Oil compounds, name Total Petroleum Hydrocarbons (TPH) in soil chemistry, content in polluted soil cause dramatic changes of physicochemical and biological topsoil characteristics and destruction of ecosystems. Selecting and applying appropriate strategies for in situ phytoremediation of the oil soil polluted with 95.5 ± 25.0 g TPH kg–1 D.M., leads to their rehabilitation by planting and maintaining crops of pastures with grasses and leguminous species. The oil polluted soil addition of 50 t ha–1 fertilizer with nitrogen content, like stabilized sewage sludge, mixed with adsorbents material, i.e. fly ash waste derived from power plants that use fossil fuel or volcanic indigenous tuff has led to the installation of abundance and healthy culture. The areas were covered by grasses and leguminous species were up to 90% of sown areas. Resulting harvest from treated variants with fertilizer mixed with adsorbents, material were 2–3 times higher versus harvests obtained from fertilized variants in the absence of fly ash on indigenous volcanic tuff. The harvest characteristics obtained on oil-polluted soil fertilized with sewage sludge mixed with fly ash or volcanic tuff were correlated with national forage norms.

There are many arguments that underlie research on rehabilitation of large areas of land that were set aside from the agricultural circuit and became heaps of storage for inert waste materials like bottom and boiler slag and fly ash. On the other hand result of biological materials with potential for land recycling i.e. sewage sludge. On the dumps of boiler slag composed of particles of 2-3 mm was gradually installed a layer of grass with the help of sewage sludge as a fertilizing agent and microbial activity stimulating agent, based on an extract of brown seaweed EKO GEA Slovenia. In the second year the amount of biomass harvested was 2 to 2.9 times higher than in the first year of cultivation. Moreover plants not harvested in the second year of culture bore fruit. Also, the root network strongly stabilized the slag and boiler ash particles against land spreading. Rapid and effective rehabilitation of the landscape destroyed was achieved with the use of herbaceous crops of the species Lolium perenne. Monitoring bioaccumulation of heavy metals i.e. Cd, Cr, Cu, Ni, Pb, Ni, Zn, etc. in aerial plant tissue was needed to decide the sector where the biomass harvested from inert waste dump covered with vegetation.

The atmospheric dispersion model (ADM) is the mathematical simulation of how pollutants are released into the atmosphere. ADMs are used to estimate the concentration of air pollutants emitted by industrial activity or car traffic in the wind direction. ADM was applied to the flue gases discharged on the chimney of a technological furnace from the diesel hydrofining plant in an oil refinery.

One of the challenges brought by the circular economy requires a reconsideration of waste, which may under certain circumstances turn into genuine resources. By extension, soil pollution with heavy metal is a major concern since it directly affects the health of the population. The goal of the present research work is to analyze the impact of the use of waste from other technological processes in agriculture: fly ash (resulting ash from thermal power plants), zeolite bush (resulting from the processing of rock from zeolite quarries), and manure (garbage from zoo technical farms). In this respect, complex treatments based on inorganic substances (fly ash and volcanic indigenous tuff with 70% clinoptilolite) were applied to less-favored agricultural soils in the absence and in the presence of an organic fertilizer (manure), respectively. After cultivating sunflower ( Helianthus annuus L.),a semi-early hybrids grown in the type soil which fly ash has been applied,there have been obtained\ seed crops 15.8% higher than the seed crops grown in the soil on which no fertilizer has been applied. The results obtained when combining fly ash and manure tend to amoun to those obtained when combining manure with indigenous volcanic tuff with 70% clinoptilolite.The quality of the seed crops, obtained in the case of the three types of soil on which amendments were added in the absence/presence of the fertilizer, corresponds to the requirements of the national rules and allows their food processing.

Phytoremediation involves the ability of plants to remove pollutants and is a promise on low costs and efficient processes for cleaning oil polluted soil. Studies for phytoremediation of soils polluted with petroleum products were critical and were based on monitoring strategies implemented efficiency. These strategies are based on the necessity of treating polluted soil and plant cultivation. Treatment was performed with recycled materials, sewage sludge as fertilizer and fly ash as amendment. The studies took on the characteristics of qualitative and quantitative of Lotus corniculatus crops, plants tolerant to conditions for phytoremediation strategy implemented on polluted soils by 80.5±3.9 g·kg-1 D.M. The use of sewage sludge mixed with fly ash resulted in formation of a layer covering the surface with vegetable grown by 85-94% in July and by 67-83% in August. In Lotus corniculatus crops have not been registered bioaccumulation of toxic metals according to legislation from Romania.

Oil is composed of organic compounds with varied molecular structure; in water suppress the respiration of plants and animals, and have toxicity effects on flora and fauna. An important pretreatment step for the water containing oil is coagulation with optimal dose of coagulant such as polyaluminum chloride (PAC). The addition of coagulating aids had reduced the PAC optimal dose for by 25-50%. The UV analysis of the treated/untreated water showed significant preferential adsorption for total petroleum hydrocarbons at 254 nm wavelength (A254) and the correlation of this parameter with conventional control parameters - total organic carbon (TOC) and chemical oxygen demand (COD).

