Organic Micro Research Articles

Unraveling the detrimental effect of polymeric microcapsules on the corrosion performance of epoxy resin coatings

Organic micro- or nanocapsules are widely used as reservoirs to carry sealing agents or corrosion inhibitors to achieve the self-healing functionality of coatings. To understand the impact of the capsules' incorporation on the barrier properties of organic coatings, composite epoxy resin coatings containing different concentrations (e.g., 5 wt%, 10 wt% and 20 wt%) of urea-formaldehyde (PUF) microcapsules were deposited on the top of Q235 carbon steel. The features of PUF microcapsules and composite coatings were characterized, and the corrosion behaviors of the coating-protected carbon steel were investigated in NaCl solution. The results showed that the spherical PUF microcapsules (∼40 μm) with 290 nm thick shell and hexyl acetate core are synthesized through in situ polymerization. The prepared microcapsules can uniformly distribute within the epoxy resin coatings, which in turn deteriorates the corrosion resistance of the microcapsules-containing composite coatings (MCECs). Lower volume (5 wt%) microcapsules incorporation caused a slight reduction in the corrosion resistance (Rc) and effective capacitance (Ceff) from 4.39 × 107 Ω·cm−2 and 6.50 × 10−5 mF·cm−2 to 8.72 × 106 Ω·cm−2 and 5.63 × 10−5 mF·cm−2, respectively. For higher volume (10 wt% and 20 wt%) groups, the Rc further decreases to 7.47 × 105 Ω·cm−2 and 1.45 × 105 Ω·cm−2, whereas the Ceff increases to 5.63 × 10−5 mF·cm−2 and 5.63 × 10−5 mF·cm−2, respectively. The failure mechanism of the MCECs can be ascribed to the rupture of the PUF microcapsules during the curing process and/or immersion in NaCl electrolyte, which suggested the mechanical strength and chemical stability of the capsules should be carefully determined to avoid their negative impact on the barrier property of polymeric coatings.

Mechanisms by Which an Evaporated Lagoon Sedimentation System Controls Source–Reservoir Preservation in Lei32 Sub-Member Unconventional Oil and Gas

The muddy limestone in the Lei32 sub-member of the Middle Triassic Leikoupo Formation in the well Chongtan 1 (CT1) of the Sichuan Basin has yielded promising industrial oil and gas production. This discovery has the potential to become a significant strategic reservoir in the future for oil and gas exploration in the Sichuan Basin. However, the understanding of hydrocarbon accumulation in the muddy limestone of the Lei32 sub-member remains insufficient, which poses limitations on further exploration selection and deployment strategies. This study focuses on the analysis of core samples and laboratory data in the wells CT1 and Jianyang 1 (JY1), aiming to investigate the source rock and reservoir characteristics of the muddy limestone in the Lei32 sub-member, as well as the primary controlling factors influencing the development of the source rock and reservoir. The results show that the Lei32 sub-member in the Central Sichuan Basin is an evaporated lagoon deposition; the tight argillaceous limestone and limy mudstone exhibit the characteristic of source–reservoir integration, belonging to a new type of unconventional oil and gas reservoir. The reservoir space of the argillaceous limestone and limy mudstone in the Lei32 sub-member primarily consists of inorganic and organic micro–nanopores and microfractures. The average porosity and permeability are 2.7% and 0.19 mD, indicating a low-porosity and low-permeability unconventional reservoir. The clay minerals and gypsum content are the important factors influencing reservoir porosity, and the fractures are key factors influencing permeability. This study will elucidate the specific features of hydrocarbon accumulation in the muddy limestone reservoirs of the Lei32 sub-member and provide insights into its exploration potential.

