Kf Values Research Articles

Sorption and transport of atrazine for stable manure-amended agricultural soil from Kahramanmaraş, Turkey

ABSTRACT This study investigated how adding stable manure affected the transport of atrazine within agricultural soils from Kahramanmaraş, Turkey. Based on the batch and miscible-displacement experiments, it was found that atrazine sorption was nonlinear, following a Freundlich isotherm, and was rate-limited and reversible for both the non-amended and amended soil. The addition of manure resulted in higher retardation of atrazine, with R values of 10.1 to 19.1, compared to values of 3.2 to 4.3 for the non-amended soil. The KF values for stable-manure amended soil calculated from batch experiment was three times higher than non-amended soil. The transportation of atrazine shows non-ideal behavior, characterized by significant elution tailing at low concentrations due to the organic carbon content of the soil. This effect was more prominent in soil with a 10% stable-manure amendment. By incorporating non-linear sorption, a two-site transport modeling approach provides a reasonably accurate representation of the atrazine breakthrough curves. The distinct sorption-desorption characteristics of atrazine have significant implications for risk assessment of atrazine-contaminated soil and should be considered in the regulation, management, and remediation of such contaminated sites.

Valorization of Olive Leaf Polyphenols by Green Extraction and Selective Adsorption on Biochar Derived from Grapevine Pruning Residues.

Given today's increasingly intensive agriculture, one key problem area considers the valorization and reuse of wastes from food and agricultural production with minimal impact on the environment. Due to its physicochemical characteristics, biochar (BC) derived from grapevine pruning residue has shown considerable potential for use as an adsorbent. High-value phytochemicals found in abundance in the olive leaf (OL) can be employed in many different industrial sectors. The potential application of BC in the removal of specific polyphenolic components from OL extracts has been investigated in the present study. Water, as the most available and greenest of solvents, was investigated as to its use in the extraction of polyphenols, which was carried out by comparing maceration, ultrasound-assisted extraction, and microwave-assisted extraction, considering different temperatures and solid-to-liquid (s/l) ratios. The BC adsorption capacity of selected polyphenols was fitted with both the Langmuir and Freundlich isotherm models. The Freundlich model fitted better relative to OL polyphenols adsorption. Oleuropein was the most abundant compound identified in the extracts, obtaining the highest Kf value (20.4 (mg/g) × (L/g)n) and R2 coefficient (0.9715) in the adsorption on the biochar's surface. The optimum conditions in the dosage experiment suggest the use of 0.5 g of BC using 3 g/L extracts, with an exception for oleuropein and hydroxytyrosol, for which the highest biochar dose (2.5 g) performed better. Considering the compounds' concentrations and the BC dose, BC from grapevine pruning residues demonstrated a potential use in the uptake of specific polyphenols from olive leaves, making it a promising adsorbent for such applications.

Polyethylene microplastic can adsorb phosphate but is unlikely to limit its availability in soil

In plant growth experiments, the presence of microplastics (MPs) often reduces plant growth. We conducted laboratory experiments to investigate the potential of microplastics to adsorb the major soil nutrient phosphate; adsorption to MPs was then compared to adsorption to soil. Adsorption experiments used two contrasting soils, pristine high density polyethylene and artificially weathered material (the same material but exposed to 185 nm UV light for 420 h over 105 days), phosphate solutions (dissolved KH2PO4) ranging from 0.2 to 200 mg L−1 and a solid (g) to liquid (mL) ratio of 1: 150 at different values of pH (2–12) and different concentrations of background electrolyte (0.00–0.10 M NaNO3). The adsorption data were best fitted to linear and Freundlich isotherms. In initial experiments where pH was not fixed and with a background electrolyte of 0.10 M NaNO3, Kd values ranged from 3.37 to 27.65 L kg−1, log Kf from 1.21 to 1.96 and 1/n from 0.36 to 0.84. Exposure of the MP to 185 nm UV radiation led to the appearance of a C=O functional group in the MP; the partition coefficient Kd, calculated from the linear isotherm did not increase but the logKf value derived from fits to the Freundlich isotherm increased by a factor of 1.5. Kd values for soils were 3–7.5 times greater than those for MPs and log Kf values 1.1–1.7 greater. In the experiments in which initial pH and ionic strength were varied, adsorption was similar across all treatments with adsorption parameters for the higher organic content soil sometimes having the highest values and the pristine microplastic the lowest. In the desorption experiments most of the adsorbed phosphate desorbed. Overall our findings indicate that despite their ability to adsorb phosphate, MPs are unlikely to control the fate and behaviour of phosphate in soil.

