Effect Of Organic Content Research Articles

Effects of organic content on sewage sludge compression behaviour

Five sewage sludge specimens with different organic contents were prepared by mixing mass ratios of 0, 5, 10, 20 and 40% dry soil powder into raw sewage sludge. The addition of dry soil powder can reduce the organic content of sewage sludge without significantly changing its particle composition. Oedometer tests were conducted, starting from a small effective vertical stress [Formula: see text]. It is observed that the [Formula: see text] compression curves show an inverse ‘S’ shape due to suction pressure resisting deformation. The suction pressure decreases exponentially with the organic content, a regression equation for which is provided. Burland’s concept of the intrinsic compression line (ICL) is adopted for correlating the compression curves of sludge with various organic contents. It is found that the ICL with a high organic content lies above the low one – that is, the higher the organic content, the greater the void index. In addition, the shape of the ICL for organic sludges is an inverse S rather than slightly concave upwards for inorganic reconstituted clays. An average ICL is provided to normalise the compression curves of sludges with different organic contents. The intrinsic compression parameters [Formula: see text] and [Formula: see text] can be correlated with the organic content, which increase linearly with the organic content, and the regression equations for them are provided.

Effect of organic content on compression properties of municipal sewage sludge

Urban sewage sludge is rich in a large amount of organic matter, which has a significant impact on the compression characteristics of sludge, and ultimately affects the landfill disposal and resource utilization of sludge. Quartz sand was mixed into the sewage sludge to prepare sludge samples with an organic content of 8%, 16% and 26% (raw sludge) respectively, and then a standard consolidation test was carried out to explore the influence of the organic content on the compression properties of the sludge and mechanism of action. The results show that the compressibility of urban sludge increases with the increase of organic content. The compression coefficient and index of sewage sludge both increase exponentially with the increase of organic content. The ln(1+e)∼lgp curve of urban sludge has a significant "inflection point" and a certain consolidation yield stress. With the increase of organic content, the consolidation yield stress decays exponentially. Organic matter in the sludge has a flocculent structure and a large specific surface area. It is easily adsorbed on the surface of the clay particles, hindering the cementation of the clay particles and reducing the permeability of the sludge. At the same time, organic matter has water-retaining property, hinders the consolidation and drainage of sludge, and ultimately affects the compression properties of sludge.

Uptake of Chromium by Portulaca Oleracea from Soil: Effects of Organic Content, pH, and Sulphate Concentration

Phytoextraction is an effective and environment-friendly approach for remediation of soil polluted with toxic metals. Portulaca oleracea is a potential hyperaccumulator of Cr(VI) from polluted soil. In this study, the effect of soil organic content, pH, and sulphate concentration on phytoextraction of Cr(VI) using Portulaca oleracea was investigated. Seedlings of Portulaca oleracea were grown in soils with (i) three organic content compositions, (ii) six levels of pH, and (iii) six concentrations of sulphate salts; all were irrigated with Cr(VI) solutions at 200 ppm concentration. Chromium concentration in different tissues of plants was monitored under the variant conditions. Results indicated that the uptake of Cr(VI) by Portulaca oleracea is favoured at (i) low organic content soil (0.42%), (ii) slightly alkaline pH range (∼8), and (iii) with sulphate concentration in the range of 300–600 ppm.

Fast simultaneous determination of main components and impurity sodium ion in PAMA injection by mixed-mode chromatography

This study describes an analytical method to control the quality of potassium aspartate and magnesium aspartate (PAMA) injection based on the simultaneous detection of the main components (K+, Mg2+ and Asp) and impurities (Na+) using a mixed-mode chromatography coupled with charged aerosol detector. To obtain optimal chromatographic separation, the effects of organic content, column temperature, buffer types, pH and concentrations were evaluated. A Response Surface Methodology (RSM) optimal design was performed after single factor experiment. The mixed-mode HPLC method is proved to be a complementary approach to the conventional ion chromatography (IC). The optimized method was successfully validated and applied to the analysis of Asp, K+, Na+ and Mg2+ in PAMA injection with good specificity, linearity, accuracy, and repeatability. The method would be useful for quality control in PAMA injection and other similar drugs, which can provide references for the analysis of drug quality by enterprises and drug regulatory department.

