180014 |
Iran |
Removal of Nutrients by Chlorella Vulgaris Microalgae in Bandar Abbas Municipal Wastewater |
Avicenna research center |
Marzieh Salemi
Fatemeh Salemi |
The entry of nutrients into the environment can cause the creation of eutrophication of aquatic ecosystems. One of the methods of removing nutrients from effluents is the use of algae. Algal purification is a new and inexpensive technology for this purpose. The present study investigated the rate of cell growth and nutrient removal of urban wastewater in Bandar Abbas in winter 2020 by the Chlorella vulgaris microalgae in the phycolab of Fisheries Research. Treatments with different dilutions (0%, 25%, 50% and 75%) were prepared; in addition, specific growth rate, cell density and removal efficiency of phosphate, nitrate, nitrite were examined during a 14 day period with initial constant density (1×10⁶ cells / ml ) of microalgae. The results indicated that 0% and 75% dilution had the highest and lowest cell densities (8.675×10⁶ and 56.633×10⁶), respectively; moreover, they had the specific growth rate (0.166 and 0.311). Furthermore, there was a significant difference between them (P≥ 0.05). The highest nitrate and nitrite removal efficiencies were -40.75 and -79.84 in effluent dilution of 50%; in addition, the lowest were 1.26 and -40.26 in dilution of 75% and 25% respectively. Phosphate had the highest removal efficiency at 0% dilution with a mean of -79.65 that showed a significant difference with the lowest at 25% dilution (P≥ 0.05). Therefore, high or low levels of nutrients can affect the removal efficiency and growth rate of microalgae.
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180015 |
Mexico |
Ecological inks for markers |
Centro de Bachillerato Tecnológico Industrial y de Servicios No.271 |
Bella Elisabet Perales Melendez y Alcocer |
Markers have become essential in school and work life due to their great usefulness for teaching and homework. Despite the benefits they have brought, markers are the cause of great contamination from the ink manufacturing process to the excessive production of plastic. Ecological inks in markers and the innovative design of a refillable marker, allow to generate less pollution without having to stop using this product. From dyes created with coffee, fruits and vegetables that pass through different processes like dehydration, natural inks arise that replace the use of polluting dyes. Likewise, implementing recycling plans in different institutions, markers that were no longer used were collected to be filled with ecological inks and used again. In addition, the excessive production of plastic is reduced by selling and refilling markers and ink kits.
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