus in Europe, and to relate them to tea quality and their impact on consumer safety. F- concentrations were determined using a fluoride-ion-selective electrode and Al concentrations using inductively coupled plasma optical emission spectroscopy. A comparison of the results obtained for four selected tea samples using the calibration curve and a standard addition technique showed good agreement, with no interferences caused by the sample matrix. The concentrations of 35 commercial teas ranged from 0.34 to 4.79 and 0.51 to 8.90 mg/L for F- and Al, respectively. The average concentrations of the two elements followed the same descending order: black filter > green filter > black leaves ≈ green leaves. Single and multivariate statistical methods supported the categorisation of teas by packaging but not by type, with tea in filter bags being more expensive than loose tea. The linear relationship between F- and Al concentrations in infusions (C(Al) = 1.2134 · C(F-)) allows for the determination of one element and estimation of the other, leading to a significant reduction in laboratory effort and cost. This research advances tea assessment by proposing Al concentration alongside F- as a quality indicator and provides the basis for tea-monitoring protocols. Finally, the daily consumption of larger quantities of tea (≈1 L) with elevated F- and Al concentrations could potentially pose a health risk.

Patterns and abiotic drivers of soil organic carbon in perennial tea (Camellia sinensis L.) plantation system of China

Understanding soil organic carbon (SOC), the largest carbon (C) pool of a terrestrial ecosystem, is essential for mitigating climate change. Currently, the spatial patterns and drivers of SOC in the plantations of tea, a perennial leaf crop, remain unclear. Therefore, the present study surveyed SOC across the main tea-producing areas of China, which is the largest tea producer in the world. We analyzed the soil samples from tea plantations under different scenarios, such as provinces, regions [southwest China (SW), south China (SC), south Yangtze (SY), and north Yangtze (NY)], climatic zones (temperate, subtropical, and tropical), and cultivars [large-leaf (LL) and middle or small-leaf (ML) cultivars]. Preliminary analysis revealed that most tea-producing areas (45%) had SOC content ranging from 10 to 20 g kg−1. The highest SOC was recorded for Yunnan among the various provinces, the SW tea-producing area among the four regions, the tropical region among the different climatic zones, and the areas with LL cultivars compared to those with ML cultivars. Further Pearson correlation analysis demonstrated significant associations between SOC and soil variables and random forest modeling (RF) identified that total nitrogen (TN) and available aluminum [Ava(Al)] of soil explained the maximum differences in SOC. Besides, a large indirect effect of geography (latitude and altitude) on SOC was detected through partial least squares path modeling (PLS-PM) analysis. Thus, the study revealed a high spatial heterogeneity in SOC across the major tea-producing areas of China. The findings also serve as a basis for planning fertilization strategies and C sequestration policies for tea plantations.

Spatiotemporal variability on local-regional scale in subtidal meiofaunal assemblages along the southern coast of Korea

This study was conducted to investigate the spatiotemporal variability in subtidal meiofaunal assemblages off the southern coast of Korea at local and regional scales. Abiotic and biotic samples were collected by site (three sites at least 10 km apart) within region (three coastal regions at least 50 km apart) over 7 years (2015–2021). The density and taxon richness of meiofaunal assemblages differed significantly among sites, but not among regions or years. The meiofaunal assemblage composition differed significantly among sites, regions, and years. A distance-based multivariate multiple regression analysis revealed that the mean sediment grain size and total nitrogen, lead, nickel, chromium, and aluminum concentrations were key environmental variables determining the variation of the meiofaunal assemblages. This study can provide basic ecological data for understanding the spatiotemporal distribution of meiofauna assemblages and aid in the development of management strategies to mitigate marine pollution on the southern coast of Korea.

