Spent mushroom substrates （SMS） are usually treated as wastes. One of the main beneficial uses of SMS is as soil amendment, after further composting, for horticulture. Avocado orchards in Northern Israel, are grown ...Spent mushroom substrates （SMS） are usually treated as wastes. One of the main beneficial uses of SMS is as soil amendment, after further composting, for horticulture. Avocado orchards in Northern Israel, are grown mainly on heavy clay soils, suffering from poor drainage and limited aeration. This situation can cause yield decrease and lead to tree＇s degeneration. In the present study, two soil cover （mulch） treatments were compared, in an avocado orchard, as means to solve this problem： SMS and cattle manure compost （CMC）. The yields of two avocado varieties were higher on SMS than CMC mulch. Thick growth of avocado roots was found in and under both mulch types. Soil＇s electrical conductivity （EC） values were high under both mulch types, although they later decreased, due to annual rainfall. There are treatments （leaching etc.） that can be used, for minimizing the increase of soil＇s salinity after SMS application. Enhancement of avocado root growth into and under the mulch can lead to improvement of avocado trees growth, especially on heavy un-drained soils. Therefore, SMS recycling is advantageous for both avocado and mushroom growers. The commercial utilization of SMS in avocado orchards should be done carefully, with monitoring its impact on soil＇s EC （salinity） and taking the needed measures to avoid unnecessary damages.展开更多
The purpose of this work is to remove Pb（II） from the aqueous solution using a type of hydrogel composite. A hydrogel composite consisting of waste linear low density polyethylene, acrylic acid, starch, and organo-m...The purpose of this work is to remove Pb（II） from the aqueous solution using a type of hydrogel composite. A hydrogel composite consisting of waste linear low density polyethylene, acrylic acid, starch, and organo-montmorillonite was prepared through emulsion polymerization method. Fourier transform infrared spectroscopy（FTIR）, Solid carbon nuclear magnetic resonance spectroscopy（CNMR））, silicon-29 nuclear magnetic resonance spectroscopy（Si NMR））, and X-ray diffraction spectroscope（（XRD） were applied to characterize the hydrogel composite. The hydrogel composite was then employed as an adsorbent for the removal of Pb（II） from the aqueous solution. The Pb（II）-loaded hydrogel composite was characterized using Fourier transform infrared spectroscopy（FTIR））,scanning electron microscopy（SEM））, and X-ray photoelectron spectroscopy（（XPS））. From XPS results, it was found that the carboxyl and hydroxyl groups of the hydrogel composite participated in the removal of Pb（II）. Kinetic studies indicated that the adsorption of Pb（II）followed the pseudo-second-order equation. It was also found that the Langmuir model described the adsorption isotherm better than the Freundlich isotherm. The maximum removal capacity of the hydrogel composite for Pb（II） ions was 430 mg/g. Thus, the waste linear low-density polyethylene-g-poly（acrylic acid）-co-starch/organo-montmorillonite hydrogel composite could be a promising Pb（II） adsorbent.展开更多
文摘Spent mushroom substrates （SMS） are usually treated as wastes. One of the main beneficial uses of SMS is as soil amendment, after further composting, for horticulture. Avocado orchards in Northern Israel, are grown mainly on heavy clay soils, suffering from poor drainage and limited aeration. This situation can cause yield decrease and lead to tree＇s degeneration. In the present study, two soil cover （mulch） treatments were compared, in an avocado orchard, as means to solve this problem： SMS and cattle manure compost （CMC）. The yields of two avocado varieties were higher on SMS than CMC mulch. Thick growth of avocado roots was found in and under both mulch types. Soil＇s electrical conductivity （EC） values were high under both mulch types, although they later decreased, due to annual rainfall. There are treatments （leaching etc.） that can be used, for minimizing the increase of soil＇s salinity after SMS application. Enhancement of avocado root growth into and under the mulch can lead to improvement of avocado trees growth, especially on heavy un-drained soils. Therefore, SMS recycling is advantageous for both avocado and mushroom growers. The commercial utilization of SMS in avocado orchards should be done carefully, with monitoring its impact on soil＇s EC （salinity） and taking the needed measures to avoid unnecessary damages.
基金supported by the USM short-term grant (Ac No.: 8044043)by the USM fellowship scheme for PhD study (to M. Irani)Water Program at University of Wyoming
文摘The purpose of this work is to remove Pb（II） from the aqueous solution using a type of hydrogel composite. A hydrogel composite consisting of waste linear low density polyethylene, acrylic acid, starch, and organo-montmorillonite was prepared through emulsion polymerization method. Fourier transform infrared spectroscopy（FTIR）, Solid carbon nuclear magnetic resonance spectroscopy（CNMR））, silicon-29 nuclear magnetic resonance spectroscopy（Si NMR））, and X-ray diffraction spectroscope（（XRD） were applied to characterize the hydrogel composite. The hydrogel composite was then employed as an adsorbent for the removal of Pb（II） from the aqueous solution. The Pb（II）-loaded hydrogel composite was characterized using Fourier transform infrared spectroscopy（FTIR））,scanning electron microscopy（SEM））, and X-ray photoelectron spectroscopy（（XPS））. From XPS results, it was found that the carboxyl and hydroxyl groups of the hydrogel composite participated in the removal of Pb（II）. Kinetic studies indicated that the adsorption of Pb（II）followed the pseudo-second-order equation. It was also found that the Langmuir model described the adsorption isotherm better than the Freundlich isotherm. The maximum removal capacity of the hydrogel composite for Pb（II） ions was 430 mg/g. Thus, the waste linear low-density polyethylene-g-poly（acrylic acid）-co-starch/organo-montmorillonite hydrogel composite could be a promising Pb（II） adsorbent.
