Clean Soil Research Articles

Utilization of Rice Husks into Biochar and Nanosilica: For Clean Energy, Soil Fertility and Green Nanotechnology

Utilization of Rice Husks into Biochar and Nanosilica: For Clean Energy, Soil Fertility and Green Nanotechnology

Cover Picture: Clean Soil Air Water. 2/2020

Cover Picture: Clean Soil Air Water. 2/2020

Lead Impact on the Earthworm Eisenia fetida and Earthworm Recovery after Exposure

This study investigates the effects of lead (Pb) on earthworm Eisenia fetida and its potential to recover from Pb exposure. Adult earthworms E. fetida were exposed for 4 weeks to lead (40–2500 mg Pb kg−1) in soil, and after the period of exposure, earthworms were transferred to clean unpolluted soil for 4 weeks to recover. Pb had no effect on the earthworm’s survival but inhibited earthworm growth; growth rate decreased with Pb concentration in the soil. During the recovery period, Pb pre-exposed earthworms did not manage to recover completely their growth. Lead had a highly significant effect on the malondialdehyde (MDA) concentration during both exposure and recovery periods. Pb showed concentration dependent toxicity relationships (weight, lipid peroxidation) for total earthworm Pb concentration. However, earthworm Pb bioconcentrations after recovery period could not explain the higher MDA concentration and lower earthworm fresh weight. Earthworms pre-exposed to low Pb levels have the potential to recover their growth and decrease Pb bioconcentrations, though more prolonged recovery period is needed to full recovery.

Investigations of electrophysical monitoring in a full-scale experiment to clean soil contaminated with oil

This article presents the main results of the study of electrophysical processes occurring in the zone of electrical processing during the cleaning of soils from oil pollution. The main conclusions are formulated about the processes occurring in the electric processing zone by changing the relative electrical resistance of the soil, which was measured using microprobe sensors. A comparative analysis of the results of a laboratory experiment on the electrochemical cleaning of contaminated soil in a tank is carried out with the results of a full-scale experiment conducted on a plot of a soil mass in real conditions, but artificially contaminated with oil products (gasoline, used oil. Using single measurements of electrical resistivity by microprobe sensors, the spread of the pollutant in the soil was clarified , the relationship between the physical properties of the array and its electrical wire is established conductive properties. Confirmed high efficiency of this type of control in the study of complex processes occurring in the contaminated ground array.

Cover Picture: Clean Soil Air Water. 1/2020

Cover Picture: Clean Soil Air Water. 1/2020

Study of the Processes of Electroosmotic Cleaning of Soils from Oil Pollution on a Three-dimensional Physical Model

The methods and results of laboratory modeling of processes in clay soils contaminated with oily substances are reviewed: on samples, on one-dimensional and three-dimensional physical models. Laboratory facili- ties, the procedure for conducting experiments and processing their results are described. The possibility of a point and integral forecast of the degree of soil contamination by the results of measurements of its electrical re- sistance is confirmed. The dynamics of changes in porosity, humidity, and particle size distribution of oil-contaminated soils during electric treatment as a result of thermal and osmotic effects by comparing direct measure- ment data and electrophysical monitoring using a system of micro-sensors was revealed. A comparison of the results of the electric treatment of clean soil, contaminated with liquid and viscous oil products is given.

