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PubMedDate not supplied

In situ monitoring of soil dissolution dynamics: a rapid and simple method for determining worst-case soils for cleaning validation.

A common approach utilized in validating the cleaning of multi-product equipment is to challenge the cleaning cycle with the hardest-to-clean, or "worst-case", soil. The worst-case soil is often determined through bench-scale experiments. These experiments can be tricky and time-consuming, especially when the dissolution dynamics of the soils are characterized by crossovers beyond the limit of visual detection. This paper describes a simple in situ method for monitoring soil dissolution dynamics and rapidly determining worst-case soils for cleaning validation. The method utilizes the real-time response of electrical conductivity to identify crossovers and to determine the optimal time for endpoint analysis. The results address the sensitivity and reproducibility of the method and the identification of critical experimental parameters. The dissolution dynamics of several parenteral products are compared.

Drug Contamination↗
PubMed2004

[Determination of soil organic carbon adsorption coefficients of pollutants using soil column liquid chromatography with stepwise adsorption].

A novel method for the determination of soil organic carbon adsorption coefficients (K(oc)) of pollutants was established using soil column liquid chromatography with stepwise adsorption. With this method the adsorption amount of samples at various concentrations on soil can be obtained in a single experiment. The values of K(oc) can be calculated through adsorption isotherms. The soil column can be used without change or desorption throughout the whole experiment. This method leads to a shorter experimental duration, simplified experimental procedure and experimental error reduction. The values of log K(oc) for tebuconazole, azinphos-methyl, diuron, atrazine, prometryn, phenol and naphthalene on the European reference soil of 3# were measured to be 2.70, 2.87, 2.47, 2.26, 3.09, 1.51 and 2.77, respectively, which are consistent with the values reported in the literature.

Adsorption↗
PubMed1987

[Iron, manganese and cobalt levels in soil, pasture grass and bodies of young bulls after irrigation of the soil with waste water].

The effect of irrigation of meadows with the water of the river. Ner on the levels of iron, manganese and cobalt in the soil and vegetation was studied. Experiments were also carried out on 30 young bulls fed with the hay grown on these meadows. The levels of iron and cobalt were determined in the blood plasma, and the manganese level in the hair of the bulls. The experiments were carried out twice during 93 days. The animals were divided into 3 groups. Group I and II received the hay from the irrigated meadows (group II received the hay from the meadows more intensively irrigated). Group III (control) received hay from non-irrigated meadows. The daily diet consisted of 5 kg of hay and 3 kg of dried sugar beet residues. It was found that the irrigation caused an increase of iron content of the soil and the vegetation. This increase was proportional to the degree of irrigation. The iron level in the blood plasma of the bulls from group I, II and III did not show significant differences. The irrigation caused an increase of the manganese content the soil but the plants growing on this soil contained less manganese than those growing on non-irrigated meadows. There were no differences between the manganese content of the hair of the bulls from the three groups. The irrigation caused an increase of the cobalt content in the soil but it had no effect on cobalt content in the plants and the blood plasma of the bulls.

Animal Feed↗
PubMed1986

[Sodium and potassium levels in the soil, grass and blood serum of bulls after irrigation of the soil with sewage water].

The main purpose of the studies was to find the influence of a long-term irrigation with the water of the Ner river, containing sewage on the content of sodium and potassium in soil, its vegetation and in the blood serum of the bulls fed on the hay from the meadows irrigated with this water. The soil irrigated with drain water and its vegetation were analysed and the bulls of the Black and White breed fed on the hay from the irrigated meadows were examined carefully. There were 30 bulla tested. Their initial average weight was 250 kilograms. The experiment was repeated twice. It lasted 93 days each time. The animals were divided into three groups. The animals from group 1 and 2 received the hay from the meadow irrigated with drain water. The animals from group 2 were fed on the hay from the meadow with a higher dose of irrigation. The animals from the third group were given the hay from the meadows which were not irrigated. The daily ration of food consisted of 5 kilograms of hay and 3 kilograms of dry beet pulp. The available forms of Na2O and K2O were determined in the soil on a flame photometer. Sodium and potassium in the samples of plants were determined using the atomic absorptive spectrophotometry method (AAS). Botanical and weight analyses were also done. Blood samples were taken once a month. Sodium and potassium in blood serum were determined by AAS method. The amount of sodium in the soil and hay on the meadows irrigated with drain water was significantly higher, and the amount of potassium was lower in comparison with the amount of sodium and potassium in the soil and hay on non-irrigated meadows. The content of sodium increased with the increase of the irrigation rate. According to the experimental fodder no changes were observed in the bulls' blood serum as regards the amount of sodium and potassium.

