Bacterial Treatment of Drill Cuttings: Experimental Investigation | Chapter 13 | Innovations in Microbiology and Biotechnology Vol. 1

The presence of polycyclic aromatic hydrocarbons (PAH) from crude oil and gas condensate, ferrochrome lignosulphate, and lead compounds in drill cuttings and drilling mud additives is a cause of worry for the environment during exploration and development drilling operations. Environmental toxicants detected during drilling operations sparked this inquiry. In order to achieve the millennium goal of a sustainable environment, this study focused on applying scientific and technological solutions that are both efficient and cost-effective in lowering chemical toxicants in the environment to levels below the allowed limit. This was accomplished by employing microorganisms found in drill cuttings to induce PAH and TPH breakdown in the hydrocarbon. The physiochemical parameters that enhance the multiplication of bacteria that use hydrocarbons have been discovered. Microbial populations, total petroleum hydrocarbon (TPH), and PAH levels were assessed at regular intervals throughout the experiment. A sample of drill cutting (Dc) was taken from an oil well in the Usan field for bioremediation treatment. The five treatment options Dc, Dc+S, Dc+F, Dc+S+F+D, and Dc+D were established in triplicates in different cells using plastic bowls. A total of 15 plastic bowls, each measuring 35cm in diameter and 11cm in depth, were used. The setup was sampled at regular intervals for analysis throughout the study period. Biostimulated with soil (S), NPK fertiliser (F), or Gold Crew dispersant (D), with controls (DC) and heat-treated (HT) (hDC). 40g of treatment material was added to 2 kg (wet weight) of drill cutting for each treatment option. The bioremediation process was investigated during a 56-day period. On day 0, Dc had the highest heterotrophic bacterial count (4.5 x 105 cfu/g), while Dc+D had the lowest (3.0 x 103 cfu/g) on day 56.

According to the hydrocarbon using bacterial count, Dc+D had the maximum count (6.5x 103 cfu/g) on day 28 and the lowest level (2.6 x 102 cfu/g) on day 56. Total petroleum hydrocarbons (TPH) varied from 33.22 to 46.00 mg/kg on day 0, whereas polycyclic aromatic hydrocarbons (PAH) ranged from 3.51 to 6.4 mg/kg for all treatment options. TPH was 8.0mg/kg and PAH was 2.5mg/kg in all treatment options at day 56. Dc(71.82 percent ), Dc+S(77.09 percent ), Dc+F(83.58 percent ), Dc+S+F+D(79.95 percent ), Dc+D(81.58 percent ), Dc+S+F+D(79.95 percent ), Dc+D(81.58 percent ), Dc+D(81.58 percent ), Dc+D(81.58 percent ), Dc+D(81.58 percent (30.56 percent ). Dc (49.92%), Dc+S (52.35%), Dc+F (86.09%), Dc+S+F+D (64.74%), Dc+D (74.20%), and heat-treated PAH degradation rates were as follows: Dc (49.92%), Dc+S (52.35%), Dc+F (86.09%), Dc+F+D (64.74%), Dc+D (74.20%) (2.23 percent ). For both TPH and PAH, Dc+F yielded the highest percentage degradation. Using bacterial isolates, 52 hydrocarbons were generated. Bacillus spp. (26.92%), Proteus spp. (1.92%), Pseudomonas spp. (7.36%), Alcaligenes spp. (5.77%), Micrococcus spp. (7.55%), Acinetobacter sp. (1.92%), Aeromonas spp. (21.15%), and unidentified bacteria were among the bacteria isolated (28.85 percent ). According to a screen test for degradative potential, many of the bacterial isolates had hydrocarbon degradative capability. The drill cuttings studied could be remediated using microbiological agents, as shown in the heat-treated control, and ambient variables (abiotic factors) had a role in hydrocarbon alternation.

Author (S) Details

S. E. Ibekwe
Department of Microbiology, University of Port Harcourt, P.M.B 5323 Port Harcourt, Nigeria.

G. C. Okpokwasili
Department of Microbiology, University of Port Harcourt, P.M.B 5323 Port Harcourt, Nigeria.

View Book :- https://stm.bookpi.org/IMB-V1/article/view/3987

Investigation and Documentation of Acidic Mining Exploration Drill Cuttings at the Pebble Copper– Gold Mineral Prospect, Southwest Alaska | Chapter 6 | International Research in Environment, Geography and Earth Science Vol. 5

 

During the Pebble copper-gold-molybdenum (Cu-Au-Mo) deposit discovery drilling, drilling waste was directly disposed of on the landscape or passed through unlined sumps prior to disposal. The ore and host rock are high in sulphides, which are weathered by metal leaching to sulfuric acid. Oxidized cuttings were visually noticeable and verified to have a pH of 2.7-4.3 by laboratory and field research. Cu and Mo reached or were at the high end of the natural history at these locations. Cu was within the range of 545 mg / kg to 4865 mg / kg, with one exception. At all sites with drill cuttings on the soil, dead vegetation was observed. There has also been observed dead vegetation on Covers of sump rock, unrelated to drilling waste. Places where vegetation had not been preserved were between the ages of four and thirteen. The possible surface and groundwater effect has not been determined. It could lead to better site management to understand the source and nature of damage from cuttings. In order to determine the rate of chemistry shifts, drill cuttings sump contents require more sampling and whether groundwater downgradient from sumps is being affected. Finally, more research should be carried out to determine if sulfidic drill waste accumulated in isolated bodies of water, such as glacial kettles, is having an effect. In order to ensure clean control samples, testing sites should be examined before and after drilling.

Author (s) Details

David M. Chambers,
Center for Science in Public Participation, Bozeman, MT 59715, USA.

Dr. Kendra Zamzow,
Center for Science in Public Participation, Chickaloon, AK 99674, USA.

View Book :- https://bp.bookpi.org/index.php/bpi/catalog/book/279