12 Exposure to Metals and Particles in Welding and Episodes of Asthma/Wheeze and Rhinitis: a Canadian Cohort Study.

Abstract Introduction Welders are exposed through welding fume to particles and metals, including nickel and chromium, that may act as respiratory sensitizers. In a Canadian study of male and female welders we investigated the relation of modelled welding exposures to episodes of asthma/wheeze and rhinitis. Methods Welders who had been registered in an apprenticeship were recruited and followed up at 6-month intervals for up to five years. Women were recruited from across Canada, men just from Alberta. At each contact participants were asked about their health and specifically about symptoms of asthma and rhinitis and age these had first occurred. A complete job history was taken and at each contact after recruitment the participant completed a detailed welding task questionnaire. A job exposure matrix was developed, reflecting type of welding, base metal and consumables. This was validated against urinary metal concentration. Results 1001 welders, including 447 women, were recruited. In bivariate analyses, hours of welding/week, hours grinding/day and estimated exposures to total particles, manganese, nickel and aluminum were related to episodes of asthma/wheeze. Hours welding, grinding and nickel exposure were related to rhinitis. In multivariable models, including all exposures and confounders, the number of hours welding/week and hours grinding/day were related to asthma/wheeze episodes and hours grinding and nickel exposure to rhinitis. Conclusions Duration of welding tasks was related to episodes of asthma/wheeze and rhinitis. There was less evidence that estimated metal concentrations were associated with respiratory ill-health, having adjusted for hours welding.

Fluidized-bed homogeneous crystallization of α-Al(OH)3 for continuous aluminum removal from aqueous solution: Parameter optimization and crystallization mechanism

Fluidized-bed homogeneous crystallization (FBHC) is utilized to recover dissolved aluminum from the solution. Aluminum is crystallized homogeneously using NaOH as a precipitant. Under the optimum pH of 9.7; cross-sectional surface loading (L) of 0.5 kg/m2.h; up-flow velocity (U) of 62 m/h, the total aluminum removal (TR%) in the FBHC reactor reached about 98.5% that is corresponding to the residual aluminum concentration of 10 mg/L. The crystallization ratio of aluminum pellets reached about 93%. The aging process of FBHC effluent solution in the sedimentation tank (SED) lowered the residual dissolved aluminum concentration to below 0.2 mg/L due to the polymorph change from amorphous Al(OH)3 to crystalline Al(OH)3. SEM image shows the round-shape pellet product of FBHC that consists of two different structures of the inner and outer parts due to the different operating supersaturation index. Meanwhile, XRD and FTIR patterns show that during 24 h of aging time, the precipitated compound was changed from amorphous Al(OH)3 to pseudo-AlOOH, and then α-Al(OH)3 crystal. Bayerite (α-Al(OH)3) was predominating the compound of the final pellet product. The production of low-moisture bayerite leads to a disposal cost reduction of up to 80%. FBHC proposed an alternative method to treat aluminum ions in the solution by reclaiming it as high separability and low moisture Al(OH)3 granulated crystal.

Impact assessment of metals realeased by aluminium-based galvanic anode on the physiology of the abalone Haliotis tuberculata in controlled conditions.

To protect metal structures immersed in the sea from corrosion, the galvanic anode cathodic protection system (GACP) is often applied. However, this association leads to continuous oxidation of the galvanic anode and therefore to a release of a metal cocktail in the forms of ions or oxy-hydroxides. Therefore, the main objective of our study was to investigate the toxicity of elements released from the dissolution of an aluminium-based galvanic anode (∼95% Al, ∼5% Zn, <0.1% for In, Cu, Cd, Mn, Fe) on a grazing gastropod, the abalone Haliotis tuberculata. The present study was carried out in complement to other research currently in submission. Gastropods were exposed for 16 weeks (12 weeks of exposure and 4 weeks of decontamination phase) to 6 conditions including a control, 4 concentrations based on total aluminium level (86, 425, 1096 and 3549 µg L-1) and a trophic control, corresponding to abalones placed in non-contaminated natural seawater but fed with contaminated algae. The effects of metals on growth, glycogen levels, brix index of hemolymph, MDA levels in digestive gland and gills, hemocyte phagocytic activity, ROS production, lysosomal system and the progress of gametogenesis were investigated throughout the entire exposure allowing the realization of kinetics. The results revealed that the aluminium-based anode does not seem to have an effect on the health status of the individuals for environmentally realistic concentrations. However, in extreme conditions strong effects were reported on the growth, immune system and reproduction of abalone.