Animal Feed↗
PubMed1979

Pesticide residue levels in soils and crops from 37 states, 1972--National Soils Monitoring Program (IV).

Residue data from the 1972 (FY--73) National Soils Monitoring Program are summarized. Composite samples of agricultural soil and mature crops were collected from 1,483 of the 1,533 selected 4-hectare sites in 37 states. Analyses were performed for organochlorine and organophosphorus compounds, trifluralin and polychlorinated biphenyls (PCBs); analysis for atrazine was performed only when pesticide application data indicated current-year use. Organochlorine pesticides were detected in 45 percent of the soil samples. The most frequently detected compound was dieldrin, found in 27 percent of all soil samples. Other compounds detected, in order of frequency, included DDT, aldrin, chlordane, and heptachlor epoxide, found, respectively, in 21, 9, 8, and 7 percent of all soil samples. Crop samples were collected from 727 sites. All were analyzed for organochlorines; analyses were performed for organophosphates and atrazine only when pesticide application data indicated current-year use. For all crops, 40 percent of the samples contained detectable levels of organochlorines and 10 percent contained detectable levels of organophosphates. Atrazine was not detected.

Agriculture↗
PubMed1982

[Number, species composition and antagonistic properties of Actinomadura from soddy-podzolic soils and from soils in the tundra zone].

Occurrence of Actinomadura in the turf-podzol soils of the Moscow region and in the tundra soils of Taimir was studied. It was found that there were practically no Actinomadura in the tundra soils, while their occurrence in the turf-podzol soils was rather high and amounted to 5 per cent of the actinomycetous flora. The occurrence of Actinomadura in cultured soils was higher and their species composition was more diverse as compared to those in virgin lands. The isolates represented 10 species and only 6 of them were detected in the virgin lands. The Actinomadura cultures showed moderately antagonistic properties when tested with the streak plate method. The majority of the Actinomadura cultures were active only against grampositive organisms.

Actinomycetales↗
PubMed1980

Heavy metal concentrations in soils of five United States cities, 1972 urban soils monitoring program.

Lead, mercury, cadmium, and arsenic levels were determined in soil samples from Des Moines, Iowa, Fitchburg, Massachusetts, Lake Charles, Louisiana, and Reading and Pittsburgh, Pennsylvania, as part of the 1972 Urban Soils Monitoring Program. Sampling sites within each Standard Metropolitan Statistical Area (SMSA) were defined as urban or suburban based on their position either within or outside the official city limits, respectively. In addition, each site was classified lawn or waste according to the maintenance it received. Except in Fitchburg, urban soils of each SMSA contained significantly higher mean concentrations of cadmium, lead, and mercury than did suburban soils. Mean urban soil concentrations in each SMSA except Des Moines and Reading, where urban levels were significantly higher. Generally, the metal concentrations in lawn and waste areas did not differ significantly. The results indicate a general contamination of these areas, probably as a result of fallout of airborne metal aerosols from industrial processes and/or fossil-fuel combustion.

Arsenic↗
PubMed2005

Trace metal exposure of soil bacteria depends on their position in the soil matrix.

