Impact of oil pollution on some desert plants

The environmental damage to Kuwaiti flora was studied. Four Kuwaiti desert flowering plants, Picris babylonica, Launaea mucronata, Senecio glaucus, and Sonchus oleraceous, which suffered mutagenic modifications with changes in tapetal cell characteristics, were selected for this study. Changes in growth parameters, such as photosynthetic pigments, proteins, free amino acids, phenols, and reducing sugar levels, which could have resulted from the observed genotoxicity of oil pollution, were studied. P. babylonica showed marked differences in the levels of the above parameters as compared to the other three plant species. In P. babylonica, levels of phtosynthetic pigments, reducing sugars, proteins, plamitate/stearate, Linoleate/stearate, and linolenate/stearate fatty acid ratios were higher than in the corresponding plant species collected from control areas away from blazing oil wells. On the other hand, in P. babylonica, the levels of phenols and free amino acids were lower as compared to the plants collected from the control area. It appeared that the level of these parameters was dependent on the level of photosynthetic pigments.     

Study of water quality of Hudiara drain, India-Pakistan

This paper examines the extent of pollution in Hudiara drain water due to untreated industrial and sewage waste of India and Pakistan. Ninety-nine surface water samples from the Pakistani side of the Hudiara drain were collected during September 1997, and April and June 1998. The analytical results of the Hudiara drain samples point out the industrial and sewage inputs from India and Pakistan. Higher values of biochemical oxygen demand (BOD), chemical oxygen demand(COD), total organic carbon(TOC), and trace metals in drain samples from the Indo-Pak border clearly indicate the Indian industrial and sewage pollution. Large variations in the levels of various measured parameters (COD, BOD, TOC, pH, total soluble substances, and trace metals) were observed along the Hudiara drain in the Pakistani vicinity. These variations were due to different types of industrial effluents and small village drains. The study showed that suspended solids(SS), COD, and fecal coliform (FC) were the major pollutants. Accordingly, the most feasible alternative is to convert the drainage network to a sedimentation and temporary storage reservoir. If disinfected, the runoff water can be used for restricted irrigation. Groundwater samples taken from the drain's surrounding area have also been analyzed. Thirty percent of the samples are not fit for drinking purposes due to NO3-N, Se and FC counts as prescribed by World Health Organization (WHO) guidelines. A trilinear diagram clearly indicates the influence of surface water of the Hudiara drain on ground water; moreover, higher values of nitrate and FC clearly indicate the seepage from the Hudiara drain.     

Plant–bacteria partnerships for the remediation of hydrocarbon contaminated soils

Plant–bacteria partnerships have been extensively studied and applied to improve crop yield. In addition to their application in agriculture, a promising field to exploit plant–bacteria partnerships is the remediation of soil and water polluted with hydrocarbons. Application of effective plant–bacteria partnerships for the remediation of hydrocarbons depend mainly on the presence and metabolic activities of plant associated rhizo- and endophytic bacteria possessing specific genes required for the degradation of hydrocarbon pollutants. Plants and their associated bacteria interact with each other whereby plant supplies the bacteria with a special carbon source that stimulates the bacteria to degrade organic contaminants in the soil. In return, plant associated-bacteria can support their host plant to overcome contaminated-induced stress responses, and improve plant growth and development. In addition, plants further get benefits from their associated-bacteria possessing hydrocarbon-degradation potential, leading to enhanced hydrocarbon mineralization and lowering of both phytotoxicity and evapotranspiration of volatile hydrocarbons. A better understanding of plant–bacteria partnerships could be exploited to enhance the remediation of hydrocarbon contaminated soils in conjunction with sustainable production of non-food crops for biomass and biofuel production.     

Trichoderma harzianum: a green sorbent for Pb(II) uptake from aqueous solutions

This investigation describes the use of specially cultivated, nonliving biomass of Trichoderma harzianum as a biosorbent for the batch removal of Pb(II) from a stirred system under different experimental conditions. The metal removal depended upon pH, sorbent particle size, initial Pb(II) concentration, shaking speed, and sorption time. The optimal experimental conditions for the removal of Pb(II) by T. harzianum with an initial metal concentration of 100 mg L^?1 were obtained at a particle size of 53 μm, a pH of 4.5, a shaking speed of 200 rpm, and a contact time of 720 min. The results were analyzed in terms of adsorption isotherms and kinetic models. The Freundlich isotherm model and pseudo second-order model fitted well in the data. T. harzianum proved to be a good biomaterial for accumulating Pb(II) from aqueous solutions (q = 460 mg g^?1).     

