Journal of Hazardous, Toxic, and Radioactive Waste

In the field of wastewater management, it is a challenging issue to develop a cost-effective and environment-friendly adsorbent for the removal of toxic metals. In this study, Vetiveria zizanioides was used as an active bioadsorbent for the removal of Cr(VI) using raw and chemically modified grasses and roots. Batch experiments were conducted using raw and modified bioadsorbents to observe the sorption behavior and to evaluate the performance parameters like pH of the solution, initial concentration, contact time, adsorbent dose, and the system temperature. Results showed that acidic-modified bioadsorbents [i.e., Vetiveria zizanioides grass (AVG) and roots (AVR)] exhibited the highest removal efficiency of Cr(VI) from the synthetic wastewater. Characterization studies were performed to examine the changes in morphology and functional groups of the activated carbon through a scanning electron microscope (SEM) and a Fourier transform infrared spectrometer (FTIR) including proximate and elemental analysis, Brunauer-Emmett-Teller (BET) surface area, and ${\mathrm{pH}}_{zpc}$. Kinetic parameters were determined to achieve equilibrium for the proposed biosorption process and mass transfer resistance was investigated for diffusion rate. Values of $q_{cal}$, i.e., 16.010 and $17.915\mathrm{mg}/\mathrm{g}$ suggested that a pseudo-second-order model was applicable. Adsorbate–adsorbent interaction was investigated by using Langmuir, Freundlich, and Dubinin-Radushkevich isotherms. Maximum adsorption capacity was observed to be 8.429 and $9.199\mathrm{mg}/\mathrm{g}$ using raw Vetiveria zizanioides grass (RVG) and roots (RVR), respectively. Results obtained from thermodynamic study clearly stated that process is endothermic and spontaneous in nature.

The moisture content of process sludges generated by industries is an important problem affecting the cost and convenience of sludge management. Sludge can be dried to decrease its volume and reduce most of the moisture. This research analyzes the microwave drying process of water-based paint sludge from the automotive industry by investigating the influence of dielectric constant, sludge form (raw or ground), drying method (microwave and conventional), drying period, and air curing, and by conducting numerical modeling. The drying period of sewage sludge is also analyzed for comparison. The moisture losses range between 8 and 12% and between 26 and 31% for 5 and 10 min microwave drying periods, respectively. The moisture losses obtained with conventional heating range between 0.2 and 1.2% and between 0.7 and 2.9% for 5 and 10 min drying, respectively. Air curing of the samples following microwave drying results in a 3% increase in the moisture losses. Numerical modeling results show that the dielectric characteristics of the paint sludge might change during the drying process inside the oven and different chemical compositions of the sludges might lead to temperature changes during the drying process. By modeling the microwave oven, it is possible to determine the regions that can dissipate more heat without measuring, which is confirmed with the dissipated power density maps and electric field distribution obtained.

Northeast India is rich in biodiversity; however, in recent decades due to increase in population and demand for economic development, this region has encountered massive changes in its land use. In this study, we analyzed the changes of carbon storage in Assam, Meghalaya, Manipur, Nagaland, and Tripura as a result of land-use conversion and land-use management between 2006 and 2013. Results indicated an increase in settlement areas and agricultural areas at the expense of forest areas and other land-use cover. However, the extent of various land uses varies from state to state. Whereas Assam, Manipur, and Tripura experienced a net accumulation of soil organic carbon (SOC) as a result of land-use conversion by an amount of approximately 3.91, 0.22, 0.13 TgC, SOC declined in Meghalaya and Nagaland by approximately 0.11 and 0.62 TgC, respectively. Assam, Manipur, Meghalaya, and Nagaland experienced net decreases in carbon biomass between 2006 and 2013 by approximately 0.43, 1.51, 0.31, and 0.49 TgC, respectively; however, Tripura experienced a net accumulation of carbon biomass by approximately 0.12 TgC. Fuel wood gathering from forest and grassland management in Northeast (NE) India resulted in significant amounts of carbon emissions. However, there is a regional difference in the amount of changes in carbon stock due to agricultural management. Our result highlights the paramount significance of proper land-use management in NE India in view of reducing carbon emission and in fighting against climate change.

