Bioreactor-based bioremediation of hydrocarbon-polluted Niger Delta marine sediment, Nigeria

Abstract

Crude oil-polluted marine sediment from Bonny River loading jetty Port Harcourt, Nigeria was treated in seven 2.5 l stirred-tank bioreactors designated BNPK, BNK5, BPD, BNO3, BUNa, BAUT, and BUK over a 56-day period. Five bioreactors were biostimulated with either K2HPO4, NH4NO3, (NH4)2SO4, NPK, urea or poultry droppings while unamended (BUNa) and heat-killed (BAUT) treatments were controls. For each bioreactor, 1 kg (wet weight) sediment amended with 1 l seawater were spiked with 20 ml and 20 mg of crude oil and anthracene which gave a total petroleum hydrocarbons (TPH) range of 106.4–116 ppm on day 0. Polycyclic aromatic hydrocarbons (PAH) in all spiked sediment slurry ranged from 96.6 to 104.4 ppm. TPH in each treatment was ≤14.9 ppm while PAH was ≤6.8 ppm by day 56. Treatment BNO3 recorded highest heterotrophic bacterial count (9.8 × 108 cfu/g) and hydrocarbon utilizers (1.15 × 108 cfu/g). By day 56, the percentages of biodegradation of PAHs, as measured with GC–FID were BNK5 (97.93%), BNPK (98.38%), BUK (98.82%), BUNa (98.13%), BAUT (93.08%), BPD (98.92%), and BNO3 (98.02%). BPD gave the highest degradation rate for PAH. TPH degradation rates were as follows: BNK5 (94.50%), BNPK (94.77%), BUK (94.10%), BUNa (94.77%), BAUT (75.04%), BPD (95.35%), BNO3 (95.54%). Fifty-six hydrocarbon utilizing bacterial isolates obtained were Micrococcus spp. 5 (9.62%), Staphylococcus spp. 3 (5.78%), Pseudomonas spp. 7 (13.46%), Citrobacter sp. 1 (1.92%), Klebsiella sp. 1 (1.92%), Corynebacterium spp. 5 (9.62%), Bacillus spp. 5 (9.62%), Rhodococcus spp. 7 (13.46%), Alcanivorax spp. 7 (13.46%), Alcaligenes sp. 1 (1.92%), Serratia spp. 2 (3.85%), Arthrobacter spp. 7 (13.46%), Nocardia spp. 2 (3.85%), Flavobacterium sp. 1 (1.92%), Escherichia sp. 1 (1.92%), Acinetobacter sp. 1 (1.92%), Proteus sp. 1 (1.92%) and unidentified bacteria 10 (17%). These results indicate that the marine sediment investigated is amenable to bioreactor-based bioremediation and that abiotic factors also could contribute to hydrocarbon attenuation as recorded in the heat-killed (BAUT) control.

Evaluation of the effects of inorganic and organic fertilizers and activated carbon on bioremediation of soil contaminated with weathered crude oil

“…Effect of different amount of organic fertilizer (cattle dung + pig dung+ poultry droppings) on TPH biodegradation were investigated at the same condition of inorganic NPK fertilizer and activated carbon (run numbers 6 and 8, and run numbers 10 and 12) and the results showed that addition of organic fertilizer (cattle dung + pig dung + poultry droppings) can enhance the bioremediation process of soil contaminated with crude oil. This is in agreement with the observations of Ibiene et al (2011), Nduka et al (2012, Chikere et al (2012) and Obiakalaije et al (2015) who respectively used poultry droppings and/or cow dung as organic fertilizer (biostimulation agents) in the remediation of petroleum hydrocarbon contaminated environment. Agarry et al (2010) and Agarry et al (2013b) had in their previous studies also reported the enhancement of bioremediation in soil contaminated with petroleum hydrocarbons using cow dung, pig dung, poultry dung as well as the mixture of cow dung and pig dung, respectively.…”

“…Similar observations have been reported (Chorom et al, 2010;Chikere et al, 2012;Ogunleye, 2012a, 2012b). Thus, the observed results seems to suggest that high nutrient amendment dosage can accentuate the rate of initial petroleum hydrocarbon biodegradation and then reduce the remediation period of environment contaminated with crude oil.…”

Biotechnological advances in bioremediation of heavy metals contaminated ecosystems: an overview with special reference to phytoremediation

“…For example, Vullo et al (2008) isolated bacteria which were resistant to both Zn and Cd. Chikere et al (2012) reported bioreactor-based bioremediation of hydrocarbonpolluted marine sediments biostimulated with either K 2 HPO 4 , NH 4 NO 3 , (NH 4 ) 2 SO 4 , NPK, urea or poultry droppings across the Bonny river, Port Harcourt, Nigeria.…”

Enzyme-mediated biodegradation of long-chain n-alkanes (C32 and C40) by thermophilic bacteria

“…These hydrocarbons and alkanes have been considered as priority pollutants (NRC 2000;Ekperusi and Aigbodion 2015), which are biohazards and biomagnified in the environment (Kramer and Van der Heijden 1990;Mohamed et al 2006). While, there are special group of microorganisms that can biodegrade and biotransform these hydrocarbons and alkanes to assimilate as biomass in the ecosystem (Chikere et al 2012;Rajasekar et al 2012;Roy et al 2015;Kumar et al 2016). However, few alkanes are recalcitrant in the environment (e.g., long chain and high molecular weight hydrocarbons) due to their non-polar and chemically inert nature (Labinger and Bercaw 2002).…”