Use of silicate by-products in water treatment processes and development of eco-friendly self-polishing antifouling coatings

Abstract

The production waste involvement in processing and recycling-one of the urgent tasks in the development of environmentally oriented and resource-saving technologies. In this work, two types of silicate-containing materials of plant (silicon dioxide from rice husk) and technogenic (calcium hydrosilicate) origin are studied as sorbents for removal of heterotrophic bacteria from water and as fillers for eco-friendly marine antifouling coatings. Characterizations (morphology, chemical composition, specific surface area, zeta-potential), bacterial adsorption performance and prepared samples efficiency in antifouling coating were investigated. The results showed that the sample of calcium hydrosilicate obtained from technogenic raw materials has a macroporous needle-like structure and characterized by high removal efficiency to Escherichia coli and Bacillus subtilis in 0,05 M NaCl. Sample of biogenic silicon dioxide characterized by globular micromorphology with high value of specific surface area. Incorporation of inorganic filler particles of biogenic and technogenic samples in the coating enhanced the paint hardness. Improved antifouling performance was shown for coatings with SiO 2 from rice husk coupled with bacterial antifouling extract during 9 months of field test.

Экологические Исследования На Дальнем Востоке России История И Современность

“…Кроме того, эффективность образцов, полученных из отходов, можно объяснить игольчатой морфологией частиц гидросиликатов кальция (тоберморита, ксонотлита), формирующихся в гидротермальных условиях (рис. 24.5) [66]. Как видно из представленной таблицы, уже через 2 ч эффективность адсорбции бактерий E. coli и B. subtilis образцами силикатов кальция выше по сравнению с препаратом «Белый уголь», даже после 24 ч контакта с культурами микроорганизмов.…”