Showing 4 results for Petroleum Hydrocarbons
Volume 1, Issue 3 (9-2023)
Abstract
In this study, we investigated the effectiveness of both single and hybrid systems, incorporating UV photolysis and a Moving Bed Biofilm Reactor (MBBR), for treating synthetic wastewater contaminated with petroleum hydrocarbons. Petroleum hydrocarbons pose significant environmental threats due to their high toxicity, stability, accumulation potential, and resistance to biodegradation. In the hybrid system, the wastewater underwent chemical treatment first and then was introduced into the biological reactor. For the photolysis system, we explored the impacts of different concentrations and various radiation powers of UV-C lamps. Optimal conditions were determined to be a Chemical Oxygen Demand (COD) of 350 mg/L and a radiation power of 80 W. In the MBBR system, various concentrations were introduced into the reactor, achieving a maximum removal efficiency of 85% for an initial COD of 1000 mg/L over 72 hours with a 50% filling capacity. In the hybrid system, we achieved a remarkable hydrocarbon removal efficiency of 99% after 123 hours. Although the operational time of the hybrid system was relatively long, it demonstrated itself as a suitable treatment process compared to other conventional methods for removing these challenging, hard-to-biodegrade compounds.
Fateme Zarinkamar, Fateme Reypour, Khosro Khajeh,
Volume 5, Issue 2 (8-2014)
Abstract
Laccase (benzenediol: oxygen oxidoreductase), is a multicopper polyphenol oxidase enzyme which has glycoprotein structure. The Researches are indicated that laccase enzyme can play role in detoxification of aromatic pollutants (as petroleum derivatives) and conversion them to less toxic compounds. On the other hand, because of its extensive, fibrous root system; Festuca arundinacea, creates an appropriate environment that causes increased catalysis of petroleum contaminants. Considering the fact that increasing in catalysis of pollutants can be provided by presence and changes in activity of various plant enzymes, in this research; the changes in laccase activity of Festuca's vegetative organs under soil pollution with different concentration of diesel fuel has been investigated. For this purpose, at first, the seeds of Festuca were cultivated in pots containing diesel fuel polluted soils and also control pots in greenhouse conditions. Then in specified time treatments, plants were harvested and plant extract containing laccase were extracted from aerial parts and roots of the plant, separately. After doing centrifuge, changes in enzyme activity were calculated by spectrophotometer. The results show that creation of soil pollution treatments compared with control samples, leads to increase in laccase activity in many cases. In other words, by increasing in laccase activity, the plant will increase its potency of decomposition and assimilation of pollutant hydrocarbons.
Volume 6, Issue 2 (7-2018)
Abstract
Aims: The contamination of soils and groundwater by toxic, hazardous organic pollutants is a widespread environmental problem. The use of vegetation for the treatment of contaminated soils is an attractive and cost-effective alternative, especially for petroleum-contaminated soils.
Materials and Methods: Three species including Calotropis procera L., Stipagrostis plumosa, and Medicago sativa were selected. To evaluate the abilities of S. plumosa, M. sativa, and C. procera in the degradation of petroleum hydrocarbons, a greenhouse study was conducted with two trial factors: (1) Urban waste compost and (2) biochar (each 0, 1, and 2%). At the end of the experiment, aerial and underground parts of the plants were collected, and some important soil properties and plant morphological characteristics were measured. The total amount of hydrocarbons was measured by gas chromatography, Flame Ionization type, Agilent 7890A model.
Findings: The results showed that the strongest hydrocarbon reduction by C. procera, S. plumosa, and M. sativa was 62.5%, 57.3%, and 53.5%, respectively. The results also demonstrated that control/biochar 2% had the highest/lowest (21922/14511 mg/kg) hydrocarbon level left in the soil. Therefore, biochar 1% or 2% is the best treatment for the remediation of petroleum-contaminated soils. C. procera L. is a good potential candidate to be cultivated for the phytoremediation of petroleum-contaminated soils.
Conclusion: Overall, using the amendment seedbed including biochar and urban waste compost treatments is suitable to promote phytoremediation of petroleum hydrocarbons. Biochar and urban waste compost provide optimal conditions for plant growth and at least help to promote the process phytoremediation. Regarding plant species diversity in Iran and petroleum contamination, application of phytoremediation may apply with effective and applied solution in soils contaminated.
Volume 13, Issue 1 (1-2024)
Abstract
In this study, a comprehensive assessment of the occurrence and spatial distribution of heavy metals including Nickel, Lead, Zinc, Copper, Cadmium and Chromium, as well as, TPHs in the surface sediments of the coastal areas and far from the coast of the Persian Gulf in Bushehr and Khuzestan provinces were performed to identify the possible sources of sediment contamination and determining the degree of pollution. Eight pollution indices were used to evaluate the quality of sediments in terms of heavy metal and TPH pollution. The investigated areas could be distinguished by a significant degree of heavy metal pollution of Nickel, Cadmium and Zinc. High concentrations of Nickel and Zinc were observed in stations around Nakhiloo, Bushehr. The comparison of average pollution indices between regions showed that both Bushehr and Khuzestan provinces, respectively, with the average of contamination degree (CD) (20.25 and 22.11), modified contamination degree (MCD) (3.38 and 3.69), pollution load index (PLI) (31.17 and 57.57), potential ecological risk index (PERI) (353.54 and 349.39) have a significant degree and risk of Nickel and Cadmium pollution, especially in Nakhiloo area, Bushehr. Investigating the spatial fluctuations of the concentration of TPHs in two provinces showed an increasing trend from Bushehr to Khuzestan. However, areas were located in no pollution or low pollution zonation and were safe from the adverse biological effects of TPHs. Comprehensive and impressive strategies to control and reduce these pollutions, especially in polluted areas, should be considered, so that the sources of these pollutions be managed.
