Mixture Of Humic Acid Research Articles

Cefadroxil photodegradation processes sensitized by natural pigments: mechanistic aspects and impact on the antimicrobial function.

Cefadroxil is a widely used antibiotic with a low elimination efficiency in wastewater treatments plants, so it represents a contaminants of emerging concern that should be removed. The photosensitization process that involves natural pigments and visible sunlight can be offered as an environmentally friendly alternative to be considered for Cefadroxil degradation. In this investigation, we carried out a mechanistic and kinetic approach to Cefadroxil photodegradation sensitized by Riboflavin and Humic Acid, in individual and combined processes. Our experiments indicate that Cefadroxil is able to interact with the excited states of Riboflavin as well as with the photogenerated reactive oxygen species, with an important contribution of singlet oxygen. The antibiotic was less sensitive to the photodegradation in the presence of Humic Acids and in the mixture of Riboflavin and Humic Acids. Self-sensitization processes and internal filter effects are proposed as possible explanations for the observed phenomenon. The reaction between Cefadroxil and singlet oxygen showed a dependence with the pH of the medium, the photodegradation kinetic constants are greater at alkaline pH compared to neutral pH. The reaction is favored when the anionic species of the antibiotic is present. Microbiological tests on S. aureus indicated that the antibiotic reduce its antimicrobial activity as a consequence of the photooxidative process mediated by singlet oxygen. We believe that the results are relevant since, the sensitized photodegradation process could lead to the oxidation of Cefadroxil and to the progressive loss of its antimicrobial function, this fact could contribute to the decrease in the generation of bacterial multi-resistance to antibiotics in the environment.

The removal of pathogenic bacteria and dissolved organic matter from freshwater using microporous membranes: insights into biofilm formation and fouling reversibility

Pathogenic bacteria in drinking-water pose a health risk to consumers, as they compromise the quality of portable water. Chemical disinfection of water containing dissolved organic matter (DOM) causes harmful disinfection by-products. In this work, 4-hydroxybenzoic acid (4-HBA) blended polyethersulfone membranes were fabricated and characterised using microscopic and spectroscopic techniques. The membranes were evaluated for the removal of bacteria and DOM from synthetic and environmental water. Permeate flux increased from 287.30 to 374.60 l m−2 h−1 at 3 bars when 4-HBA increased from 0 to 1.5 wt.%, suggesting that 4-HBA influenced the membrane’s affinity for water. Furthermore, 4-HBA demonstrated antimicrobial properties by inhibiting bacterial growth. The membrane with 1 wt.% 4-HBA recorded 99.4 and 100% bacteria removal in synthetic and environmental water, respectively. Additionally, DOM removal of 55–73% was achieved. A flux recovery ratio (FRR) of 94.6% was obtained when a mixture of bacteria and humic acid was filtered, implying better fouling layer reversibility during cleaning. Furthermore, 100% FRR was achieved when a multimedia granular filtration step was installed prior to membrane filtration. The results illustrated that the membranes had a high permeate flux with low irreversible fouling. This indicated the potential of the membranes in treating complex feed streams using simple cleaning protocols.

Effects of Addition of Humic and Fulvic Acids on Soil Properties and Germination Percentage of Cucurbit Plants (Zucchini and Cucumber)

