Effects of Soil Conditions on Survival and Growth of Black Willow Cuttings

Current streambank restoration efforts focus on providing bank stability, enhancing water quality, and improving woody habitat using native vegetation rather than traditional engineering techniques. However, in most cases harsh site conditions limit restoration success. A two-year field study was conducted at Twentymile Creek, in northern Mississippi, investigating edaphic factors governing the survival of black willow (Salix nigra) cuttings used for streambank restoration. Low height growth, above-ground biomass production, and average leaf area were observed in willow cuttings grown in plots subjected to moisture deficits. However, sediment texture emerged as the dominant factor determining willow post growth, health, and survival. Shoot biomass, leaf biomass, and total above-ground biomass were 15-, 10-, and 14-fold greater for large willow cuttings (posts) grown in plots with sandy sediments relative to those grown in plots with similar moisture and soil redox potential but with silt and clay sediments. Average leaf size, average leaf mass and specific leaf area were all lower in fine textured plots. Under moisture conditions present at our sites, coarse-grained sediment (sand) was more conducive to willow growth, biomass production, and survival than were fine-grained sediments (silt/clay). Our results strongly suggest that soil texture and moisture conditions can determine restoration success. Therefore, it is critical that site conditions are factored into the selection of project locations prior to the initiation of willow planting restoration projects.     

Evaluation of heavy metal contamination hazards in nuisance dust particles, in Kurdistan Province, western Iran

The effects of natural andgeochemical factors depending on heavy metal contamination in nuisance dust particles were evaluated. The nuisance dust particles were sampled using passive deposit gauge method for one year from April2010 to March2011 and the obtained samples were measured for the total contents and the contamination levels of Fe, Mn, Cu and As usinggeo-accumulation index (Igeo ), enrichment factor (EF) and the integrated pollution index (IPI). The results showed that, the contamination levels of Fe and Mn based on Igeo values, were uncontaminated (Igeo < 0) (variations of the Igeo index was from -3.11 to -1.751 for Fe, from -0.630 to -1.925 for Mn), while the values of Cu and As were demonstrated to have moderate contamination based on Igeo values (variations of Igeo index was from -1.125 to 0.848 for Cu, and from -2.002 to 1.249 for As). The analysis of EF also revealed minor to moderate enrichment for Mn (1.215-4.214), minor to moderately severe enrichment for Cu (2.791-6.484), and As (1.370-8.462), respectively. The variation of the IPI index also showed low to moderate level of heavy metal pollution in nuisance dust particulates (0.511-1.829). The analysis of the results also approved that the natural processes andgeochemical variables (the changing meteorological parameters) can significantly affect the availability of heavy metals in nuisance dust particles in Western Iran.     

226Ra concentration in the teeth of habitants of areas with high level of natural radioactivity in Ramsar

The level of natural radiation in some regions of Ramsar, a northern coastal city of Iran, is known to be among the highest levels of natural radiation in the world. 226Ra existing in high concentrations in the soil of this region is washed by underground water and transferred to the surface. In this way, 226Ra enters the food chain of residents and substitutes within the hard body tissues of humans. 226Ra is one of the so-called bone seekers as its metabolic processes in the human body are similar to calcium and remains in hard tissues of body because of its long half-life, and being an alpha emitter causes dangerous effects on human health. The purpose of this study is to determine the concentration of 226Ra in the teeth of residents of these high-level natural radiation areas, compared with a control group. Thirteen teeth in five groups were studied as the case group and thirteen teeth in five corresponding control groups were inspected. The mean values of the activity of 226Ra in the case group and in the control group were 0.32 and 0.18mBqg(-1), respectively.     

A comprehensive review of heavy metal pollution in the coastal areas of Bangladesh: abundance,bioaccumulation, health implications,and challenges

Environmental Science and Pollution Research - The coastal zone of Bangladesh, with a population density of 1278 people per square kilometer, is under serious threat due to heavy metal pollution....     

Numerical study of scouring downstream of a stilling basin

Environmental Fluid Mechanics - The aim of the present study is to numerically investigate the scouring phenomenon downstream of a stilling basin for a wide range of Froude number and size of bed...     

Impact of roof rain water harvesting of runoff capture and household consumption

Environmental Science and Pollution Research - In recent years, the occurrence of floods is one of the most important challenges facing in Hamadan city. In the absence/inefficiency of urban...     

Removal of Reactive Blue 19 dye from synthetic wastewater using UV/H2O2 and UV/Cl advanced oxidation processes

The textile and dyeing industries are among the largest water-consuming and polluting industries in the world. The most important feature of the textile dyeing industry wastewater is its color, due to the use of colored materials. Most of these dye compounds are resistant to conventional purification methods and their biodegradation is very low through secondary purification processes, resulting in incomplete removal. Therefore, selecting the optimal method to remove these color compounds is essential. In this study, we studied the removal of an organic dye contaminant (Reactive Blue dye 19 [RB19]) using advanced oxidation processes (AOPs). For this purpose, ultraviolet (UV) mercury lamps with a wavelength of 254 nm and a voltage of W16 inside a reactor were used as an energy source. The experiments were performed in a collimated beam reactor inside a dark chamber. Two oxidizers, sodium hypochlorite (NaOCl) and hydrogen peroxide (H₂O₂), were used to remove RB19 from the artificial sewage stream. Removal of RB19 with a concentration of 20 mg/L with variable pH (5, 7, and 9), oxidant concentrations (5, 10, and 20 mg/L), and time (5, 10, 15, and 30 min) were investigated during the processes of photolysis, chemical oxidation (by H₂O₂ and NaOCl), and UV/NaOCl and UV/H₂O₂ AOPs. The photolysis process did not remove the RB19. The highest removal efficiencies of RB19 by chemical oxidation processes with NaOCl and H₂O₂, UV/NaOCl, and UV/H₂O₂ at optimal conditions (pH = 5, [oxidant] = 20 mg/L, RB19 = 20 mg/L, and radiation intensity of 1005 mJ/cm²) were 64.49%, 0.88%, 99.7%, and 13.31%, respectively. These results indicate that the hydroxyl radical was produced, under optimum conditions, more in the acidic medium; thus, the RB19 removal efficiency was higher in the acidic medium. The combination of UV rays with oxidants resulted in the production of more hydroxyl radicals and increased removal efficiency.