Utilization of polyethylene sleeves with forced aeration for composting of broiler carcasses on mass depopulation events: Laboratory-scale simulations and sensitivity analyses.

Composting poultry carcasses and the infected litter is considered feasible during mass depopulation events in response to disease outbreaks. We demonstrate the effect of temperature (40, 50, 60 °C) and aerobic/anaerobic conditions on the degradation of broiler carcasses and broiler litter (BL) and the elimination of pre-inoculated Avian flu and Newcastle viruses and SalmonellaInfantis (3.3 × 105.6 EID50, 7 × 106.0 EID50 and 2 × 107 CFU g-dry matter (DM)-1, respectively). Six broiler carcasses and BL were inoculated and treated with a water-based foam, simulating a common culling method. After 30 days of composting, both viruses were eliminated under all conditions, whileSalmonellapersisted at 40 °C under aerobic and anaerobic conditions (7.4 × 105and 4.4 × 103CFU g-DM-1, respectively). Mass losses were 42-44, 24-26, and 18-22% (aerobic) and 18-27, 21-23, and 0-7% (anaerobic) at 40, 50, and 60 °C, respectively. In the end, the associated odors were not typical of carcasses (aerobic), or they were strong and offensive (anaerobic). Considering the observed mass losses and biomass water holding capacity, we present a sensitivity analysis of the water balance expected in composting sleeves if they are utilized on mass depopulation events. Composting of the carcasses and the BL in enclosed sleeves with forced aeration, following culling by means of water-based foam will generate excess water, depending on sleeve volumes, aeration conditions, and co-addition of absorbing materials like sawdust. No excessive moisture is expected if dry culling methods are used.

Effectiveness of hydrogen peroxide treatments in preventing biofilm clogging in drip irrigation systems applying treated wastewater.

The application of treated wastewater (TWW) via pressurized drip irrigation (DI) systems, specifically micro-irrigation, is an effective solution to mitigate water scarcity. TWW contains a higher concentration of nutrients and microbial activity compared to fresh water (FW) and poses a larger danger of fouling and subsequent clogging to DI systems. The goal of this paper was to characterize the effectiveness of chemical treatments, specifically hydrogen peroxide (H2O2) in preventing clogging in DI systems utilizing secondary (ST) and tertiary (TT)_TWW. A novel field model was employed to compare the flow rate (FR), fouling accumulation and composition in laterals and emitters of different treatments. Under ST_TWW irrigation, control treatment performance quickly declined while regular low concentration H2O2 treatments exhibited the lowest amounts of fouling and maintained nominal FR and coefficient of variation (CV). Shock treatments, defined as periodical applications of concentrated chemicals combined with lateral flushing, were ineffective in maintaining satisfactory irrigation performance.

Effects of compost application on soil vulnerability to heavy metal pollution.

Soil vulnerability to heavy metal pollution is low in soils exhibiting an ability to strongly adsorb heavy metals on their geochemical fractions. Organic matter (OM) is among other components of soils, one of the most effective sorbing fractions. Compost addition is often used for soil remediation thereby enriching the soil with OM. However, compost is often enriched with heavy metals and thereby may induce adverse effects on the soil and plants growing in them. Compost-derived dissolved organic matter (DOM) can mobilize heavy metals. The balance between two contrasting effects of compost-mobilization and immobilization of heavy metals-was studied under the conditions of adsorption-desorption batch experiment. Metal adsorption to different geochemical fractions of soil treated with compost was examined by a combined batch-adsorption experiment and a sequential extraction procedure. Compost-derived DOM mobilized Cu at low loading levels, whereas adsorption of Cd and Pb was not decreased by DOM application. Compost was found to be a source of an important reducible oxides fraction (RO-sorbing and fixation fraction) and also of the OM geochemical fractions that most commonly immobilizes heavy metals. The Langmuir and Freundlich models employed in our study exhibited a good fit for most of data the experimental data obtained on bulk samples. Adsorption of the metals on operationally defined geochemical fractions was described by a linear function in several experimental instances.

Composted biosolids and treated wastewater as sources of pharmaceuticals and personal care products for plant uptake: A case study with carbamazepine.