Glacial meltwater and sediment resuspension can be important sources of dissolved and total dissolvable aluminum and manganese to coastal ocean surface waters

AbstractThe supply of aluminum (Al) and manganese (Mn) to the Gulf of Alaska from coastal sources is poorly constrained. Here, we investigate the seasonality of sources to better constrain Al and Mn cycling in the coastal Gulf of Alaska region and add to our understanding of seasonal and interannual inputs. We examine Mn and Al behavior over the shelf to distinguish between redox‐induced release of dissolved trace metals (i.e., diffusion from sediments), sediment resuspension, and meltwater release. Data suggest that, prior to the onset of stratification in the spring, shelf sediment resuspension from deep mixing is an important mechanism for trace metal delivery to surface waters. As spring and summer ensue, increased meltwater discharge coupled with increased surface water temperatures result in stratification of the water column within the coastal Gulf of Alaska, and meltwater becomes a more important source of Al and Mn to the surface waters. The limited data available suggest that a redox‐driven flux of Mn from shelf sediments is not as important as the meltwater flux during the summer. In addition, dissolved trace metal concentrations in meltwater‐influenced plumes over the shelf exhibit conservative mixing, while particulate trace metal concentrations do not behave conservatively. This indicates that there are different physical controls (particle settling vs. mixing) on the spatial distributions of dissolved and particulate Al and Mn in coastal waters, the manifestation of which are likely highly variable and dependent on the trace metal composition of the river and the hydrodynamics governing this interaction at any given time.

Total organic carbon, aluminium and iron in bulk samples and aggregate size fractions of a sandy clay loam humic soil under sugarcane relative to native forest in northern KwaZulu-Natal, South Africa

The distribution of total aluminium (Al) and iron (Fe) and organic carbon (TOC) in aggregate fractions gives an insight into the dynamics of these elements in soil. This study determined the effects of over 30 years of sugarcane cultivation, compared to adjacent native forest, on Al, Fe and TOC in bulk soil and aggregate fractions within the 100 cm depth of a sandy clay loam humic soil. Samples were separated into large macro-aggregates: LM (>2000 μm), small macro-aggregates: SM (250–2000 μm), micro-aggregates: M (250-63 μm) and silt + clay: SC (<63 μm) fractions. The TOC was analyzed by dry combustion and total Al and Fe by X-ray fluorescence spectrometry. Sugarcane cultivation (i) reduced macro-aggregates and TOC and (ii) increased the SC fraction and total Al and Fe. The mean weight diameter declined from 1.32 mm (0–30 cm) to 1.06 mm (30–100 cm) under forest. Average (0–100 cm) Al and Fe contents (g kg−1) increased in LM (6–16 for Al; 6 to 9 for Fe), SM (7–11 for Al), M (5–14 for Al; 6 to 9 for Fe) and SC (7–16 for Al; 9 to 10 for Fe) under sugarcane relative to forest. The TOC (g kg−1) declined in the LM (13–7) and SM (7–6) but increased in the M (5–9) and SC (10–13) due to cultivation. These findings suggested that sugarcane cultivation decreases aggregate stability and TOC in macro-aggregates, and increases Al and Fe in all aggregates. Adoption of practices inclined to improve or maintain TOC as well as liming to increase pH are necessary management practices for sustainable production.

The Combination of Dolomite and Hydrated Lime with Different Compositions in Sulfuric Acid Soil for Fish Culture Ponds