ОЦЕНКА ВЛИЯНИЯ БЕНЗ(А)ПИРЕНА НА БИОЛОГИЧЕСКУЮ АКТИВНОСТЬ ЧЕРНОЗЕМА РОСТОВСКОЙ ОБЛАСТИ

Актуальность исследования обусловлена необходимостью оценить влияние многолетнего токсического загрязнения полициклическими ароматическими углеводородами с использованием ярового ячменя (Hordeum sativum distichum) на ферментативную активность черноземов и морфометрические показатели ячменя. Яровой ячмень использовали для оценки отрицательного влияния загрязнения чернозема бензо[а]пиреном как признанным канцерогеном и мутагеном среди полициклических ароматических углеводородов. Выбранные дозы были близки к уровню техногенного давления в исследуемой зоне – 0–800 мкг кг–1 бензо[а]пирена. Содержание бензо[а]пирена в почве в течение 4 лет эксперимента повлияло на морфометрические показатели ячменя и поглощение растениями, а также на ферментативную активность почв. Цель: оценить влияние бензо[а]пирена на биологическую активность чернозема Ростовской области. Объекты. Исследования проводились с образцом почвы, отобранным из верхнего (0–20 см) слоя чернозема обыкновенного карбонатного тяжелосуглинистого на территории Государственного почвенного заповедника «Персиановская заповедная степь», расположенного в Ростовской области (юг Российской Федерации), вдали от источников загрязнения. Данная почва имеет следующие характеристики: Corg – 3,4 %, pH – 7,3, емкость катионного обмена – 37,1 ммоль (+)/100 г; содержание CaCO3 – 0,1 %, содержание физической глины – 53,1 %. Методы. Модельные эксперименты проводили в естественных условиях. Два килограмма воздушно-сухой почвы просеивали через сито диаметром 1 мм и помещали в вегетационные сосуды объемом 4 литра. Раствор бензо[а]пирена в ацетонитриле перемешивали с почвой для создания концентраций бензо[а]пирена в образцах почвы, равных 20, 200, 400 и 800 мкг кг–1 (сухой вес), что соответствует 1, 10, 20 и 40 уровням предельно-допустимой концентрации бензо[а]пирена, соответственно. Незагрязненная почва использовалась в качестве контроля, фоновым образцом служил образец с внесением ацетонитрила аналогично образцам с бензо[а]пиреном. Результаты. Основным фактором, обуславливающим увеличение содержания бензо[а]пирена в черноземе обыкновенном и растениях модельного эксперимента, была доза внесения токсиканта в чернозем обыкновенный. Активность оксидоредуктаз (каталазы и дегидрогеназы) чернозема была ингибирована с ростом содержания бензо[а]пирена в почве. Наибольшее токсическое действие бензо[а]пирена оказал на активность дегидрогеназ. Тенденции выраженной фитотоксичности почв наблюдали для всех морфометрических показателей ярового ячменя, таких как энергия прорастания, длина побегов, вес растений и длина колоса. Количественные уровни поглощения бензо[а]пирена корнями ярового ячменя превышали уровнипоглощения в вегетативной части более чем в 2,5 раза во всех загрязненных вариантах. Таким образом, переход бензо[а]пирена в побеги и корни ярового ячменя из чернозема, сопровождающийся ингибированием активности дегидрогеназы и каталазы, демонстрирует оценку воздействия полютанта на живые организмы.

Effects of Fly Ash and Granulated Ground Blast Furnace Slag on Stabilization of Crude Oil Contamination Sandy Soil

This paper deals with on stabilization of crude oil-contaminated soil. Industrial waste materials such as GGBFS and fly ash (FA) are used to achieve acceptable results for compaction and strength properties. GGBFS and FA utilized in two groups of soil (clean soil and 6% contaminated with crude oil) with varying proportions of GGBFS and FA by weight of soil. The primary goals of this study explain to establish a conclusion that GGBFS and FA are the best byproduct stabilizer material for increasing the strength and stability of soil by investigating samples of soil. In this study, the effect of GGBFS and FA on compaction properties (OMC and MDD) and direct shear strength (cohesion and angle of friction) observed. Different percentages of GGBFS (0%, 10%, and 15%) and FA (0%, 10%, and 15%) by dry weight were utilized in mixtures of sandy soil samples for different experiments. Ultimately, bases on the experimental results, it is summarized that the use of industrial wastes, i.e. GGBFS and Flyash, are affected in shear strength and compaction properties. Although, they have environment-friendly behavior for the construction project purpose.