Extraction of platinum at high phase ratio via a rotating packed bed integrated with falling film

The recovery of platinum is an urgent requirement because of its limited resources and wide application in catalysis, electrochemistry, and so forth. Liquid-liquid extraction is an efficient process in metal recovery due to high product selectivity and purity. However, the extraction of platinum was challenging at a high aqueous-to-organic phase ratio (R), restricted by insufficient contact between phases. This work developed a rotating packed bed integrated with falling film (FF-RPB) to intensify the platinum extraction process. The organic phase consisting of TOA, TBP, and kerosene was broken into droplets by rotating packing. The aqueous phase, the Pt(IV) acidic chloride solution, flowed downward as liquid film on the FF-RPB’s inner wall. The organic micro droplets impacted on the aqueous film, and the extraction was gradually completed during the coflowing process. Results indicated that the extraction efficiency was improved with the increment of rotational speed and TOA concentration and reduced with the enlargement of pH value, Pt(IV) concentration and aqueous-to-organic phase ratio. The extraction efficiency and enrichment factor reached 0.993 and 14.9 at R = 15 and aqueous phase flowrate of 300 L·h−1, respectively. Compared with batch apparatus and microreactors, the FF-RPB showed great advantages, which realized prominent extraction of platinum at a higher aqueous-to-organic phase ratio and a larger throughput.

Evaluation of Polyurethane Foam Derived from the Liquefied Driftwood Approaching for Untapped Biomass

Nowadays, climate change has become a serious concern, and more attention has been drawn to utilizing biomass sources instead of fossil sources and how petroleum chemical plastics should be reduced or replaced with bio-based materials. In this study, the optimized condition of liquefaction of driftwood was examined. There was a concern that driftwood might have some decay and chemical change. However, according to the Organic Micro Element Analyzer (CHN analyzer) test and Klason lignin and Wise methods, the results proved that lignin content (37.5%), holocellulose content (66.9%), and CHN compositions were very similar to regular wood. The lowest residue content of bio-polyols was produced using liquefaction conditions of 150 °C, reaction time of 180 min, catalyst content of 10%w/w, and 12.5%w/w driftwood loading. Polyurethane foam (PUF) derived from the liquefaction of driftwood and bio-based cyanate was prepared. The PUF prepared from the liquefaction of the driftwood exhibited slightly decreased thermal durability but was superior in terms of 3-time faster biodegradation and 2.8-time increased water adsorption rate compared to pure petroleum-based PUF. As a result, it was shown that driftwood can be identified as a biomass resource for biodegradable PUF.

Supramolecular self-assembly of micro spherical CL-20/TNT energetic Co-crystal

We reported an ultrasonic-assisted emulsion approach for the synthesis of micro spherical CL-20/TNT energetic co-crystal via supramolecular self-assembly. It was demonstrated that the architected CL-20/TNT co-crystal displays advanced thermal properties and improved sensitivity performance. For the micro spherical CL-20/TNT co-crystal with mean practical size = 6.8 μm, it has only one decomposing peak at 254.8 °C and higher impact sensitivity (H50: 57.8 cm) and lower friction (41%). Herein, for the first time, organic energetic co-crystal of micro spheres was synthesized by simultaneously tailoring the energy level and safety based on the intermolecular hydrogen-bonding interactions. This novel strategy is expected to provide new opportunities for exploring the synthesis of various organic micro spherical co-crystals towards their applications.