This research was conducted to study the effect of adding humic and fulvic acids to the irrigation water on soil properties and germination percentage of two cucurbit plants: zucchini and cucumber. The study was conducted in an open field in Sokhna District in the governorate of Zarqa (Jordan). The field soil was transported to calcareous sandy soil. In the beginning, the weeds and stones were removed, and the land was smoothed and plowed. Effort was made to control weeds and insects at all stages of plant growth. Then, an irrigation network was installed. The fulvic acid-humic acid (FA-HA) biostimulant mixture was incorporated with the irrigation water, and irrigation was practiced three days per week for four weeks. During this period, every irrigation round lasted for two to three hours. A mixture of humic acid (8.0%) and fulvic acid (8.0%) was added to the irrigation water. Three treatments were considered, corresponding to three acid mixture concentrations: 0.50 mL.L-1, 1.00 mL.L-1, and 1.50 mL.L-1. The acid mixtures were added continuously at all stages of plant growth until plant maturity and harvest. Four replicates of the experiment were made. The plant growth variables of interest were germination percentage, number of leaves, date of fruition, size of fruit, and overall mass of fruits. Meanwhile, the soil parameters of interest were soil pH and soil salinity (electric conductivity (EC)) before and after adding the FA-HA mixture. The study found that the 0.5 mL.L-1 acid mixture treatment led to the early growth of the zucchini plant seeds and that fruition took place 12 days after planting. In addition, the results showed an increase in plant germination under the 0.5 mL.L-1 acid mixture treatment in light of the increase in the number of male and female plant flowers, with fruiting taking place on time. In conclusion, the relationship between zucchini growth and yield with FA-HA mixture concentration is non-linear. It is also concluded that the optimum acid mixture concentration and application rate are crop-specific. Hence, for each crop, the most appropriate acid mixture concentration should be determined first before the broad-scale application of amendments to the soil to ensure the contribution of this environmentally friendly practice to sustainable agriculture.

Influence of organic matters on the adsorption-desorption of 1,2-dichloroethane on soil in water and model saturated aquifer.

1,2-Dichloroethane (1,2-DCA) is a typical organic chlorinated compound largely utilized in chemical manufacturing and industrial production and also a common pollutant in organically contaminated sites. The adsorption of 1,2-DCA on soil grains significantly influences its environmental fate and removal process. This study investigated the influence of fulvic acid (FA) and humic acid (HA) on the adsorption-desorption of 1,2-DCA in solid-liquid interfaces in water or constructed porous media. Experimental findings demonstrated the influence of organic matter on the adsorption of 1,2-DCA at the solid-water interface. 1,2-DCA adsorption increased in the FA or HA-treated soils when organic matter was present on the solid surfaces. The 1,2-DCA adsorption in the mixture of FA and HA was slightly lower than that in single organic acids, depending on the binding of FA and HA to the soil grains/colloids. Basic conditions reduced the adsorption of 1,2-DCA on soils, whereas acidic conditions enhanced adsorption due to the increased interactions via adsorption sites and hydrogen bonds. Conversely, the presence of organic matter in solutions (liquid phase in constructed porous media) will reduce the adsorption of 1,2-DCA on solid surfaces and increase the transport in the model aquifer. The combination of FA, HA, and rhamnolipids is helpful for the removal of 1,2-DCA from solid surfaces. Additionally, because of the enhanced desorption, the risk of 1,2-DCA contamination in groundwater can be increased when the organic matter or surfactant is present in the liquid phase if the eluent is not collected. This study helps to better understand the cooperative interaction of soil organic matter and chlorinated hydrocarbons at solid-water interfaces and the environmental fate and potential removal strategies of chlorinated hydrocarbons in contaminated sites.

Preparation of landscape gardening soil using undersized fraction from aged MSW by EDTA or citric acid coupled with humic acid: Effect assessment, properties, and optimization