Irrigation with treated wastewater (TWW) and application of biosolids to arable land expose the agro-environment to pharmaceuticals and personal care products (PPCPs) which can be taken up by crops. In this project, we studied the effect of a carrier medium (e.g., biosolids and TWW) on plant (tomato, wheat and lettuce) uptake, translocation and metabolism of carbamazepine as a model for non-ionic PPCPs. Plant uptake and bioconcentration factors were significantly lower in soils amended with biosolids compared to soils irrigated with TWW. In soils amended with biosolids and irrigated with TWW, the bioavailability of carbamazepine for plant uptake was moderately decreased as compared to plants grown in soils irrigated with TWW alone. While TWW acts as a continuous source of PPCPs, biosolids act both as a source and a sink for these compounds. Moreover, it appears that decomposition of the biosolids in the soil after amendment enhances their adsorptive properties, which in turn reduces the bioavailability of PPCPs in the soil environment. In-plant metabolism of carbamazepine was found to be independent of environmental factors, such as soil type, carrier medium, and absolute amount implemented to the soil, but was controlled by the total amount taken up by the plant.

Water quality and daily temperature cycle affect biofilm formation in drip irrigation devices revealed by optical coherence tomography.

Drip irrigation is a water-saving technology. To date, little is known about how biofilm forms in drippers of irrigation systems. In this study, the internal dripper geometry was recreated in 3-D printed microfluidic devices (MFDs). To mimic the temperature conditions in (semi-) arid areas, experiments were conducted in a temperature controlled box between 20 and 50°C. MFDs were either fed with two different treated wastewater (TWW) or synthetic wastewater. Biofilm formation was monitored non-invasively and in situ by optical coherence tomography (OCT). 3-D OCT datasets reveal the major fouling position and illustrate that biofilm development was influenced by fluid dynamics. Biofilm volumetric coverage of the labyrinth up to 60% did not reduce the discharge rate, whereas a further increase to 80% reduced the discharge rate by 50%. Moreover, the biofilm formation rate was significantly inhibited in daily temperature cycle independent of the cultivation medium used.

Iron uptake mechanism in the chrysophyte microalga Dinobryon.

The mechanism of iron uptake in the chrysophyte microalga Dinobryon was studied. Previous studies have shown that iron is the dominant limiting elements for growth of Dinobryon in the Eshkol reservoir in northern Israel, which control its burst of bloom. It is demonstrated that Dinobryon has a light-stimulated ferrireductase activity, which is sensitive to the photosynthetic electron transport inhibitor DCMU and to the uncoupler CCCP. Iron uptake is also light-dependent, is inhibited by DCMU and by CCCP and also by the ferrous iron chelator BPDS. These results suggest that ferric iron reduction by ferrireductase is involved in iron uptake in Dinobryon and that photosynthesis provides the major reducing power to energize iron acquisition. Iron deprivation does not enhance but rather inhibits iron uptake contrary to observations in other algae.

Adsorption of carbamazepine by carbon nanotubes: effects of DOM introduction and competition with phenanthrene and bisphenol A.

Carbon nanotubes, organic contaminants and dissolved organic matter (DOM) are co-introduced into the environment. Thus, the interactions between these components have to be evaluated to better understand their environmental behavior. In this study, single-walled carbon nanotubes (SWCNTs) were used as sorbent, carbamazepine was the primary adsorbate, and bisphenol A and phenanthrene were used as competitors. Strong competition with bisphenol A and no effect of phenanthrene on adsorption of carbamazepine was obtained. The hydrophobic neutral fraction of the DOM exhibited the strongest reductive effect on carbamazepine adsorption, most probably due to interactions in solution. In contrast, the hydrophobic acid fraction decreased carbamazepine adsorption mainly via direct competition. When DOM and bisphenol A were co-introduced, the adsorption of carbamazepine was significantly reduced. This study suggests that the chemical nature of DOM can significantly affect the sorptive behavior of polar organic pollutants with carbon nanotubes when all are introduced to the aquatic system.

Odorants and malodors associated with land application of biosolids stabilized with lime and coal fly ash.