Effect of organic content and frequency on degradation and pore pressure in marine organic soils

ABSTRACTThe effects of organic content and the frequency of cyclic shear straining on the cyclic degradation and the normalized pore water pressure in 27 fibrous marine organic soil specimens were investigated with the two-way cyclic strain-controlled dynamic triaxial testing system. The testing program included three cyclic shear strain amplitudes, γc = 0.25, 0.5, and 1%, three ranges of the organic contents, OC = 13.3–18.4%, 23.3–27.9%, and 36.9–45.3%, and three loading frequencies, f = 0.05, 0.25, and 1 Hz. The results clearly exhibit that the degradation parameter, t, which means the rate of the cyclic degradation with the number of loading cycles, N, decreases with the OC and increases with the f. At the γc = 0.25–1%, if the OC decreases from 40.8 to 13.3%, the degradation parameter t may increase by 82.9–221.1%. If f is increased 20 times, from 0.05 to 1 Hz, then t may increases by 34.7–117.9%. The cyclic pore water pressure normalized by the effective consolidation pressure, , increases with the OC and decreases with the f was also observed.

Effect of Organic Content in Biosolids on the Properties of Fired-Clay Bricks Incorporated with Biosolids

AbstractBiosolids are produced following the treatment of wastewater sludge. Millions of metric tons of biosolids are produced around the world each year. This study has investigated the effect of ...

Permeability prediction of shale matrix reconstructed using the elementary building block model

Representative elementary volume (REV)-scale structure of shale matrix is reconstructed based on elementary building block (EBB) model using a stochastic reconstruction method called Quartet Structure Generation Set. In the EBB model, various constituents with different pore morphologies in shale matrix including organic matter and inorganic minerals are considered as different EBBs, and in each EBB, specific structural parameters and transport properties are locally defined. A generalized lattice Boltzmann model for fluid flow through tight porous media with slippage is employed to simulate fluid flow through the reconstructed REV-scale structures. A four-EBB shale matrix including clay, calcite, pyrite and organic matter is studied and its permeability is predicted. Effects of organic content, grain size, interparticle pores on the permeability of the REV-scale matrix are investigated. It is found that smaller grain size and interparticle pores can increase the permeability. The influences of complex physical processes such as slippage and adsorption on the REV-scale permeability are also explored. Slippage effect increases as the pore size decreases. Adsorption has two opposite effects on the permeability, and which one dominates depend on pressure. The present study can help understand gas transport in shale matrix and improve reservoir scale studies.

Effect of Organic Content on Anaerobic Biodegradability by Agricultural Waste Biomass

Recently interest on production of biogas from biomass resources has increased because of climate change in worldwide. In this study, anaerobic digestion efficiency of 17 different types of agricultural waste was evaluated using biochemical methane production potential estimated from the International biochemical methane potential standard method (Germany VDI4630). As a result, theoretical biochemical methane potential (<TEX>$B_{th}$</TEX>) of agricultural waste biomass ranged from 0.266 to <TEX>$0.488Nm^3kg^{-1}$</TEX>-Volatile Solid <TEX>$(VS)_{added}$</TEX>. Ultimate biochemical methane potential (<TEX>$B_u$</TEX>) of agricultural waste biomass ranged between 0.176 and <TEX>$0.417Nm^3kg^{-1}-VS_{added}$</TEX>. The agricultural waste biomass anaerobic biodegradability with <TEX>$B_u/B_{th}$</TEX> and VDI4630 determined by VS contents was 36.0~95.9% and 30.8~91.1%, respectively. Ultimate methane potential and anaerobic biodegradability given by the VS term showed more reasonable results.