ABSTRACT Undersized fraction from aged municipal solid waste (UFAMSW), as a kind of soil-like material, has been proved effective in providing a large amount of organic matter and nutrients for soil and plants. The characteristics and effectiveness of heavy metal pollution removal in UFAMSW attracted tremendous research interest from scientists recently. In this study, the heavy metal removal efficiencies and bioavailability of washing on contaminated UFAMSW were evaluated with three washing reagents including ethylene diamine tetra acetic acid (EDTA), citric acid (CA), and humic acid (HA). The effects of chelating agent concentration, pH, and washing time on metal removal were investigated and response surface methodology (RSM) was employed to optimize the washing conditions. The results indicated that the removal efficiencies of Cu, Zn, and Mn could be 53.68%, 52.12%, and 30.63% by EDTA/HA washing and 42.36%, 39.67% and 28.49% by CA/HA washing, respectively. The European Community Bureau of Reference (BCR) sequential extraction was applied to analyze the fraction change of heavy metals in UFAMSW before and after washing, and it was found that chelating agent combined with HA could contribute to the removal of the exchangeable fraction. Physical and chemical properties of UFAMSW were improved to some extent after washing with mixed HA and chelating agent and could achieve the quality standard of landscape gardening soil. Accordingly, the mixture of HA and other chelating agents could be a promising washing process for preparation of landscape gardening soil using UFAMSW. Implications: Our manuscript studies the removal of heavy metals from the contaminated undersized fraction from aged municipal solid waste (UFAMSW). UFAMSW, as a kind of soil-like material, has been proved effective in providing a large amount of organic matter and nutrients for soil and plants however often limited by heavy metal pollution. The UFAMSW used in this experiment was collected after the excavation and screening-sorting of aged refuse from Changshankou Domestic Waste Sanitary Landfill in Wuhan City, Hubei Province, Southern China. This study investigated the effects of EDTA, CA, HA, mixed EDTA/HA, and mixed CA/HA washing on heavy metal removal (Cu, Zn, and Mn), bioavailability of residual heavy metal and properties. The effects of chelating agent concentration, pH, and washing time on metal removal were investigated and then response surface methodology was employed to optimize the washing conditions. The results showed that washing by CA/HA and EDTA/HA, had a higher removal efficiency of heavy metals (Cu, Zn, and Mn) in UFAMSW compared to single HA. Meanwhile, HA has a higher removal for exchangeable fraction of heavy metals, the exchangeable concentration of Cu, Zn, and Mn in CA/HA and EDTA/HA washed UFAMSW were lower compared with UFAMSW washed by single CA and EDTA. Thus, mixing HA with EDTA or CA makes a less risk to environmental and the removal efficiency is acceptable. Additionally, CA/HA and EDTA/HA washing tend to improve soil physicochemical properties and soil fertility. Thus, mixing HA with different washing agent are potential methods for preparation of landscape gardening soil using UFAMSW.

<i>In Vitro</i> Pharmacological Evaluation of Fulvic Acid and Humic Acid Novel Combination in Amyloid Beta Intoxicated SH-SY5Y Cell Lines Model of Alzheimer’s Disease

Alzheimer’s disease is the most widespread advancing neurodegenerative disorder, and it is estimated that more than 50 million people have been affected worldwide. It is characterized by dementia, loss of sensory and motor function and difficulty in performing work. NMDA antagonists and acetylcholinesterase inhibitors are currently being used as treatment options for AD, but the treatment would not decline the disease progression as well as neurodegeneration. We used a unique humic acid and Fulvic acid mixture in the current investigation for the treatment of amyloid-β intoxicated Alzheimer’s in vitro model in SH-SY5Y cell line. Humic acid and fulvic acids are organic substances which will be produced by microorganism from the biomass such as dead matter of animal as well as plants. Both the components were used in the 1:1 ratio against AD induced cell line with optimum concentration 50μM/ml of each compound. The inflammatory mediators like Reactive Oxygen Species (ROS) were estimated using flow cytometry - H2DCFDA staining assay and cytokines such as TNF-α and IL-1β levels were estimated using ELISA. The results obtained from present study implicating that the humic acid and fulvic acids and their novel combinations lessen the ROS, cytokines level and decreased the apoptosis levels there by it exhibiting the neuro-protective mechanism via inhibiting neuro-inflammatory pathway in AD.

Differences in the Effect of Mn2+ on the Reverse Osmosis Membrane Fouling Caused by Different Types of Organic Matter: Experimental and Density Functional Theory Evidence.