The performance of a microwave applicator loaded with a lossy dielectric sludge material is affected by several factors. In this study, the effect of the geometry, properties, and position of the sludge material load inside the oven on the microwave heating efficiency and electric field distribution were investigated numerically and experimentally. Electric field distribution was simulated for different load geometries, dielectric values, and positions of the sample in different locations inside the oven. The temperature distributions on the sludge samples were experimentally measured and found compatible with the simulation results, which show that the electric field distribution and efficiency of the system are greatly affected. In addition, we found the optimal location to improve the performance of the microwave applicator.

Ruthenium (Ru) was removed from molten borosilicate glass containing simulated radioactive waste by using tin as the solvent metal. The metal and glass phases were separated from each other and examined by X-ray diffraction (XRD), scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDX). The composition of alloy and glass phases was analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES) and atomic absorption spectroscopy (AAS). The percent extraction fraction of Ru was found to be ~90%. Significant quantities of Fe, Te, Ni, and Mo were also found in the alloy phase. Formation of the ${\mathrm{Ru}}_3{\mathrm{Sn}}_7$ intermetallic compound was observed in the Sn-Ru alloy. The recovery of Ru was ~90%. Some amounts of Ni, Fe, Te, and Mo were found to migrate to the metal phase, leaving Cs, Sr, and Zr in the glass phase.

The purpose of this study was to investigate the recycling potential of marble sludge, which is generated from the cutting and grinding of marble. Geopolymerization technology was applied to this aim. Waste marble sludge was combined with cement, fly ash, clay, gypsum, and blast furnace slag in different combinations to prepare paste samples without aggregate. NaSilNaOH and 8 M NaOH solutions were used as alkaline activators for geopolymerization. Samples were analyzed for unconfined compressive strength (UCS), and the formulations yielding the highest UCS results were determined. The sample prepared using the NaSilNaOH solution and containing 25% fly ash, 25% cement, 25% blast furnace slag, and 25% marble sludge yielded the highest UCS level among the samples, 52 MPa. The results of the study showed that marble sludge is a suitable material for geopolymerization purposes and yields high compressive strength compared to standard cement paste.

This study aimed to determine hydrocarbon removal in oil-contaminated soil using composting with an amendment of yard waste and rumen waste. Hydrocarbon-contaminated soil samples from a public oil-mining field in Wonocolo District, Bojonegoro, Indonesia, were composted with yard waste (Y), rumen waste (R), and mixed YR in varied compositions. Manual agitation was applied every 3 days for air supply and homogenization. The experiment was conducted in two replicates in reactors of 3.5 L capacity for 80 days. Moisture was kept within the range of 50–60%. Measurements of temperature, pH, and moisture content were done every 3 days, whereas total Kjeldahl nitrogen (TKN), nitrite, nitrate, total bacterial count, organic carbon, and hydrocarbon concentration were measured every 20 days. The results showed that the highest hydrocarbon removal efficiency (45.26%) was observed in the reactor containing 50% contaminated soil amended with mixed YR. The second- and third-highest hydrocarbon removal efficiencies of 42.11 and 38.33% occurred in contaminated soil reactors to which 50% w/w R and Y were added, respectively. The hydrocarbon removal in these reactors followed first-order kinetics with a rate constant range of $0.006–0.007\mathrm{da}{\mathrm{y}}^{-1}$. In order to meet the quality standard limit for oil-contaminated soil, the estimated composting time was 135–181 days.

The probable impacts of climate change on water resources are of great concern to hydrologists, water managers, and policymakers. The impact of climate change on hydrological variables in the upper Godavari River basin has not been studied and was the focus of this research. Two general circulation model (GCMs), the Hadley Centre Coupled Model, Version 3 (HadCM3) and the Canadian Centre for Climate Modelling and Analysis’s Coupled Global Climate Model, Version 3 (CGCM3), which have been shown to produce good results in India, were used to study climate change impacts in the study area. Downscaled projected results of a statistical downscaling model (SDSM) were used to simulate runoff for future climatic scenarios using the soil and water assessment tool (SWAT). The SWAT model was calibrated using the sequential uncertainty fitting algorithm. The Nash–Sutcliffe efficiency (NSE) and the determination coefficient ($R^2$) were used for performance assessment during calibration and validation. The values of both NSE and $R^2$ were 0.63 during calibration and 0.71 during validation for the daily time step. The SWAT simulation results showed that at the end of the 21st century, the increase in runoff will be 70% and 61% under Scenarios A2 and A1B (obtained using the CGCM3 model) and 47% and 36% under Scenarios A2 and B2 (obtained using the HadCM3 model). Because the downscaling results showed a greater $R^2$ value for the HadCM3 model than for the CGCM3 model, the runoff scenario developed using the HadCM3 model will be used for future water resource planning and management.