Selecting the plant species to grow on aged petroleum hydrocarbons polluted soils is an important factor for a successful phytoremediation. Phytoremediation is a green technology that can become a promising solution for decontaminating polluted soils and ecological restoration of the landscape. Our comparative studies evaluate the effect of oil hydrocarbon pollution with high initial concentration on the growth leguminous plant species: Vicia sativa and Glycine max. The experimental block contains control variants, polluted soil unfertilized/fertilized with municipal sludge anaerobically stabilized in absence/presence of modified volcanic tuff amendment. After period of time the experiment’s soil in which plant species had grown well was sampled and analyzed for petroleum hydrocarbons removal. Both species showed promising efficiency in the phytoremediation of petroleum hydrocarbon highly polluted soils but a reduced growth of the surveyed plants was noticed. The efficiency of the petroleum hydrocarbons diminution is increased in the case of the addition of fertilizer 16.6% for Vicia sativa and 30% for Glycine max vs. the initial quantity. In the case of the phytoremediation of polluted soils treated with fertilizer and volcanic tuff, the efficiency of the petroleum hydrocarbons reduction was 72.9% for Vicia sativa and 53.7% for Glycine max.

The effects of vegetation with herbaceous species Lolium perenne were assessed in different experimental variants using: thermal plant slag and fy ash topsoil fertilised with slaughterhouse sludge or sewage sludge. The amounts of fertilizer agent ranged between 5.0–25.0 t ha–1. The study was conducted over a period of two consecutive years of herbaceous culture. Fertilization process efficiency were not influenced by the nature of fertilizing agent, but they were directly proportional to the amount of fertilizer used. Using a large amount of fertilizer agent of 25.0 t ha–1 determined the highest yields of green mass. In contrast, the use of small amounts of fertilizer agent, 5.0 t /ha, resulted in the obtaining of seed quantities up to two times higher versus the seed quantities obtained on other experimental variants. During the two years, plants of Lolium perenne formed stable layers of vegetation resistant to hydro-climatic conditions in western Romania, ensuring through fruition the continuity of the restored landscape. Biomass and/ or harvested seeds for optimum phytoremediation variant of slag and fly ash dump will be directed to different sectors after an assessment on metal accumulation in tissues.

In this study are presented in pot experimental variants regarding alternatives to improve the characteristics of soils polluted with 74.12 ± 3.50 g kg-1 D.M. total petroleum hydrocarbon (TPH) in order to apply the phytoremediation process using technical plants from the common flax (Linum usitatissimum). The harmful effects of TPH polluted soils to plants was reduced by using fly ash from thermal plant as temporary adsorbent of non-polar pollutants, petroleum products. The increase of water retention capacity of the soil was achieved by treatments with indigenous volcanic tuff. The lack of nutrients, based on N and P in soils contaminated with TPH rich in C compounds are completed using sewage sludge anaerobically stabilized. The use of appropriate amounts of fly ash and fertilizer agents in the presence of volcanic tuff caused the formation of strong networks of roots and rich harvests of plants, stems and seeds from the treated soil. The TPH reduction efficiency of TPH polluted soils treated with fly ash (TPH soil: fly ash ratio 12:1 wt./wt.) and anaerobically stabilized sewage sludge respectively indigenous volcanic tuff during one vegetative cycle of crops was in the range of 56.2-63.25%.

The study covers the advantages of phytoremediation processes of soils heavily polluted with total petroleum hydrocarbon (TPH) with the use of Linum usitatissimum (flax). To increase the potential development of technical crops on TPH soils polluted with 74.12±3.5 g·kg-1 D.M., the contaminated soils were amended with fly ash; the ratio of polluted soil: fly ash 12:1 wt./wt. and fertilized with sewage sludge. The degree of accumulation of Fe in the stems was 21-33% higher than in the control sample and 6-27% in the seeds; the accumulation of Mn in the stems was 13.5-30% higher than in the control sample and 8-17% in the seeds; the accumulation of Cu in stems was 17-6% higher than in the control sample and for seeds 20-60%; the accumulation of Zn in stems was 13-27% higher than in the control sample with 49-63% in the seeds. In the harvested plant tissues from the studied variants the content of heavy metals Cd, Cr, Pb and Ni was less than the detection limit. Monitoring bioaccumulation of heavy metals in aerial plant tissue was needed to decide the sector where the biomass harvested from TPH polluted soil covered with vegetation.

The phytoremediation of destroyed soil by anthropogenic activities with appropriate species of plants has multiple applications in the treatment of contaminated areas and environmental management. The aim of the study was to determine the abilities of Onobrychis viciifolia species to form a vegetative cover on contaminated soil with 2.86% total petroleum hydrocarbons (TPH) and to assess the degradation efficiency from the rhizosphere. This study is performed on experimental variants of contaminated soil in the absence/presence of the fertilizer agent combined/non-combined with volcanic indigenous tuff. Each experimental variant was done in 3 replicates. The fertilization of contaminated soil with 50 t ha–1 fertilizer agent, municipal sludge anaerobically bio-stabilized (biosolids), combined with indigenous volcanic tuff, 5 t ha–1, determined the vegetation of Onobrychis viciifolia, resistant to prolonged drought. Furthermore, leguminous species, Onobrychis viciifolia, has demonstrated the ability to biodegrade oil products (TPH). The results obtained on the experimental variants fertilized with municipal sludge in the absence/presence of indigenous volcanic tuff showed oil products degradation by 55–70%, after the vegetative cycle (8 weeks). Furthermore, biomass quantity resulted from treated soil with fertilizer agent and volcanic tuff was 50% higher than the amount of biomass that resulted from volcanic tuff untreated experimental variants.