Genotypic Variation in the Phytoremediation Potential of Indian Mustard for Chromium

The term “phytoremediation” is used to describe the cleanup of heavy metals from contaminated sites by plants. This study demonstrates phytoremediation potential of Indian mustard (Brasicca juncea (L.) Czern. & Coss.) genotypes for chromium (Cr). Seedlings of 10 genotypes were grown hydroponically in artificially contaminated water over a range of environmentally relevant concentrations of Cr (VI), and the responses of genotypes in the presence of Cr, with reference to Cr accumulation, its phytotoxity and anti-oxidative system were investigated. The Cr accumulation potential varied largely among Indian mustard genotypes. At 100 μM Cr treatment, Pusa Jai Kisan accumulated the maximum amount of Cr (1680 μg Cr g⁻¹ DW) whereas Vardhan accumulated the minimum (107 μg Cr g⁻¹ DW). As the tolerance of metals is a key plant characteristic required for phytoremediation purpose, effects of various levels of Cr on biomass were evaluated as the gross effect. The extent of oxidative stress caused by Cr stress was measured as rate of lipid peroxidation. The level of thiobarbituric acid reactive substances (TBARS) was enhanced at all Cr treatments when compared to the control. Inductions of enzymatic and nonenzymatic antioxidants were monitored as metal-detoxifying responses. All the genotypes responded to Cr-induced oxidative stress by modulating nonenzymatic antioxidants [glutathione (GSH) and ascorbate (Asc)] and enzymatic antioxidants [superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR)]. The level of induction, however, differed among the genotypes, being at its maximum in Pusa Jai Kisan and its minimum in Vardhan. Pusa Jai Kisan was grown under natural field conditions with various Cr treatments, and Cr-accumulation capacity was studied. The results confirmed that Pusa Jai Kisan is a hyperaccumulator of Cr and hypertolerant to Cr-induced stress, which makes this genotype a viable candidate for use in the development of phytoremediation technology of Cr-contaminated sites.     

Sustainable Development in Jordan

Sustainable development is a process which aims at establishing a harmonious relationship between man, on the one hand, and environmental and natural resources, on the other, capable of coping with ever-increasing changes and challenges over time. This paper investigates, in a conceptual and qualitative manner, the practices and procedures of sustainable development in Jordan and outlines constraints and difficulties facing Jordan in pursuing such development. The paper concludes with a presentation of some prerequisites for the process in the light of the national objectives and suggests recommendations for future action.     

Effects of the homogeneous traffic on vertical dispersion parameter in the near field of roadways – A wind tunnel study

The vertical dispersion parameter of Pasquill–Gifford needs some modification in the close vicinity of urban roadways by considering the influence of traffic-induced turbulence. Wind tunnel simulation experiments have been carried out with controlled traffic parameters to evaluate traffic-induced effect on vertical dispersion parameter (σ_z) in the near field of roadways. The aerodynamic similarities in atmospheric flow, vehicles size and speeds have been considered with appropriate similarity criteria. The tracer gas experiments have been performed to evaluate σ_z in the near field of the roadways for variable traffic volumes and two approaching wind directions (i.e. 90^○ and 60^○). The results showed that the value of σ_z increased monotonically with increase in traffic volumes and becomes nearly constant at a particular downwind distance. It has also been found that the σ_z was considerably affected by approaching wind directions. Further, the comparison of experimental σ_z values for both approaching wind directions with those of Chock (1978) and Rao and Keenan (1980), showed an agreement within ±15%.     

Foliar Metal Content and Changes in Epidermal Traits of LAGERSTROEMIA PARVIFLORA (L.) Roxb.

A comparative study of the physico-chemical properties of soil, leafmetal content and foliar surface traits in Lagerstroemia parviflora(L.) Roxb. plants, growing in an iron-rich mineralized and anon-mineralized area was carried out. Metal accumulation wasmaximum in summer; in the peak growing season, it declined duringthe rainy season but picked up again in winter. In leaves sampled froma mineralized region, epidermal cells were much smaller in size buthigher in number per unit area. Changes in the number and size of glandular papillae were also observed. Characteristic non-glandular,elongate trichomes with acute tip were also recorded in mineralizedpopulations. Scanning electron microscopic examination of the foliarsurface configuration revealed distortions in epicuticular wax structuresand wider cuticular striations with typically parallel arrangement inthese populations.The present study shows that high Fe-accumulation in leaves of L.parviflora during the exponential growth phase as well as changes inthe epicuticular structures may be indicators of metal stress in the populations of the mineralized area.     