Cover Picture: Clean Soil Air Water. 12/2019

Cover Picture: Clean Soil Air Water. 12/2019

Atmospheric deposition of hazardous elements and its accumulation in both soil and grain of winter wheat in a lead-zinc smelter contaminated area, Central China

Hazardous elements (HEs) and its deposition from atmosphere have become a major healthy and environmental concern worldwide, however, the risks to food safety of deposited HE are still largely unknown, especially for wheat grains (Triticum aestivum L.). This research was to characterize atmospheric deposition of high HEs [such as lead (Pb), cadmium (Cd) and arsenic (As)] at deposited site (TS) and assess its impacts on the soil and winter wheat accumulation in a lead‑zinc smelter contaminated area of Central China. Results indicated that deposited As, Cd and Pb at TS site were 31.15, 15.94 and 281.86 mg m−2 during the winter wheat growing season, contributing 86.9%, 81.7% and 80.4% to the annual total, respectively. Most of deposited HEs were retained in top 35-cm soil, resulting in soil Cd concentration above the national soil regulatory limit (0.6 mg kg−1; GB 15618-2018). The newly deposited HEs could contribute 57.7–88.2% and 16.2–29.1% to total HEs of wheat grains in clean soil based on a soil transplanted experiment and in contaminated soil based on a two-year in-situ experiment, respectively. Moreover, the newly deposited HEs significantly increased HE concentration of wheat grain by 22.9–57.5% in the contaminated soil when an immobilizing amendment were applied (p < 0.05), and grain Cd concentration exceeded the national grain limit (0.1 mg kg−1; GB 2762-2017). Thus, deposited HE could be accumulated in soil and wheat grain and decrease the remediation effectiveness of passivation amendments in contaminated soils, which would raise a public awareness of HE deposition and provide a scientific data in support of environmental pollution control and remediation.

Treatment of diesel-contaminated soil using thermal water vapor arc plasma.

Soil pollution with petroleum-based fuels is a serious issue causing environmental problems. Recently, the use of plasma technologies for soil remediation has shown an interest and great potential. The remediation process can be performed in a fast timeframe without adding supplementary chemical reagents or without additional pre-treatment of the polluted soil. As a result, the use of plasma enables to obtain highly effective degradation of pollutants. Thus, in the present experimental research, diesel fuel removal from contaminated soil by utilizing thermal water vapor arc plasma was investigated. It was found that increased concentration of diesel fuel in the soil raised carbon and hydrogen concentrations in the soil. Moreover, soil surface morphology was modified by causing the formation of bigger agglomerates. It was also determined that after the plasma treatment process, soil grains became akin in size and structure to clean soil grains. A complete desorption of carbon, which came from diesel fuel to the soil, and a slight decomposition of organic carbon present in the soil were observed during the soil remediation process. Thermogravimetric analysis showed that regardless of the diesel fuel concentration in the soil, four stages of mass loss were observed: moisture loss, vaporization, and combustion of diesel fuel as well as reduction of volatiles and char in the soil. Producer gas analysis indicated that during soil remediation diesel fuel was mainly converted to synthesis gas, i.e., a mixture of H2, CO, and CO2. Moreover, the decomposition of diesel fuel and the formation of synthesis gas depended on the amount of pollutant in the soil. According to the obtained results, thermal water vapor arc plasma was able to completely remove diesel fuel from polluted soil in the form of synthesis gas with no significant influence on soil's properties.

Can Local Enhancement in Earthworms Affect the Outcome of the Standard Earthworm Avoidance Test?

Earthworms exhibit clumping behaviour in and out of the soil. However, it remains unknown if such social behaviour ultimately influences the outcome of ecotoxicological experiments in the laboratory. We performed several overnight avoidance tests to determine whether social behaviour (i.e., local enhancement) is a factor in pollution avoidance behaviour in the earthworm Eisenia fetida. The results showed that there was no clear influence of social behaviour on the choice or avoidance of Cd contaminated soils, although we suspect that 50mgCd/kg might not have been high enough to elicit a significant avoidance response. Nevertheless, when offered a choice between clean undisturbed soil and previously inhabited soil, the worms preferred the previously inhabited soil (p < 0.01). While the level of metal pollution investigated in this study did not disrupt or help predict social dynamics, local enhancement, perhaps driven by some sort of habitat imprinting, was successfully documented in Eisenia fetida.

