perlite and vermiculite

Topics: Biofuels; Methane; Oxidation-Reduction; Prospective Studies; Refuse Disposal; Waste Disposal Facilities

To screen environment-friendly seedling cultivation substrates which could replace peat and with less cost, we compared the effects of different agricultural and forestry residue mixed substrates on cutting propagation of. 为研究不同农林废弃物混合基质对崖柏扦插育苗的影响,筛选可替代草炭、成本低廉的环保型育苗基质,配制草炭+蛭石+珍珠岩(T

Topics: Agaricales; Charcoal; Forestry; Nitrogen; Oryza; Phosphorus; Potassium; Seedlings; Soil; Thuja

The purpose of this research was to investigate the efficiency of Dracaena marginata planted biofilters to decontaminate urban runoff. A new biofilter growth substrate was prepared using low-cost and locally available materials such as red soil, fine sand, perlite, vermiculite, coco-peat and Sargassum biomass. The performance of biofilter substrate was compared with local garden soil based on physical and water quality parameters. Preliminary analyses indicated that biofilter substrate exhibited desirable characteristics such as low bulk density (1140 kg/m(3)), high water holding capacity (59.6%), air-filled porosity (7.82%) and hydraulic conductivity (965 mm/h). Four different biofilter assemblies, with vegetated and non-vegetated systems, were examined for several artificial rain events (un-spiked and metal-spiked). Results from un-spiked artificial rain events suggested that concentrations of most of the chemical components in effluent were highest at the beginning of rain events and thereafter subsided during the subsequent rain events. Biofilter growth substrate showed superior potential over garden soil to retain metal ions such as Al, Fe, Cu, Cr, Ni, Zn, Cd and Pb during metal-spiked rain events. Significant differences were also observed between non-vegetated and vegetated biofilter assemblies in runoff quality, with the latter producing better results.

Topics: Aluminum Oxide; Aluminum Silicates; Biomass; Dracaena; Metals; Rain; Sargassum; Silicon Dioxide; Soil; Water Quality

Conventional stormwater treatment techniques such as sedimentation and filtration are inefficient for removing the dissolved and colloidal phases of hydrophobic organic compounds (HOCs) present in stormwater. Adsorption could be a promising technique for removing colloidal and dissolved pollutants. Five low-cost sorbent materials were investigated in this project, including two minerals – vermiculite and perlite – and three waste products – two pine barks and a sawdust – as potential adsorbents for removal of polycyclic aromatic hydrocarbons (PAHs), alkylphenols and phthalates; HOCs commonly found in stormwater. Adsorption capacity and kinetics were studied through batch adsorption tests using synthetic stormwater spiked with a mixture of HOCs. Vermiculite and perlite exhibited insignificant removal of the organic contaminants. The three wood-based materials retained >80% of the initial HOC concentration (10-300 μg/L). The two barks exhibited slightly higher adsorption capacities of HOCs than the sawdust. For all compounds tested, maximum adsorption onto the wood-based media was reached in <10 min. The highest adsorption capacity was found for PAHs (up to 45 μg/g), followed by alkylphenols and phthalates. No correlation was found between adsorption capacity and physical-chemical parameters such as solubility and partition coefficients (log K(ow)). Agreement between empirical data and the pseudo-second order kinetic model suggest chemisorption of HOCs onto a monolayer on wood-based media. This could lead to early saturation of the materials and should be investigated in future studies through repeated adsorption of HOCs, for example in column studies.

Topics: Adsorption; Aluminum Oxide; Aluminum Silicates; Filtration; Hydrophobic and Hydrophilic Interactions; Phthalic Acids; Polycyclic Aromatic Hydrocarbons; Silicon Dioxide; Waste Products; Water Pollutants; Water Purification

The objective of this study was to reduce volatile organic compounds (VOCs) produced during composting of poultry litter. The natural zeolite, expanded perlite, pumice and expanded vermiculite as the natural materials were used for the reducing of VOCs. Composting was performed in a laboratory scale in-vessel composting plant. Poultry litter was composted for 100 d with volumetric ratio of natural materials:poultry litter of 1:10. The VOCs were tested using the FT-IR method by VOCs analyzer. Studies showed that VOCs generation was the greatest in the control treatment without any natural materials. The natural materials significantly reduced VOCs. At the end of the processes, removal efficiency was 79.73% for NZ treatment, 54.59% for EP treatment, 88.22% for P treatment and 61.53% for EV treatment. Potential of removal for VOCs on poultry litter matrix using natural materials was in order of: P>NZ>EV>EP.

Topics: Aluminum Oxide; Aluminum Silicates; Animals; Manure; Poultry; Silicates; Silicon Dioxide; Soil; Volatile Organic Compounds; Zeolites

Poultry litter compost is used as fertilizer on agricultural land because of its high nutrient content. A major limitation of land application of poultry litter compost is the loss of nitrogen via NH3 volatilization. The present work was conducted to monitor nitrogen availability during composting of poultry litter with natural zeolite, expanded perlite, pumice and expanded vermiculite. Poultry litter was composted for 100 days using five in-vessel composting simulators with a volumetric ratio of natural materials:poultry litter of 1:10. It was found that natural materials significantly reduced NH3 volatilization. At the end of the process, the control treatment without any natural materials had the lowest rate of total N: 72% of the initial total N was lost from the compost made with no amendment, while 53, 42, 26 and 16% of initial total N was lost from compost containing expandable perlite, expandable vermiculite, pumice and natural zeolite, respectively.

Topics: Aluminum Oxide; Aluminum Silicates; Ammonia; Animals; Manure; Nitrogen; Poultry; Refuse Disposal; Silicates; Silicon Dioxide; Soil; Volatilization; Zeolites

We are planning a short-term experiment with Superdwarf wheat on the U.S. Space Shuttle and a seed-to-seed experiment on the Russian Space Station Mir. The goals of both experiments are to observe effects of microgravity on developmental steps in the life cycle and to measure photosynthesis, respiration, and transpiration by monitoring gas exchange. This requires somewhat different hardware development for the two experiments. Ground-based research aims to understand plant responses to the environments in the space growth chambers that we will use (after some modification): the Plant Growth Unit (PGU) on the shuttle and units called Svet, Svetoblock 2, or Oasis on Mir. Low irradiance levels (100 to 250 micromoles m-2 s-1 at best) pose a particular problem. Water and nutrient supply are also potentially limiting factors, especially in the long-term experiment. Our ground-based studies emphasize responses to low light levels (50 to 400 micromoles m-2 s-1); results show that all developmental steps are delayed by low light compared with plants at 400 micromoles m-2 s-1. We are also testing various rooting substrates for the shuttle experiment. A 1:1:1 mixture of peat:perlite:vermiculite appears to be the best choice.

Topics: Aluminum Oxide; Aluminum Silicates; Culture Media; Ecological Systems, Closed; Environment, Controlled; Evaluation Studies as Topic; Life Support Systems; Light; Lighting; Seeds; Silicon Dioxide; Soil; Space Flight; Triticum; Weightlessness