Malodor emissions limit public acceptance of using municipal biosolids as natural organic resources in agricultural production. We aimed to identify major odorants and to evaluate odor concentrations associated with land application of anaerobically digested sewage sludges (Class B) and their alkaline (lime and coal fly ash)-stabilized products (Class A). These two types of biosolids were applied at 12.6 tonnes ha(-1) (dry weight) to microplots of very fine clayey Vertisol in the Jezreel Valley, northern Israel. The volatile organic compounds (VOCs) emitted from the biosolids before and during alkaline stabilization and after incorporation into the soil were analyzed by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry. Odor concentrations at the plots were evaluated on site with a Nasal Ranger field olfactometer that sniffed over a defined land surface area through a static chamber. The odors emitted by anaerobically digested sewage sludges from three activated sludge water treatment plants had one characteristic chemical fingerprint. Alkaline stabilization emitted substantial odors associated with high concentrations of ammonia and release of nitrogen-containing VOCs and did not effectively reduce the potential odor annoyance. Odorous VOCs could be generated within the soil after biosolids incorporation, presumably because of anaerobic conditions within soil-biosolids aggregates. We propose that dimethyl disulfide and dimethyl trisulfide, which seem to be most related to the odor concentrations of biosolids-treated soil, be used as potential chemical markers for the odor annoyance associated with incorporation of anaerobically digested sewage sludges.

Involvement of ligninolytic enzymes and Fenton-like reaction in humic acid degradation by Trametes sp.

Trametes sp. M23, isolated from biosolids compost was found to decompose humic acids (HA). A low N (LN) medium (C/N, 53) provided suitable conditions for HA degradation, whereas in a high N (HN) medium (C/N, 10), HA was not degraded. In the absence of Mn(2+), HA degradation was similar to that in Mn(2+)-containing medium. In contrast, MnP activity was significantly affected by Mn(2+). Laccase activity exhibited a negative correlation to HA degradation, while LiP activity was not detected. Thus, ligninolytic enzymes activity could provide only a partial explanation for the HA-degradation mechanism. The decolorization of two dyes, Orange II and Brilliant Blue R250, was also determined. Similar to HA degradation, under LN conditions, decolorization occurred independently of the presence of Mn(2+). We investigated the possible involvement of a Fenton-like reaction in HA degradation. The addition of DMSO, an OH-radical scavenger, to LN media resulted in a significant decrease in HA bleaching. The rate of extracellular Fe(3+) reduction was much higher in the LN vs. HN medium. In addition, the rate of reduction was even higher in the presence of HA in the medium. In vitro HA bleaching in non-inoculated media was observed with H(2)O(2) amendment to a final concentration of 200 mM (obtained by 50 mM amendments for 4 days) and Fe(2+) (36 mM). After 4 days of incubation, HA decolorization was similar to the biological treatment. These results support our hypothesis that a Fenton-like reaction is involved in HA degradation by Trametes sp. M23.

Microbial activity and organic matter dynamics during 4 years of irrigation with treated wastewater.

The global changes in rainfall frequency and quantity have subjected arid and semi-arid regions to long periods of drought. As this phenomenon corresponds to increasing trend of water shortage, the use of treated wastewater (TWW) has been suggested as an alternative for irrigation of agricultural crops in these areas. The aim of the study was to investigate the short- and middle-term effects of TWW irrigation on the soil microbial activities and organic carbon content. The microbial community activity was measured every 1-3 months for 4 years in a persimmon (Diospyros kaki) orchard. These activities were used here as an indicator for the soil health. The hydrolysis activity (detected by fluorescein diacetate hydrolysis (FDA) assay) increased during the irrigation season and was significantly higher in soils irrigated with TWW compared to those irrigated with freshwater (FW). This activity was also negatively correlated with dissolved organic carbon (DOC) concentrations during the irrigation season, suggesting that the community degraded the DOC in the soils regardless of its origin. The irrigation season was also characterized by an increase in nitrification potential in both TWW- and FW-irrigated soils, which coincided with high concentrations of nitrate (50 mg kg(-1) soil). Overall, there was an increase in all measured activities during the irrigation season, and they were higher in the TWW soils. However, it appears that after each irrigation season, the potential activity of the community returned to levels similar to or even slightly lower than those of FW-irrigated soil during the wet season, suggesting that the periodic irrigation did not significantly change the soil microbial activity.

Mechanisms of humic acids degradation by white rot fungi explored using 1H NMR spectroscopy and FTICR mass spectrometry.