Multisource spectral-integrated estimation of cadmium concentrations in soil using a direct standardization and Spiking algorithm

Benefiting from the advantages of a wide spatial sampling range and strong continuity, hyperspectral analysis provides a potential way to detect heavy metals in soil. However, it is still a great challenge to identify the spectral response characteristics of heavy metals from naturally polluted soil samples. This paper innovatively produces near standard soil samples for exploring the exact spectral response of cadmium (Cd) in soil and presents a novel method by combining the direct standardization (DS) and Spiking algorithms for integrating multisource spectra to improve the accuracy of Cd concentration estimation. A total of 46 naturally polluted soil samples were collected from a known Cd-contaminated mining area in Xiangjiang River Basin, China. The soil spectra of the naturally polluted soil samples were synchronously measured in the field. Moreover, clean soils with low heavy metal contaminants were collected to produce 65 near standard soil samples with known Cd levels. Then, the spectra and Cd concentrations of all 111 soil samples were measured under laboratory conditions. The principle component stepwise regression (PCSR) analysis results illustrated that the reflectance at all the wavelengths (380–2460 nm) is indicative of the differences in the soil Cd concentrations. Among these, the sensitivity of the spectral reflectance is the strongest at approximately 400 nm, 1000 nm and above 2300 nm. Additionally, the integrated multisource spectra significantly improved the accuracy of soil Cd concentration estimation (coefficient of determination, R2 = 0.96; root mean square error, RMSE = 0.29; ratio of prediction to deviation, RPD = 1.21) when 30 transfer samples and 15 training samples were simultaneously implemented in the combined DS and Spiking algorithm. This will provide a feasible scheme for exploration of spectral response characteristics of multiple soil heavy metals, and highlight the potential of developing low-level and satellite remote sensing on a large scale.

Cover Picture: Clean Soil Air Water. 11/2019

Cover Picture: Clean Soil Air Water. 11/2019

PENGELOLAAN LIMBAH BAHAN BERBAHAYA DAN BERACUN DI PERGURUAN TINGGI KOTA BALIKPAPAN

Management of hazardous and toxic waste is one of the most important things in handling waste for better nature. Good management can result in a clean water, air and soil environment, good quality of human life and a balanced human future.

City Branding and Industrial Transformation from Manufacturing to Services: Which Pathways do Cities in Central China Follow?

A potentially attractive way for cities to maintain economic growth while reducing environmental harm is to let their production structures undergo industrial transformation, a process otherwise known as ecological modernization. This attraction lies mainly in the fact that residents, visitors and corporations prefer clean air, water and soil as a milieu to invest their resources in. Municipal governments can use city branding as an important instrument to force off such a transformation, if it is taken as a point of departure for the adoption of a strategy to which they are deeply committed and for the benefit of which they are willing to deploy their various policy instruments. In the literature on ecological modernization, five different pathways for industrial transformation in cities have been identified and these have been matched with city branding practices. In this contribution, the abovementioned conceptual framework is further detailed and specified to account for a variety in types of secondary and tertiary sector industries. In the empirical sections, all cities in the Chinese provinces Hubei and Hunan, where the transition from manufacturing to services is typically most pressing, are examined in terms of their industrial structures, pathways to industrial transformation and city branding choices. The results indicate, inter alia, that further subdivision of the secondary and tertiary economic sectors is useful in understanding key features of the transformation, and that different sub-pathways affect tradeoffs between economic expansion and ecological preservation differently. Branding practices among Hubei and Hunan cities also indicate that some industries are more easily embraced and utilized than others in establishing brand identities and adopting popular city labels.

Phytotoxic assessment of sewage treatment methods in disposal sites

The paper presents the assessment of the impact of disposal sites on biota through definition of phytotoxic influence of polluted soil and landfill leachate on seedlings, growth and root system of plants Triticum aestivum. It is found that soil collected around a disposal site of municipal solid waste, the seedlings of plants are 16% lower in comparison with standard (clean soil), the length of a land part is 22% lower, the average length of roots is 44% less. The green weight of top and the weight of a root system of plants in the soil from a disposal site is 52% and 43% less respectively. This influence is characterized as above the average toxicity level. It is defined that with the introduction of Sviteco-PBG prebiotic (10% dilution) to the polluted soil the seedlings of plants are 5.2% better in comparison with the polluted soil without the prebiotic, the length of a land part – by 11.6%, the average length of roots – by 40.2% respectively; the green weight of top and the weight of a root system of plants is 14% and 16.5% higher in comparison with the polluted soil without the prebiotic. Thus, the use of prebiotics allows improving the quality of soil and reducing its phytotoxicity. In particular, if the influence on a root system of the polluted soil is characterized as toxic above the average, then after the application of prebiotics – as the average toxicity by root weight and absent (weak) toxicity by root length. It is found that when Sviteco-PBG (10% dilution) and Ca(OH)2 are added to sewage waters of a MSW dump at pH 10, their maximum purification from heavy metals is reached, the phytotoxic effect is estimated as weak toxicity. The phytotoxic effect of the polluted filtrate without purification – above the average toxicity. Thus, prebiotics allow improving the efficiency of soil cleanup from heavy metals, giving an opportunity in the long term to return contaminated land to their economic circulation. Ca(OH)2 and Sviteco-PBG (10% dilution) at pH 10 allows improving the quality of technogenically polluted soil, reducing toxic impact on biota and increasing the efficiency of sewage treatment in waste disposal sites.