Photosensitized Inactivation of Cyst Forms of the Freshwater Amoeba <Emphasis Type="Italic">Vahlkampfia hartmanni</Emphasis> by Aluminium (III) Phthalocyanine Tetrasulfonate

Summary In this work we attained a successful cysticidal effect against Vahlkampfia hartmanni cysts using mild to moderate experimental conditions, regarding light energy delivered and concentrations of aluminium phthalocyanine tetrasulfonate (AlPCS4). The dark and phototoxic activity of AlPCS4 towards the cyst forms of Vahlkampfia hartmanni, a freshwater amoeba previously isolated from keratitic patients, were tested. The photosensitized deactivation of the cyst form of this amoeba depends mainly on the concentration of AlPCS4 and the light fluence rate as well as the total fluence delivered during the irradiation process. Upon irradiation of the cyst suspension at 100 mW/cm² for 10 minutes in the presence of 3 μ M AlPCS4, a complete photodamaging effect on the cysts was induced. The photodamaging effect on Vahlkampfia cysts induces a state of inability of the cysts to excyst, vacuolation of the inner contents as well as a significant damage of the outer cyst wall upon microscopic examination.     

Value of arsenic-free drinking water to rural households in Bangladesh

Using contingent valuation survey data for about 2700 households in rural Bangladesh, and applying a multinomial logit model, the paper estimates the value of arsenic-free drinking water to the rural people. The estimates indicate that the rural people in arsenic-affected areas of Bangladesh place a low value on arsenic-free drinking water. It is about 10-14 percent of the amount they are willing to pay for piped water and only about 0.2-0.3 percent of the average household income. The implication of the result is that robust but costly arsenic reduction technologies such as activated alumina technology may find little social acceptance, unless heavily subsidized.     

Greenbelt conservation as a component of ecosystem,ecological benefits and management services: evidence from Peshawar City,Pakistan

Environment, Development and Sustainability - Conservation of greenbelts is the most enduringly successful and popular basic need for today to protect green land, preserve ecological landscape and...     

Adsorption studies of hazardous malachite green onto treated ginger waste

Adsorption of malachite green (MG) from aqueous solution onto treated ginger waste (TGW) was investigated by batch and column methods. The effect of various factors such as initial dye concentration, contact time, pH and temperature were studied. The maximum adsorption of MG was observed at pH 9. Langmuir and Freundlich isotherms were employed to describe the MG adsorption equilibrium. The monolayer adsorption capacities were found to be 84.03, 163.9 and 188.6 mg/g at 30, 40 and 50 °C, respectively. The values of thermodynamic parameters like ΔG°, ΔH° and ΔS° indicated that adsorption was spontaneous and endothermic in nature. The pseudo second order kinetic model fitted well in correlation to the experimental results. Rechienberg's equation was employed to determine the mechanism of adsorption. The results indicated that film diffusion was a major mode of adsorption. The breakthrough capacities were also investigated.     

Polypropylene/poly (butylene terephthalate) melt spun alloy fibers dyeable with carrier-free exhaust dyeing as an environmentally friendlier process

Carrier agent as one of the synthetic persistent molecules present in textile effluents considered as one of the most highly toxic, carcinogenic and serious inhibitor of the microbial respirometric activity. This chemical is used as accelerants in the dyeing or printing the hydrophobic fibers by dispersed dyes. Hydrophobic polypropylene (PP) fibers cannot be dyed by conventional dyeing process due to the absence of dye sites in the molecular chain and their high crystallinity. This study presents a carrier-free exhaust dyeing as an environmentally friendlier and cleaner process. In order to produce dyeable PP fibers, the PP was blended and melt spun with poly(butylene terephthalate) (PBT) at various ratios. First PP and PBT granules at blend ratios of 5, 10, 20, 30, 40 percent of PBT dispersed phase were physically mixed then the melt spinning of blended samples was carried out by a Maddock mixing zone extruder. The results showed that suitable exhaust dyeing process without using any carrier agents was possible for all PP/PBT alloy fiber samples. The dye uptake of samples significantly increased by increasing the PBT dispersed phase content. By increasing the PBT dispersed phase content decrease in the crystallinity percent resulting in significant enhancement in dye uptake of the alloy fiber samples was observed. A degree of four polynomial equation for dye uptake against blend ratio was obtained by which the optimum blend ratio was 72/28 percent of PP/PBT alloy fiber composition. In all alloy fiber dyed samples uniform coloration was observed. No considerable changes in the mechanical properties for dyed samples against undyed samples were observed. Interestingly, the best mechanical property among alloy fiber samples was observed in the sample containing 30 percent PBT dispersed phase which approximately corresponds to optimum blend ratio gained from mathematical calculations. In all PP/PBT alloy fiber samples strong fastness to soaping and very good to excellent fastness to light were achieved.