Intelligent Sonocatalytic Nanoagents for Energy Conversion‐Based Therapies

AbstractSonodynamic therapy (SDT) utilizes ultrasound‐irradiating sonosensitizers to convert ultrasonic vibrations into chemical energy and produce reactive oxygen species (ROS) that cause cell apoptosis or necrosis. SDT demonstrates significant potential in the treatment of deep tumors without normal tissue damage. Rapid advances in the efficacy of SDT have enabled the rational design and construction of novel intelligent sonocatalytic nanoagents (SCNs) with various functions for versatile biomedical applications. Herein, the most recent critical advancements in intelligent SCNs for energy conversion‐based therapies are discussed. Typical SCNs including organic molecules, organic micro‐/nanoparticles, inorganic micro‐/nanoparticles, organic/inorganic hybrids, and piezoelectric materials are introduced and summarized in detail. Furthermore, these intelligent SCNs are designed for different energy conversion‐based therapies such as SDT, SDT‐assisted chemotherapy, SDT‐assisted photodynamic therapy, SDT‐assisted photothermal therapy, SDT‐assisted gas therapy, SDT‐assisted sonoporation from the cell membrane to the blood brain barrier, and high‐intensity focused ultrasound‐based sonothermal therapy. It is believed that this review will provide an overview of the application of intelligent SCNs in sonodynamic therapies to better understand the limitations and challenges of these SCNs and further promote their advancements for a broad range of biomedical applications.

Importance of hydraulic travel time for the evaluation of organic compounds removal in bank filtration

The growing global demand for drinking water is driving both the diversification of water supply sources and their sustainability. River bank filtration (RBF) is an excellent option since it strongly reduces the extent of treatment steps compared to direct usage of surface water. Organic micropollutants (e.g. pharmaceuticals) are widely recognized as a hazard in drinking water production from surface water. Due to their potentially high mobility, stability, bioaccumulation and persistency, these substances can pass through RBF-systems. Scientific studies on compound removal and attenuation efficiency of RBF rely on the knowledge of travel time to compare concentrations in the river to the ones in the bank filtrate since water quality in rivers can change rapidly. However, bank filtrate samples represent a mixture of water with different travel times as the flow paths vary. This has not yet been considered in studies of bank filtration removal efficiency for organic micro pollutants.Here we present a method that considers the residence-time distribution of the bank filtrate sample obtained by groundwater modelling to evaluate the removal efficiency of RBF for organic micropollutants. The method was tested in a comprehensive study with 50 samples taken over a one-year-period at a river bank filtration site in Vienna (Austria). Our findings revealed that better coverage of varying river water quality (higher sampling frequency during the period of infiltration) resulted not only in a higher number of compounds considered as removed but also significantly reduced the number of compounds considered to have formed during the RBF process. The application of the presented method indicated that RBF is very effective in removing organic micropollutants. Considering different travel times will provide better models and a better understanding of the potential of RBF for pollutant removal and thus supports its safe application as a solution to the growing demand for drinking water.

Direct Visualization of UV-Light on Polymer Composite Films Consisting of Light Emitting Organic Micro Rods and Polydimethylsiloxane.

We experimentally demonstrate the direct visualization of ultraviolet (UV) light using flexible polymer composite films consisting of crystalline organic tris-(8-hydroxyquinoline) aluminum (Alq3) micro-rods and polydimethylsiloxane (PDMS). The representative organic mono-molecule Alq3, which is a core material of organic light-emitting diodes, was used to detect light in the invisible UV region and visualize photoluminescence (PL). Alq3 shows absorption in the UV region and light-emitting characteristics in the green region, making it an optimal material for UV visualization because of its large Stokes transition. Crystalline Alq3 micro-rods were fabricated in a deionized water solution through a sequential process of reprecipitation and self-assembly. Highly bright photoluminescence was observed on the highly crystalline Alq3 micro-rods under UV light excitation, indicating that the crystalline structures of Alq3 molecules affect the visible emission decay of excitons. The Alq3 micro-rods were manufactured as flexible polymer composite films using a PDMS solution to observe UV photodetector characteristics according to UV intensity, and it was confirmed that the intensity of the fine UV light reaching the earth’s surface can be visualized by making use of this UV photodetector.

