Activity of Arylsulphatase in Soil Contaminated with Polycyclic Aromatic Hydrocarbons

Abstract An experiment has been performed to deter-mine the activity of arylsulphatase in soil submitted to pressure of four polycyclic aromatic hydrocarbons: naphthalene, phenanthrene, anthracene, and pyrene, in the amount of: 0, 1,000, 2,000, and 4,000 mg kg−1 dm of soil. Soil samples were also applied some organic sub-stances, such as: cellulose, sucrose, and compost, in the amount of 0 and 9 g kg−1 dm of soil. The experiment was run under laboratory conditions. It was established on soil which belonged to loamy sand. The soil resis-tance (RS) and resilience (RL) indices were computed. It has been discovered that the PAHs stimulated arylsulphatase activity, with anthracene raising the ac-tivity of the enzyme to the highest degree. The activity of arysulphatase depended significantly on the dose of a PAH, duration of pressure, and type of organic sub-stances added to soil. The highest resistance (RS) was determined in soil exposed to phenanthrene, and the lowest one—in soil polluted with pyrene. Low values of the RL index prove that polycyclic aromatic hydro-carbons cause lasting disorders in the activity of arylsulphatase

The effect of nitrogen on the microbiological and biochemical properties of zinc-contaminated soil

The aim of  these studies was to determine the influence of excessive zinc doses on the microbiological and enzymatic properties of soil. Also, an evaluation of the possibility to stimulate remediation processes by nitrogen fertilisation of the soil was attempted. Zinc was applied to loamy sand in the amounts of 0, 250, 500, 750, 1000, 1250 mg Zn2+ kg–1 DM soil, while nitrogen in the form of urea in doses of 0, 250, 500 mg N kg–1 DM soil. Soil samples were incubated at a temperature of 25 °C, maintaining a constant humidity equal to 50% of the maximum water capacity. In the 2nd and 20th week of the experiment, the following factors were determined: activity of dehydrogenases and catalase, and number of organotrophic bacteria, copiotrophic bacteria, oligotrophic bacteria, actinomycetes, and fungi. Zinc inhibited the enzymatic activity of the soil, while causing a slight increase in populations of microorganisms. Only fungi reacted unequivocally positively to contamination of the soil with zinc, therefore demonstrating changes in the biodiversity of microorganisms. Nitrogen fertilisation of the soil resulted in stabilization of the environment contaminated with zinc by stimulation of growth of microorganisms resistant to the influence of this metal

Mitigation of the Adverse Impact of Copper, Nickel, and Zinc on Soil Microorganisms and Enzymes by Mineral Sorbents

Despite numerous studies on the influence of heavy metals on soil health, the search for effective, eco-friendly, and economically viable remediation substances is far from over. This encouraged us to carry out a study under strictly controlled conditions to test the effects of Cu2+, Ni2+, and Zn2+ added to soil in amounts of 150 mg·kg−1 d.m. of soil on the soil microbiome, on the activity of two oxidoreductases and five hydrolases, and on the growth and development of the sunflower Helianthus annunus L. The remediation substances were a molecular sieve, halloysite, sepiolite, expanded clay, zeolite, and biochar. It has been demonstrated that the most severe turbulences in the soil microbiome, its activity, and the growth of Helianthus annunus L. were caused by Ni2+, followed by Cu2+, and the mildest negative effect was produced by Zn2+. The adverse impact of heavy metals on the soil microbiome and its activity was alleviated by the applied sorbents. Their application also contributed to the increased biomass of plants, which is significant for the successful phytoextraction of these metals from soil. Irrespective of which property was analysed, sepiolite can be recommended for the remediation of soil polluted with Ni2+ and zeolite—for soil polluted with Cu2+ and Zn2+. Both sorbents mitigated to the highest degree disturbances caused by the tested metals in the soil environment

Effect of Bentonite and Barley Straw on the Restoration of the Biological Quality of Agriculture Soil Contaminated with the Herbicide Successor T 550 SE

Environmentally safe ways are sought to prevent the accumulation and to accelerate the degradation of herbicide active substances in agricultural soil. This study aimed to determine the effectiveness of finely-ground barley straw and bentonite in mitigating the effects of agricultural soil contamination with Successor T 550 SE. This herbicide was applied in the following doses: 0, 0.73, and 14.63 mg of the active substance per kg. The bentonite and spring barley straw were used at 10 g/kg. The action of these additives was compared to soil without the addition of straw and bentonite. The application of the experimental herbicide disturbed microbial systems, such as organotrophic bacteria, oligotrophic bacteria and their spores, actinobacteria, and fungi. A positive response to the herbicide dose of 14.63 mg a.s./kg was observed only for spores of oligotrophic bacteria. Further disturbances were observed in the agricultural soil biochemical properties, i.e., in the activity of dehydrogenases, urease, catalase, acid, and alkaline phosphatase, arylsulfatase, and β-glucosidase. A significant decrease in the activity of dehydrogenases, acid phosphatase, and arylsulfatase was observed following the application of 14.63 mg a.s./kg. The yield of maize decreased following the application of the analysed plant protection agent. Based on the soil quality index (BA), the addition of straw was more effective in restoring soil homeostasis than bentonite. Both bentonite and straw can be successfully used to improve agricultural soil biological activity. However, more effective mitigation of the negative effects of the herbicide in soil was observed in objects supplemented with barley straw. This improved the microbiological and biochemical properties of the soil. Barley straw was more effective than bentonite in restoring soil biological balance