Landfill leachate from some sites contains a high concentration of Mn2+, which may cause reverse osmosis (RO) membrane fouling during RO treatment. In this study, the effect of Mn2+ on RO membrane fouling caused by typical organic pollutants (humic acid (HA), protein (BSA), and sodium alginate (SA)) was systematically investigated, and it was found that Mn2+ exacerbates RO membrane fouling caused by HA, SA, and HBS (mixture of HA + BSA + SA). When the Mn2+ concentration was 0.5 mM and 0.05 mM separately, the membrane fouling caused by HA and SA began to become significant. On the other hand, with for HBS fouling only, the water flux decreased significantly by about 21.7% and further decreased with an increasing Mn2+ concentration. However, Mn2+ has no direct effect on BSA. The effect degrees to which Mn2+ affected RO membrane fouling can be expressed as follows: HBS > SA > HA > BSA. The density functional theory (DFT) calculations also gave the same results. In modeling the reaction of the complexation of Mn2+ with the carboxyl group in these four types of organic matter, BSA has the highest energy (-55.7 kJ/mol), which predicts that BSA binding to Mn2+ is the most unstable compared to other organic matter. The BSA carboxylate group also has the largest bond length (2.538-2.574 Å) with Mn2+ and the weakest interaction force, which provides a theoretical basis for controlling RO membrane fouling exacerbated by Mn2+.

Evaluación técnico-económica de consorcios bacterianos en el cultivo de fresa en dos sistemas de producción

Strawberry production is predominantly carried out in open fields, rendering it vulnerable to pest attacks, which can lead to reductions in yield. This susceptibility is further exacerbated by adverse climatic conditions. Another challenge is the high cost of inputs like fertilizers. Consequently, the aim of this study was to evaluate both technically and economically the impact of applying bacterial bio-fertilizers to strawberry crops under two production systems. The experimental design employed was a subdivided-plot arrangement in a randomized complete block, with the main plot focusing on the production system (either open field or macrotunnel), the subplot on plastic mulch (either with or without), and the sub-subplot on bacterial consortia treatments commercial. These were as follows: (a) control, which corresponded to traditional farmer management; (b) Bacillus subtilis, (c) consortium 1, comprising a mixture of humic acids and Rhodopseudomonas palustris, Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus licheniformis; and (d) consortium 2, composed of Azospirillum brasilense, Azotobacter chroococcum, Lactobacillus acidophillus, Saccharomyces cerevisiae. The combination of macrotunnel production and plastic mulch, along with the application of bacterial consortium 2, yielded the best results in the second year, producing gross and net yields of 25.041 kg ha-1 and 17.330 kg ha-1, respectively. This was associated with the most favorable benefit-cost ratio of 1.41 in the second year.

Bioactivation effects of spirulina microalga and humic acid on safflower (Carthamus tinctorius)

The Carthamus tinctorius, commonly known as safflower, is an annual plant with numerous branches and thorns from the Asteraceae family. For this experiment, three treatments were applied to the pots: humic acid, spirulina microalgae, and a mixture of both to analyze their bioactivation effects. These treatments were applied three times per week over the course of two weeks, with irrigation taking place every other day. The wet weight of the aerial parts of the harvested plants was measured and placed in liquid nitrogen, then stored in a freezer. Chlorophyll, carotenoids, proline, protein, phenol, antioxidants, and malondialdehyde were measured. The results show that several bioactivators significantly increased the growth, chlorophyll, carotenoids, protein, and proline of safflower plants when compared to the control. The three treatments reduced the antioxidant and malondialdehyde content significantly. In contrast to the control condition, the mixture of humic acid and spirulina microalgae, as well as humic acid alone, decreased the phenolic content. The findings demonstrated that humic acid and spirulina microalgae can serve as positive plant bioactivators for safflower by boosting its growth and reducing stress.

Advanced Electrochemical Degradation of Organic Pollutants from Water using Sb-Doped SnO2/Ti Anode and Assisted by Granular Activated Carbon

In this paper, mesoporous electrodes consisting of Sb-doped SnO2 deposited onto Ti plates that had undergone controlled corrosion under acidic medium were synthesized via a spin-coating method and morpho-structurally characterized via X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrodes were electrochemically tested to examine their degradation/mineralization through electrooxidation (EO) of doxorubicin (DOX) as a single component and multi-component, together with capecitabine (CCB) from the cytostatic class and humic acid (HA) from the natural organic matter (NOM) class in the absence/the presence of activated carbon (AC) as a particulate electrode. The best mineralization efficiency of 67% was achieved for DOX mineralization using Sb-doped SnO2 deposited onto a Ti plate that had undergone controlled corrosion with oxalic acid during the electrooxidation process. The presence of AC within the electrolysis process generated a synergistic effect of 52.75% for total organic carbon (TOC) parameter removal, which is in accordance with and significantly better than the results reported in the literature. The aspects related to the complex mechanism of DOX degradation and mineralization are discussed. The superiority of AC assisted electrooxidation, as electrochemical filtering (EF), was proved, considering simultaneous degradation and mineralization of mixture of doxorubicin, capecitabine and humic acid.