Challenges for Sustainability in Packaging of Fresh Vegetables in Organic Farming

The policy of circular economy focuses on phasing out fossil-based packaging and replacing it with more sustainable alternatives. Companies face the challenge of choosing packaging for their products that are functional and affordable, and place relatively less pressure on the environment. This is especially important for organic farms that make voluntary commitments to undertake sustainable decisions regarding practices and methods of farming and types of packaging used. This publication attempts to analyze the determinants of the choices of sustainable packaging solutions made by organic farming companies with the example of Scilly Organic, an organic micro farm from the Isles of Scilly, United Kingdom—a producer of organic vegetables. There are many options for fresh vegetable packaging, which include fossil-based packaging, bio-based packaging, and packaging manufactured from material that is a mixture of synthetic, natural, or modified polymers. Biodegradable packaging, including compostable ones, is currently of particular interest because, when separated and disposed of in the correct manner in the waste management phase, they have sustainability potential. Biodegradable plastics constitute over 55.5% of global bioplastics production. Packaging is the largest market segment for bioplastic, with 48% of the total bioplastics market in 2021. Although the use of biobased packaging brings some advantages, it also comes with certain limitations that are the subject of intensive research. In this publication, the Life Cycle Assessment (LCA) tool was used and a critical review of the literature was carried out. Based on the analysis, the key factors and aspects influencing the environmental performance of selected types of packaging were identified. The LCA was carried out for the three selected packaging types, including low-density polyethylene (LDPE) bags, polylactic acid (PLA) bags, and polyester starch biopolymer (PCSB) bags. The research showed that the selection of more sustainable packaging is not straightforward. The analysis performed was the basis for providing recommendations for improving the sustainability of organic farms with regard to the selection of packaging for fresh vegetables. The critical processes in the life cycle that have to be considered are, in the first place, the production of polymer-based materials, and to a lesser extent, the production of the packaging bags and post-consumption waste utilization. In the case of PLA bags, 51% of the total impact is attributed to the production of polymer material. For starch polyester bags, this share is 58%, and for LDPE it constitutes 41% of the total score. At the same time, the choice of packaging should be made in the context of the specific properties of the packaging material, the requirements for disposal methods, and local waste management systems.

Adsorptive removal of propranolol under fixed-bed column using magnetic tyre char: Effects of wastewater effluent organic matter and ball milling

We investigated the competitive effects of different fractions of wastewater treatment plant effluent organic matter (EfOM) on adsorption of an organic micro pollutant (OMP), propranolol (PRO), in a fixed bed column packed with magnetic tyre char (MTC). The results showed that the presence of EfOM inhibited PRO adsorption in wastewater leading to decreased PRO adsorption capacity from 5.86 to 2.03 mg/g due to competitive effects and pore blockage by smaller EfOM fractions. Characterization of EfOM using size exclusion chromatography (LC-OCD) showed that the principal factor controlling EfOM adsorption was pore size distribution. Low molecular weight neutrals had the highest adsorption onto MTC while humic substances were the least interfering fraction. Effect of important parameters such as contact time, linear velocity and bed height/diameter ratio on MTC performance was studied in large-lab scale columns. Linear velocity and contact time were found to be effective in increasing adsorption capacity of PRO on MTC and delaying breakthrough time. Increase in linear velocity from 0.64 cm/min to 1.29 cm/min increased mass transfer and dispersion, resulting in considerable rise of adsorbed amount (5.86 mg/g to 22.58 mg/g) and increase in breakthrough time (15.8–62.7 h). Efficiency of non-equilibrium Hydrus model considering dispersion and mass transfer mechanism was demonstrated for real wastewater and scale up purposes. Ball milling for degradation of adsorbed PRO and regeneration of MTC resulted in 79% degradation of PRO was achieved after 5 h milling (550 rpm), while the addition of quartz sand increased the efficiency to 92%.

Organic ultrathin nanostructure arrays: materials, methods and applications.