ANALYSIS OF PHONONS BEHAVIOR IN QUASI-ONE-DIMENSIONAL CRYSTALS OF TTT(TCNQ)2 NEAR THE PEIERLS STRUCTURAL TRANSITION IN A 3D APPROXIMATION

This research paper focuses on investigating the metal-insulator transition occurring in quasi-one-dimensional organic crystals of TTT(TCNQ)2. The study utilizes a 3D approximation approach and introduces a physical model that incorporates two essential electron-phonon interactions. The first interaction is akin to the deformation potential, while the second interaction follows a polaron type behavior. By employing the random phase approximation, the renormalized phonon spectrum is calculated across different temperatures and various values of the dimensionless Fermi momentum kF. The findings indicate that the transition exhibits characteristics of the Peierls type, and the critical temperature associated with the Peierls transition is determined. Furthermore, an interesting observation is made that the Peierls critical temperature experiences a notable decrease with an increase in carrier concentration.

CHANGES IN HYDROGEOLOGICAL CONDITIONS DURING BOGGING IN THE SOUTHEAST OF THE WEST SIBERIAN PLAIN

Link for citation: Savichev O.G. Changes in hydrogeological conditions during bogging in the southeast of the West Siberian plain. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 10, рр. 187-198. In Rus. Relevance of the research is determined by the need to understand the mechanisms of interaction between groundwater, swamp and river waters in conditions of severe swampiness in the taiga zone of Western Siberia to solve a number of scientific and engineering problems both at present and in the future. The aim: quantitative assessment of changes in the levels of groundwaters during the characteristic periods of swamping of the southeast of the West Siberian Plain: 1) the beginning of an intensive spread of peat swamps with a peat deposit thickness of 0,3 m or more; 2) oligotrophization of swamps. Methods: methods of mathematical modeling, statistical methods. Results and conclusions. The author has carried out the analysis of peat deposit structure in the southern part of the Chaya river (a tributary of the Ob river) catchment area. The large-scale formation of peat swamps (with a peat thickness of 0,3 m or more) in the area under consideration occurred approximately 4 thousand years ago; the oligotrophization of the peat deposit (on a regional scale) occurred approximately 2,0…1,5 thousand years ago. In both cases, the main part of the swamps presumably could be attributed to the lowland type, but compared with the modern period in the first case their total area was 2 times less, and in the second was 1,7 times more. Taking into account these estimates, the average values of infiltration Inf and filtration coefficients Kf were determined, the ratio Inf/Kf dependence on the area of low-moor peat swamps was obtained, and groundwater levels were calculated at the present time and for periods of 1,7 and 4,1 thousand years ago. During the oligotrophization of the peat deposit (approximately 2,0...1,5 thousand years ago), with a high probability, there was a deterioration in water exchange between swamps and underground aquifers and an increase in groundwater levels. The beginning of intensive regional swamping (about 4 thousand years ago) occurred against the background of intense water-erosion processes. This results in accumulation of river alluvium accompanied by a rise in the levels of river water and then groundwater.