Electroactive membrane with the electroactive layer beneath the separation layer to eliminate the interference of humic acid in the oxidation of antibiotics

Removing harmful antibiotics is essential to reclaiming water from municipal secondary effluent. Electroactive membranes are effective in the removal of antibiotics but challenged by the abundant coexisting macromolecular organic pollutants in municipal secondary effluent. To eliminate the interference of macromolecular organic pollutants in the removal of antibiotics, we propose a novel electroactive membrane with a top polyacrylonitrile (PAN) ultrafiltration layer and a bottom electroactive layer composed of carbon nanotubes (CNTs) and polyaniline (PANi). When filtering the mixture of tetracycline (TC, a typical antibiotic) and humic acid (HA, a typical macromolecular organic pollutant), the PAN-CNT/PANi membrane performed sequential removal. It retained HA at the PAN layer (by ∼96%) and allowed TC to reach the electroactive layer where it was electrochemically oxidized (e.g., by ∼92% at 1.5 V). The TC removal of the PAN-CNT/PANi membrane was marginally affected by HA, unlike that of the control membrane with the electroactive layer on the top that showed decreased TC removal after the addition of HA (e.g., decreased by 13.2% at 1 V). The decreased TC removal of the control membrane was attributed to the attachment (but not competitive oxidation) of HA on the electroactive layer that impaired the electrochemical reactivity. The HA removal prior to TC degradation realized by the PAN-CNT/PANi membrane avoided the attachment of HA and guaranteed TC removal on the electroactive layer. Long-term filtration for 9 h revealed the stability of the PAN-CNT/PANi membrane, and its advantageous structural design was conformed in the context of real secondary effluents.

Aliquots of MIL-140 and Graphene in Smart PNIPAM Mixed Hydrogels: A Nanoenvironment for a More Eco-Friendly Treatment of NaCl and Humic Acid Mixtures by Membrane Distillation.

The problem of water scarcity is already serious and risks becoming dramatic in terms of human health as well as environmental safety. Recovery of freshwater by means of eco-friendly technologies is an urgent matter. Membrane distillation (MD) is an accredited green operation for water purification, but a viable and sustainable solution to the problem needs to be concerned with every step of the process, including managed amounts of materials, membrane fabrication procedures, and cleaning practices. Once it is established that MD technology is sustainable, a good strategy would also be concerned with the choice of managing low amounts of functional materials for membrane manufacturing. These materials are to be rearranged in interfaces so as to generate nanoenvironments wherein local events, conceived to be crucial for the success and sustainability of the separation, can take place without endangering the ecosystem. In this work, discrete and random supramolecular complexes based on smart poly(N-isopropyl acrylamide) (PNIPAM) mixed hydrogels with aliquots of ZrO(O2C-C10H6-CO2) (MIL-140) and graphene have been produced on a polyvinylidene fluoride (PVDF) sublayer and have been proven to enhance the performance of PVDF membranes for MD operations. Two-dimensional materials have been adhered to the membrane surface through combined wet solvent (WS) and layer-by-layer (LbL) spray deposition without requiring further subnanometer-scale size adjustment. The creation of a dual responsive nanoenvironment has enabled the cooperative events needed for water purification. According to the MD's rules, a permanent hydrophobic state of the hydrogels together with a great ability of 2D materials to assist water vapor diffusion through the membranes has been targeted. The chance to switch the density of charge at the membrane-aqueous solution interface has further allowed for the choice of greener and more efficient self-cleaning procedures with a full recovery of the permeation properties of the engineered membranes. The experimental evidence of this work confirms the suitability of the proposed approach to obtain distinct effects on a future production of reusable water from hypersaline streams under somewhat soft working conditions and in full respect to environmental sustainability.