Micropores and biofilms of soils may protect bacteria against chemical stress, predation, and competition phenomena, explaining the great diversity and robustness of soil microbial communities and functions. We used sequential dispersion/density gradient centrifugation to separate free and loosely attached cells (FLA) from strongly attached cells (SA). The two fractions of the soils communities were investigated along a Zn and Cd pollution gradient, and the pollution-induced trace metal community tolerance (PICT) for SA and FLA was analyzed. FLA had developed a strong PICT in response to the 80 years of Zn and Cd pollution, whereas SA was virtually unaffected. It appears that the position of SA in biofilms and micropores has effectively protected them against toxic metal concentrations. The estimated free ion activity showed that the Cd activity was too low to reach toxic levels (PICT(cd) was probably caused by Zn). In contrast, the estimated Zn ion activity was close to a critical level, and could have caused the observed PICT(Zn) in FLA, at least if temporal/ spatial fluctuations of soil pH are taken into account. Such fluctuations could also explain the protection of SA as a result of diffusion constraints; which would be of little help under constant conditions because chemical equilibrium would be reached throughout.

Bacteria↗
PubMed1984

The fate of methoxychlor in soils and transformation by soil microorganisms.

Methoxychlor was found to be sufficiently persistent in soil and its residues were present even 18 months after the soil treatment. Saprophytes, fungi and actinomyces were unaffected by varying concentrations of methoxychlor, azotobacter however was susceptable. Soil strains isolated did not utilize methoxychlor as a sole carbon source except for 9 cultures belonging to the genera Bacillus, Acinetobacter and Rhodococcus which carried out the complete dechlorination, demethylation and splitting of one of methoxychlor aromatic rings. Anaerobic conditions were more favorable for methoxychlor biodegradation by soil and pure microbial cultures.

Acinetobacter↗
PubMed2006

[Effects of pesticides metolachlor and S-metolachlor on soil microorganisms in aquisols. II. Soil respiration].

An incubation test on the soil microbial respiration as affected by 0, 5, 20, and 100 mg x kg(-1) of metolachlor and S-metolachlor (Dual Gold) showed that at the early period of incubation, 5 mg x kg(-1) of metolachlor had a stronger stimulation effect on the respiration than 5 mg x kg(-1) of Dual Gold, but after then, metolachlor presented an inhibition effect while Dual Gold had the effects of stimulation or recovery. 20 mg x kg(-1) of Dual Gold had little effect on the respiration, while metolachlor with the same concentration stimulated it. 100 mg x kg(-1) of metolachlor had a stronger stimulation effect on the respiration than 100 mg x kg(-1) of Dual Gold, but both of them had the same inhibition effect during the later period. The higher the concentration of metolachlor or Dual Gold, the greater the stimulation effect was. There was a significant difference in soil microbial respiration between treated and blank soil at the beginning of incubation, while no significant difference was observed during the later period. With the same concentration of 20 or 100 mg x kg(-1), metolachlor had more harm than Dual Gold. It was suggested that metolachlor and Dual Gold belonged to lower poisonous pesticides, and had less harm on soil microbes.

Acetamides↗
PubMed1996

Differences between super-centrifuged and membrane-filtrated soil solutions obtained from bulked and non-bulked topsoils by soil centrifugation.

The composition of the soil solution must be known to estimate the mobility and availability of plant nutrients and contaminants. When soil centrifugation is used to obtain the soil water for analysis, bulked soil samples are normally used in order to reduce random variations. In the present study, large systematic differences between the centrifugates from bulked and core samples are reported. For most of the soil solution components, no, or only small differences could be detected between super-centrifuged and membrane-filtrated solutions.

Journal Article↗
PubMed1987

Zinc, copper and nickel concentrations in soil extracts and crops grown on four soils treated with metalloaded sewage sludges.

Sludges containing high concentrations of zinc, copper or nickel and an uncontaminated sludge were added to two sandy loams (pH 6.5 and 7.1), a heavy clay (pH 6.3) and a calcareous clay (pH 7.8) to give ten sludge treatments for each soil. The mixtures were incubated fallow, cropped continuously with clover, or cropped with barley and red beet in rotation for 21 months. The quantity of added metal either in the soil solution or extracted by 0.1m CaCl(2) depended on the metal loading, pH and soil cation exchange capacity, and changed with time after mixing soils and sludges. Crop metal concentrations, and the occurrence of metal-induced yield reductions, also depended on soil properties as well as metal loading. The best chemical extractant for predicting plant metal concentrations was 0.1m CaCl(2).

