Heavy metal accumulation in soil after application of organic wastes

Municipal solid waste compost and cattle manure are used as organic fertilizers in agriculture and horticulture. These wastes, however, may also have some negative effects on the agricultural environment. This study investigates the effects of municipal solid waste compost of Kerman (MSC) and cattle manure (CM) on availability of the heavy metal in calcareous soil (extractable with EDTA) in greenhouse conditions. The MSC and CM were mixed thoroughly with soil at rates of 0%, 2%, and 4% of dry matter. After 90 days of incubation, the soil samples were analyzed. Addition of levels of each two organic wastes into soil significantly decreased the soil pH and increased the soil EC as compared with control (unamended soil).The available contents (EDTA-extractable) of Cd, Pb, Cu, Zn, and Cu in the soil samples were increased because of each two organic treatments applied. The heavy metal contents in the soil samples amended with MSC were more than CM. The heavy metal contents of organic wastes were well below the maximum allowed by USEPA. It is recommended that in Iran, the legal maximum permissible limit for heavy elements in organic wastes must be determined.     

Modeling the effects of controlled drainage at a watershed scale using SWATDRAIN

The recently developed SWATDRAIN model was employed to assess the impact of controlled drainage on the water table dynamics, subsurface drainage, and surface runoff in an agricultural watershed in Ontario, Canada. Controlled drainage was defined with a depth of 1.0 m to restrict flow at the drain outlet to maintain the water table at 0.5 m below the surface level during the winter (November–April) and at 0.6 m during the summer (June–August) months. The effects of the absence, or implementation, of drainage water management were predicted for the 3-year period of 1991–1993. Implementing controlled drainage resulted in a 16 % reduction in the mean annual drain flow, while increasing surface runoff by as much as 71 %. This indicates that overall watershed hydrology could be significantly impacted by the implementation of controlled drainage. This research demonstrates the SWATDRAIN model’s ability to predict the controlled drainage in small agricultural watersheds.     

A reconnaissance study of platinum group elements (PGE) contents from sulfide mineralization in pyroxenites in Faryab ophiolite of Iran

Platinum group elements (PGE) enrichment occurs in Zn–Cu and Ni-rich ophiolities in a number of geological settings. Platinum group elements (PGE) mineralization in Pyroxenite from the Faryab ophiolities of Zagros belt in south Iran was studied. The ophiolite rocks represent blocks of Tethyan oceanic crust that were emplaced on the continental margin during the late Cretaceous period. Much of lower ophiolitic section is composed of homogeneous harzburgite, while upper sections harzburgite interlayer with dunite and pyroxenite are included. This study focused on pyroxenite that includes most of sulfide mineralization in Faryab. More than 500 samples were investigated from polished thin sections; that cover all area of Faryab. The sulfide phases include pyrrhotite, pentlandite, millerite, violarite, smythite, and heazlewoodite. The results show that in almost all the samples Os is below the 2 ppb detection limit, Platinum values vary from <5 to 91 ppb and the light PGE (Ru, Rh, and Pd) relative to the heavy PGE (Os, Ir, and Pt) are more concentrated. Calculation showed that in pyroxenites Pd–Pt is occurring with orthopyroxenite and Rh–Os is occurring in clinopyroxenite. Ni/Pd ratios in Faryab vary between 7 and 356 and Pd/Ir ratio is 0.1–27. This indicates that in Faryab area partial melt of mantle occurred. Pd/Rh ratio in Faryab is 0.1–11, and Pd/Pt varies between 0.2 and 1.5. Pd/Ir ratio in Faryab decreases and shows that PGE in Faryab occurred.     

Prediction of sediment yield at storm period in Northwest Algeria

This paper studies the hydrodynamics and variability of stream flow and sediment yield in Wadi El Hammam, located in the semi-arid region of Algeria. In this location, hysteresis effects are obvious especially during high discharge periods. The sediment concentration and load maxima go several months before discharge maxima, while decreased sediment concentrations are noticed during the discharge peaks. In order to explain these phenomena, we have adopted a methodology that consists of finding a simple regression model capable of explaining the sediment load as a function of the water discharge measured at gauging stations of three rivers at various scales, e.g., annual and seasonal. Suspended sediment concentrations are measured during a 22-year period (1986/1987–2007/2008). The results have shown that the power model explains the greatest part of the variance (80%). The changes in sediment availability result in so-called hysteresis effects. In this work, we have described different loops: clockwise or positive hysteresis loops and anti- or counter-clockwise hysteresis loops. The analysis of the seasonal sediment yields has shown that the autumn season contributes a large proportion of the annual sediment yield (62%).     