Sorption, leaching, and degradation of dicamba in two Brazilian soils: A study into soil layers

Understanding the behavior in soil of soluble and mobile herbicides, such as dicamba, is essential for efficient weed management. Thus, the objective of the research was to understand the sorption, leaching and degradation processes of dicamba along the profile of two Brazilian soils (Oxisol and Ultisol). The Oxisol collected is a very deep soil, the A horizon was collected in a layer of 0.10 m deep, the B horizon 2.0 m and the C horizon ranging from 5.0 to 6.0 m. In contrast, the Ultisol presents a difference between the most superficial horizons, the A horizon was collected at a depth of 0.10 m, the B horizon at around 1.0 m depth and the C horizon at a depth of 2.0–3.0 m. A High-Performance Liquid Chromatography (HPLC) was used to determine the herbicide in the soil solution. The Freundlich sorption coefficient (Kf) values of dicamba ranged from 0.53 to 0.88 mg (1-1/n) L1/n kg−1 in Oxisol and 0.25–0.69 mg (1-1/n) L1/n kg−1 in Ultisol, indicating a low sorption capacity of the herbicide in all profiles. The dicamba mobility index was higher in the Ultisol, ranging from 4.22 to 65.8 compared to the Oxisol, which ranged from 0.46 to 8.10. The degradation half-life time (DT50) of dicamba was short (∼4 days) in the A horizon of both soils compared to the other horizons. Moreover, persistence in the B and C horizons was higher in Oxisol (182 and > 250 days) compared to Ultisol (85.6 and 52.1 days, respectively). The sorption and mobility index of dicamba showed a correlation with soil pH and DT50 values, depending on the organic matter (OM) content. The recommendation of use of dicamba should consider the physical and chemical attributes of the soil as an alternative to reduce the risk of environmental contamination.

Adsorption kinetics and equilibrium performance of Di-n-butyl phosphate on XAD-4 and XAD-7 from alkaline medium

ABSTRACT The present study investigates the feasibility of adsorption method for the removal of Di-n-butyl phosphate from sodium carbonate solution on adsorbents such as XAD-4 and XAD-7. The fundamental aspects of equilibrium and kinetics of adsorption have been studied. The experimental equilibrium data were fitted well with Sips isotherm, and maximum solid uptake capacity for monolayer coverage (qm) was found to be 0.363 × 10−3 mol/g and 0.385 × 10−3 mol/g for XAD-4 and XAD-7, respectively. The adsorption kinetics was well described by the pseudo-first-order model, and estimated first-order rate constant values were found to be 0.041 min−1 for XAD-4 and 0.027 min−1 for XAD-7. The transport mechanism of solute from the bulk solution to adsorbent was described in detail with suitable mathematical model, and experimental kinetic data were superimposed on numerically solved concentration profiles to calculate external mass transfer coefficient (kf) and effective diffusivity (De). The values of kf and De were estimated as 4.632 × 10−7 m/s and 8.849 × 10−13 m2/s, respectively, for XAD-4, whereas for XAD-7, the values were found to be 2.132 × 10−6 m/s and 1.389 × 10−12 m2/s. XAD-7 is found to have slightly better adsorption capacity and transport characteristics than XAD-4.

Characteristics of organic matter released from drinking water treatment sludge under different storage conditions: Evaluation based on activated carbon adsorbability

Recycling water from drinking water treatment sludge (DWTS) as raw water raises several problems in the drinking water supply. In this study, the impact of storage temperatures and oxygen conditions for DWTS on the characteristics of dissolved organic matter (DOM) released from sludge was evaluated in terms of adsorbability by activated carbon. Results showed that the adsorbability of the released DOM varied greatly with storage temperatures and oxygen conditions. The modified Freundlich isotherm model revealed that the average adsorption strength (KF) estimated based on dissolved organic carbon (DOC) and ultraviolet absorbance at 260 nm (UV260) varied in the ranges of 4.01–12.1 (mg g−1)1-1/n and 23.1–52.6 (L m−1 g−1)1-1/n, respectively. DOM released under the condition without aeration possessed higher adsorbability compared to DOM released under the condition with aeration (1.41–3.01 times for DOC-based; 1.14–2.28 times for UV260-based). Moreover, the KF values of fluorescence excitation-emission matrix (EEM)-based fulvic acid-like and humic acid-like substances were higher than those of tyrosine-like and tryptophan-like substances, indicating humic-like substances released from DWTS were more adsorbable than protein-like ones. The methods or adsorption conditions that can enhance the removal of protein-like substances are essential for dealing with water quality problems associated with recycling water from drinking water treatment sludge.