Organic ultrathin semiconductor nanostructures have attracted continuous attention in recent years owing to their excellent charge transport capability, favorable flexibility, solution-processability and adjustable photoelectric properties, providing opportunities for next-generation optoelectronic applications. For integrated electronics, organic ultrathin nanostructures need to be prepared as large-area patterns with precise alignment and high crystallinity to achieve organic electronic devices with high performance and high throughput. However, the fabrication of organic ultrathin nanostructure arrays still remains challenging due to uncontrollable growth along the height direction in solution processes. In this review, we first introduce the properties, assembly methods and applications of four typical organic ultrathin nanostructures, including small molecules, polymers, and other organic–inorganic hybrid materials. Five categories of representative solution-processing techniques for patterning organic micro- and nanostructures are summarized and discussed. Finally, challenges and perspectives in the controllable preparation of organic ultrathin arrays and potential applications are featured on the basis of their current development.

Environmental Impacts of Pesticides - A Review

Pesticides are applied in various sectors such as agriculture, domestic, material building, personal and public health for control of weeds, pests, rodents; household and garden spray, control of animals and birds; incorporation of paints, glues, plastic protection sheeting; for application of clothing and skincare; and for control of malaria, dengue fever and cholera. In agriculture, chemicals are purposefully discharged into the environment. Application of pesticides in agriculture is a subcategory of the largest group of manufactured compounds used in the present world. Excessive and inappropriate use of pesticides has resulted in contamination of environment. Pesticides are degraded into organic micro pollutants that have negative effects on the environment. By the mechanism of biomagnification and bioconcentration, they cause deleterious effects on the living organisms. Ecological impacts of pesticides are different but they are chronic and inter-related. During precipitation, pesticides from land, float to aquatic systems and become harmful to fishes, birds, non-target creatures, etc. They also interact with injurious algal blooms, which enhances the original poisonous nature of the pesticides. This review focuses on environmental impacts of pesticides on contamination of water, fate, effects and behaviour in the environment, effects of contamination on natural resources, food safety, non-target organisms and threats to biodiversity. This study recommends application of suitable amounts of less harmful formulation of pesticides, as and when required.

(Invited) Atmospheric Pressure Plasma Treatment and Decontamination of Water Samples

As water scarcity becomes widespread concern in many countries, new approaches for water processing are being considered. In order to have the potential to be applied in the industry, these new methods should be primarily environmentally friendly and with low-energy consumption. Employment of non-equilibrium plasma for water treatment entirely satisfies these two points and therefore makes plasma a good candidate. Non-equilibrium (or cold) plasma at atmospheric pressure has so far been successfully used in various applications related to biology and medicine. Plasma rich-chemistry environment produced at room atmosphere with ambient temperature enabled treatment of cells, plants, bacteria, tissues etc. with aims ranging from destruction of pathogens to healing or enhancing the growth in biological systems. Therefore, these applications clearly point out that plasma sources can deliver broad spectrum of treatment conditions.The latest research direction related to plasma and liquid treatment is plasma agriculture where different approaches for application of plasma in agricultural processes are investigated. Within these novel research area we investigate two possible applications: for the treatment of clean water samples for the production of plasma activated water (PAW); and for decontamination of polluted water containing organic micro pollutants (OMPs). PAW in comparison to clean water is rich in reactive oxygen and nitrogen species (RONS) and this proves to be an important asset when applied to seeds and plants. We showed that germination and plant growth can be enhanced when PAW is applied for seed imbibition and plant watering. On the other hand, the presence of reactive oxygen species in plasma and inside the treated water samples (especially droplets or aerosols) induces the decomposition of different molecules of OMPs. We demonstrated ability of plasma decontamination for several different organic molecules, such as decomposition of Malathion in atmospheric pressure plasma jet with high efficiency, and also for some chemicals used as chemical warfare surrogates. Apart from direct treatment of polluted samples by plasma, we have investigated a possibility of using PAW as a decontamination chemical to decompose organic dye Acid Blue 25 dissolved in water. Along the line of plasma agriculture research we combined the effects of two plasma applications in the plasma processing of agricultural waste water for reuse in irrigation. The experimental results showed that pesticide-containing polluted water can be decontaminated and at the same time enriched with RONS that positively influence germination of maize and radish.These successful applications unfold many questions related to the plasma properties, plasma gas and liquid phase chemical reactions, an entangled connection between plasma produced reactive species and their chemical interactions with organic molecules in water. In order to make a detailed insight into the treatment process, we performed comprehensive diagnostics of the plasma and of the liquid samples. Our results provide information about electrical and optical plasma properties and make connection with physical parameters of the liquid sample (pH, electrical conductivity). We used colorimetric methods to determine RONS in the treated liquids. To acquire information about plasma-induced decomposition and obtain by-products in the treated samples we performed liquid chromatography coupled with mass spectrometry. All these results provide important knowledge on plasma water treatments and represent another step towards understanding which are the best parameters for treatment monitoring and techniques for up-scaling plasma devices to treat large amounts of water.Acknowledgement: This study was partially supported by NATO SPS 984555, projects ON141037 and III 41011 of MESTD Republic of Serbia and H2020-MSCA-ITN 812880 Nowelties.