Enzymatic activities involved in decay processes of natural aromatic macromolecules, such as humic acids (HA) and lignin by white rot fungi, have been widely investigated. However, the physical and chemical analysis of degradation products of these materials has not been intensively explored. Fourier transform cyclotron resonance mass spectrometry (FTICR MS) and 1H NMR as well as CHNOS and size exclusion chromatography were employed to study the mechanisms of HA degradation by Trametes sp. M23 and Phanerochaete sp. Y6. Size exclusion chromatography analyses demonstrate and provide evidence for HA breakdown into low MW compounds. The 1H NMR analysis revealed oxidation, a decrease in the aromatic content, and an indication of demethylation of the HA during biodegradation. Evidence for oxidation was also obtained using CHNOS. Analysis of FTICR MS results using a new software program developed by our group (David Mass Sort) revealed consecutive series of masses suggesting biochemical degradation trends such as oxidation, aromatic cleavage, and demethylation. These results are in agreement with the 1H NMR analysis and with the suggested role of the ligninolytic system leading to HA degradation.

Novel software for data analysis of Fourier transform ion cyclotron resonance mass spectra applied to natural organic matter.

Natural organic matter (NOM) occurs as an extremely complex mixture of large, charged molecules that are formed by secondary synthesis reactions. Due to their nature, their full characterization is an important challenge to scientists specializing in NOM as well as analytical chemistry. Ultra-high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis enables the identification of thousands of masses in a single measurement. A major challenge in the data analysis process of NOM using the FT-ICR MS technique is the need to sort the entire data set and to present it in an accessible mode. Here we present a simple targeted algorithm called the David Mass Sort (DMS) algorithm which facilitates the detection and counting of consecutive series of masses correlated to any selected mass spacing. This program searches for specific mass differences among all of the masses in a single spectrum against all of the masses in the same spectrum. As a representative case, the current study focuses on the analysis of the well-characterized Suwannee River humic and fulvic acid (SRHA and SRFA, respectively). By applying this algorithm, we were able to find and assess the amount of singly and doubly charged molecules. In addition we present the capabilities of the program to detect any series of consecutive masses correlated to specific mass spacing, e.g. COO, H(2), OCH(2) and O(2). Under several limitations, these mass spacings may be correlated to both chemical and biochemical changes which occur simultaneously during the formation and/or degradation of large mixtures of compounds.

Interactions of hydrophobic fractions of dissolved organic matter with Fe(3+) - and Cu(2+)-montmorillonite.

Interactions of dissolved organic matter (DOM) with clays can significantly affect a variety of soil processes. We studied adsorption and fractionation of hydrophobic acid (HoA) and hydrophobic neutral (HoN) fractions of DOM on Cu(2+)- and Fe(3+)-montmorillonite. Adsorption of both samples was higher on Fe(3+)-montmorillonite than on Cu(2+)-montmorillonite. A pH increase of about one unit was recorded followed by HoA adsorption by Fe(3+)-montmorillonite. This suggested exchange of negatively charged DOM groups on surface hydroxyl groups of Fe(3+)-montmorillonite surfaces. Adsorption of HoA on Cu(2+)-montmorillonite and HoN on Fe(3+)- and Cu(2+)-montmorillonites was governed mainly by van der Waals interactions. Spectroscopic analyses showed a distinct HoA fractionation by molecular size and aromaticity only by Fe(3+)-montmorillonite. On the basis of the pH measurements (increase in pH following adsorption of acid components) and enhanced DOM fractionation by molecular size and aromaticity we suggest that DOM reacted with Fe(3+)-montmorillonite similar to goethite.

Chemical fractionation of phosphorus in stabilized biosolids.

Three chemicals-ferrous sulfate (FeSul), calcium oxide (CaO), and aluminum sulfate (alum)-were applied at different rates to stabilize P in fresh, anaerobically digested biosolids (FBS) obtained from an activated sewage treatment plant. A modified Hedley fractionation procedure was used to assess P forms in these sludge-borne materials and in a biosolids compost (BSC) prepared from the same FBS. Each biosolids material exhibited a unique pattern of P distribution among fractions. The most available P forms, namely: (i) water-soluble P (WSP); (ii) membrane-P; and (iii) NaHCO(3)-P, were stabilized by small rates of each of the chemicals; but the P transformation into more stable forms depended on the type of chemical added. The stabilized P forms were enhanced by high rates of CaO and FeSul, but were reduced by high rates of alum. The organic P (P(o)) in the first three fractions of the FeSul- and alum-stabilized biosolids was enhanced by the chemical addition, and P(o) transformation from NaOH-P(o) into NaHCO(3)-P(o) was found in calcium-stabilized biosolids. A positive relationship was found between NaHCO(3)-P(o) and the NaHCO(3)-extracted organic C in all chemically stabilized biosolids. One-step extraction by NaHCO(3) or NaOH underestimated P extraction compared to the stepwise extraction. The reported results are consistent with solid-state P speciation reported earlier and contribute important information for optimizing biosolids stabilization to reduce P loss after incorporation in soils and for maximizing soil capacity to safely store pre-stabilized biosolids.