Influence of humic and fulvic acid addition on soil N P K availability and broad bean output (Vicia Faba L.)

A field experiment was carried out during the agricultural season 2021-2022 at Al-Muthanna Governorate to study the effect of adding humic and fulvic acid in the soil on the availability of N P K in the soil, a simple RCBD experiment was designed with three replicates, it included the addition of a mixture of humic and fulvic acid (0, 5, 10 and 15) for L ha-1. The results showed a significant superiority in increasing the concentration of availability NPK in the soil; the H2 treatment gave the highest rate of 204.00 and 32.76 mg kg soil-1 for NK elements, respectively. The H3 treatment also showed the highest increase in the concentration of significant factors availability NPK in the soil after harvest; it reached 28.62, 14.30 and 155.00 mg kg soil-1, respectively. The highest individual yield was 169.00 g plant-1 when treated with H3, compared to the control treatment, which amounted to 134.80 g plant-1. Keywords: Humic, Fulvic acids, Faba beans, NPK

New Insights into the Fouling of a Membrane during the Ultrafiltration of Complex Organic–Inorganic Feed Water

This paper presents an analysis of the fouling of a ceramic membrane by a mixture containing high concentrations of humic acid and colloidal silica during cross-flow ultrafiltration under various operating conditions. Two types of feed water were tested: feed water containing humic acid and feed water containing a mixture of humic acid and colloidal silica. The colloidal silica exacerbated the fouling, yielding lower fluxes (109-394 L m-2 h-1) compared to the humic acid feed water (205-850 L m-2 h-1), while the retentions were higher except for the highest cross-flow rate. For the humic acid feed water, the irreversible resistance prevails under the cross-flow rate of 5 L min-1. During the filtration of an organic-inorganic mixture, the reversible resistance due to the formation of a colloidal cake layer prevails under all operating conditions with an exception. The exception is the filtration of the organic-inorganic mixture of a 50 mg L-1 humic acid concentration which resulted in a lower flux than the one of a 150 mg L-1 humic acid concentration under 150 kPa and a cross-flow rate of 5 L min-1. Here, the irreversible fouling is unexpectedly overcome. This is unusual and occurs due to the low agglomeration at low concentrations of humic acid under a high cross-flow rate. Under lower transmembrane pressure and a moderate cross-flow rate, fouling can be mitigated, and relatively high fluxes are yielded with high retentions even in the presence of nanoparticles. In this way, colloidal silica influences the minimization of membrane fouling by organic humic acid contributing to the control of in-pore organic fouling.

Calcium- and Magnesium-Enriched Organic Fertilizer and Plant Growth-Promoting Rhizobacteria Affect Soil Nutrient Availability, Plant Nutrient Uptake, and Secondary Metabolite Production in Aloe vera (Aloe barbadensis Miller) Grown under Field Conditions

This work investigates the effects of an organic fertilizer enriched in Ca and Mg and two bacterial inoculants, applied alone and in combination, on soil fertility, plant growth, nutrition, and production of secondary metabolites, namely, acemannan and total phenolic compounds (TPCs), by Aloe vera (Aloe barbadensis Miller), under field cultivation. The first inoculum consisted of five native bacterial strains (Pseudomonas sp., Enterobacter sp., and three strains of Pantoea sp.), characterized in vitro as putative plant growth promoters, isolated from local organic farming fields of Aloe vera. The second inoculant was a commercial product (BACTILIS-S and HUMOFERT) and consisted of three Bacillus species: B. pumilus, B. amyloliquefaciens, and B. subtilis. The organic fertilizer (HUMO-CAL M-8O) was a mixture of humic and fulvic acids, with an additional CaCO3 (40% w/w) and MgO (4% w/w). The most significant increase in the content of acemannan and TPCs was detected under single application of the organic fertilizer, which was linked to enhanced concentration of Mg and Ca in the leaf gel. The concentration of acemannan tended to be increased with the combined application of the organic fertilizer and microbial inoculants. TPCs were significantly increased in both single and combined treatments, seemingly related to Fe concentration in the leaf rinds.