Three different concrete models were chosen to calculate contamination of flushing water from concrete wastes of a heavy-ion accelerator facility after 50 years of operation (with $7.2\times {10}^{15}\mathrm{carbon}\mathrm{ions}/\mathrm{year}$) and one year of cool-down time. In addition to the main ingredients, isotopic trace elements such as Eu-151, Eu-153, Co-59, and Cs-133 were included in the chemical composition of the concrete for a more conservative estimation. Monte Carlo N-Particle eXtended (MCNPX) version 2.7.0 and CINDER’ version 90 activation simulation tools were used. After one year of decay time, the sum of the maximum ratio to the permitted limit, $\mathrm{\Sigma }(\text{specific}\text{activity}/\text{permitted}\text{limit})$, was 0.3, which means that the concrete wastes can be recycled with no radiological precautions. However, when water flushed out the activated part of the concrete and resolved the remnant radioactive isotopes into water, the waste water was severely contaminated. Many residual radioactive isotopes with long half-lives such as K-40, Co-60, Cs-134, Eu-152, and Eu-154 exceeded the unrestricted release limits. Thus, great care must be taken when the contaminated water from recyclable concrete wastes is discharged into the environment.

This study identified the environmental policy instruments for a program on environment, health, and safety (EHS) that could impose certain penalties on stakeholders for the improper disposal of spent portable batteries. Stakeholders of the program were obligated physically and financially for a market defined by local area-specific parameters. Expert opinions were taken, and surveys were conducted to quantify the parameters. Obligations of the stakeholders and their interactions in the program constituted the policy for the collection and recycling of portable battery waste management. Noncooperative strategic game modeling was used to review the policies of the EHS program. Equilibria of game models served as the keys to identify the win-win situation and to optimize the incentives to the actors in different modules of the program. Results suggest that the recycler prefers to collect the spent batteries directly from consumers rather than from manufacturers if the incentive to the consumer is less than 7.938% of battery cost and the recycling fee is less than $4,000 per t. Further, the manufacturer prefers outsourced recycling up to 8.5625% of battery cost. Schemes were evaluated economically to formulate policies that would be helpful in developing a stewardship program.

The natural gross radioactivity in milk from farms in different locations in Van and in milk purchased from Kahramanmaraş markets were determined. In the milk samples, natural gross alpha and beta activity concentrations were measured. The evaporation and ashing procedures were applied to the milk samples collected from farms and markets. Nuclear spectroscopic systems containing gas-flow proportional counters were used to measure the gross alpha and beta activity concentrations of the milk samples. The gross radioactivity in milk from markets was generally lower than the gross radioactivity in milk from farms. The annual effective dose resulting from gross radioactivity for adults, children, and infants and excess lifetime cancer risk values were calculated. The highest total annual effective dose (AED) values were $\mathrm{1,105.9}\mathrm{mSv}{\mathrm{y}}^{-1}$ for adults, $\mathrm{6,456.2}\mathrm{mSv}{\mathrm{y}}^{-1}$ for children, and $\mathrm{10,267.0}\mathrm{mSv}{\mathrm{y}}^{-1}$ for infants in milk samples. The excess lifetime cancer risk (ELCR) values from gross alpha and beta activities range from 0.010 to 3.870 in milk samples.

Red mud is the bauxite residue generated from aluminum industries, and due to its low utilization rate, a large volume of red mud in slurry form is stored. The high alkalinity ($\mathrm{pH}>11$) favors leachate and hinders the sedimentation of red mud. Occasional collapse of a red mud reservoir dam like Ajka in Hungary leaves an adverse impact on the greater vicinity due to spreading of red mud particles over a large area. In this research, an attempt has been made to control the dispersive nature of red mud and accelerating sedimentation by adding different additives. Based on pinhole and cylindrical dispersive test, biopolymers (xanthan gum and guar gum) were found to be effective in controlling the dispersiveness of red mud due to the formation of ionic and hydrogen bonds. The high magnitude of the zeta potential ($>30\mathrm{mV}$) of red mud slurry was found to be the hindrance in the sedimentation. Phosphogypsum and salt (NaCl) solutions were found effective in reducing the zeta potential and pH, thereby accelerating the rate of sedimentation of the red mud slurry. The column sedimentation test showed that phosphogypsum is more effective in accelerating the rate of sedimentation due to the formation of agglomerated particles as observed in scanning electron micrography.

