The Effect of Land Abandonment on Biological, Physical and Chemical Properties of Soils

Introduction Changing land use may have a major influence on physical, chemical, and biological soil properties with a consequence for soil functioning and productivity. Abandonment of agricultural lands is actually a kind of restoration of these lands to their original natural conditions, which is often done through human intervention. Soil restoration after land abandonment is a complex phenomenon. The pastures of our country are typically cultivated in rainfed methods, and the use of agricultural inputs such as animal manure, poisons, and chemical fertilizers is not very common. Therefore the continuous cultivation of a product and the lack of use of agricultural inputs causes a gradual decrease in fertility and increase erosion. Hence, after years of cultivation, the production potential decreases, and the land is abandoned. Materials and Methods This study was conducted to determine the effects of land abandonment on some physical, chemical, and biological soil properties in the 0-20 and 20-40 cm depth at three different sites including Lal Abad, Qaleh Kohneh and Chalab-e Pain, using 2×2 factorial layout arranged in a completely randomized design (CRD) with three replications. The physical, chemical, and biological characteristics of the soil were measured by conventional laboratory methods. Electrical conductivity of saturated paste extract (ECe) with electrical conductivity meter device in saturated paste extract, pH of saturated paste with pH meter device, and bulk density by cylinder method were determined in the samples. The amount of dispersible clay (DC) was determined by the method of Gee and Bauder and the Mean Weight Diameter (MWD) was determined by the method of the wet sieve. The amount of absorbable phosphorus by extraction method and total soil nitrogen by Keldahl method were measured in the samples. The amount of soil organic carbon (OC) in the samples was determined by the method of Walkley and Black. Mineralization of organic carbon (soil respiration) (Cmin) and metabolic quotient (qCO2) were obtained by validated and conventional methods. Results and Discussion  The results showed that the abandonment of agricultural lands significantly increased the MWD and reduced the amount of dispersible clay. Bulk density also decreased due to the abandonment of agricultural land in all areas except the Qaleh Kohneh area. The results of the analysis of the chemical characteristics of the soil indicated a decrease in soil pH in all areas and depths, except in the Qaleh Kohneh area. The biological results also showed that the abandonment of agricultural lands caused the change in biological characteristics. Abandonment of agricultural lands in all three regions led to an increase in microbial biomass carbon and soil microbial respiration. High microbial respiration in abandoned lands is probably related to more organic carbon in these soils. Loss of soil organic matter due to cultivation and improper soil management is often the main reason for reducing soil respiration in agricultural lands compared to abandoned lands. Conclusion Changing land use from agriculture to abandonment improved the physical, chemical, and biological indicators of soil quality, especially the surface layer of the soil, which ultimately led to the improvement of soil quality in all the studied areas. It can be concluded that the release of agricultural lands has increased soil health by increasing the carbon input into the soil, improving the soil aggregates, and improving the microbial activity of the soil

Prioritization and Management of Industrial Waste in the Ninth Refinery of South Pars Gas Complex

The gas production operation in the gas refinery, in addition to creating special and ordinary wastes, also leads to the production of industrial wastes. Failure to properly manage special waste in such refineries will cause environmental hazards and threaten the workforce’s health. This research aimed to identify, differentiate and prioritize industrial wastes in this refinery to eliminate or reduce environmental risks. After collecting waste information, 19 cases of industrial waste were identified in process units and facilities. Then the data was analyzed through documentation, expert theory and Delphi method, and according to the importance of multi-criteria decision-making method for ranking and waste management, TOPSIS method was used for prioritization. The findings showed waste Sulfur with an amount of 86%, has the highest priority of relative proximity to high-risk waste and mixed laboratory containers, with an amount of 20%, have the least priority of relative proximity to low-risk waste among industrial wastes. Also, based on the percentage distance of the relative closeness of the residues to each other, 5 groups (about 26%) are at the high level, 6 groups (about 32%) are at the medium level and 8 groups (about 42%) are at the low level of industrial wastes were placed