Evaluation of Contributing Factors on Strength Development of Lime Stabilized Artificial Organic Soils Using Statistical Design of Experiment Approach

Lime is widely used as chemical stabilizer in soft soil stabilization. However, lime is reported to be less effective when dealing with organic soil. It is believed that the organic matter in the soil will retard the pozzolanic reaction which is responsible for strength enhancement. The heterogeneity nature of the organic matter in the soil makes the study complicated and reduced the repeatability of the test results. Hence, artificial organic soil with known organic matter and content are preferred by researchers when repeatability of the test results are required in determining the influential effect of each contribution factor. Various factors such as additive contents, effect of aging (curing periods), curing temperature, density of materials and moisture content are reported by previous researchers as the potential contributing factors towards the strength development. It is believed that the interaction of the factors also will contribute to the strength enhancement. Hence, this study is carried out to evaluate the contributing factors and its interactions on strength development of artificial organic soils with known type and contents of organic matter. Statistical design of experiment (DOE) approach was utilized to evaluate the factors and its interaction on the strength development of lime stabilized artificial organic soils by using commercial statistics package. Three main factors were investigated: effect of organic content, effect of curing periods, and effect of additive, while other factors namely curing temperature, molding water content, types of compaction and compactive effort were keep constant through controlled experiments. Processed kaolin (inorganic material) is mixed with humic acid (organic matter) to simulate the organic soil which comprised of inorganic soil and organic matter. The density of the soil specimen and its moisture content were recorded before and after the curing process. General Linear Model (GLM) was utilized to determine the significance of the main factors, two-factor interactions, and three factor interactions. The significance factors and interactions were utilized in multiple regression analysis to develop the strength prediction model which can be utilized to predict the strength of stabilized materials within the inference space defined by the experiment.

Evaluating Drying Potential of Different Sludge Types: Effect of Sludge Organic Content and Commonly Used Chemical Additives

Drying of residual treatment sludge is one of prerequisites in final disposal of this hazardous material. In this study, sludge drying potential (SDP) of different sludge types (DST) and the effect of organic content and commonly used chemical additives, including polyelectrolyte and lime, on SDP were investigated in a full-scale municipal wastewater treatment plant (WWTP). Freshly collected sludge samples were used in all experiments, which were conducted in onsite laboratory of sludge treatment facility. Studied sludge types were composed of raw biological sludge (RBS), raw primary sludge (RPS), mixed sludge (MS), dewatered sludge (DS), and limed sludge (LS). Halogen radiation was used for sludge drying. Organic content of sludge was represented by total organic carbon (TOC), dissolved organic carbon (DOC), and lost on ignition (LOI) parameters. Relations and interactions among the SDR(s) of DST(s) were statistically determined using independent samples t-test. The effect of organic content and chemicals additives on SDP was also statistically analyzed using linear regression model. Results of the study imply that each surveyed sludge type had a different SDP. Furthermore, organic composition of sludge and chemical additives had a significant impact on SDP.

Stabilization/solidification of acid tars

This work involve a systematic treatability study of the treatment of acid tars (AT), a waste generated during the processing of petroleum and petrochemical, by stabilization/solidification with Portland cement (CEM I), with the addition of high carbon fly ash (HCFA), an industrial by-product, as a novel sorbent for organic contaminants. A factorial design experiment was adopted to investigate the effects of organic content, HCFA:AT ratio, percentage CEM I addition, and curing time on response variables including unconfined compressive strength (UCS), hydraulic conductivity, porosity, and leachability-related properties of the stabilized/solidified (s/s) products, and to assess management options for the s/s products based on performance criteria adapted from regulatory and other guidance. Results show that all studied factors had significant effects on the tested properties of the s/s products. Acid tar reduced UCS, but strength increase was observed with increased curing time. Increased HCFA addition led to an improvement in hydraulic conductivity. Assessment of management options indicates that the treated acid tars could find application as controlled low-strength materials, landfill liner, and landfill daily cover. The work demonstrates how a systematic treatability study can be used to develop a S/S operating window for management of a particular waste type.