NAFTOS PRODUKTŲ GARAVIMO EKSPERIMENTINIAI TYRIMAI / EXPERIMENTAL RESEARCH OF PETROLEUM PRODUCTS EVAPORATION

Oil products are usually released into the environment during transportation of oil, from storage, oil bases or accidents, accounting for about 60% of total soil pollution. Heavy metals, phenols, cyanides, aromatic hydrocarbons (benzene, toluene, ethylbenzene, xylene) also enter the soil together with oil products. After the contamination enters the soil, it affects the pH of the soil, the activity of the biota weakens due to the toxic elements that react with oxygen, the soil degradation increases. In the course of the dissemination of these pollutants, not only the soil, but also groundwater is contaminated – pollution by oil products and heavy metals creates 53% of all groundwater pollution. The aim of the research is to determine the lowest possible optimal temperature by choosing the temperature range of the heating temperature (100−300 °C) and to investigate the dependence of evaporation of oil products on the heating time. The minimum temperature is required to preserve the soil’s properties, reduce the amount of energy used and the cost of the method. During the heat treatment of the selected oil products, the vapor passes through the condenser and is collected in the form of a liquid, avoiding leaks, which is a safe way if toxic substances are potentially exposed at the site of heating (the method safely removes pollutants from mixtures). It has been established that in the temperature range 250−300 °C, clean oil evaporates intensively and achieve 90.1−97.1% efficiency over 2 hours and the maximum evaporation rate is at the first hour, in the case of used oil, an efficiency of 38.6−60.6% is achieved and vapor intensity at maximum after 2 hours of evaporation. This heating technology can be used to clean heavy soil fractions from contaminated oil products, and comparatively low temperatures (250−300 °C) will have less harm to soil properties than high-temperature methods (burning, glazing, pyrolysis).

Cover Picture: Clean Soil Air Water. 10/2019

Cover Picture: Clean Soil Air Water. 10/2019

Hematite-facilitated pyrolysis: An innovative method for remediating soils contaminated with heavy hydrocarbons

As a recalcitrant fraction of petroleum, heavy hydrocarbons (including aromatics, resins, and asphaltenes) can remain in contaminated soils even after decades of weathering, thereby causing serious harm to the soil ecosystem and human health. Pyrolysis is a promising technique for remediating petroleum-contaminated soil. However, this technique still presents some drawbacks, such as high energy consumption and damage to soil properties. Therefore, an innovative method using hematite (Fe2O3) for the catalytic pyrolysis of weathered petroleum-contaminated soil was developed in this study. Compared with soil pyrolyzed without Fe2O3 at 400 °C for 30 min, the residual concentrations of aromatics, resins, and asphaltenes in soil pyrolyzed with 5.0% Fe2O3 were reduced by 67.8%, 52.3%, and 67.9%, respectively. After pyrolysis with 5.0% Fe2O3, the water-holding capacity of soil was considerably increased and the soil became darker and rougher. Scanning electron microscopy analysis showed that many small holes occurred on the surface of the pyrolytic soil. X-ray photoelectron spectrometer analysis showed that a thin layer of graphitic C was formed and deposited on the surface of the pyrolytic soil. We also observed that the wheat germination percentage and biomass yield in the soil pyrolyzed with 5.0% Fe2O3 were even higher than those in clean soil.