Influence of biosolids and sewage effluent application on sitagliptin soil sorption

Biosolids and sewage effluent application to agricultural fields is becoming a win-win practice as both an economical waste management strategy and a source of nutrients and organic matter for plant growth. However, these organic wastes contain a variety of trace chemicals of environmental concern such as pharmaceuticals and personal care products (PPCPs), which may pose a risk to agricultural fields and ecosystems. This work aims to investigate the sorption of sitagliptin on four agricultural soils, evaluate the effects of biosolids and sewage effluent application, and elucidate the main sorption mechanism of the pharmaceutical on soils. The sorption study revealed that the sorption capacities of sitagliptin on different soils were positively related to the contents of soil organic matter and negatively associated with soil pH values. The application of biosolids and sewage effluent decreased the sorption capacity of sitagliptin, which may be attributed to the loading of dissolved organic matter derived from organic wastes. The Freundlich isotherm model demonstrated that the addition of biosolids from 0 to 100 % (W/W) consistently decreased the sorption affinity (Kf) of sitagliptin from 1.69 × 102 to 3.82 × 101 mg(1-n) Ln kg−1. Sewage application at 0, 10, 50, and 100 % (V/V) also reduced the Kf values from 1.69 × 102 to 9.17 × 101 mg(1-n) Ln kg−1. Attenuated Total Reflection (ATR)-Infrared (IR) spectroscopy analyses suggested that electrostatic interactions between carbonyl and amino groups of sitagliptin and the negatively charged soil surface are the main sorption mechanisms. In a co-solute system, the sorption affinity of sitagliptin on the soil decreased with increasing metformin concentrations, suggesting that competitive sorption may reduce the sorption capacity of individual contaminants in soil systems containing multiple PPCPs.

Biometric indices, growth pattern, and physiological status of captive-reared indigenous Yellowtail brood catfish, Pangasius pangasius (Hamilton, 1822).

The current study was conducted to comprehend the variation of the growth pattern and the physiological status of Pangasius pangasius (Hamilton, 1822) reared in the pond from July 2021 to September 2021. A total of 90 brood individuals were collected from the Meghna River and studied for the present experiment. The overall growth pattern for P. pangasius was isometric (b = 3.00) in the Meghna River, while the male fish showed positive (b > 3.00) and the female showed a negative allometric growth pattern (b < 3.00). The Fulton's condition factor (KF) value was greater than 1, indicating a healthy population and a habitat with abundant food sources. Moreover, the KF value was found to be substantially related to total body mass. On the other hand, both sexes of P. pangasius had relative weight average values of more than 100, simply indicates the fish is naturally obese and has enough stored energy to maintain its physiology. The calculated form factors suggested an elongated body shape, which is typical of many riverine fishes. In addition, a small number of morphological traits varied significantly in the current study. Likewise, in the case of morphometric features, the principal component analysis showed a considerable degree of connectedness between the male and female individuals. The blood values showed no significant difference between the sexes. This might result from feeding fish the same kind of food and maintaining them in the same environment. However, the higher temperature might have caused slight blood abnormalities in both sexes. The current findings strongly support raising this fish in captivity and would offer useful information for fish farm owners, entrepreneurs, stakeholders, and other concerns in Bangladesh and surrounding nations.