Dielectric properties of Jordanian oil shales

Microwave heating has been suggested by various authors as a suitable technology for extraction of organic material from oil shales. However, one of the limiting factors in the development of this technology is a lack of accurate dielectric property data for design purposes. In this study the dielectric behaviour of El-lajun oil shale is quantified. The dielectric constant and loss factor of El-lajun oil shale were measured at 2470 and 912 MHz using the cavity perturbation technique. The effects of organic content, temperature, and moisture content on the microwave heating efficiency were quantified. Coaxial probe technique was also employed to study the effect of frequency on dielectric properties of oil shale. Generally, it was found that all samples were of low dielectric loss at room temperature with the imaginary part of permittivity falling significantly after the moisture was removed. This suggests that the major contribution in the dielectric loss is due to the presence of free and/or interlayer water. It was found that both the real and imaginary part of complex permittivity increased with a rise in temperature from 20 up to 80 °C, then dropped significantly at about 100 °C before staying approximately constant up to a temperature of about 480 °C. From this temperature both the real and imaginary parts of complex permittivity increased sharply with further increase in temperature. An attempt was also made to correlate the dielectric properties of the bulk shale sample with the organic content. However, no correlation between dielectric properties and organic matter content was found.

Effect of Organic Content, Clay Type and Aging on the Oral Bioavailability of Hexachlorobenzene in Rats

Effect of Organic Content, Clay Type and Aging on the Oral Bioavailability of Hexachlorobenzene in Rats

Perphenylcarbamoylated β‐cyclodextrin bonded‐silica particles as chiral stationary phase for enantioseparation by pressure‐assisted capillary electrochromatography

Perphenylcarbamoylated beta-cyclodextrin bonded-silica particles (5 microm) were packed into 75-mum fused-silica capillaries, and used for the enantiomer separation of neutral and basic solutes by pressure-assisted capillary electrochromatography. Triethylammonium acetate and phosphate buffer were employed as the BGEs. A cathodic EOF was observed with these two BGEs. Seven chiral analytes were successfully resolved into their enantiomers under optimized conditions, and five of them could be baseline-separated within 12 min due to their high electrophoretic mobility. Better results were achieved with phosphate buffer as the BGE. The effects of organic content and pH on the enantioseparation were also investigated.

Synthesis of molecular sieves using ketal structure-directing agents and their degradation inside the pore space

Molecular sieves are synthesized using degradable, ketal-containing structure-directing agents (SDA). Eight quaternary ammonium compounds that contain ketal groups are synthesized and used as degradable SDAs for the synthesis of ZSM-5, mordenite, ZSM-12 and VPI-8. The ketal-containing SDAs are degraded into smaller fragments by acidic hydrolysis while in the micropore space, and the degradation products observed by 13C CP MAS NMR. This synthetic methodology is used to circumvent the need for SDA removal by calcination. The effects of organic content, hydrophilicity and pore connectivity of the synthesized molecular sieves on the ability to degrade the entrapped SDA are investigated. The SDAs are degraded more readily inside molecular sieves with more hydrophilic character and higher pore connectivity. This is likely due to better mass transfer of H 2O and H + that are necessary for the hydrolysis of the SDA within the micropore space.

Effects of organic content and H 2O/TEOS molar ratio on the porosity and pore size distribution of hybrid naphthaleneaminepropylsilica xerogel

The hybrid naphthaleneaminepropylsilica material was obtained by a sol–gel route, varying the organic loading and the water/TEOS molar ratio. Infrared spectroscopy was used to identify the organic and inorganic phases. The morphology of the hybrid material was studied by using scanning electron microscopy and N 2 adsorption–desorption isotherms. It was observed that the increase in the organic content produces a decrease in the size and volume of the pores as well as in the surface area of the xerogel. The best porosity was obtained for water/TEOS molar ratio between 4 and 6.

Bioaccumulation of benzo(a)pyrene from sediment by fathead minnows: effects of organic content, resuspension and metabolism.