Adsorption of pesticides by salorthids and camborthids of Punjab,Pakistan

This study was conducted to examine adsorption of pesticides bifenthrin, carbosulfan, λ-cyhalothrin, cypermethrin, endosulfan, parathion methyl, monocrotophos and 4-nitrophenol by sandy clay loam (S.C.L) and sandy loam (S.L) soils (with varying organic content). There was no significant difference between the observed soil water partitioning coefficient values (K _d) derived from linear and nonlinear Freundlich isotherms. Adsorption of pesticides on S.C.L soils was higher than those on S.L soils. K _d values showed significant correlations (r ²?=?0.8???0.99 and 0.65???0.97) with soil organic carbon content (OC) and weak correlations (r ²?=?0.2???0.29 and 0.1???0.18) with clay contents of S.C.L and S.L soil at p?≤?0.05, respectively for all pesticides (except monocrotophos). Observed K _oc values (soil-water partitioning constants based on the organic C fraction of the soil) were in accordance with the literature values of Wauchope and Tomlin with a maximum deviation of less than 0.5 log units. Ten Quantitative Property-Property Relationships (QPPR) among water solubility, n-octanol water coefficient (K _ow) and K _oc were proposed for studied pesticides except monocrotophos. The models were considered acceptable when predicted-observed difference for log?K _ow and log?K _oc were ≤?0.3 and ≤?0.5?log units, respectively, during the validation procedure. This work indicates that the log?K _oc derived from the log K_ow, from some of existing relationships, may be a fair predictor where observed values (i.e., K _d and K _oc) are not available. Furthermore, predicted leaching potential by groundwater ubiquity scores (GUS) equation was solved by using observed K _oc values and literature reported half lives of pesticides. GUS ranked the mobility of nonvolatile compounds i.e., bifenthrin, λ-cyhalothrin, cypermethrin and endosulfan extremely low; methyl parathion very low; 4-nitrophenol low; carbofuran and monocrotophos very high in S.C.L and S.L soils, respectively. Results discussed in this paper provide background to prioritize pesticides or chemical groups that should be evaluated under field conditions with regard to their leaching potential to groundwater in arid climates.     

Preconcentration and determination of lead and cadmium levels in blood samples of adolescent workers consuming smokeless tobacco products in Pakistan

The present study was aimed to evaluate the cadmium (Cd) and lead (Pb) levels in the blood samples of adolescent boys, chewing different smokeless tobacco (SLT) products in Pakistan. For comparative purpose, boys of the same age group (12–15 years), not consumed any SLT products were selected as referents. To determine trace levels of Cd and Pb in blood samples, a preconcentration method, vortex-assisted liquid–liquid microextraction (VLLME) has been developed, prior to analysis by flame atomic absorption spectrometry. The hydrophobic chelates of Cd and Pb with ammonium pyrrolidinedithiocarbamate were extracted into the fine droplets of ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate, while nonionic surfactant, Triton X-114 was used as a dispersing medium. The main factors affecting the recoveries of Cd and Pb, such as concentration of APDC, centrifugation time, volume of IL and TX-114, were investigated in detail. It was also observed that adolescent boys who consumed different SLT products have 2- to 3-fold higher levels of Cd and Pb in their blood samples as compared to referent boys (p?<?0.001).     

Fate of carbosulfan and monocrotophos in sandy loam soils of Pakistan under field conditions at different watertable depths

Information regarding pesticide mobility is critical for the evaluation of pesticide management practices. For this purpose, lysimetric studies were conducted to develop assessment schemes to protect groundwater from unacceptable effects caused by pesticide use. By using these studies, specific monitoring actions and prevention measures for the protection of waters can be studied, and the results thus obtained can provide the local authorities and the decision makers with an identification tool for demarcating risk areas. Pesticide residues were found at the bottom of lysimeters in the following pattern i.e., 1.52 > 2.1 > 2.74 m which could represent an "index of risk" for groundwater pollution. Regressions built for carbofuran and monocrotophos against watertable depths showed a decreasing trend of pesticide in higher watertable treatments. These findings support the existence of a significant role for chromatographic flow in sandy texture soil. Moreover, the higher values of pesticide residue at the bottom of lysimeters reflect that chromatographic flow as well as preferential flow pattern prevails during higher precipitation events. The precipitation received during the study was higher than the 10 year average and can be considered relatively as a worst case scenario. Finally, the authors have recommended a standardized pesticide monitoring scheme for groundwater in accordance with the already validated generic schemes in developed countries.