Physical Sciences and Mathematics Commons^™

Bioremoval Of Phenol From Aqueous Solutions Using Native Caribbean Seaweed, Abel E. Navarro, Anibal Hernandez-Vega, Md Emran Masud, Loretta M. Roberson, Liz M. Diaz-Vázquez

Publications and Research

Among several Puerto Rican algae, Sargassum sp. (SG) and Chaetomorpha (CM) showed the highest phenol adsorption capacity from aqueous solutions and were used in optimized adsorption batch experiments at room temperature. The effects of pH, adsorbent dose, phenol concentration, salinity and presence of interfering substances were evaluated. Initial solution pH exhibited a strong effect, mainly on the phenol aqueous chemistry; showing the maximum adsorption at pH 10. Sorption isotherm results were modelled according to the Langmuir, Tempkin and Freundlich equations. Isotherm modelling indicated a maximum adsorption capacity (qmax) of 82.10 and 17.7 mg of phenol per gram of SG and …

Adsorption Of Antibiotics By Vermiculite, Mosa J. Ferdous

Dissertations and Theses

The occurrence of residual antibiotics in the environment has been a worldwide issue and warrants the development of inexpensive yet effective methods for antibiotics removal from contaminated water. In this thesis work, the adsorption of four antibiotics, namely chlorotetracycline (CTC), oxytetracycline (OTC), ofloxacin (OFL), and enrofloxacin (ENR), onto natural vermiculite has been studied using batch (static) and column (dynamic) adsorption techniques. The Langmuir and Freundlich isotherm models were initially used to explain the adsorption processes. The separation factor (RL) values derived from the Langmuir model and the 1/n values derived from Freundlich model in the present investigation were less than …

Comparative Sorption Of Methylene Blue Onto Hydrophobic Clays, Alvaro D. Sponza, Natalia J. Fernandez, David Yang, Karla A. Ortiz, Abel E. Navarro

Publications and Research

Chemical modifications of clay to remove methylene blue (MB) from aqueous solutions at room temperature were compared. Natural bentonite (NC) was modified by cation exchange with hexadecyltrimethylammonium chloride (HC), bencyltriethylammonium chloride (BC), and tetramethylammonium chloride (TC) to reverse the surface polarity of the hydrophilic bentonite. The adsorption of MB was studied and fitted by the adsorption theories of Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin. Equilibrium parameters were calculated, indicating that chemical modification did not improve the adsorption, due to the electrostatic adsorption mechanism. Specific surface area was determined, reporting the following trend: NC > TC > BC > HC. Isotherms show that TC is …

The Interaction Between Arsenic And Struvite During Coprecipitation And Adsorption Processes, Ning Ma

Dissertations, Theses, and Capstone Projects

The formation of struvite, MgNH4PO4*6H2O (MAP), from wastes is one of the methods that can be used to recover P from wastes efficiently. However, since there are usually toxic components in the wastes, like arsenic (As), the possibility of having toxic contaminants in MAP is a big concern. So, the interaction between As and MAP during coprecipitation (CPT) and adsorption (ADS) processes were studied at pH 8-11. MAP precipitated without As at pH 8-11 was also characterized.

During CPT process, the MAP was precipitated from a MgCl2-(NH4)2HPO4-NaCl-H2O system spiked with As at an initial pH (pHi) of 8-11. The batch …

Decolorization Of Hair Dye By Lignocellulosic Waste Materials From Contaminated Waters, Habib Zahir, Michelle Naidoo, Rada-Mayya Kostadinova, Karla A. Ortiz, Rosario Sun-Kuo, Abel E. Navarro

Publications and Research

Basic yellow 57 (BY57) was chosen as a model hair dye due to its prevalence in cosmetics wastewaters. This study proposes the use of lignocellulosic materials like spent tea leaves of peppermint (PM), chai tea (CT), and chamomile (CM) as raw adsorbents for the removal of BY57 from contaminated solutions. Batch adsorption experiments were carried out at room temperature to achieve the maximum adsorption capacity. Results indicate that the highest removal is achieved at pH 6–8, with a minimum adsorbent mass of 75 mg and in the absence of salinity, crowding agents and heavy metals. Adsorption equilibria were modeled according …