The accumulation of 14C-benzo(a)pyrene (BaP) sorbed to sediment was examined in fathead minnows (Pimephales promelas) to compare uptake from sediment with a high organic carbon (OC) content (7.7%), to that with a low OC content (2%). Ingestion of sediments was quantified by co-labeling the sediment with 141Cerium, which was not assimilated by the fish. Results of this study indicated that (1) significantly greater quantities of BaP were dissolved in water over low-OC sediment, compared to water over high-OC sediment, (2) fish disturbed the sediment and increased the concentration of BaP in centrifuged (particle-free) water, (3) fish ingested significantly more of the low-OC sediment than high-OC sediment, perhaps in response to the lower food quality of the low-OC sediment, and (4) uptake of BaP from sediment ingestion contributed <3% of the total flux of BaP into the fish. Primarily as a result of the greater concentration of BaP in water, fish from the low-OC exposures had significantly higher rates of BaP accumulation. However, after 48 h the body burdens in these fish declined by 50%, likely due to the induction of MFO enzymes in response to accumulation of BaP. A smaller effect was apparent in the fish from the high-OC exposures, consistent with the lower dose of BaP they experienced. These results illustrate the complex, and sometime counterintuitive, interactions that affect the uptake and bioaccumulation of sediment-associated contaminants.

Lowered nutritional quality supplements nudibranch chemical defense.

Reduced palatability through lowered nutritional content is a common defense for modular or gelatinous organisms, but commonly thought unavailable for active, mobile animals. However, nudibranchs - a group of brightly colored, shell-less snails - may supplement their chemical defenses via increased water and ash content. Among 33 gastropod species, nudibranchs differed from prosobranch snails by containing approximately half the digestible organic material per unit wet weight, indicating their caloric value per unit volume will likewise be less than that of shelled snails. Nudibranchs also allocated proportionally less organic material to exterior body regions than to the viscera. Because exterior regions are more easily regenerated and often contain nematocysts or high concentrations of chemical defense, the areas of slug bodies most vulnerable to attack are the best defended, the least valuable to potential predators, and the least costly for nudibranchs to replace. To test how these differences in organic content affect palatability to predators, I offered to Cancer productus, a common molluscivorous crab, pellets differing in organic content (12% or 22% of wet weight) and secondary chemistry (presence or absence of Archidoris montereyensis extract). In no-choice bioassays, chemical extracts reduced feeding by approximately 50%, while lowered organic content reduced feeding by approximately 19%. The effects of organic content did not significantly interact with those caused by chemical extracts, suggesting that, in some contexts, reduced nutritional quality offers a somewhat independent form of antipredator deterrence. Although the nutritional context of defenses is often considered in studies of plants and other organisms suffering partial predation, this study shows that such a multi-factor approach should be more commonly extended to mobile animals.

Influence of physicochemical properties of soil on pH of pore water

pH of soil pore water is the important factor in heavy metal retention and migration in soil. Buffer capacity of clays such as kaolinite, hectorite, attapulgite, and Na-bentonite were determined. The magnitude of buffer capacity is in the order of hectorite>Na-bentonite>attapulgite>kaolinite. Carbonate content and CEC of soil affect most on the magnitude of buffer capacity while effects of organic content and surface area were negligible. Attempts were made to simulate buffer capacity experimental results in this research. In order to model the buffer capacity of soil, chemical interactions between proton and surface functional group were modeled using the diffuse double layer theory. An empirical model as functions of carbonate content and CEC were proposed as well. Predictions made by the diffuse double layer model agreed with experimental results well.

Densification of Paper Mill Sludge Materials

Dewatered paper industry primary sludges have a consistency similar to very soft remolded clays. Densification involves removal of additional water, usually by placement of a surcharge load after deposition in a landfill. Solids composition includes a noncombustible fraction, primarily kaolin clays, and the organic constituents which include wood fibers and other components. Use of kaolinite-pulp fiber mixtures to simulate these sludges permitted control over organic content, fiber type and size, and mineral type. Decomposition was accelerated by the addition of nutrients and seed microorganisms. Use of the ignition test to determine current organic fractions permitted changes in the degree of decomposition to be monitored concurrent to changes in the model sludge compressibility. The effects of organic content, pressure, and decomposition on sludge densification was shown by compression tests. Experimental data permitted development of a method for computation of void ratio as a function of pressure and organic content. Excellent agreement was observed with limited field data. Using the degree of decomposition, procedures for settlement prediction of decomposing paper mill sludges were formulated. Examples are included.