Comparison of the Efficiency of Different Plants to Remove Total Petroleum Hydrocarbons from Oilfield Soils

IntroductionCrude oil is a complex combination of many hydrocarbon and non-hydrocarbon compounds, including heavy metals, which affect the physical and chemical properties of the soil, cause the soil particles to stick and connect and then cause the soil to become stiff and impenetrable. Contamination of soil with petroleum hydrocarbons is a significant environmental problem, which has received remarkable attention in recent decades. Petroleum hydrocarbons are resistant and hazardous pollutants. Some petroleum hydrocarbons such as benzene are mutagenic and carcinogenic materials for humans. There are many physical and chemical methods to remediate oil-contaminated soils. Phytoremediation is a relatively new technology for refining contaminated soils in which resistant plants are used to remove or reduce the concentration of inorganic, radioactive, and organic pollutants, especially petroleum compounds, from the environment.Materials and MethodsSufficient amounts of about 50 kg of soil contaminated with petroleum hydrocarbons were collected from regions (0-30 cm soil depth) adjacent to the oil wells west of Kermanshah province. Uncontaminated soil samples were also taken from sites at the lowest distance to the contaminated sites. The aim of this study was to compare the efficiency of different plants to remove total petroleum hydrocarbons from oilfield soils. In this study, after determining the total amount of petroleum hydrocarbons, the contaminated and uncontaminated soils were mixed in 4 treatments with different weight ratios (0, 10, 25, and 35%). This experiment was established as completely randomized design with 3 replications for 6 different plants (Barley, Grass, Alfalfa, Hemp, Camelina, and Vicia ervilia). One treatment without plant was considered to remove soil matrix effects on petroleum hydrocarbon concentrations. Plants were harvested at the end of their growing season (90-120 days). Soils and plant samples from the experimental pots were analyzed for their important properties (including some physiological characteristics of the plants, as well as the percentage of reduced petroleum hydrocarbons in the soils). The gravimetric method was used to determine the concentration of petroleum hydrocarbons in the soil. After measuring the properties of the soil and plant, the normality of the data was checked by the Anderson–Darling test, and the homogeneity of the variance of the treatments was checked by using Levene's test. Analysis of data variance was done using ANOVA and average data comparison was done using LSD test at 5 and 1 percent probability levels (SAS 9.4 and SPSS 26).Results and DiscussionIn general, the growth of most plants showed a decreasing trend in proportion to the increase in soil pollution levels. However, the growth decline rates of different plants were not similar. Camelina was very sensitive to oil pollution and the plant could not tolerate pollution even at 10% level. After camelina, alfalfa was highly sensitive to oil pollution. The highest dry weight of the aerial parts of the hemp plant in the soil without oil contamination was observed at the rate of 111.22 grams in the pot. The leaf area of all studied plants in contaminated soils decreased compared to the control treatment (without contamination) so with the increase in the percentage of contamination, the leaf area of the plants was significantly reduced. The highest amount of leaf surface was observed in unpolluted soil and in the hemp plant. Except for the Camelina plant, which was completely destroyed at different levels of pollution, the rest of the plants showed a noticeable decrease in growth. The total petroleum hydrocarbons in soil were measured again 120 days after the start of cultivation, and its difference with the total amount of petroleum hydrocarbons at the beginning of cultivation was determined as the reduction of petroleum hydrocarbons and reported as a percentage. According to the mean comparison results, the percentage of reduced petroleum hydrocarbons was not significantly different among cultivated and non-cultivated treatments, although, it was significantly affected by soil pollution levels. Since all the studied soils contained natural bacteria and were not sterilized, the eliminated part of petroleum hydrocarbons is probably decomposed and removed by native bacteria in the soils. Therefore, the strengthening of native bacteria in these soils may increase the decomposition and degradation of petroleum hydrocarbons.ConclusionThe results of this research show that the presence of petroleum hydrocarbons in the soil caused a decrease in growth and other physiological characteristics in all studied plants. Although the Camelina was able to germinate in soils contaminated with petroleum hydrocarbons, the presence of these pollutants in the soil prevented the optimum growth of the plant, so its use in subsequent studies of phytoremediation of oil-contaminated soils, was not recommended. The results showed that there is no statistically significant difference between cultivated and non-cultivated treatments at different pollution levels, and the reduction of the total petroleum hydrocarbons in the soil was probably done by native microorganisms in the soil. It is recommended to take into consideration the efficiency of the plant species used, the type of polluting hydrocarbons, and the duration of contamination in future research to obtain better results