Molecular analysis of bacterial community succession during prolonged compost curing.

The compost environment consists of complex organic materials that form a habitat for a rich and diverse microbial community. The aim of this research was to study the dynamics of microbial communities during the compost-curing phase. Three different methods based on 16S rRNA gene sequence were applied to monitor changes in the microbial communities: (1) denaturing gradient gel electrophoresis of PCR-generated rRNA gene fragments; (2) partial rRNA gene clone libraries; and (3) a microarray of oligonucleotide probes targeting rRNA gene sequences. All three methods indicated distinctive community shifts during curing and the dominant species prevailing during the different curing stages were identified. We found a successional transition of different bacterial phylogenetic groups during compost curing. The Proteobacteria were the most abundant phylum in all cases. The Bacteroidetes and the Gammaproteobacteria were ubiquitous. During the midcuring stage, Actinobacteria were dominant. Different members of nitrifying bacteria and cellulose and macromolecule-degrading bacteria were found throughout the curing process. In contrast, pathogens were not detected. In the cured compost, bacterial population shifts were still observed after the compost organic matter and other biochemical properties had seemingly stabilized.

Solid phosphorus phase in aluminum- and iron-treated biosolids.

Stabilization of phosphorus (P) in sewage sludge (biosolids) to reduce water-soluble P concentrations is essential for minimizing P loss from amended soils and maximizing the capacity of the soil to safely serve as an outlet for this waste material. The chemical form at which P is retained in biosolids stabilized by Al(2)(SO(4))(3) x 18H(2)O (alum) or FeSO(4) x 7H(2)O (FeSul) was investigated by scanning electron microscopy (SEM) equipped with energy-dispersive X-ray elemental spectrometry (EDXS) and by X-ray diffraction (XRD). Both treatments resulted in the formation of a Ca-P phase, probably brushite. Phosphorus was further retained in the alum-treated biosolids by precipitation of an Al-P phase with an Al/P molar ratio of about 1:1, while in the FeSul-treated biosolids, P was retained by both precipitation with Fe/P molar ratios of 1:1 or 1.5:1, and by adsorption onto newly formed Fe hydroxides exhibiting an Fe/P molar ratio of up to 11:1. All of these mechanisms efficiently reduced P solubility and are crucial in biosolids environmentally safe agronomic beneficial use for this waste product; however, each P phase formed may react differently in the amended soil, depending on soil properties. Thus, the proper P stabilization method would depend on the target soil.

Thermospectroscopic study of the adsorption mechanism of the hydroxamic siderophore ferrioxamine B by calcium montmorillonite.

The behavior of iron-chelating agents in soils is highly affected by interactions with the solid phase. Still this aspect is frequently ignored. In this research the adsorption of the siderophore ferrioxamine B by Ca-montmorillonite, as a free ligand (desferrioxamine B, DFOB) and as a complex with Fe3+ (ferrioxamine B, FOB), was studied, using thermo X-ray diffraction (thermo-XRD) in the temperature range 25-360 degrees C and thermo-FTIR spectroscopy in the temperature range 25-170 degrees C. The effect of pH (4-7.5) on the adsorption was examined. Extensive use of curve-fitting analysis was required due to significant overlapping of the characteristic absorption bands of the various functional groups. Thermo-XRD analysis showed that both DFOB and FOB penetrated into the interlayer space of Ca-montmorillonite. FTIR results indicated strong interactions of DFOB within the interlayer, which involved all functional groups (NH3+, secondary amide groups, and hydroxamate groups). In contrast, the folded Fe complex of FOB retained its molecular configuration upon adsorption, and the basal spacing of the clay increased correspondingly. FOB interacted in the interlayer space of the clay, mainly through the NH of the secondary amide groups and NH3+, while the functional groups bound to the central Fe cation remained unchanged. The suspension pH had no significant effect on both DFOB and FOB adsorption at the examined range. Adsorption protected the adsorbates from thermal degradation compared to the nonadsorbed samples up to 105 degrees C. At 170 degrees C both DFOB and FOB were already partially degraded, but to a lesser extent than the nonadsorbed samples. Degradation of the molecules occurred mainly through the hydroxamic groups, which constitute the Fe-chelating center in the hydroxamic siderophore.