In the context of waste gas energy recovery and management, the gray relational analysis method is applied to construct the optimum parameters and management of the operation conditions for a heating furnace used in the petrochemical industry. Comparing the results of tail gas recycling, the operational parameters are adjusted and the residual oxygen concentration in flue gases, preheated air temperature, and fuel oil temperature are studied for saving energy. The results show that the efficiency of the heating furnace is improved and the fuel consumption and carbon dioxide emissions are reduced. In addition, gray relational analysis is used to predict the parameters to optimize the operation and best energy saving demand. The results show that the optimal operating conditions are between 3.1% and 2.9% by volume, between 226°C and 232°C, and between 127°C and 129°C for residual oxygen concentration in flue gases, preheated air temperature, and fuel oil temperature, respectively. These values agree with the conditions actually used on-site for the optimum operation of heating furnaces. Therefore, gray relational analysis is the best way to evaluate and manage the operation parameters of a reheating furnace.

Shenfu coal particles with a mean diameter of $71.55\mathrm{\mu m}$ were modified to contain functional surface groups by chemically grafting dithiocarbamate (DTC) onto the coal particles using $\gamma$-aminopropyltriethoxysilane as a coupler. The properties of ${\mathrm{Ni}}^{2+}$ adsorption using the functionalized coal particles were studied using batch experiments and compared with adsorption using the original coal particles. The mechanisms of coal particle modification and adsorption are discussed. Results show that the process of ${\mathrm{Ni}}^{2+}$ adsorption onto the functionalized coal particles follows pseudo-second-order kinetics. The adsorption isotherm of ${\mathrm{Ni}}^{2+}$ on functionalized coal particles can be described by the Langmuir model. The amount of saturated monomolecular layer adsorption ($Q^0$) onto the functionalized coal particles for ${\mathrm{Ni}}^{2+}$ was found to be $82.37\mathrm{mg}/\mathrm{g}$, which is much higher than that found for the original coal particles. The related thermodynamic parameters, $\mathrm{\Delta }H$ and $\mathrm{\Delta }G$ of ${\mathrm{Ni}}^{2+}$ adsorption onto functionalized coal particles were negative, indicating that the process is exothermic and spontaneous. The Fourier transform infrared spectroscopy (FTIR) spectrum analysis illustrated that the DTC grafted onto the surface of the coal particles and successfully reacted with ${\mathrm{Ni}}^{2+}$ from the aqueous solution. The specific surface area analysis showed that the specific surface area of functionalized coal particles was $7.9126\mathrm{mg}/\mathrm{g}$, which was much higher than that of original coal particles ($2.0618\mathrm{mg}/\mathrm{g}$). The scanning electron microscopy (SEM) analysis showed that the surfaces of functionalized coal particles were rougher than original coal particles. The paper concludes that functionalized coal with chelating groups is an efficient way to improve the adsorption capacity of coal used for removing heavy metal ions from aqueous solutions.

Riverbank filtration (RBF) is a simple yet effective treatment technology that uses the natural soil and aquifer media to remove various pollutants from river water during induced infiltration of river water to pumping wells. However, RBF may not be capable of fully removing chemicals of emerging concern such as personal care products, household chemicals, and pharmaceutically active compounds. As a result, additional treatment systems may be needed. Aquifer storage and recovery (ASR) may be one of the options to further improve water quality. In other instances, advanced oxidative treatment of the bank filtrate prior to ASR may also further improve quality. In RBF–ASR coupled systems, bank filtrate is again injected into the aquifer, stored, and then pumped out. A major application for coupling RBF and ASR is to store water to meet peak demands. This is applicable in developed and developing countries to cope with high demand during droughts.