Adsorptive desulfurization properties of refractory sulfur compounds onto Al2O3-Ga2O3 nanomaterials

The impact of the synthesis method on the structural, textural, and surface properties of the Al2O3-Ga2O3 sample was investigated, and the adsorbents were evaluated for their adsorptive desulfurization properties. The incorporation of Ga atoms into the Al2O3 framework (via SGM) resulted in an increase in specific surface area and pore volume, but a decrease in average pore size. XRF analysis confirmed Ga loading, while SEM-EDS and STEM-EDS techniques revealed well-distributed elements with irregular spherical morphologies. XRD diffractograms confirmed the formation of γ-Al2O3, with a slight shift of diffraction peaks due to the presence of Ga (via SGM), suggesting that Ga atoms are part of the structure. The obtained solids exhibit values in the Freundlich equation that indicate a degree of nonlinearity in adsorption for Al2O3, while Al2O3-Ga2O3(SGM) and Al2O3-Ga2O3(IM) suggest a possible chemical process and favorable adsorption. The small KF values demonstrate weak adsorption on the adsorbents, which can be explained by sulfur-to-metal interaction, π-complexation, and non-specific interactions such as Van der Waals forces. The adsorbent showed the greatest affinity for BT and the least for DBT. The selectivity order from strongest to weakest adsorption was BT: Al2O3-Ga2O3(SGM) > Al2O3-Ga2O3(IM) > Al2O3, and DBT: Al2O3-Ga2O3(IM) > Al2O3-Ga2O3(SGM) > Al2O3.

Sorption desorption behaviour of Imidacloprid in agricultural soils of Deccan plateau of Southern India: kinetics and thermodynamic analysis

ABSTRACT Soil sorption has a significant impact on the fate and behaviour of agrochemicals in soil and water. The current study attempts to investigate the sorption desorption behaviour of Imidacloprid, a neonicotinoid insecticide, in three different types of black cotton soils (BC-1, BC-2, BC-3) and red soil (RS) of Southern India using batch equilibrium technique under two different temperature conditions (273/300K). The data revealed that the Freundlich model provided the best explanation for the observed adsorption isotherms. BC-2 soil had higher adsorption coefficient (Kf) value, followed by BC-3, BC-1, and RS. Clay content, cation exchange capacity (CEC) and specific surface area (SSA) all had a positive correlation with Kf value, indicating that they are responsible for Imidacloprid adsorption in the soil. The change in enthalpy (ΔH°) value was found to be negative in all of the investigated soils, indicating that the sorption process was spontaneous and exothermic, and that hydrogen bonding may be responsible for sorption. The low value of Kf and organic carbon partition coefficient (Koc) indicates that Imidacloprid is mobile in black cotton and red soils and has potential to contaminate groundwater resources.

Keragaman Morfologi Pertumbuhan 7 Klon dan 2 Varietas Tanaman Tebu (Saccharum officinarum L.) di PT Perkebunan Nusantara X Ploso Klaten-Kediri

Sugarcane (Saccharum Officinarum L.) is the basic ingredient for making sugar. In Indonesia, in the last 5 years, sugar productivity only reached 5.2 tons/ha, very different from the productivity in 1935-1940, which averaged 17 tons/ha. This is because this Aat variety has not yet reached the desired productivity rate. The purpose of this study was to determine the diversity of growth of sugarcane (Saccharum officinarum L.) in clone SB01, clone SB03, clone SB04, clone SB11, clone SB12, clone SB19, clone SB20, variety PS862 and variety Bululawang. This research was carried out in the Djengkol garden, Ploso Klaten, Kediri. The tools used are sickle, cloth, tape measure, caliper, camera and stationery. The materials used are clone SB01, clone SB03, SB11, SB12, SB19, SB20, PS862 variety, Bululawang variety. Observations included growth variables (stem height, number of stems, number of leaves, stem diameter). Data analysis used ANOVA with a 5% F test. If there is a significant difference, proceed with the 5% DMRT test, correlation test, genetic diversity, heritability, genetic progress. Clone SB12 had an advantage in variable stem height of 395.83 (cm), number of stems 5.67 (stem), number of leaves 9.44 (strands), while clone SB01 had an advantage in stem diameter with the highest value of 31.99 (mm). Correlation relationship on sugarcane plant growth variables. The diversity of 7 clones and 2 varieties is heavily influenced by genetics and slightly influenced by the environment as shown by the KKG values in the medium-high category, the KF values in the low-high category, the Heritability (H2) medium-high category and the genetic progress (KG) category. rather high.