Practical and mechanistic aspects of the removal of cadmium from aqueous systems using peat.

A sphagnum peat moss removed Cd from aqueous solutions very efficiently, and its effectiveness in taking up the metal was significantly enhanced by exposure to a 1N NaOH solution. The capacity of the untreated peat for Cd reached 300 g/kg and that of the NaOH-activated peat was over 400 g/kg. Although saturation was rarely reached, the Cd uptake from concentrated solutions often exceeded 200 g/kg. In column experiments, 1g of the NaOH-activated peat completely removed the metal from over 0.2L of a 200-mg/L Cd solution (final Cd concentration<0.1mg/L), while 1g of non-activated peat cleared Cd from less than 25% of that volume. The cation exchange capacity measured for the peat depended on the time of contact with the exchanging solution. After 72 h contact, the value for the NaOH-activated peat was 135 cmol(c)/kg. In addition to uptake by exchange, a significant amount of Cd was sorbed by non-exchange mechanisms. FTIR spectroscopy revealed the importance of carboxyl groups in the uptake.

Thermo-FTIR spectroscopic study of the siderophore ferrioxamine B: spectral analysis and stereochemical implications of iron chelation, pH, and temperature.

FTIR spectra of the microbial siderophore, ferrioxamine B, and its nonchelated form (iron free; desferrioxamine B) were studied to facilitate in-depth investigation on the undisrupted structure of the siderophore and its interactions with the environment. Effects of iron chelation as well as those of various levels of pH and temperature on the stereochemical structure of the free ligand and the ferric complex were examined. The presence of a number of functional groups in these compounds and the mutual interaction between them resulted in significant shifts and overlapping of their characteristic absorption bands. Thermal and pH treatments combined with a comprehensive use of curve-fitting analysis facilitated bands resolution. Absorption bands of all functional groups were identified. The results imply that the compact and rigid structure of the ferric complex (ferrioxamine B) is sustained by intense and specific intramolecular hydrogen bonds. Dehydration was the main process observed at low temperature (25-60 degrees C). At 105 degrees C the free ligand form (desferrioxamine B) had already begun to decompose, whereas ferrioxamine B exhibited stability. The thermal destruction became acute at the 170 degrees C treatment for both molecules. The secondary amide groups and the hydroxamate groups, which comprise the binding site for the Fe atom in the complex, were found to be the most sensitive to the thermal degradation. Significant pH effects were observed only for desferrioxamine B samples at pH 9, accompanied by partial decomposition, similar to that observed at 105 degrees C. Deprotonation of desferrioxamine B was found to begin with the deprotonation of the NH(3+) group. Characteristics of the rigid conformational structure of the ferric complex and the state of the NH(3+) group, both assumed to play an important role in the recognition and uptake of the siderophore by membranal receptors, were elaborated by means of FTIR and are discussed in detail.

High resolution electron microscopy structural studies of organo-clay nanocomposites.

Engineering of clay nanocomposite materials by modification of their surfaces can enable the control of retention, transport, and persistence of toxic chemicals in the geosystem. The properties and interactions of clay nanocomposites have been widely studied, but little information exists on their microstructure at a range of scale extending down to atomic dimensions. The pairing of Na-montmorillonite clay with organic cations as well as with the herbicide fluridone, chosen as a model for an organic pollutant, was studied. Three organic cations were selected: hexadecyltrimethylammonium, benzyltrimethylammonium, and benzyltriethylammonium at 0%, 60%, and 100% of cation exchange capacity (CEC) loadings. A detailed microstructural analysis of the organo-clay nanocomposites and of the fluridone nanocomposites was undertaken by high-resolution transmission electron microscopy (HRTEM) and X-ray energy-dispersive spectroscopy (EDS). Morphological observations and chemical analyses were performed simultaneously on the same sample. The combined HRTEM and EDS measurements strongly suggest (a) heterogeneous local intercalation of the organic cations manifested by a range in the measured d001 spacing, implying random expansion of the clay layered structure with increased loading of the organic cations; (b) intercalation within the external layers, which is thoroughly influenced by local defect microstructure and/or edge availability of the montmorillonite nanoparticles as well as by the molecular structure of the intercalating organic cation. Additional intercalation of fluridone molecules did not affect the structure (d001 spacing) of the organo-clay nanocomposites.