Organic multicomponent microparticle libraries

Multimetallic nanostructures can be synthesized by integrating up to seven or eight metallic elements into a single nanoparticle, which represent a great advance in developing complex multicomponent nanoparticle libraries. Contrary, organic micro- and nanoparticles beyond three π-conjugated components have not been explored because of the diversity and structural complexity of molecular assemblies. Here, we report a library of microparticles composed of an arbitrary combination of four luminescent organic semiconductors. We demonstrate that the composition and emission color of each domain as well as its spatial distribution can be rationally modulated. Unary, binary, ternary, and quaternary microparticles are thus realized in a predictable manner based on the miscibility of the components, resulting in mixed-composition phases or alloyed or phase separated heterostructures. This work reports a simple yet available synthetic methodology for rational modulation of organic multicomponent microparticles with complex architectures, which can be used to direct the design of functional microparticles.

Organic Micro-/Nanocrystals of SFX-Based Attractor–Repulsor Molecules with the Feature of Crystal-Induced Luminescence Enhancement

Spirofluorenexanthanes (SFXs), as burgeoning second-generation spiro compounds beyond spirobifluorenes (SBFs), can serve as versatile scaffolds for low-cost organic semiconductors in various fluore...

Synthesis and Characterization of 1-Methyl-2-phenylindolin Induced by UV light: A Comprehensive Organic Micro Chemistry Experiment Converted from NSFC Research

Synthesis and Characterization of 1-Methyl-2-phenylindolin Induced by UV light: A Comprehensive Organic Micro Chemistry Experiment Converted from NSFC Research

Water pollution of world and human health

In the twenty-first century, water deficiencies are a massive obstacle for mankind. Here, we look at the many types of aquatic pollutants, their impact on human health, and how to protect freshwater resources from contamination. Chemical pollution is emphasized, especially inorganic and organic micro pollutants such as hazardous metals and metalloids, as well as a wide range of synthetic organic compounds. Some elements of waterborne illnesses are also addressed, as well as the urgent need for better sanitation in poor nations. The study looks at recent scientific advancements in dealing with a wide range of contaminants. It's divided into sections based on the many temporal and geographical dimensions of global water pollution. For more than five decades, persistent organic pollutants (POPs) have had an impact on global water systems; throughout that period, geogenic pollutants, mining activities, and hazardous waste sites were the most significant causes of long-term regional and local water pollution. On a regional to local scale, agricultural chemicals and wastewater sources have a shorter-term impact.

Organic Semiconductor-DNA Hybrid Assemblies.