Exploration of haematite-loaded rice husk biochar as a low-cost nanosorbent to remove Cr (III) from the aqueous media

ABSTRACT In this study, the biochar of rice husk was modified to a nanosorbent upon loading with haematite for Cr (III) removal from aqueous solutions. Three adsorbents, rice husk, rice husk biochar and haematite-loaded rice husk biochar, were used for equilibrium adsorption studies. SEM and FTIR analysis revealed the presence of pores and various surface active sites on a nanomaterial, which were responsible for the adsorption of Cr (III). C–H, –O–H, C=O stretching vibrations were observed in characterised FTIR peaks. Modelling of adsorption isotherms indicated best fit for Freundlich isotherm with maximum Kf value of 12,218 and 39.5 for linear and non-linear nanomaterial experimental calculations, and positive n value in range of 1–10 for all forms of adsorbents, Dubinin–Radushkevich adsorption saturation capacity qs showed high readings of 9417 and 76.8 for haematite nanomaterial, Elovich isotherm favoured non-linear results in case of nanomaterial with increased Qm values 43.4–112.3 from raw form to nanosorbents and Temkin isotherm with. Kinetic and Thermodynamic results were also summarised. Constants k and h and Qe capacity were tabulated for Pseudo second order model with highest Qe in the range of 20.36–22.52 for haematite loaded biochar nanomaterial. Hence, haematite based rice husk biochar nanostructure was employed as an efficient adsorbent for uptake of chromium.

Adsorption Characteristics of Cd2+ Ions in Aqueous Solution on Modified Straw Biochar

Rice straw and corn straw were selected as raw materials to prepare biocharby anoxic carbonization and the biochar was loaded on the surface with FeCl3, MnCl2 and Fe(NO3)3 &amp; KMnO4, respectively, and then two types of straw biochar and six types of modified biochar were prepared. FT-IR, SEM, and XRD were used to characterize and analyze the physical and chemical properties of the biochar. The adsorption kinetics and adsorption isothermal tests of Cd2+ ions in aqueous solution were carried out. The results showed that modified biochars attached more active sites and surface group, especially iron-manganese-modified biochar (FMBC1, FMBC2). The kinetic adsorption tests showed that the adsorption process of eight kinds of biochar all conformed to the quasi-second-order kinetic equation, and chemisorption maybe dominated the adsorption process. The adsorption isothermal test showed that the adsorption process of Cd2+ ions by FeCl3-modified biochar (FBC1, FBC2) and Fe(NO3)3 &amp; KMnO4-modified biochar (FMBC1, FMBC2) conforms to the Freundlich model, and the adsorption process of Cd2+ ions by MnCl2-modified biochar (MBC1, MBC2) conforms to Langmuir model. Compared with other kinds of biochar, the KF value of Fe(NO3)3 &amp; KMnO4-modified biochar of rice straw biochar (FMBC1) was the largest, reached 18.602 L·mg−1, and its 1/n value was the smallest, it reached 0.474, indicating that the adsorption effect on Cd2+ of FMBC1 was the best.

