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Showing 2 results for Wastewater
Amirhosein Fazilati, Nader Mokhtarian, Alimohammad Latifi, Mohammad Fazilati, Volume 3, Issue 4 (1-2022)
Abstract
Background and Aim: With the industrialization of aquatic ecosystems, the concentration of ammonia in surface water and groundwater have been much higher than standards, and large amounts of industrial, municipal and agricultural effluents containing ammonia are released into water sources, producing unhealthy and harmful products. The aim of this study was to synthesis the biological nanocomposite hydrogels based on kappa-carrageenan/Fe3O4 nanoparticles to absorb three samples of agricultural effluent containing ammonia.
Methods: Hydrogels are the most suitable bio-sorbents that exist naturally and synthetically. In this study, carrageenan and acrylic acid hydrogels in the form of radical polymerization were prepared in the room by methylene bis-acrylamide as the crosslinking agent and ammonia persulfate as the initiator. Then, a magnetic hydrogel was prepared using divalent and trivalent iron by co-precipitation method.
Results: By adsorbing the ammonia in the two prepared effluent samples, the optimal values for contact time, pH, temperature and adsorbent were 40 minutes, 5, 15 ° C and 40 mg, respectively. The ammonia equilibrium adsorption process by nanomagnetic hydrogels was studied by the Langmuir, Freundlich and Temkin adsorption isotherms, which show that the maximum adsorption belongs to the Langmuir isotherm. Comparison of experimental data with adsorption models showed that these data follow a quasi-quadratic adsorption model. The optimum temperature for the removal of ammonia from both effluents is 15 ° C and the removal capacity in both effluents increases with rising pH from 2 to 10.
Conclusion: According to the results of this study, it can be estimated that the adsorbent studied in this study, which is a nanomagnetic hydrogel of iron oxide, had a significant reduction in the amount of ammonia in the effluents. It can be said that the nanomagnetic hydrogel of iron oxide is an effective adsorbent for the rapid removal of ammonium ions from an aqueous solution.
Aliakbar Takhtdar, Arash Shakuri, Volume 4, Issue 3 (9-2022)
Abstract
Heavy metals are one of the most common environmental pollutants that can enter coastal areas from natural and human sources and affect marine organisms and the human population. Heavy metals are a serious threat to human health, living organisms and natural ecosystems due to their toxicity, persistence and bioaccumulation characteristics. Many heavy metal ions are toxic or carcinogenic to humans. Heavy metals can lead to the destruction of marine ecosystems by reducing the diversity and number of species and through accumulation in living organisms and food chains. Heavy metals enter coastal and marine environments through various sources, including industries, and domestic sewage. Heavy metals from ship traffic effluents are among polluting sources. This study investigated the effect of this pollution on macrobenthic communities. The findings show that heavy metals have an effect on premature spawning, increase in mortality and decrease in the body's defense system in fish, decrease in growth and survival and irregular cell division in sea urchins, increase in mortality, delay in growth and prevention shell development and irregular cell division in crustaceans, and increased mortality, reducing body defenses, delaying growth, losing breeding capacity and reducing eggshell thickness in seabirds, and irregular structure and acute toxic condition and delay in growth in benthos. Urban and industrial activities are the main sources of marine environment pollution. As a result, it can be stated that environmental quality assessment in this sector can provide useful information for pollution control in coastal areas. Recently, the implementation of environmental legal frameworks in the European Community has increased the awareness of the importance of heavy metals in shipping effluents in order to achieve "good environmental status".
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