Organic semiconductors are photonic and electronic materials with high luminescence, quantum efficiency, color tunability, and size-dependent optoelectronic properties. The self-assembly of organic molecules enables the establishment of a fabrication technique for organic micro- and nano-architectures with well-defined shapes, tunable sizes, and defect-free structures. DNAs, a class of biomacromolecules, have recently been used as an engineering material capable of intricate nanoscale structuring while simultaneously storing biological genetic information. Here, the up-to-date research on hybrid materials made from organic semiconductors and DNAs is presented. The trends in photonic and electronic phenomena discovered in DNA-functionalized and DNA-driven organic semiconductor hybrids, comprising small molecules and polymers, are observed. Various hybrid forms of solutions, arrayed chips, nanowires, and crystalline particles are discussed, focusing on the role of DNA in the hybrids. Furthermore, the recent technical advances achieved in the integration of DNAs in light-emitting devices, transistors, waveguides, sensors, and biological assays are presented. DNAs not only serve as a recognizing element in organic-semiconductor-based sensors, but also as an active charge-control material in high-performance optoelectronic devices.

Evaluating the effects of sewage sludge compost applications on the microbial activity, the nutrient and heavy metal content of a Chernozem soil in a field survey

Sewage sludge contains organic matter and micro and macronutrients which are potentially useful for agricultural usage. However, it can be harmful when containing undesirable amounts of organic pollutants, heavy metals, or pathogens. Our study focused on examining the changes in the extractable nutrient, organic matter and heavy metal contents of a Chernozem soil and the alteration of the soil biological activity as a consequence of low-dose municipal sewage sludge compost applications (0.5 t/ha). Sampling campaigns were done in 2018 near Újkígyós (SE Hungary) during which composite soil samples (0–30 cm and 30–60 cm) and groundwater samples were collected for assessing changes in the nutrient and heavy metal concentrations as a result of compost amendments’ use. Additionally, upper soil (0–50 cm) and subsoil (50–80 cm) were sampled for assessing biological parameters, considered to be aerobic and anaerobic soil layers, respectively. Soil samples were analyzed for the basic pedological parameters (pH, organic matter, carbonates and texture), nutrients (K2O, P2O5, N-forms and organic matter) and heavy metal concentrations following standard extraction procedures. The microbial properties were characterized by colony-forming units (CFUs) and enzyme activity measurements. The results of the nutrient analyses show significantly increased soil-bound K2O, P2O5 and NO2− + NO3− contents linked to the sewage sludge treatments. However, neither the organic matter nor the heavy metal content varied significantly in the sludge-amended soil compared with a control site. The microbiological analyses revealed that the sewage sludge treatments tended to increase the aerobic CFUs, but not that of the anaerobic microbes. The average catalase enzyme activity in both the aerobic and anaerobic samples and the average dehydrogenase activity only in the aerobic layers showed a slight but not significant increase in the compost-amended soils. Overall, these results convincingly demonstrated that amending soils with low doses of municipal sewage sludge composts (lacking any industrial sources) can be a sustainable fertilizing practice taking advantage of their high N, P and K contents that are slowly converted to their bioavailable forms thus preventing their excessive leaching in the groundwater.

Physico-Chemical Properties of Soil as Influenced by Integrated Nutrient Management in Onion (Allium cepa L.) Crop

The present investigation was conducted at the Research Farm, Khalsa College, Amritsar during rabi season of 2017-18 in order to evaluate the impact of organic manures (FYM, Vermicompost, Poultry manure) and inorganic fertilizers on soil physico-chemical properties and available nutrient status in soil after onion (Allium cepa L.) harvest. The experiment was laid out in randomized block design with twelve treatments and replicated thrice. It was observed that significant variation in organic carbon, bulk density, available macro (N, P, K and S) and micro (Fe, Mn, Zn and Cu) nutrients status was noticed when organic manures were integrated with inorganic fertilizers as compared to sole use of inorganic fertilizers and initial status of soil. The maximum available nutrient status was recorded with treatment T12 {25% RDNF + 25% N (FYM) + 25% N (VC) + 25% N (PM)} whereas lowest was recorded with treatment T1 (control). The soil properties such as pH, EC, particle density and porosity did not showed any significant difference.