Bio-efficiency Studies of Plant biotiX product “BP100” on Okra (Abelmoschus esculentus (L.) Moench) cultivation

Present investigation was done to evaluate the results of applying industrial product “BP-100” on growth, yield and quality of okra in comparison with domestic popular product as standard check “IFFCO Sea Secret”. Both the products were mixture of humic acid and seaweed extract. Experiment was conducted on the agriculture field, LPU, Phagwara in summer, 2023. Okra variety Arka Anamika was obtained from IIHR, Bengaluru. Experiment was based on RBD with five treatments and five replications. Interestingly, most of the parameters like germination percentages, plant height, number of leaves, branches, flowers and fruit, fruit yield, net returns and cost benefits were found maximum under T5 (standard check) while some other traits like seedling length, seedling fresh weight and seedling vigour index I T4 gave higher results. T5 gave also maximum TSS content, ascorbic acid and mucilage content in okra while least fibre content and physiological loss of weight after harvesting was also observed in T5. Based on those observations, the conclusion made out of this experiment is, highest results in almost all parameters are coming from T5 because of more number of applications (as per recommended) on okra and less price of the product compared to test product “BP-100” used in T2, T3 and T4

Response of foliar application of humic acid and micronutrient mixture on growth and grain yield of maize crop

The efficiency of humic acid (HA) and micronutrient (MN) mixtures as a source, either separately or in combination, was studied to increase the productivity and growth of maize (Zea mays L.). The research was carried out in the College of Agriculture, Azamgarh, Uttar Pradesh, India during the spring season of 2022. The treatments were replicated three times in a randomized complete block design. The HA and MN mixtures were sprayed separately at 0.2% and 0.4% each. Further, the combination of HA @ 0.2% + MN @ 0.2% and HA @ 0.4% + MN @ 0.4% was also applied. The application was done by foliar spray twice on 35 and 50 DAS, along with control using water. The result revealed that foliar spraying of HA at 0.4% + MN at 0.4% significantly (P=0.05) improved the height (cm), LAI, and dry matter accumulation (g m-2) of the maize crop. In comparison to the MN combination, HA generally had more maize growth and yield. A foliar spray with a combination of HA and MN at 0.4% each could result in a higher grain yield of the maize crop, which recorded a 42.62% higher grain yield than the control. Hence, based on the study, foliar application of the HA+MN mixture at 0.4% could be advised to boost maize crop growth and grain yield during the spring season.

Catalytic degradation of carbamazepine by metal organic frameworks (MOFs) derived magnetic catalyst Fe@PC in an electro-Fenton coupled membrane filtration system: Performance, pathway, and mechanism

The treatment of pharmaceutical and personal care products (abbreviated as PPCPs) have the problems of high energy consumption and low efficiency. Herein, an electro-Fenton (EF) coupled membrane filtration system was constructed to cost-efficiently degrade micromolecular carbamazepine (CBZ, a kind of PPCPs) from aquatic environment. Aqueous solution containing CBZ and the mixture of humic acid (HA, a kind of dissolved organic matters, with the molecular weight bigger than 400) was firstly filtered by polyvinylidene fluoride (PVDF)/carbon fiber cloth composite cathode membrane, which rejected HA while let CBZ pass through the membrane. The CBZ was then participated in the following EF process and decomposed with high efficiency. In the EF process, Fe-based metal–organic frameworks (Fe-MOFs) derived magnetic nanoconfinement catalyst, with iron nanoparticle as core and porous carbon (PC) as shell (abbreviated as magnetic Fe@PC), was prepared and applied to the EF process. The results indicated the rejection rates of the cathode membrane towards HA and CBZ were 69.91% and 3.35%, respectively, indicating most of the HA was rejected in the filtering process. In the EF process, the magnetic Fe@PC exhibited excellent catalytic degradation performance towards CBZ, with a total removal rate of 98.34%. Among which, the contributions of different processes including adsorption, electrodegradation and EF degradation were 0.90%, 4.97%, and 89.08%, respectively. Quenching test indicated both OH radical and O2– radical played crucial roles during the degradation process, which were generated by the in-situ decomposition of H2O2 in the coexistence of the magnetic Fe@PC. Based on the degradation intermediates of CBZ, four probable degradation pathways were proposed, and the most accessible pathway was also verified by theoretical calculations. The eco-toxicity assessment results showed most of the intermediate products were in lower toxicity than CBZ. Besides CBZ, the system also exhibited excellent degradation performance towards various kinds of PPCPs. This work indicated the EF coupled cathode membrane system is one of the efficient technologies in the removal of PPCPs in complex water environment.

