The present study aimed to assess the relationship of soil properties in salt-affected soils. The soil samples were collected from 14 districts of Pakistan. Soil salinity and sodicity are the common features of the arid and semiarid regions. The effects of the salt’s interactions with soil micronutrients have not been well studied. Therefore, saline and non-saline soil samples were collected from different locations. The microelements (Fe, Cu, Mn, and Zn) were fractionated into water-soluble, exchangeable, carbonate, Fe + Mn oxide, organic, and residual fractions. Univariate and multivariate analysis (PCA) was carried out to determine the linear relationship between soil properties and micronutrients fractions. Results showed that the magnitude of micronutrients appeared to be affected by the salinity in soils. In saline soil, the Fe fractions differed in the order of residual > organic bound > Fe + Mn bound > carbonate bound > exchangeable > water soluble. Iron fractions varied in the non-saline soils as residual > Fe + Mn bound > organic bound > exchangeable > carbonate bound > water soluble. Copper concentration was higher in the residual and carbonate forms, and the amount was lower in the exchangeable and water-soluble forms under both saline and non-saline conditions. The water-soluble Mn fraction was lower, and the residual Mn fraction was proportionately higher than other forms of Mn in soils. Zinc was found mostly in the residual fraction in both saline and non-saline soils. The mobility factor of micronutrients in non-saline soil was greater than in saline soil. PCA revealed that organic matter (OM) and pH directly affected the fractionation of Cu, Mn, Zn, and Fe in soil. Thus, it could be inferred that salts can bring changes to the composition of micronutrients depending on the nature of the soil and the magnitude of salts.
A b s t r a c t This research work mainly focuses on improving the concrete strength based on fiber reinforcement both in compression and tension. Concrete with various mix proportions containing dosage of Polypropylene (PP) fiber of lengths ranging from 13 to 25 mm with coarse aggregate replacement levels at 10%, 20%, and 30% by dismantled road aggregate were made and the compressive and tensile strengths were investigated. The experimental test results revealed high compressive and tensile strength at curing period of 28 and 56 days. The specimens tested observed that due to addition of fiber, the fibers could hold the matrix together even after extensive cracking and crushing. Net result of all these is to impart to the fiber composite pronounced post-cracking ductility which is absent in traditional concrete. In order to provide base for comparison, concrete specimens as a reference were cast without the addition of polypropylene fiber. Test result revealed that by adding polypropylene fibers at 6grams per one kg of cement a considerable improvement in the strength of concrete of 37.68 MPa and 43.59 MPa at 28 and 56 days respectively with 10% coarse aggregate replacement by recycled aggregate is achieved.
Phosphorus (P) fractionation is the validation of the nature, solubility and relative bioavailability of P. A sequential P extraction was used to determine the distribution of plant-available P fractions in soils. The relationships of these P fractions to soil properties and foliar P contents were also determined. Results of this study showed substantial differences in soil properties among orchards. Higher amounts of soil organic matter (SOM), cation exchange capacity (CEC) and major plant nutrients were found under orchard soils when compared with control soil. Most of the soil variables varied among orchard species as loquat > citrus > guava. The orchard soil exhibited a slightly higher soil pH. Overall, the P fractions were higher in all types of orchard soils and lowered in the control soils. Among tree species, P fractions in soils were achieved as loquat > citrus > guava. The extracting agents differed for P in the order residual P > HCl-P > NaOH-P > NaHCO3-P > H2O-P. Mostly higher amounts of the P fractions were achieved in the topsoil. The average amount of extractable P was found significantly higher in those soils of fruit orchards where the total amount of P was actually higher. The higher r2 values between P fractions versus SOM, clay and CEC of soils predicted a strong interrelationship among these soil variables. Leaf N contents of loquat and guava trees were consistently higher, and leaf P contents varied as loquat > citrus > guava. Potassium and Ca contents were higher in citrus than in the other two species. Micronutrients were found as Fe > Zn > Mn > Cu in the leaves. Regression models indicated a sufficient relationship between Hedley P fractions and the foliar P contents in tree species. This study indicates that the above soil properties can be used to ascertain soil P fractions, and that can influence the bioavailability of P from orchard soils.
The Hindukush-Karakoram-Himalayan (HKH) ranges and their massive cryosphere extend over the Upper Indus Basin (UIB) and are prone to incapacitated water supply due to the proclivity of globally increased temperature. Due to excessive carbon emissions, frequent incursions including extreme climatic events, are likely to happen sooner than expected on a regional scale due to recent climate change. The present study examined the variability of climatic extremes (18 indices) during 1971 to2018 over the UIB. The Mann-Kendall (MK) test and Sen’s methods were applied for statistical analysis as the former deals with the magnitude of trends while the direction of observed trends was identified by the latter in climatological time-series data. The frequency and intensity of summer days (SU25 > 25 °C/year) at 13 out of 27 stations significantly increased, particularly in lower regions. The same warming proclivity was dominant in tropical nights (TR20 > 20 °C/year) at 20 stations including Astore, Bunji, Gilgit, Gupis, Murree and Skardu. Similarly, significant increases were observed in extremes of annual precipitation in western and high northern areas; however, significantly, the highest drops in R25 and R5day were exhibited in Chitral at the rates of 13 and 29 days, respectively. These findings tend to support the accelerated summer warming and a rather stable winter warming while stable winter warming showed that overall the UIB seems to be more sensitive towards warming.
Polycyclic aromatic hydrocarbons (PAHs), due to their mutagenic, carcinogenic, and teratogenic potential, can lead to numerous chronic and fatal diseases. PAHs have been found in several wastewater streams, including “produced water,” which is wastewater generated during the extraction of oil and gas. The PAHs’ removal from produced water using physical, chemical, biological, and combined methods is crucial. Water is a vital ecosystem component and is extremely vulnerable to PAHs. This article reviews the current PAH situation, including their physical and chemical properties, types, characteristics, and removal methods from produced water. The mechanism of each method of removal of PAHs has been discussed. The current study results show that adsorption by nanoparticles and integrated methods are promising methods to meet the strict authoritarian limit with advanced increase potential in the direction of commercialization for the removal of PAHs and provide opportunities to use produced water as a source of water. The current study results can help the policy/decision makers in the efficient management of water resources.
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