Робота присвячена визначенню фізико-хімічних властивостей поверхні сорбенту (питомої площі поверхні, питомої густини кислотних та основних активних центрів), оскільки ці параметри є визначальними для ефективного вилучення важких металів зі стічних вод. Об’єктами досліджень були немодифікована та оброблена розчином карбаміду соснова тирса. Установлено, що після оброблення карбамідом питома площа поверхні тирси збільшилася на 35 %. Визначено, що кількість поверхневих карбоксильних груп зменшилася, лактонних – не змінилася, а відносна кількість фенольних груп значно зросла та з’явилися оснóвні групи, що є додатковими активними центрами сорбції.

The main goal of the paper was to determine physicochemical properties of sorbents surface (specific surface area, the specific density of the acid and alkaline active centers) as they pay significant role in the effectiveness of water treatment process. The non-modified and modified by carbamide solution pine sawdust were the objects of the study.

Determining of the surface of functional groups, with the presence of background electrolyte 0.1M NaNO3 to remain the constant value of the ionic power of solution, by acidic-alkali titration among temperature 20˚C the suspension of modified and non-modified pine sawdust were conducted.

The value of specific surface area for modified and non-modified pine sawdust was determined from adsorption isotherm of methylene blue and constituted respectively 109 m2 and 147 m2. Adsorption of the dye goes on wet sorbent and the obtained numbers of specific surface area show conditions of sorbent, that was used for water purification, in a more realistic way.

The water suspensions of modified and non-modified pine sawdust were titrated and the results were processed in the ProtoFit software. Best results while modelling 3-acidic active centres in case of non-modified sawdust and
3-acidic and 1-alkali active centers, which are able to participate in proton exchange reactions in case of modified sawdust, were achieved.

The improvement of sorption properties of pine sawdust after treatment by carbamide solution may be explained by changes of physical-chemical properties of its surface, namely, due to the formation of additional nitrogen-containing active sites, revealing alkaline properties at titration by acid.

To sum up this paper, as a result of treatment by carbamide, the specific surface area increased at 35 %. Also, it was investigated by the acid-base titration followed by mathematical processing that quantity of surface carboxylic groups decreased, the quantity of lactonic groups was constant, while relative concentration of phenol acid groups increased and basic groups, which are the active centers of sorption of heavy metals, appeared.

ХОХОТВА О. П., к.т.н. доц.; АВЕТІСЯН Ю. І., асп.; ДЕГТЯРЬОВА А. В., магістрант