The influence of elevated CO2 concentrations and UVB radiation in antioxidant activity of selected Chenopodium quinoa varieties

Ecosystems have been affected by climate change. Both agriculture and environmental changes are correlated with various features since climate change is the main cause of abiotic and biotic stress, which affects crop plants. Climate change and its severe impact on plant productivity showed great intensity due to the effects of abiotic stress. In the present investigation, we selected two quinoa varieties to study the response to future climatic factors such as eCO2, enhanced UVB radiation, and UVB+eCO2 combined effects in open-top chambers in the hot climate of the UAE. The treatments were administered for 90 days in the hot UAE weather conditions and the experiment was carried out in a transparent OTC facility. The response of the studied quinoa varieties was measured by analyzing their non-enzymatic antioxidant and antioxidant enzyme activities. Our findings showed that quinoa varieties are suitable as industrial crops for their levels of antioxidants under stimulating climatic conditions because the quantity and quality of their yield have not been affected. Based on the results obtained in the present investigation, further study is warranted for screening more varieties with the addition of climate change factors such as temperature and humidity to find more tolerant varieties of quinoa suitable for future climatic conditions

Response of two different Phoenix dactylifera cultivars to future climate conditions

Plants are naturally exposed to various environmental stresses that affect their growth and development. As a desert plant, Phoenix dactylifera (date palm) has developed strategies to protect itself from most abiotic stresses. However, projected climate changes and the interaction between the various abiotic stressors will have profound effects on date palm adaptation and production In the present study, the two date palm cultivars, Sultana and Zamli cultivars were exposed to elevated levels of CO2 and enhanced UVB radiation and non-enzymatic antioxidants (total phenols, α-tocopherol, reduced glutathione content) and antioxidant enzyme activities (polyphenol oxidase, peroxidase, superoxide dismutase, catalase, ascorbate peroxidase) activities were analysed. The results showed that the Sultana cultivar is tolerant to future climate conditions. However, more biotic stress and yield parameters are needed for the identification of biotic stress tolerant date palm cultivars

Roasted-modified Date Pits In Remediation Of Bromide Ions From Desalinated Water: Kinetic Studies

Disinfection of drinking water is one of the extreme public health activities in Qatar. Chlorination, ozonation, ultra-violet, chloramination, and others are the most important treatment processes used and they can cause the formation of toxic by-products. The existence of bromide (Br-), for example, in water sources might cause in formation of brominated toxic by-products. Up-to-date drinking water treatment methodologies are challenged to successfully eliminate Br- before final consumption. Remediation onto activated carbons has a number of restrictions. Date pits are suitable as raw remediating adsorbent for preparing various modified adsorbents, because particular surface functional groups and the micro-pore structures can be attained by active modifications. The overall objective of this study was to develop an economical and environmentally acceptable process to safely eliminate the levels of Br- from desalinated water. Roasted date pits (RODPs) and activated charcoal (AC) (used as a control) were crushed and sieved with four different particles size ranges. The percentage of Br- removal was also studied under different experimental conditions such as pH, sorbent mass and initial concentration. In addition, surface characterization was also investigated. Experimental date analyses were investigated using different isotherm and kinetic sorption models. The modification of the date pits surface enhanced the Br- removal capacity at high initial concentration of bromide (200 ppm) by 27%. Using scanning electron microscope (SEM), the date pits surface images showed a different in pore sizes upon modification. Removal capacity of RODPs reached 39% at pH 4. In this study the heterogeneity of adsorbing mechanisms and the fitting with pseudo second order model and inter particulate diffusion models were concluded, and more than 35% of Br- removal efficiency was achieved within the RODPs at the first hour of contact time. The adsorption Br- onto RODPs was not fitted well with the pseudo-first order model. It was found that the kinetics of Br- adsorption was followed the pseudo-second order. It was also observed fluctuations in the removal efficiency for smaller particle sizes; indicating heterogeneity of adsorption/desorption and potential chemical bindings, this particular behaviour was not observed and investigated elsewhere in the literature (Figure below). The surface of RODPs contains oxygen functional groups such hydroxyl; hence the presence of such functional groups on the surface of date pits considerably influences on the adsorption mechanism of organic and inorganic compounds on the RODP. Economically RODPs are successfully used to remove Br-, comparing to AC. However, both adsorbents have nearly the same removal efficiency after one hour contact time. Apparently, the removal efficiency of both systems was quite significant. This may cover the way for the cheap and widely available date pits to be used as an adsorbent in water purification process.qscienc

INVESTIGATION OF BACTERIAL DIVERSITY AND CHEMOMETRIC ASSESSMENT FOR ENHANCING BIOREMEDIATION OF HYDROCARBONS IN QATARI SOILS

Qatar is one of the leading countries in oil and gas industry worldwide. Qatar is located in the middle of the Arabian Gulf sea, a semi-closed sea surrounded by many petrochemical sites, besides the active offshore traffic of oil and gas transportation. Side-effects of production and transportation activities are expected and can affect the environment seriously. Bioremediation offers alternatives to alleviate such pollution caused by the thousands of oil components known by their high diversity, instability, toxicity and low bioavailability and biodegradability. Weathering, is an additional factor, making bioremediation of oil-polluted areas more difficult. Oil Weathering Processes results to changes of oil in terms of properties and composition. This is why Petroleum-derived contamination events constitute a unique environmental issue. In Qatar and the region in general, the weathering processes are accentuated due to harsh conditions, representing the main origin of failure of bioremediation applications. Some bacteria are able to adapt to such weathering conditions and absorb particles rich in pollutants through their hydrophobic wall to form biofilms. Others produce surfactants to improve accessibility. In this study, a multidisciplinary approach was implemented to solve such an environmental issue, starting from the identification of the potential sources of the polluting oil along AlZubara coast to Chemometric investigations allowing determination of weathered status. Following systematic sampling and chemical analyses of soils, biodiversity of hydrocarbon-degrading bacteria was studied. Through an integrated isolation and screening program, isolates were identified and differentiated through several molecular techniques and screened for their potential to remove classes of hydrocarbons with special focus on high efficiencies never reported with concentrations and weathered status. Biostimulation of indigenous bacteria showed low rates of removal. However, combining stimulation to augmentation improved the removal of weathered oil. Interestingly, by using ex-situ biopiling, augmentation using indigenous bacteria exhibited the best approach, but a high negative interaction was observed by using exogenous bacteria. These findings confirm the initial hypothesis of this work, that weathered hydrocarbons removal was enhanced by using adapted indigenous bacteria. It is then considered that bioremediation of a given area should be separately treated, using corresponding appropriate bioremediation strategy