FeOOH and Mn8O10Cl3modified zeolites for As(V) removal in aqueous medium
BACKGROUND Arsenic in drinking water poses serious potential health risks in more than 30 countries with total affected population of around 100 million people. The present study is devoted to the development of innovative sorbents based on zeolite materials for As(V) sorption by modifying raw materials with iron oxyhydroxide and manganese oxychloride. Natural clinoptilolite and synthetic zeolite A were modified in order to obtain improved sorption of As(V). Sorption properties of newly developed sorbents were studied. Zeolites containing natural clinoptilolite are chosen due to relatively low cost and their broad use in industrial production as well as characteristic large surface area. RE…
FeOOH-modified clay sorbents for arsenic removal from aqueous solutions
The presence of arsenic (As) in natural and anthropogenic soils causes severe pollution of groundwater due to its harmful carcinogenic effects. The present work describes the research activities for searching of appropriate innovative sorbents based on clay material for As sorption using iron oxy-hydroxide modification. Natural and manufactured clay was chosen for comparison of modification efficiency in order to obtain best sorption results for As(V). The results of pilot testing were obtained and the sorption was studied as a function of initial arsenic concentration. Obtained results indicate that modification of clay with Fe compounds significantly improves the sorption capacity of a ne…
Modular Paradigm for Composites: Modeling Hydrothermal Degradation of Glass Fibers
Fiber-reinforced composite materials are often used in structural applications in humid, marine, and offshore environments. Superior mechanical properties are compromised by environmental ageing and hydrolytic degradation. Glass fibers are the most broadly used type of fiber reinforcement to date. However, they are also most severely affected by environmental degradation. The glass fiber degradation rates depend on: (1) glass formulation; (2) environmental factors: pH, T, stress; (3) sizing; (4) matrix polymer; (5) fiber orientation and composite layup. In this short review (communication), seven modules within the Modular Paradigm are reviewed and systematized. These modeling tools, encomp…
Darba aizsardzības sistēmas pilnveidošana rūpniecisko avāriju risku objektos
“Darba aizsardzības sistēmas pilnveidošana rūpniecisko avāriju riska objektos” maģistra darba autors: Andrejs Krauklis. Darba zinātniskais vadītājs: Mg. sc. ing. Ainārs Cars. Darbs izklāstīts uz 100 lpp., ietver 12 attēlus, 28 tabulas, 5 pielikumus un 35 informatīvos avotus. Darbā apskatīta rūpniecisko avāriju riska objektu klasificēšana un pētītas šādiem objektiem izvirzītas prasības avārijgatavības nodrošināšanai, kā arī rūpniecisko avāriju potenciālā riska ietekme uz nodarbināto veselību un apkārtējo vidi. Vienlaikus tika analizēts, kā rūpniecisko avāriju riska novērtējuma rezultāti tiek integrēti objektu darba aizsardzības sistēmā. Pētījums sastāv no 4 daļām. Pirmajā daļā ir pētīta un a…
Removal of Brilliant Green Dye from Water Using Ficus benghalensis Tree Leaves as an Efficient Biosorbent
The presence of dyes in water stream is a major environmental problem that affects aquatic and human life negatively. Therefore, it is essential to remove dye from wastewater before its discharge into the water bodies. In this study, Banyan (Ficus benghalensis, F. benghalensis) tree leaves, a low-cost biosorbent, were used to remove brilliant green (BG), a cationic dye, from an aqueous solution. Batch model experiments were carried out by varying operational parameters, such as initial concentration of dye solution, contact time, adsorbent dose, and pH of the solution, to obtain optimum conditions for removing BG dye. Under optimum conditions, maximum percent removal of 97.3% and adsorption…