Regionalization of precipitation characteristics in Iran’s Lake Urmia basin

Theoretical and Applied Climatology - Lake Urmia in northwest Iran, once one of the largest hypersaline lakes in the world, has shrunk by almost 90% in area and 80% in volume during the last four...     

Improving microbial oil production with standard and native oleaginous yeasts by using Taguchi design

Production of microbial oil has attracted a great attention in recent years. The potential of lipid production by the yeast strains is the reason for using microorganisms for biodiesel production. Microbial lipid has high similarity to the oil obtained from plants and animals in type and composition. Production of oil from yeasts must be economical, so optimization of the cultivation condition to reach higher production must be done. Native oleaginous yeast, Cryptococcus albidus, was isolated from soil by the nitrogen-limited medium and screened by Nile red staining. Yarrowia lipolytica DSM 8218 was used for lipid production as a standard strain. C. albidus was an excellent oleaginous yeast, and the lipid quantity, dry biomass and lipid productivity of this strain were 11.81 g/l, 19.65 g/l and 60.1 %, respectively, in shaking flask cultivation at 150 rpm and 25 °C in nitrogen-limited medium containing per liter 75 g glucose, 1 g (NH₄)₂SO₄, 1 g yeast extract, 3 g KH₂PO₄, 1.5 g MgSO₄.7H₂O, 0.15 g CaCl₂, 0.06 g MnSO₄.H₂O, 0.02 g ZnSO₄.7H₂O and 0.15 g FeCl₃.6H₂O with pH adjusted to 6.5. Fourier transform infrared spectroscopy was used for analyzing and confirming the production of microbial oil in this study.     

Utilization of SPOT 5 data for mapping gold mineralized diorite–tonalite intrusion,Bulghah gold mine area,Saudi Arabia

The present study utilizes the processed SPOT 5 data to discriminate and to generate 1:10,000 geologic image map to delineate the mineralized diorite–tonalite intrusion around Bulghah gold mine area, Saudi Arabia. The rock units exposed in the area include gossan, marble, Hulayfah volcanics, diorite–tonalite, gneissose granite, and alkali granite. Gold mineralization at Bulghah mine is hosted mainly by Syn- to Late-tectonic diorite–tonalite intrusion aligned along N–S direction and is associated mainly with cataclastic zones and quartz veins. Gossans and jasparoidal gossans (Hulayfah group), recorded at the western side of Bulghah mine area as discontinuous small lenses, can be easily discriminated on 4/2 and 4/3 band ratio SPOT images by their white and black image signatures, respectively. Granitoids (gneissose granite and alkali granite) are easily discriminated in 3/2 ratio image, in which gneissose granite has gray image signature, whereas alkali granite has dark gray image signature. On the SPOT false color composite band ratios image (3/2 R, 4/2 G, and 4/3 B), gossan, marble, Hulayfah volcanics, diorite–tonalite, gneissose granite, and alkali granite have sky blue, blood red, bluish light brown, orange, brick red, and deep blue colors, respectively. Fusion of the false color composite SPOT ratios image (3/2 R, 4/2 G, and 4/3 B) with the high spatial resolution SPOT pan image is performed using IHS transformation method. The fused image is used to delineate the mineralized diorite–tonalite intrusion and to produce 1:10,000 geologic image map for Bulghah gold mine area. The present study reveals the usefulness of the processed SPOT 5 data for adding new extensions at the southern and northern boundaries of diorite–tonalite intrusion.     

Groundwater geochemistry in the Meshkinshahr basin of Ardabil province in Iran

The chemical analysis of 59 water wells in Meshkinshar area, Ardabil province NW of IRAN has been evaluated to determine the hydrogeochemical processes and ion concentration background in the region. The dominated hydrochemical types are Na–SO₄, Ca–HCO₃, Na–HCO₃ and Na–Cl in the whole area. Based on the total hardness, the groundwater is soft. According to electrical conductivity and sodium adsorption ratio, the most dominant classes are C1–S1, C2–S1 and C3–S1. The major ion concentrations are below the acceptable level for drinking water. The groundwater salinity hazard is medium to high but the Na hazard is low to medium and in regard of irrigation water the quality is low to medium. So the drainage system is necessary to avoid the increase of toxic salt concentrations.