Explosive biodegradation in soil slurry batch reactors amended with exogenous microorganisms

2001 ◽  
Vol 43 (3) ◽  
pp. 291-298 ◽  
Author(s):  
C. F. Shen ◽  
J. A. Hawari ◽  
L. Paquet ◽  
G. Ampleman ◽  
S. Thiboutot ◽  
...  

The present study explores the feasibility of biotreatment of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)-contaminated soils in slurry batch reactors. Radiorespirometric assays showed that anaerobic sludge was able to mineralize 59% RDX to CO2 although significant mineralization of TNT was not observed in all cases. TNT and RDX at concentrations higher than 50 and 100 mg/L respectively were inhibitory to methanogenesis (used as a bioindicator), however, methanogenesis recovered after TNT was transformed into less toxic triaminotoluene. Bioslurry batch reactors containing 40% of contaminated soil (2000 mg RDX and 1000 mg TNT/kg dry soil) were operated under various conditions. Both TNT and RDX were persistent to soil indigenous microbes. Degradation of both TNT and RDX was enhanced by the municipal sludge amendment, although degradation of RDX was only achieved under anaerobic conditions.

Biologia ◽  
2014 ◽  
Vol 69 (10) ◽  
Author(s):  
Raj Boopathy

AbstractAnaerobic degradation of 2,4,6-trinitrotoluene (TNT) was studied under sulfate- and nitrate-reducing conditions using enrichment cultures developed from a TNT-contaminated soil from the Louisiana Army Ammunition Plant (LAAP) in Minden, Louisiana, USA. The soil samples were enriched using mineral salt media with either nitrate or sulfate as electron acceptors in the presence of TNT under strict anaerobic conditions. The enriched samples were experimented with TNT as either the sole source of carbon or nitrogen and also under co-metabolic conditions with molasses as co-substrate. The results revealed that TNT was removed under both electron acceptor conditions. However, the TNT degradation efficiency was significantly higher under sulfate-reducing conditions than the nitrate-reducing conditions. Under sulfate-reducing conditions, TNT removal was faster when molasses was used as co-substrate. The metabolic analysis showed that TNT was mineralized and the major end product was acetic acid, CO2, and ammonia. A soil slurry reactor with TNT-contaminated soil showed more than 90% of TNT removal within 60 days of incubation.


2020 ◽  
Vol 10 (1) ◽  
pp. 94-109
Author(s):  
Vera V. Redkina ◽  
Regina R. Shalygina ◽  
Mariya V. Korneykova

The analysis of algal-mycological complexes in Albic Podzolic soils affected by emissions of the Kandalaksha Aluminum Smelter (KAS) was carried out. The number and biomass of microscopic fungi in the maximum fluorine-polluted zone (fluorine-content >1000 mg/kg) more than 2 times lower than in distanced areas and amounted to 17.3 thousants colony-forming units/g and 1.33 mg/g respectively. Altogether, 31 species of soil fungi were isolated. The species Penicillium trzebinskii and P. miczynskii dominated the zone of maximum pollution. P. glabrum, P. spinulosum, and Memnoniella echinata prevailed in the zones of moderate pollution and background. The part of opportunistic fungi in contaminated soil increased in comparison with the background soil. The reduction of dark-colored fungi biomass in contaminated soil was noted. In total, 56 species of eukaryotic algae and 7 species of cyanobacteria were found. Among green algae, the species from families Chlorophyceae and Trebouxiophyceae dominated in all plots. In the zones of maximum and strong contamination, 53 algae species were found including xanthophytes, which were absent in unpolluted areas. The number of viable cells in the litter of the maximum contaminated soils varied from 100 thousand to 1.5 million in 1 g of absolutely dry soil. The species composition of algae and cyanobacteria in these soils showed the characteristic features of the Arctic biological soil crusts.


Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 448
Author(s):  
Mahrous Awad ◽  
Zhongzhen Liu ◽  
Milan Skalicky ◽  
Eldessoky S. Dessoky ◽  
Marian Brestic ◽  
...  