Combined use of biochar and alternative management systems for imazamox induced pollution control in rice growing environments

Imazamox (IMZX) is a persistent herbicide having probable risks for non-target organisms in the environment and water contamination. Alternatives to conventional flooding rice production, including biochar amendment, may induce changes in soil properties which can greatly modify the environmental fate of IMZX. This two-year study is the first to evaluate how tillage and irrigation practices, with or without fresh or aged biochar (Bc), that are alternatives to conventional rice production impact IMZX's environmental fate. The treatments were: conventional tillage and flooding irrigation (CTFI), conventional tillage and sprinkler irrigation (CTSI), no-tillage and sprinkler irrigation (NTSI), and the corresponding Bc-amendment treatments (CTFI-Bc, CTSI-Bc, and NTSI-Bc). Fresh and aged Bc amendment decreased IMZX's sorption onto the soil in tillage treatments, with Kf values decreasing 3.7 and 4.2-fold (fresh case) and 1.5 and 2.6-fold (aged case) for CTSI-Bc and CTFI-Bc, respectively. The transition to sprinkler irrigation reduced IMZX persistence. Overall, Bc amendment also reduced chemical persistence with half-life values decreasing 1.6 and 1.5-fold for CTFI and CTSI (fresh year) and 1.1, 1.1, and 1.3-fold for CTFI, CTSI, and NTSI (aged year), respectively. Sprinkler irrigation reduced IMZX leaching by up to a factor of 2.2. The use of Bc as amendment led to a significant decrease in IMZX leaching only under tillage conditions, but notable in particular for the CTFI case where leaching losses were reduced in the fresh year from 80% to 34% and, in the aged year, from 74% to 50%. Hence the change in irrigation from flooding to sprinkler either alone or in combination with the use of Bc (fresh or aged) amendment could be considered an effective way to sharply mitigate IMZX contamination of water in environments where rice is grown, particularly in those managed with tillage.

Prediction of heavy metal biosorption mechanism through studying isotherm kinetic equations

The kinetic constants for free and immobilized cells were determined by measuring reaction rates at different metal concentrations at the optimum reaction conditions. (Kmax and Vmax) were calculated from the slope and intercept of the straight lines. The pseudo-second-order rate constants are derived based on the sorption capacity of the solid phase, where K2 is the rate constant for the pseudo-second-order model. Determined experimentally by plotting t/q against t. The mean free vitality of adsorption (E) was figured as 2.62 kJ mol−1 and the extent of E communicated gives data on the adsorption mechanism. An E value ranging from 1 to 8 indicates physisorption and 8–16 kJ mol−1 predicts ion exchange. Thus, the evaluated value of 2.62 kJ mol−1 predicts the phenomenon of physisorption, which suggests that metal ions were favorably adsorbed by this biosorbent in a multi-layer fashion. The overall result suggested that 98.2% of U (VI) by biosorption of U in the mechanism of adsorption will include chemisorption mechanistic pathway: Langmuir, Freundlich, equations and the values of Kf 5.791 where KL 3.9 were determined from the linear plot of log qe vs. log Ce at 30 °C, indicating that metal ions were favorably adsorbed by this biosorbent in a multi-layer fashion and instrumentation of beads characterizing novel Binding sites using FTIR & SEM beside change in peaks position which assigned for its groups confirm biosorption of metal.

Transport and Environmental Risks of Propachlor Within the Soil-Plant-Water Phase as Affected by Dissolved Organic Matter as a Nonionic Surfactant.