Highlight Research Sulfuric acid soil causes extreme acidity of the water (pH&lt;3) and is unsuitable for fish culture Well management for sulfuric acid soil reduce the high risk of soil and water acidity The use of an appropriate combination of different liming is better than the single material to solve the very low pH Combination of dolomite and hydrated lime increased the pH and alkalinity Abstract The application of liming material should consider the amount and quality of chemicals related to cost expenditure and target of expected soil properties since it is usually done with an incorrect number’s estimation and expected soil-water quality which produces unsuccessful results. This study aimed to analyze the effect of different percentages from each combination of dolomite and hydrated lime (DH); DH1 (75:25), DH2 (50:50), and DH3 (25:75), which used five replications to the soil and water quality. The soil samples were taken from the earthen pond of semi-intensive tilapia fish (Oreochromis niloticus) culture in Lat Bua Luang, Rangsit, Thailand, placed into 50 plastic pots (volume = 1.5 L), and mixed with lime of different compositions. Based on the results, the mixture of dolomite and hydrated lime (DH) increased the soil and water pH into the desirable ranges (7.4-8.6). The alkalinity of DH treatments was not higher than that of the single dolomite (DA) or hydrated lime (HA). However, the value was still sufficient (&gt;75 mg/L as CaCO3) to buffer water quality changes. Several depletions of the toxic materials (total aluminum, iron, and manganese) caused by sulfuric acid (FeS2) had been observed in combination treatment, especially in DH1. On the contrary, the essential base cations, calcium, and magnesium increased beyond the single treatment, either dolomite (DA) or hydrated lime (HA). A combination of dolomite and hydrated lime (DH1) as an alternative treatment to remedy aquaculture ponds in acid-containing soil is suggested in terms of efficiency and possible cost-effectiveness.

An investigation of the seasonal relationships between meteorological factors, water quality, and sporadic cases of Legionnaires' disease in Washington, DC.

Since the discovery of Legionnaires' disease (LD), limited progress has been made in understanding the epidemiology of sporadic cases of LD. Outbreaks have confirmed that air conditioning and potable water systems can be sources of community-acquired LD. However, studying the association between water quality and LD incidence has been challenging due to the heterogeneity of water systems across large geographic areas. Furthermore, although seasonal trends in incidence have been linked to increased rainfall and temperatures, the large geographic units have posed similar difficulties. To address this issue, a retrospective ecological study was conducted in Washington, DC, from 2001 to 2019. The study identified aseasonal pattern of LD incidence, with the majority of cases occurring between June and December, peaking in August, October, and November. Increased temperature was found to be associated with LD incidence. In surface water, higher concentrations of manganese, iron, and strontium were positively associated with LD, while aluminum and orthophosphate showed a negative association. Intreatment plant water, higher concentrations of total organic carbon, aluminum, barium, and chlorine were positively associated with LD, while strontium, zinc, and orthophosphate showed a negative association. The results for orthophosphates and turbidity were inconclusive, indicating the need for further research.

Dynamics of Acidity Component of the Soils as Influenced by Liming in Upper Brahmaputra Valley Zone of Assam, India

An incubation study was conducted to investigate the effect of lime (CaCO3 )on the acidity components in Upper Brahmaputra Valley Zone (UBVZ) of Assam. Fourteen(14) geo-referenced soil samples were collected from Sibsagar and Jorhat districts of Assam. Soils were treated with 3 different doses of lime viz. 10 per cent Lime Requirement (LR10), 25 per cent Lime Requirement (LR25) and 50 per cent of Lime Requirement (LR50) and initial properties were recorded before liming. Samples were incubated in laboratory at different period of time viz. 15, 30, 60 and 90 days after liming (DAL) with moisture content at Field Capacity (0.33 bar). At four different intervals, soils were analysed for soil acidity components viz. total acidity, exchange acidity, exchangeable Al3+ and exchangeable H+. The soil of Upper Brahmaputra Valley Zone (UBVZ) of Assam were highly acidic to moderately acidic, sandy loam to silt loam in texture with high OC content ranged from 0.72 to 2.59%. The Cation Exchange Capacity (CEC) value ranged from 7.8 to 14.2 cmol (p+)/ kg. Application of lime brought about mark decreased in acidity components viz. total acidity, exchange acidity, exchangeable aluminium and exchangeable hydrogen. Soil acidity components recorded highest decreased at 90 DAL @ LR50 and decreased started from 15 days onwards. The findings of the investigation showed that liming @ LR10 was found effective in reducing soil acidity. The residual effect of lime was found persisting till 90 days. However, the magnitude of lime was increasing with increase in application of lime@ from LR10 to LR25 and to LR50.