Heavy metals (HMs) toxicity represents a global problem depending on the soil environment’s geochemical forms. Biochar addition safely reduces HMs mobile forms, thus, reducing their toxicity to plants. While several studies have shown that biochar could significantly stabilize HMs in contaminated soils, the study of the relationship of soil properties to potential mechanisms still needs further clarification; hence the importance of assessing a naturally contaminated soil amended, in this case with Paulownia biochar (PB) and Bamboo biochar (BB) to fractionate Pb, Cd, Zn, and Cu using short sequential fractionation plans. The relationship of soil pH and organic matter and its effect on the redistribution of these metals were estimated. The results indicated that the acid-soluble metals decreased while the fraction bound to organic matter increased compared to untreated pots. The increase in the organic matter metal-bound was mostly at the expense of the decrease in the acid extractable and Fe/Mn bound ones. The highest application of PB increased the organically bound fraction of Pb, Cd, Zn, and Cu (62, 61, 34, and 61%, respectively), while the BB increased them (61, 49, 42, and 22%, respectively) over the control. Meanwhile, Fe/Mn oxides bound represents the large portion associated with zinc and copper. Concerning soil organic matter (SOM) and soil pH, as potential tools to reduce the risk of the target metals, a significant positive correlation was observed with acid-soluble extractable metal, while a negative correlation was obtained with organic matter-bound metal. The principal component analysis (PCA) shows that the total variance represents 89.7% for the TCPL-extractable and HMs forms and their relation to pH and SOM, which confirms the positive effect of the pH and SOM under PB and BB treatments on reducing the risk of the studied metals. The mobility and bioavailability of these metals and their geochemical forms widely varied according to pH, soil organic matter, biochar types, and application rates. As an environmentally friendly and economical material, biochar emphasizes its importance as a tool that makes the soil more suitable for safe cultivation in the short term and its long-term sustainability. This study proves that it reduces the mobility of HMs, their environmental risks and contributes to food safety. It also confirms that performing more controlled experiments, such as a pot, is a disciplined and effective way to assess the suitability of different types of biochar as soil modifications to restore HMs contaminated soil via controlling the mobilization of these minerals.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 798
Author(s):  
Valentina Pidlisnyuk ◽  
Andriy Herts ◽  
Volodymyr Khomenchuk ◽  
Aigerim Mamirova ◽  
Oleksandr Kononchuk ◽  
...  

Miscanthus × giganteus (M. × giganteus) is a perspective plant produced on marginal and contaminated lands with biomass used for energy or bioproducts. In the current study, M. × giganteus development was tested in the diesel-contaminated soils (ranged from 250 mg kg−1 to 5000 mg kg−1) and the growth dynamic, leaves quantity, plants total area, number of harvested stems and leaves, SPAD and NPQt parameters were evaluated. Results showed a remarkable M. × giganteus growth in a selected interval of diesel-contaminated soil with sufficient harvested biomass. The amendment of soil by biochar 1 (produced from wastewater sludge) and biochar 2 (produced from a mixture of wood waste and biohumus) improved the crop’s morphological and physiological parameters. Biochar 1 stimulated the increase of the stems’ biomass, while biochar 2 increased the leaves biomass. The plants growing in the uncontaminated soil decreased the content of NO3, pH (KCl), P2O5 and increased the content of NH4. Photosynthesis parameters showed that incorporating biochar 1 and biochar 2 to the diesel-contaminated soil prolonged the plants’ vegetation, which was more potent for biochar 1. M. × giganteus utilization united with biochar amendment can be recommended to remediate diesel-contaminated land in concentration range 250–5000 mg kg−1.


2015 ◽  
Vol 71 (8) ◽  
pp. 1128-1135 ◽  
Author(s):  
Sevcan Aydın ◽  
Bahar Ince ◽  
Orhan Ince

In this study, we aimed to develop an understanding of the triple effects of sulfamethoxazole–erythromycin–tetracycline (ETS) and the dual effects of sulfamethoxazole–tetracycline (ST), erythromycin–sulfamethoxazole (ES) and erythromycin–tetracycline (ET) on the anaerobic treatment of pharmaceutical industry wastewater throughout a year of operation. Concentrations of the antibiotics in the influent were gradually increased until the metabolic collapse of the anaerobic sequencing batch reactors (SBRs), which corresponded to ETS (40 + 3 + 3 mg/L) and ST (25 + 2.5 mg/L), ET (4 + 4 mg/L) and ES (3 + 40 mg/L). Acetate accumulation in the anaerobic SBRs, acetoclastic activity of the anaerobic sludge taken from different antibiotic feeding stages and also expression of acetyl-coA synthetase from the acetoclastic methanogenic pathway on the mRNA level were assessed. The results indicated that, while acetate accumulation and decrease of acetoclastic activity were observed after stage 3 in the ST and ES reactors, and stage 7 in the ETS and ET reactors, the expression of acetyl-coA synthetase was mostly decreased in the last stages in all SBRs, in which antibiotic mixture feeding was terminated. It might be speculated that acetoclastic methanogens have an important role in acetate degradation by expressing acetyl-coA synthetase.