Propachlor is a widely used acylaniline herbicide for weeding annual gramineous and dicot plants in farmland. As a toxic agricultural chemical, it is overused in crop production and has become one of the most serious environmental pollutants. Yet, understanding the impact of environmental factors on its behavior in farmland soils is critically important for healthy crop production and food safety. In this study, we characterized the effect of dissolved organic matter (DOM) extracted from rice straw on the mobility behavior of propachlor in farmland soil using comprehensive approaches such as the batch equilibrium experiment, soil thin-layer chromatography, soil column leaching, and wheat bioaccumulation with Triton X-100 (TX-100) as a reference surfactant. The application of DOM at 60 and 120 mg DOC L-1 and TX-100 at 96, 192, and 288 mg L-1 reduced the sorption and increased the desorption of propachlor in soil. Freundlich constant K f values (sorption) of propachlor declined with the expansion of DOM and TX-100 concentrations. The addition of DOM and TX-100 increased the mobility of propachlor and the total concentration of propachlor in the leachate of soil columns. The retention factors (R f) were evaluated in the soil thin-layer chromatography as 0.741 and 0.772 (for DOM) and 0.731, 0.763, and 0.791 (for TX-100), all of which were greater than the control (0.710) under the treatment. The application of DOM or TX-100 reduced root growth (biomass) and increased bioaccumulation of propachlor in the roots and shoots of wheat. The outcome of the study can provide important references for the rational use of propachlor and help agronomic management to minimize pesticide contamination in realistic crop production.

Effects of conservation buffer systems on adsorption of fluorescent-labeled Escherichia coli.

The magnitude of bacterial transport through runoff into surface water or infiltration into groundwater is influenced by the adsorption processes in soil. The objective of this study was to evaluate fluorescent-labeled Escherichia coli (E. coli) adsorption by soil under agroforestry buffer (AB), grass buffer (GB), and row crop (RC) management. Adsorption experiments were conducted by inoculating three masses (0.5, 1, and 10 g) of each treatment (AB, GB, and RC) with E. coli O157:H7-GFP with concentration ranges of 105 -108 colony-forming units (cfu) ml-1 . Adsorption data were evaluated using Langmuir, Freundlich, and Temkin adsorption isotherm models. The Freundlich isotherm model described the observed data well for all treatments using the 10-g soil mass, with the R2 values closer to unity in all treatments. The Freundlich Kf parameter, an indicator of adsorption capacity, was higher for the AB treatment (9.93 cfu ml-1 ) compared with the GB and RC treatments (2.32 and 1.27 cfu ml-1 , respectively). The multiple pairwise comparisons test (Tukey test) of the Freundlich 1/nf parameter demonstrated a significant difference (p<.05) between the AB treatment and the RC and GB treatments. Similarly, the Kf values were significantly (p=.05) higher for the 10-g mass under the same test conditions, but no significant differences were observed in the 0.5- and 1-g masses. This study demonstrated that AB has a higher E. coli adsorption capacity and the potential for mitigating the effects of E. coli O157:H7 transport to surface or groundwater through the soil ecosystem.

Identification of optimal irrigation and fertilizer rates to balance yield, water and fertilizer productivity, and fruit quality in greenhouse tomatoes using TOPSIS

The precise management of water and fertilizer is necessary to maximize greenhouse tomato production. Irrigation quantity and fertilizer application rate were experimentally varied to determine their effects on tomato yield, water and fertilizer productivity, and nutritional and flavor quality over four consecutive growing seasons in two cities, Yangling and Baoji. The experiment was designed as a quadratic orthogonal rotation combination with two factors at five levels and a total of 16 treatments. TOPSIS (technique for order preference by similarity to an ideal solution) models were created to predict the effects of drip irrigation water quantity and fertilizer application rate on indicators of tomato water and fertilizer productivity, yield and quality. The tomato indicators showed a downward opening quadratic relationship with irrigation quantity and a similar relationship with fertilizer application rate. The composite indicators exhibited a downward opening paraboloid relationship with irrigation and fertilizer rates. Tomato pan coefficient (Kcp) values in the range 0.74–0.78 and the fertilization coefficient (Kf) values in the range 1.13–1.27 produced optimal tomato growth in all experimental plots. To ensure the results of this study are of practical use, over 95% of the highest composite indicators were used to identify the optimal range of Kcp as 0.68–0.83 and the optimal range of Kf as 0.98–1.34 in spring, with corresponding ranges in fall being 0.68–0.82 and 1.06–1.41. This study proposes a method for analyzing tomato growth and provides guidance for precise irrigation and fertilizer management in greenhouse tomato production in Northwest China.