Особливості агрофізичного стану та накопичення важких металів в агроекосистемі рекультивованих бурових майданчиків

Abstract

Установлено, що ґрунтовий покрив на рекультивованому майданчику свердловини, що пробурена в радянські часи, характеризується підвищеною щільністю ґрунту відносно фонових значень. Орний шар досліджуваних ґрунтів характеризується дуже високими показниками варіації валового вмісту Ag, Ba, Pb, Ca, Mo, Zn. Розподіл умісту барію характеризується наявністю дуже високої аномалії в центрі ділянки (перевищення над фоном 300 разів). Концентрації рухомих форм свинцю перевищують ГДК для сільськогосподарських ґрунтів у 2–33 рази. Проте коефіцієнти біологічного поглинання Pb і Ba становлять менше 1,0, тобто активного переходу їх у рослини не зафіксовано.

Установлено, что почвенный покров на рекультивированных площадке скважины, пробуренной в советские времена, характеризуется повышенной плотностью сложения почвы относительно фоновых значений. Пахотный слой исследуемых почв характеризуется очень высокими показателями вариации валового содержания Ag, Ba, Pb, Ca, Mo, Zn. Распределение содержания бария характеризуется наличием очень высокого аномалии в центре участка (превышение над фоном 300 раз). Концентрации подвижных форм свинца превышают ПДК для сельскохозяйственных почв в 2-33 раза. Однако коэффициенты биологического поглощения Pb и Ba составляют менее 1,0, то есть активного перехода их в растения не зафиксировано.

Purpose – to estimate the agrophysical properties of soils and levels of heavy metals accumulation in agroecosystems of old remediated drill sites by the example of drilling site of the borehole № 23 Ignativka oil and gas field. Research methods - field, analytical, statistical, analysis, and synthesis. Results. Agrophysical properties of soils and heavy metals accumulation were investigated at the reclaimed drilling site within Ignativka oil and gas field in Poltava region. The drilling site of the borehole № 23, which was constructed and operated in 1980-s, was sampled in 32 points located uniformly at 3.6 ha. Background samples were taken at undisturbed arable site 200 m southwestwards from the borehole. Soil samples were taken from three intervals (0–30, 30–60 and 60–100 cm) and metals concentrations were measured by spectrometric analysis. Additional samples were taken selectively at 9 of 32 points for labile and immobilized metal forms analysis. Besides the soil density was measured using While Soil penetrometer at the depth 0–60 cm at every 3 inches. Soil sampling at three points were accompanied by corn crops investigations including visual inspections, height measurements and analysis of heavy metals levels in plants. Topsoil (8–30 cm) density at the investigated site varied mainly from 60 to 140 psi. The areas of elevated density up to 240–260 psi were identified close to the borehole mouth and flare pit pipelines. Underlying soil horizon (35–60 cm) has noticeably higher density varied from 260 to 400 psi with the maximum of 380 psi in the center of the former drilling site. Mean background density is measured as 100.8 psi for topsoil (8–30 cm) and 309.2 psi for the second soil horizon (35–60 cm). Total metals concentrations in soils varied widely within the site and with depth. The highest variation is found for Ag, Ba, Pb, Ca, Zn and Mo that are typical components of drilling muds. Concentrations of these metals exceed the background and threshold values (for Pb, Zn) predominantly in topsoil (0–30 cm). Concentrations of labile and immobilized forms of metals also vary quite extensively and tend to decrease with depth significantly. The labile form of Pb exceeds threshold value for arable soils in 5 of 9 samples taken from the topsoil (0–30 cm). Agricultural crops (corn) within the reclaimed drilling site have noticeably low height of sprouts obviously due to elevated density of topsoil. In spite of high concentrations of heavy metals in soils, their translocation coefficients are mostly low except Ag and Mo. Elevated density of soils, intensive soil pollution by heavy metals and agricultural crops alteration are the direct consequences of drilling activities and improper land reclamation. In spite of the long time gone, soils are highly polluted by Ba, which comes in barite drilling muds, and other accompanying metals such as Pb, Zn, Ag and Mo. However the levels of accumulation in crops are low for the most part of investigated metals