Polychlorinated biphenyl (PCB), metal, and chlorine contents of samples—including waste mineral oil, engine oil, edible oil, oily waste (industrial/domestic), and number 10 lube (NTL)—were investigated to evaluate possible hazards to the environment. Analyses were conducted using Turkish and United States Environmental Protection Agency standards. The results showed an uneven distribution of pollutants among all type of samples or samples that were collected from the same area at different time intervals. Although PCB usage was banned in Turkey many years ago, indicator PCB congeners were observed in NTL samples that were predominantly used as alternative fuel in heavy duty diesel engines. Waste oil and oily waste samples should be recycled as raw materials and/or recovered as an energy source, but the findings of this study yields disposal as a hazardous material due to high metal (Cr) content. The overall results of the study show that uncontrolled combustion of waste oil and oily wastes may cause environmental problems, and use of these wastes and products should be controlled and managed by strict precautions.

This paper is the first in a series presenting engineering data sets that successfully supported the permit approval process in a US midwestern state bordering the Great Lakes to use air-cooled blast furnace (ACBF) slag for phosphate removal in passive stormwater runoff systems. The ACBF slag aggregates under consideration function as reactive base/subbase layers beneath porous pavement installations. Mineralogically, the ACBF slag was dominated by akermanite (${\mathrm{Ca}}_2{\mathrm{MgSi}}_2{\mathrm{O}}_7$) and gehlenite (${\mathrm{Ca}}_2{\mathrm{Al}}_2{\mathrm{SiO}}_7$), with a considerable amorphous phase as determined by quantitative X-ray diffraction (QXRD). ACBF slag samples taken from three different northern Indiana steel mills were tested for the United States Environmental Protection Agency (USEPA) target analyte list (TAL) metals after digestion for total content and after deionized water (DIW) leaching. Comparisons between the three strongly alkaline ACBF slags showed remarkable similarity, with many analytes below quantifiable limits due to their low levels. Synthetic precipitation leaching procedure (SPLP), toxicity characteristic leaching procedure (TCLP), and pH-dependent leaching (USEPA Method 1313) tests were also conducted. Comparisons of total content and SPLP concentrations with typical soils and soil-like media showed that the ACBF slag was often associated with a higher environmental quality. Above $\mathrm{pH}=8$, the USEPA Method 1313 leaching of the Resource Conservation and Recovery Act metals was either not detected or was compliant with US federal drinking water criteria, illustrating that the naturally alkaline ACBF slag media are safe to use for passive water treatment. Moreover, acute ecotoxicity testing on ACBF slag leachates using C. dubia and P. promelas showed greater than 90% survival rate.

This paper is the second in a series on the potential use of air-cooled blast furnace (ACBF) slag for phosphate (${\mathrm{PO}}_4$) removal from passive stormwater runoff systems—that is, the ACBF slag aggregates function as reactive base/subbase layers beneath porous pavement systems. Batch tests containing simulated stormwater stock solutions of 1, 5, and $10\mathrm{mg}/\mathrm{L}$ ${\mathrm{PO}}_4$ were equilibrated with AASHTO Nos. 10, 67, and 3 ACBF slags for various periods up to 72 h and showed rapid uptake of ${\mathrm{PO}}_4$. More than 90% ${\mathrm{PO}}_4$ removal was achieved by the AASHTO No. 10 ACBF slag for all dosing levels and time intervals, and the AASHTO No. 67 ACBF slag attained similar performance after an hour of contact time. The AASHTO No. 3 ACBF slag media attained $\ge 50\%$ ${\mathrm{PO}}_4$ removal at the $1\mathrm{mg}/\mathrm{L}$ ${\mathrm{PO}}_4$ dosing level for all time intervals. Batch testing at the $1\mathrm{mg}/\mathrm{L}$ ${\mathrm{PO}}_4$ dosing level typically showed $\mathrm{pH}>9$ for all ACBF slags, and often $\mathrm{pH}\gg 9$ due to the strongly alkaline nature of ACBF slag. Conversely, a flow-through test mold containing a 15.2-cm (6-in.) thick compacted AASHTO No. 67 ACBF slag media subjected to 24 h wet/dry cycles of inundation by a $1\mathrm{mg}/\mathrm{L}$ ${\mathrm{PO}}_4$ solution maintained $\mathrm{pH}<9$ while removing $>50\%$ ${\mathrm{PO}}_4$ for 33 cycles. The measured and estimated total ${\mathrm{PO}}_4$ uptake for the AASHTO Nos. 67 and 3 ACBF slags, respectively, were used as inputs to a stormwater management model to estimate the service life of the ACBF slags for ${\mathrm{PO}}_4$ removal in three land use applications. An AASHTO Nos. 67 and 3 ACBF slag layered system with respective thicknesses of 15.2 cm (6 in.) and 76.2 cm (30 in.) was estimated to yield an average service life of 10 years for five selected cities on the Great Lakes evaluated in the model, and then also end with as little as 20% site coverage or equivalent gallery volume.

