Petroleum sludge bioremediation and its toxicity removal by landfill in gunder semi-arid conditions

Soil pollution with jet-fuel by the Russian aerospace transportation

Aviation and space transportation effect the ecosystems since the beginning and middle of 20th century, respectively. However soil pollution with jet fuel is virtually unexplored. In this article, we summarized the levels of soil pollution near the airfields (in Central Russia) and in the falling sites of the Soyuz launch vehicle debris (in Central and Northern Kazakhstan) with petroleum hydrocarbons via the concentration of jet fuel and/or total petroleum hydrocarbons. At the long-term used airfields in the central regions of Russia, the level of contamination is acceptable: we did not find any jet fuel (its concentration was below 0.1 g/kg - the lowest detected level) in all 47 soil samples collected at the impact zones of 7 airfields. At propellant spills with an area of no >7.1 m2 from the regular falling sites of the Soyuz launch vehicle first stages, the content of jet fuel and total petroleum hydrocarbons reached 128 (n = 36; 11 falling sites) and 57 g/kg (n = 2249; 230 falling sites), respectively. Four months after the jet fuel spill at Ostafyevo airfield, there was 190 g/kg of jet fuel in the impact zone. One day after the accident, up to 1.6 g/kg of total petroleum hydrocarbons were found at the site where the Soyuz launch vehicle second stage fell. Ecosystems can get rid of jet fuel pollution in a few years. For Aridisols in Kazakhstan, 0.26 g/kg total petroleum hydrocarbons is proposed as a trigger value. Fluorimetry gives lower results for total petroleum hydrocarbons than chromatography-mass spectrometry. This is probably because of different sample preparation and extraction.

Global Situation of Bioremediation of Leachate-Contaminated Soils by Treatment with Microorganisms: A Systematic Review

This systematic review presents the current state of research in the last five years on contaminants in soils, especially in leachates from solid waste landfills, with emphasis on biological remediation. In this work, the pollutants that can be treated by microorganisms and the results obtained worldwide were studied. All the data obtained were compiled, integrated, and analyzed by soil type, pollutant type, bacterial type, and the countries where these studies were carried out. This review provides reliable data on the contamination of soils worldwide, especially soils contaminated by leachate from municipal landfills. The extent of contamination, treatment objectives, site characteristics, cost, type of microorganisms to be used, and time must be considered when selecting a viable remediation strategy. The results of this study can help develop innovative and applicable methods for evaluating the overall contamination of soil with different contaminants and soil types. These findings can help develop innovative, applicable, and economically feasible methods for the sustainable management of contaminated soils, whether from landfill leachate or other soil types, to reduce or eliminate risk to the environment and human health, and to achieve greater greenery and functionality on the planet.

Petroleum sludge treatment and disposal techniques: a review

Petroleum sludge is a solid emulsified waste and contaminant commonly produced in the petroleum industry. In the recent past, there has been increased business growth in the oil sector, resulting in increased volumes of oily sludge characterized by high viscosity and toxicity. Therefore, sludge treatment before discarding is extremely necessary. This review seeks to highlight various conventional and evolving approaches in the treatment, recovery, and disposal of petroleum sludge and assess their suitability under various conditions.

Performance of Fly Ash-Based Inorganic Polymer Mortar with Petroleum Sludge Ash

Petroleum sludge is a waste product resulting from petroleum industries and it is a major source of environmental pollution. Therefore, developing strategies aimed at reducing its environmental impact and enhance cleaner production are crucial for environmental mortar. Response surface methodology (RSM) was used in designing the experimental work. The variables considered were the amount of petroleum sludge ash (PSA) in weight percent and the ratio of sodium silicate to sodium hydroxide, while the concentration of sodium hydroxide was kept constant in the production of geopolymer mortar cured at a temperature of 60 °C for 20 h. The effects of PSA on density, compressive strength, flexural strength, water absorption, drying shrinkage, morphology, and pore size distribution were investigated. The addition of PSA in the mortar enhanced the mechanical properties significantly at an early age and 28 days of curing. Thus, PSA could be used as a precursor material in the production of geopolymer mortar for green construction sustainability. This study aimed to investigate the influence of PSA in geopolymer mortar.

Assessment of the genotoxicity of antibiotics and chromium in primary sludge and compost using Vicia faba micronucleus test

The objective of this study was to investigate chemical, biological and eco-toxicological parameters of a compost produced through the co-composting of dewatered primary sludge (DPS) and date palm waste to evaluate in which extent it can exploited as a bio-fertilizer. DPS and date palm waste were co-composted in aerobic conditions for 210 days. Physico-chemical parameters were evaluated during composting (total organic carbon, total nitrogen, pH, available forms of phosphorus). Furthermore, heavy metals (Cd, Cu, Cr, Pb, Ni, Zn) and antibiotics (fluoroquinolones, macrolides and tetracyclines) content were analyzed in the DPS. To evaluate the genotoxicity of substrates, Vicia faba micronucleus test was carried out. Single and combined toxicities of a mixture of antibiotics (ciprofloxacin, enroflxacin, nalidixic acid, roxithromycin and sulfapyridin) and chromium (Cr₂ (SO₄)₃ and K₂Cr₂O₇) were examined. Although the final compost product showed a significant decrease of the genotoxicity, almost 50% of the micronucleus frequency still remained, which could be explained by the persistence of several recalcitrant compounds such as chromium and some antibiotics. Overall, the presence of antibiotics and chromium showed that some specific combination of contaminants represent an ecological risk for soil health and ecosystems even at environmentally negligible concentrations.