Role of Air Flow on Changing Soil Properties and Plant Nutrition in Egyptian Alluvial Soil

Study the effect of air flow on changing some soil properties and plant nutrition is highly important to increase crop quality and productivity. The pot experiment was carried out focusing on Agric faba bean C.V. Giza 2 in Egyptian alluvial soil (clay) during 2017-18 seasons. Two soil samples with three replicates were taken. The results revealed that hygroscopic water (HW), saturation percentage (SP) and real density (RD) have not affected by air flow, while organic matter (OM), hydraulic conductivity (HC) and bulk density (BD) have remarkable increase with air flow. The available macro and micronutrients concentrations in soil and plant are also discussed where different results have been obtained depending upon type of nutrient. The total count of bacteria (TCM) is found to be affected with air flow than without aeration techniques. The findings of this study reveal that aeration or air flow promotes healthy levels of soil gases and plays a critical role in plant growth.

Hygroscopic Water Retention and Physio-Chemical Properties of Three In-House Produced Biochars from Different Feedstock Types: Implications on Substrate Amendment in Green Infrastructure

Recent studies have proposed usage of biochar as a substrate amendment in green infrastructure, such as green roofs and bio-filtration units. However, understanding of the variation in physio-chemical properties of biochar due to the production process and feedstock is still lacking. The present study investigated the effects of pyrolysis temperature and feedstocks on the hygroscopic water content and physio-chemical properties of biochar. Biochars were produced from three feedstock types, invasive vegetation (i.e., water hyacinth), non-invasive vegetation (i.e., wood) and one animal waste (i.e., chicken manure). Biochar was produced at two different pyrolysis temperatures (i.e., 300 °C and 600 °C). Scanning electron microscopy + energy dispersive spectrometry (SEM + EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) were performed on all samples to analyze the surface morphology, pore size, element content, functional groups, and chemical bonds. Relative humidity was adjusted to reflect the biochar’s hygroscopic property by measuring the maximum moisture content at the sample equilibrium state. The characterization reveals that the lowest carbon content (42.78%) was found at 300 °C for water hyacinth biochar (WHB). The highest carbon content (92.14%) was found at 600 °C for wood biochar (WB). As the pyrolysis temperature increased, the mean pore volume (from 0.03 to 0.18 cm3/g) and diameter (from 8.40 to 10.33 nm) of the WHB increased. However, the pore diameter of chicken manure (CB) decreased (from 9.23 nm to 7.53 nm) under an increase in pyrolysis temperature. For a given pyrolysis temperature, the hygroscopicity of WHB was highest among all biochars. With an increase in pyrolysis temperature, the hygroscopicity of biochars changed differently. The hygroscopicity of WHB decreased from 82.41% to 44.33% with an increase of pyrolysis temperature. However, the hygroscopicity of CMB and WB remained unchanged. This study suggests that production process of biochars need to be considered for appropriate selection as substrate material in green infrastructure. Further, it promotes the establishment of commercial production of biochar for usage in green infrastructure.

Weakly Hydrated Anion Exchangers Doped with Cu2O and Cu0 Particles—Thermogravimetric Studies

Hybrid ion exchangers (HIXs) containing fine Cu2O and Cu0 particles were subjected to thermal analysis in order to determine their hygroscopic water content (with regard to their anomalously low porosity) and to determine the effect of the oxidation state of the copper atom in the deposit on the thermal properties of composite materials. Commercially available anion exchangers, Amberlite IRA 900Cl (macroreticular, M) and Amberlite IRA 402OH (gel-like, G), were used as supporting materials. M/Cu2O, G/Cu2O, M/Cu and G/Cu, containing 4.3–8.4 wt% Cu, were subjected to thermal analysis under respectively air and N2. TG/DTG curves revealed that dry M/Cu and G/Cu contained as little as 7.2% and 4.3% hygroscopic water, while M/Cu2O and G/Cu2O contained respectively 10.6% and 9.4% (Cu0 was a stronger water repellent than Cu2O). The oxidation state of the copper atom in the deposit was found to affect the amount of the forming char, and also Cu0 was found to contribute to the formation of more char than in the pyrolysis of the pure resin (the anion exchanger with no copper deposit). Under air the two kinds of particles transformed into CuO, while under N2 metallic copper and char (from the resin phase) made up the solid residue. This means that in the pyrolysis of the HIXs the inorganic phase participated in char formation and it also transformed itself (undergoing reduction when possible). The above findings provide a basis for in-depth research aimed at the innovative use of copper-containing HIXs and at obtaining usable composite materials with a designed (organic-inorganic) composition.

Corrosion behavior of low carbon steel under different water conditions in compacted bentonite of China-Mock-Up

<p>In some countries, low carbon steel has been considered as the candidate material of the disposal container for high-level radioactive wastes (HLWs) due to its excellent anti-irradiation, high strength, low cost and fine processing performance. However, during the long-term geological disposal, the steel disposal container will suffer from the threat of corrosion damage under the coupled THMC conditions.</p><p>This work focused on the corrosion behavior of low carbon steel under different water conditions in compacted bentonite of China-Mock-Up by in situ electrochemical impedance spectroscopy (EIS) with the infiltration of groundwater from outside to inside. Based on the EIS results, the corresponding equivalent circuit models were proposed to interpret the evolution of electrochemical characteristics of low carbon steel with the increase of water content in compacted bentonite. In the initial stage of EIS measurement, water in bentonite around the electrochemical sensors from outside to inside was hygroscopic water and chemical bonding water successively. With the running of China-Mock-Up, water in outer bentonite transformed from hygroscopic water to free water. Meanwhile, the water in the inner bentonite blocks transformed from chemical bonding water to hygroscopic water, which caused a slight corrosion of low carbon steel. After China-Mock-Up running for 1202 days, the instantaneous corrosion rate of low carbon steel located in the inner bentonite blocks was just 0.002 mm/a. While in the outside bentonite blocks, the corrosion rate reached to 0.58 mm/a after 1155 days, indicating that the free water could cause a serious corrosion of low carbon steel.</p>

Differences in Water Vapor Adsorption-Desorption of Non Aged and 3-Year Aged Biochar in Sandy Spodosols

Ageing of biochars in soil affects their surface properties and can cause changes in water vapor adsorption-desorption processes. Measurements of hygroscopic water contents and corresponding water potentials of non aged and 3-year aged biochars as well as of sandy soils with medium and high quality were carried out during 5 cycles of water vapor adsorption-desorption processes at a room temperature of 23.5 °C. The results showed a significantly lower content of maximum hygroscopic water in the aged biochars than that in the non aged biochar at the end of water vapor adsorption processes at high air humidity. A significantly higher affinity of the high quality soil to water vapor resulted in insignificant differences in the maximum hygroscopic water content and in significant changes in the corresponding water potentials as compared to the same properties of the soil with medium quality. Minimum content of hygroscopic water was significantly lower in the non aged biochar than in the aged biochars at the end of the water desorption processes at ambient laboratory atmosphere. There were insignificant differences in minimum contents of hygroscopic water and in the corresponding water potentials of the aged biochars from soils with medium and high quality.

Study of Some Soil Properties and Evaluation of the Level of Contamination with Lead in Baia Mare, Aghires and Copsa-Mica, Romania

The article is focused on soil quality studies of three contaminated areas from Romania, affected by exploitation: northwest of Baia Mare near Romplumb S.A., Aghire�squarry area, and Copsa Mica. The values of pH, the hygroscopic water content were studied along to sieves analysis applied for gradation and size analysis. A semi-quantitative analysis of the content of the soli was made by SEM-EDAX.