In India, coal-based thermal power stations presently share approximately 70% of the total power demand and generate 184 million tons of ash per annum, and this amount is expected to surpass 440 million tons per year in 2030. Due to its high content of plant nutrients and similar physicochemical characteristics, coal ash can potentially be utilized in agriculture, as well as wasteland and acidic soil reclamation. The purpose of this study was to examine the impact of ash on carrot cultivation under controlled conditions because the plant root is the part responsible for the uptake of nutrients from the soil and for the storage of food and nutrients. The current work is focused on carrot crop cultivation in fly ash–treated soil and elemental distribution patterns in soil, coal ash, and plant parts.

The stone crushing industry has doubled in size in India in the last decade because aggregate has been the most useful raw material for various structures. However, during crushing of stone aggregates in quarries, huge amounts of stone dust get generated as by-products at every quarry site, which raises the problems of safe disposal and can cause environmental hazards. The proper utilization or environment-friendly disposal of this stone dust is of concern. In this paper, a series of experimental studies were performed to investigate the interface shear strength property of expanded polystyrene (EPS) geofoam to stone dust and geofoam to geofoam using direct shear testing in dry and wet conditions. In addition, the internal shear strength behaviors of unit geofoam blocks were investigated through direct shear tests in dry and wet conditions. In order to examine the effect of density on the interface shear strength behaviors, three different densities of geofoam (12, 15, and $20\mathrm{kg}/{\mathrm{m}}^3$) were used. The effect of stone dust layer thickness and normal stress on the interface shear strength behaviors were also investigated. The test results revealed that the density of geofoam does not have a significant influence on the EPS/EPS and EPS/stone dust interface strengths. The submergence slightly decreased the EPS/EPS interface strength compared with that in dry conditions for the same density and normal stress level, whereas its effect was found to be much lower on EPS/stone dust interface strength.

The fruit and vegetable markets produce large amounts of waste each year, and the disposal of these wastes is costly, both financially and environmentally. The use of juice industry wastes for biofuel production is very important in terms of potential alternative renewable energy sources (bioethanol, biogas, and biodiesel). In this study, the theoretical biofuel quantities that can be produced from the waste potential generated during the production activities in a food industry (fruit juice) operating in Turkey are calculated. About 127 t of bioethanol can be obtained from these wastes. Using wastes as alternative biofuel is beneficial in terms of lawfully reducing sources of wastes and reducing wastewater burden on biological treatment plants.

Hydromechanical characteristics of sand–bentonite mixtures, which are generally used as geotechnical barriers, are a well-documented research interest. Because bentonite is a relatively costly material, most of the research has been focused on the influence of bentonite on the various engineering characteristics of sand–bentonite mixtures. Most studies have indicated that sand is the major component in these mixtures. While guidelines regarding the design of sand to be used in a sand–bentonite mixture are not readily available, does sand particle size really influence the engineering behavior of a sand–bentonite mixture and, if it does, to what extent is it still a matter of ambiguity? The current study is an attempt to understand the influence of sand particle size on the consolidation characteristics of sand–bentonite mixtures. Fine sand–bentonite and medium sand–bentonite mixes were prepared with sand content ranging from 50 to 90% by dry weight and tested for consolidation characteristics. The results showed that sand particle size has a significance influence on the consolidation behavior of sand–bentonite mixtures. A comparison between the two sand types for any mixtures showed that the mixture with medium sand possessed a higher coefficient of volume change, a lower coefficient of consolidation, and the lowest time to complete 90% of consolidation ($t_{90}$) at any given pressure and proportion of bentonite. In addition to the sand particle size, the proportion and swelling tendency of the bentonite also exhibited a major influence on the consolidation behavior.