planting shrub seedlings under oil mulches has frequently been used for stabilizing mobile sands in iran for during the last three decades. sandy desert of samad abad, sarakhs, northeast iran, has been fixed by cultivating seedling of haloxylon aphyllum under the oil mulches. therefore this study was designed to investigate the effects of the sand fixation project on soil and vegetation propert...

the aerobic granular systems represent a good alternative to substitute the conventional activatedsludge process in the treatment of industrial effluents due to the lower surface requirements. in this work the effluent from a seafood industry, characterized by a high variability and the presence of residual amounts of coagulant and flocculant reagents, was used to study the development of aerob...

a four - year field experiment (1999-2002) was conducted on a silty clay loam soil at laklak research field of hamedan to determine the effects of crop residue management and plowing depth on soil fertility and wheat yield in a maize-wheat rotation. in this investigation, four corn residue managements were used consisting of 1) stalk shredding by maize stalk shredder 2) stalk shredding by disk ...

to assess the effects of livestock grazing on soil compaction (density changes), the trampling action of livestock was simulated. the research field was located to the south west of nazarabad in savojbolagh district, south west of tehran province. samples were annually collected based on a completely randomized design. from the triple regions (reference, key and critical) 36 cylindrical cores w...

Natural organic matter (NOM) affects some qualitative parameters of water such as color. In addition, it can deteriorate the performance of water treatment process including coagulation, adsorption, and membranes. NOM also reacts with chlorine in the chlorination process and may form disinfection by-products. The present study was carried out in laboratory-scale in a batch system using a cylind...

Extracellular enzymes degrade complex organic compounds and contribute to carbon turnover in soils. We used physical fractionation procedures to investigate whether soil carbon is spatially isolated from degradative enzymes across a prairie restoration chronosequence in Illinois, USA. We found that carbon-degrading enzymes were abundant in all soil fractions, including macroaggregates, microagg...

Estimates of N2 fixation by substrata associated with the rhizophytic alga Caulerpa taxifolia were obtained using the acetylene reduction method. On average, growth of C. taxifolia enhanced rates of acetylene reduction in underlying dead sea grass sediments by a factor of 28, although the degree of enhancement was variable. The average rate of ethylene production was 3.96 nmol cm23 h21 (range 5...

Several factors effect on sorption of polycyclic aromatic hydrocarbons (PAHs) in soil. Coexistence of metals and organic matter of soil are among important affecting factors on sorptive behavior of PAHs. This research investigated the effect of organic matter content and heavy metals (lead, nickel and zinc), on sorption of phenanthrene onto kaolinite. For this purpose, sorption of the organic m...

Organic matter was studied in radiation fogs in the San Joaquin Valley of California during the California Regional Particulate Air Quality Study (CRPAQS). Total organic carbon (TOC) concentrations ranged from 2 to 40 ppm of C. While most organic carbon was found in solution as dissolved organic carbon (DOC), 23% on average was not dissolved inside the fog drops. We observe a clear variation of...