2021 ◽  
Vol 8 (4) ◽  
pp. 986-999
Author(s):  
Ting Wu ◽  
Yangzhi Liu ◽  
Kun Yang ◽  
Lizhong Zhu ◽  
Jason C. White ◽  
...  

This work provides a new strategy using nanomaterial-facilitated phytoremediation to promote the restoration of POP-contaminated soils.


2007 ◽  
Vol 55 (5) ◽  
pp. 319-326 ◽  
Author(s):  
D. Glindemann ◽  
J.T. Novak ◽  
J. Witherspoon

Sewage plants can experience dimethyl sulphide (DMS) odour problems by at least one mg/L dimethylsulphoxide (DMSO) waste residue in plant influent, through a DMSO/DMS reduction mechanism. This bench-scale batch study simulates in bottles the role of poor aeration in wastewater treatment on the DMSO/DMS and sulphate/H2S reduction. The study compares headspace concentrations of sulphide odorants developed by activated sludge (closed bottles, half full) after six hours under anoxic versus anaerobic conditions, with 0 versus 2 mg/L DMSO addition. Anoxic sludge (0.1–2 mg/L dissolved oxygen, DO) with DMSO resulted in about 50 ppmv DMS and no other sulphide, while DMSO-free sludge was free of detectable sulphides. Anaerobic sludge (no measurable DO to the point of sulphate reduction) with DMSO resulted in 22/4/37 ppmv of H2S/methanethiol (MT)/DMS, while DMSO-free sludge resulted in 44/8/2 ppmv of H2S/MT/DMS. It is concluded that common “anoxic” aeration tank zones with measurable DO in bulk water but immeasurable DO inside sludge flocs (nitrate reducing) experience DMSO reduction to DMS that is oxidation resistant and becomes the most important odorant. Under anaerobic conditions, H2S from sulphate reduction becomes an additional important odorant. A strategy is developed that allows operators to determine from the quantity of different sulphides whether the DMSO/DMS mechanism is important at their wastewater plant.


2001 ◽  
Vol 43 (2) ◽  
pp. 291-295 ◽  
Author(s):  
J. Vouillamoz ◽  
M. W. Milke

The effect of compost on phytoremediation of diesel-contaminated soils was investigated using 130 small (200 g) containers in two screening tests. The experiments were conducted in a controlled environment using ryegrass from seed. Containers were destructively sampled at various times and analyzed for plant mass and total petroleum hydrocarbons. The results indicate that the presence of diesel reduces grass growth, and that compost helps reduced the impact of diesel on grass growth. The addition of compost helps increase diesel loss from the soils both with and without grass, though the addition of grass leads to lower diesel levels compared with controls. A second set of experiments indicates that the compost helps in phytoremediation of diesel-contaminated soil independent of the dilution effect that compost addition has. The results indicate that the compost addition allowed diesel loss down to 200 mg TPH/kg even though the compost would be expected to hold the diesel more tightly in the soil/compost mixture. The simplicity of the screening tests led to difficulties in controlling moisture content and germination rates. The conclusion of the research is that the tilling of compost into soils combined with grass seeding appears to be a valuable option for treating petroleum-contaminated soils.


2018 ◽  
Vol 777 ◽  
pp. 256-261 ◽  
Author(s):  
André Ribeiro ◽  
André Mota ◽  
Margarida Soares ◽  
Carlos Castro ◽  
Jorge Araújo ◽  
...  

Electrokinetic remediation deserves particular attention in soil treatment due to its peculiar advantages, including the capability of treating fine and low permeability materials, and achieving consolidation, dewatering and removal of salts and inorganic contaminants like heavy metals in a single stage. In this study, the remediation of artificially lead (II) contaminated soil by electrokinetic process, coupled with Eggshell Inorganic Fraction Powder (EGGIF) permeable reactive barrier (PRB), was investigated. An electric field of 2 V cm-1was applied and was used an EGGIF/soil ratio of 30 g kg-1 of contaminated soil for the preparation of the permeable reactive barrier (PRB) in each test. It was obtained high removal rates of lead in both experiments, especially near the cathode. In the normalized distance to cathode of 0.2 it was achieved a maximum removal rate of lead (II) of 68, 78 and 83% in initial lead (II) concentration of 500 mg-1, 200 mg-1 and 100 mg-1, respectively. EGGIF (Eggshell Inorganic Fraction) proved that can be used as permeable reactive barrier (PRB) since in all the performed tests were achieved adsorptions yields higher than 90%.


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