AUF1 p42 isoform selectively controls both steady-state and PGE2-induced FGF9 mRNA decay

Fibroblast growth factor 9 (FGF9) is an autocrine/paracrine growth factor that plays vital roles in many physiologic processes including embryonic development. Aberrant expression of FGF9 causes human diseases and thus it highlights the importance of controlling FGF9 expression; however, the mechanism responsible for regulation of FGF9 expression is largely unknown. Here, we show the crucial role of an AU-rich element (ARE) in FGF9 3′-untranslated region (UTR) on controlling FGF9 expression. Our data demonstrated that AUF1 binds to this ARE to regulate FGF9 mRNA stability. Overexpression of each isoform of AUF1 (p37, p40, p42 and p45) showed that only the p42 isoform reduced the steady-state FGF9 mRNA. Also, knockdown of p42AUF1 prolonged the half-life of FGF9 mRNA. The induction of FGF9 mRNA in prostaglandin (PG) E2-treated human endometrial stromal cells was accompanied with declined cytoplasmic AUF1. Nevertheless, ablation of AUF1 led to sustained elevation of FGF9 expression in these cells. Our study demonstrated that p42AUF1 regulates both steady-state and PGE2-induced FGF9 mRNA stability through ARE-mediated mRNA degradation. Since almost half of the FGF family members are ARE-containing genes, our findings also suggest that ARE-mediated mRNA decay is a common pathway to control FGFs expression, and it represents a novel RNA regulon to coordinate FGFs homeostasis in various physiological conditions

Mitigation of Quantum Dot Cytotoxicity by Microencapsulation

When CdSe/ZnS-polyethyleneimine (PEI) quantum dots (QDs) are microencapsulated in polymeric microcapsules, human fibroblasts are protected from acute cytotoxic effects. Differences in cellular morphology, uptake, and viability were assessed after treatment with either microencapsulated or unencapsulated dots. Specifically, QDs contained in microcapsules terminated with polyethylene glycol (PEG) mitigate contact with and uptake by cells, thus providing a tool to retain particle luminescence for applications such as extracellular sensing and imaging. The microcapsule serves as the “first line of defense” for containing the QDs. This enables the individual QD coating to be designed primarily to enhance the function of the biosensor

ORIGINAL ARTICLE Corresponding Author Qualitative and Quantitative Examination of Household Hazardous Waste in Tehran

ABSTRACT Tehran Metropolitan is one of the most crowded cities in the world. A large volume of various kind of solid waste are daily produced in the city which can cause lots of adverse environmental impacts. In the meanwhile, household hazardous waste has more importance than the others whereas it contains enormous toxic materials. Such toxins, by entering food chains and accumulating in humans can lead to a variety of gene mutations, cancer and congenital anomalies. Thus separation and optimal management of these materials is extremely important. The first step for management of this class of materials is identification of compounds and determination of quantities of the components. The current study focuses on determining the hazardous rate of the household wastes in Tehran. Accordingly, the Strict 2 of Tehran Metropolitan was selected as case study. Random sampling and questionnaire were applied to conduct the research. The obtained results indicated that around 10% of entire household wastes were hazardous within 2010-2011. Besides, the findings revealed that the amount of the hazardous material in winter is more than it in summer. The findings derived from the questionnaire suggested that 30% of residents have enough knowledge of household hazardous wastes, most of which possess a bachelor's degree or higher. In the meanwhile, only less than 10% separate the hazardous materials