Optimizing maize yields using growth stimulants under the strategy of replacing chemicals with biological fertilizers.

Partial replacement of chemicals with biological fertilizers is a recommended strategy to reduce the adverse environmental effects of chemical fertilizer losses. Enhancing the reduced mineral with biological fertilizers strategy by foliar application of humic acid (HA) and amino acids (AA) can reduce environmental hazards, while improving maize (Zea mays L.) production under semiarid conditions. The recommended doses of N, P and K (e.g., 286kg N ha-1, 75kg P2O5 ha-1 and 67kg K2O ha-1) were applied as the first fertilization level (100% NPK) and were replaced with biofertilizers by 100%, 75%, 50% and 25% as levels of reducing mineral fertilization. These treatments were applied under four foliar applications of tap water (TW), HA, AA and a mixture of HA and AA. Our results reported significant reductions in all parameters, including maize ear yield attributes and grain nutrient uptake, when replacing the mineral NPK with biofertilizers by 25-100% replacement. However, these reductions were mitigated significantly under the application of growth stimulants in the descending order: HA and AA mixture>AA>HA>TA. Applying a mixture of HA and AA with 75% NPK + biofertilizers increased ear length, grain yield, grain uptake of N and K, and crude protein yield by 37, 3, 4, 11 and 7%, respectively as compared with 100% mineral fertilizer only. Moreover, all investigated parameters were maximized under the application of 75% NPK + biofertilizers combined with AA or the mixture of HA and AA, which reveals the importance of growth stimulants in enhancing the reduced chemical NPK strategy. It could be concluded that the mineral NPK rate can be reduced by 25% with biofertilization without any yield losses when combined with HA and AA under arid and semi-arid conditions. That achieves the dual goals of sustainable agriculture by improving yield, while reducing environmental adverse effects.

Effect of C/Fe Molar Ratio on H2O2 and •OH Production during Oxygenation of Fe(II)-Humic Acid Coexisting Systems.

Hydrogen peroxide (H2O2) and hydroxyl radical (•OH) production during oxygenation of reduced iron (Fe(II)) and natural organic matter (NOM) in the subsurface has been increasingly discovered, whereas the effect of the C/Fe molar ratio in Fe(II) and NOM coexisting systems remains poorly understood. In this study, aqueous Fe(II) and reduced humic acid (HAred) mixture at different C/Fe molar ratios (0-20) were oxygenated. Results show that both H2O2 and •OH accumulation increased almost linearly with the increase in the C/Fe ratio, with a more prominent increase in •OH accumulation at high C/Fe molar ratios. At low C/Fe molar ratios (C/Fe ≤ 1.6), electrons mainly transferred from dissolved inorganic Fe(II), surface-adsorbed Fe(II), and a low proportion of HA-complexed Fe(II) to O2; with the increase in the C/Fe ratio to a high level (C/Fe ≥ 5), the main electron source turned to HA-complexed Fe(II) and free HAred. The changes in the electron source and electron transfer pathway with the increase in the C/Fe ratio increased the yield of •OH relative to H2O2. This study highlights the important role of the C/Fe ratio in controlling H2O2 and •OH production and therefore in accurately evaluating the associated environmental impacts.