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Petroleum drill cuttings are usually treated by techniques suitable for particular contaminant groups. The significance of this study consists in the development of a treatment technology that can simultaneously handle the hydrocarbon and metal constituents of drill cuttings. Bioaugmentation is combined with stabilisation/solidification (S/S), within S/S monoliths and in granulated S/S monoliths. Portland cement was used for S/S treatment at 30% binder dosage. Bioaugmentation treatment involved two bacterial densities of a mixed culture bio-preparation. The effects of inclusion of compost, fertiliser and activated carbon were also evaluated. After 28 days, the combined S/S and bioaugmentation treatments recorded up to 15% higher total petroleum hydrocarbon (TPH) loss than control S/S treatment without bioaugmentation. Embedding fertiliser, activated carbon and higher bacterial density within S/S monoliths resulted in the highest (99%) TPH reduction but higher concentrations of metals. The addition of compost and lower bacterial density to granulated S/S monoliths led to similar (98%) TPH degradation and lower amounts of metals. The results suggest that with better mixture optimisation, combining S/S and bioaugmentation could engender more sustainable treatment of drill cuttings. 相似文献
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In recent years, several studies focused on the detection of hydrocarbon pollution in the environment using hyperspectral remote sensing. Particularly the indirect detection of hydrocarbon pollution, using vegetation reflectance in the red edge region, has been studied extensively. Bioremediation is one of the methods that can be applied to clean up polluted sites. So far, there have been no studies on monitoring of bioremediation using (hyperspectral) remote sensing. This study evaluates the feasibility of hyperspectral remote sensing for monitoring the effect of bioremediation over time. Benzene leakage at connection points along a pipeline was monitored by comparing the red edge position (REP) in 2005 and 2008 using HyMap airborne hyperspectral images. REP values were normalized in order to enhance local variations caused by a change in benzene concentrations. 11 out of 17 locations were classified correctly as remediated, still polluted, or still clean, with a total accuracy of 65%. When only polluted locations that were remediated were taken into account, the (user's) accuracy was 71%. 相似文献
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Isolation of PAH-degrading bacteria from mangrove sediments and their biodegradation potential 总被引：6，自引：0，他引：6
Surface sediment samples were collected from seven mangrove swamps in Hong Kong SAR with different degrees of contamination. The total concentrations of 16 PAHs in these sediments ranged from 169.41 to 1058.37 ng g−1 with the highest concentration found in Ma Wan and the lowest in Kei Ling Ha Lo Wai mangrove swamp. In each swamp, three bacterial consortia were enriched from sediments using phenanthrene (Phe) as the sole carbon and energy source, and individual bacterial colony showing Phe degradation was isolated and identified by 16S rDNA gene sequence. The consortia enriched from Sai Keng and Ho Chung sediments had highest ability to degrade mixed PAHs in liquid medium, with 90% Phe and Fla (fluoranthene) degraded in 7 days. On the other hand, Kei Ling Ha Lo Wai-enriched consortia degraded less than 40% Phe and Fla. Pyrene (Pyr) was hardly degraded by the consortia enriched from sediments. Bacterial isolates, namely Rhodococcus (HCCS), Sphingomonas (MWFG) and Paracoccus (SPNT) were capable to degrade mixed PAHs (Phe + Fla + Pyr). Their degradation percentages could be lower, comparable or even higher than their respective enriched consortia, depending on the consortium and the type of PAH compounds. These results suggest that PAH-degrading bacteria enriched from mangrove sediments, either as a mixed culture or as a single isolate could be used for PAHs bioremediation. 相似文献
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The Stockton Coal Mine, located on the West Coast of New Zealand, is evaluating the use of a mussel shell bioreactor (MSB) to treat acidic metalliferous runoff from acid forming overburden. This novel approach is similar in concept to vertical flow wetlands (VFWs) and successive alkalinity producing systems (SAPS). The MSB system is a trapezoidal pit 2 m deep, 35 m long, 3–10 m wide with 60° angle sides. During operation it contained 160 tonnes (240 m3) of mussel shell material and was saturated with a 100–200 mm water cap. Influent flowed through the reactor at a mean rate of 0.3 L s−1 resulting in a hydraulic retention time (HRT) of ≈6 days. The prototype MSB was in operation for a total of 1027 days, from June 2009 through March 2012, and effectively sequestered 99.7% of Al, 99.3% of Fe, 98.8% of Ni, 98.4% Tl and 99.3% of Zn, as determined from a previous evaluation of MSB performance. The MSB also effectively neutralized acidity, which resulted in an increase in influent pH from 2.8 to 6.9 in the effluent. Based on an examination of several excavated pits, five distinct reaction zones developed within the MSB. The reaction zones consisted of an allochthonous sediment layer (0–330 mm), an oxidized iron-rich ocherous layer (at 330–350 mm depth), an aluminum layer (at 350–600 mm depth) with geochemical variations throughout (350–500 mm and 500–600 mm); and a chemically reduced bottom shell layer (at 600–1100 mm). Representative samples were collected from each layer and analyzed using a combination of geochemical and physical methods to assess the stability of the secondary minerals and trace metal deportment within the MSB. Major elements Fe, Al, Ni, Tl, and Zn where preferentially associated with particular layers within the MSB. Elevated concentrations of Fe (110,000 mg kg−1) were observed in the allochthonous sediment and ocherous precipitate layers, while Al (27,816 mg kg−1), Ni (55 mg kg−1), and Zn (655 mg kg−1) were elevated within the aluminum and lower reduced depths within the MSB. Trace Tl (21 mg kg−1) showed varying concentrations throughout the MSB, but was strongly correlated to lower layers of the system. Microbial biofilms were observed within the reduced portions of the shell layers often proximal to bacterial shaped sulfides. The geochemical assessment of the MSB presented in this study is the first of its kind for a MSB, and supports the argument that this system is another viable option for passive treatment of AMD. 相似文献
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