College of Arts & Sciences
http://hdl.handle.net/10576/54
2024-03-28T17:50:25ZCONTAMINATION OF ARSENIC IN RICE-BASED BABY FOOD PRODUCTS AND THEIR HEALTH RISKS
http://hdl.handle.net/10576/52700
CONTAMINATION OF ARSENIC IN RICE-BASED BABY FOOD PRODUCTS AND THEIR HEALTH RISKS
ABDULLAH, HASA A.
This study aims to assess the health risks associated with arsenic exposure in consumers of rice-based infant food products. The consumption patterns of rice-based baby food products among individuals aged 4-12 months in Qatar utilized two consumption scenarios: a food balance sheet analysis and national dietary intake. The collected rice-based infant food products from four different categories (plain rice, rice with fruits, rice with vegetables, and rice with milk) and seven different brands (A, B, C, D, E, F, and G) in Qatar from three major hypermarkets during two distinct seasons (winter and summer) to investigate the potential impact of seasonal variations on arsenic contamination in rice and rice-based products. The collected products were analyzed using the ICP-MS method, revealing a total arsenic content ranging from 0.144 μg/kg to 55.14 μg/kg. Subsequently, the statistical analysis was conducted for consumption and contamination data using a non-parametric test (Kruskal–Wallis) due to the non-normal distribution of contamination data, and there were significant differences among the product brands regarding arsenic contamination. Based on these contamination data, three case scenarios were considered: the worst case (maximum arsenic concentration), in which infants consume highly contaminated products; the average case (mean arsenic concentration); and the best case (minimum arsenic concentration), where infants are assumed to consume the lowest or uncontaminated rice-based products. Utilizing these scenarios, the exposure assessment was conducted employing both probabilistic and deterministic approaches, which allowed the determination of the Hazard Quotient (HQ) and Lifetime Cancer Risk (LTCR). The findings of the study indicate that the consumption of plain rice increases the risk of arsenic exposure, and the consumption of rice-based food products poses a health risk to infants aged 4-12 months in Qatar if these products are consumed daily according to national dietary guidelines.
2024-01-01T00:00:00ZPURIFICATION OF PRODUCED WATER BY CUTTLEFISH BONE ADSORBENTS
http://hdl.handle.net/10576/52698
PURIFICATION OF PRODUCED WATER BY CUTTLEFISH BONE ADSORBENTS
ALMUHTASEB, ROBA
The cuttlefish bone powder (CFB) which is mostly composed of calcium carbonate was prepared, characterized, and modified to use it for the purification of emulsified oil/water mixtures from produced water. The focus was on the treatment of polluted water containing very low oil content (around 100 ppm) that belongs to the tertiary treatment of polluted waters. The highest challenge in tertiary treatment technologies is the removal of colloidal oil droplets (below 500 nm) that cannot be removed using common industrial sorbents such are walnut shell powder. This study demonstrated a fairly efficient method for this application, and, this treatment is efficient at very low adsorbent content. Alkali modification of CFB with sodium hydroxide (NaOH) was done to enhance porosity, and the total surface area of sorbent to improve the efficiency of oil adsorption. A batch adsorption experiments with different adsorption parameters were examined such as adsorbent dosage, contact time, temperature, and initial oil concentration for alkali-treated CFB. Alkali treatment of CFB showed an enhancement of oil adsorption efficiency from 52.7% to 71%. Kinetic studies evaluating the removal rate of CFB-NaOH were conducted. The results showed that equilibrium was reached within 60 min and the results were well fitted using pseudo-first-order kinetics with a very high correlation coefficient, R2 > 0.99, which demonstrates that during the adsorption of crude oil by CFB-NaOH, physical interaction is dominant. Adsorption capacities were very well described by Henry's isotherm since the experimental results showed linear dependence of qe versus ce. Moreover, detailed morphological, and chemical characterization of both produced water and adsorbents were conducted. Overall, the study indicated the effectiveness of CFB as a low-cost adsorbent for the removal of oil from produced water, and it may serve as one of the steps prior final treatment of water by membrane technologies, for instance.
2024-01-01T00:00:00ZTREATMENT OF RAW SEWAGE WASTEWATER IN A PILOT SCALE PLANT THROUGH A NOVEL METHOD USING MICROALGAE, AND CHARACTERIZATION OF THE PRODUCED BIOMASS FOR FERTI-IRRIGATION: A QATARI CASESTUDY
http://hdl.handle.net/10576/52699
TREATMENT OF RAW SEWAGE WASTEWATER IN A PILOT SCALE PLANT THROUGH A NOVEL METHOD USING MICROALGAE, AND CHARACTERIZATION OF THE PRODUCED BIOMASS FOR FERTI-IRRIGATION: A QATARI CASESTUDY
MOHAMED, AHMAD MUJTHABA DHEEN
Global population is on the rise. Water scarcity and demand is at an all-time high. Yet anthropogenic activities keep increasing the amount of wastewater in the environment. While humans have developed wastewater treatment technologies, the conventional method has dire consequences. Its energy intensive nature and sludge production at the end of the treatment has meant that energy requirements and landfills are on the rise. This study aims to use different microalgae to treat preliminary pretreated raw municipal wastewater and use the resulting microalgae biomass and treated effluent for ferti-irrigation of tomatoes. Findings showed Scenedesmus sp. to be the most promising in terms of growth in wastewater (OD = 1.051), nutrient removal (75% - 92% removal efficiency) and plant growth enhancement, leading to the plants with the tallest height, most number of leaves and heavies fresh root biomass, dry root biomass and dry shoot biomass. Chlorella sp. also showed promising results, Nostoc sp. showed variation in performance and Leptolyngbya sp. did not show any signs of growth.
2024-01-01T00:00:00ZANALYSIS OF HYDROLOGICAL AND CLIMATIC FACTORS ASSOCIATED WITH ALGAL BLOOMS BASED ON REMOTE SENSING PRODUCTS AROUND THE COASTAL REGION IN THE ARABIAN GULF
http://hdl.handle.net/10576/52697
ANALYSIS OF HYDROLOGICAL AND CLIMATIC FACTORS ASSOCIATED WITH ALGAL BLOOMS BASED ON REMOTE SENSING PRODUCTS AROUND THE COASTAL REGION IN THE ARABIAN GULF
AL-SHAMLAN, MARYAM YOUSUF
Algal Blooms (ABs) are a global ecological disaster threatening aquatic ecosystems, human health, and economics. In the Arabian Gulf, monitoring and early warning systems are needed due to a lack of in-situ data. This study detects ABs using advanced satellite-based remote sensing data. The study has three goals: 1) Document temporal and spatial AB patterns in the Arabian Gulf, focusing on Qatar's coastal zone; 2) Analyze key oceanographic factors causing ABs; and 3) Quantify correlations between these factors and past ABs to enable predictive models in early warning systems. Satellite image-based data revealed a modest positive association (r=0.58) between sea surface temperature and chlorophyll-a levels, with the highest AB from May to September. Salinity has a smaller negative connection (r=-0.26) with chlorophyll and a positive correlation with easterly winds. These findings have major implications for early warning systems, Arabian Gulf ABs management, and regional preparation.
2024-01-01T00:00:00Z