Journal Article↗
PubMed2006

Determination of the vertical distribution of radioelements (K, U, Th, Cs) in soils from portable HP-Ge spectrometer measurements: a tool for soil erosion studies.

Soil erosion studies, based on the 137Cs technique, require a lot of time-consuming cores to determine soil loss or gain. We show that portable HP-Ge spectrometer can be used to determine the content and the distribution in the soil of natural and artificial radionuclides. Simulations of gamma-rays transport throughout the soil profile used a Monte Carlo code. The methodology requires a unique undisturbed coring site to build the models, calibrate the spectrometer readings and derive soil denudation or accumulation thickness.

Journal Article↗
PubMed2005

Factors controlling spatial distribution of soil acidification and Al forms in forest soils.

Soil acidification and Al release in forest soils is controlled by a number of factors, like acid deposition, forest type, parent rock, altitude, etc. This paper studies the principal stand factors affecting spatial distribution of the content of KCl-extractable Al (Al(KCl), mainly exchangeable), Na4P2O7-extractable Al (Al(Na4P2O7), mainly organically bound), and other soil characteristics related to acidification in surface organic (O) and subsurface mineral (B) horizons in the Jizera Mountains region. Geostatistical methods were exploited. The highest Al(KCl) contents in the O horizons were related to high S and N content, low pH and low Ca and Mg content in soil. Liming decreased Al(KCl) contents in the O horizons. Al(Na4P2O7) in the O horizons was more abundant under spruce than under beech; in both horizons it was increased on the immission clear-cut areas populated by grass. Surface horizons are more sensitive to external influence (acid deposition, liming) and their spatial variation is stronger. In the mineral horizons, the effect of pedogenetic processes is more important. The effect of stand factors on Al behaviour is complex and often indirect, mediated for example by organic matter or soil reaction. It is difficult to clearly distinguish the effects of the particular factors.

Journal Article↗
PubMed1996

Linking plant tissue concentrations and soil copper pools in urban contaminated soils.

Copper tissue concentrations of radish (Raphanus sativa cv. Cherry Belle), lettuce (Lactuca sativa cv. Buttercrunch) and ryegrass (Lolium perenne cv. Barmultra) grown in a greenhouse in urban contaminated soils are compared to total, soluble and free ion copper pools. The tissue concentrations of copper vary between 8.1 and 82.6 mg Cu kg(-1) dry tissue and the total soil copper content varies between 32 and 640 mg Cu kg(-1) dry soil. The linear regressions with cupric ion activity and total soil copper are both significant (p < 0.01), but cupric ion activity yields a higher level of statistical significance in every case. The results support the hypothesis that free metal in the soil solution is a better indicator of plant metal bioavailability than either total or soluble metal.

Journal Article↗
PubMed1992

Hydraulic conductance and soil water potential at the soil-root interface of Pinus pinaster seedlings inoculated with different dikaryons of Pisolithus sp.

Seedlings of maritime pine (Pinus pinaster Ait.) were inoculated with different dikaryons of Pisolithus sp. from South Africa to determine the influence of extension of the extramatrical phase and diameter of the mycelial strands on water relations parameters including xylem water potential (Psi(x)), soil water potential at the soil-root interface (Psi(s)) and hydraulic conductance (L(p)) during and after a period of water stress. Seedlings inoculated with dikaryons having an extensive extramatrical phase and large diameter mycelial strands showed higher Psi(s) (-2 MPa) during severe water stress than seedlings inoculated with dikaryons producing fine hyphae and sparse extramatrical phases (-3.8 MPa). Seedlings inoculated with strand-forming dikaryons recovered faster from water stress than did non-inoculated seedlings or seedlings inoculated with non-strand-forming dikaryons. Architectural aspects of the extramatrical phase, including the presence of large diameter mycelial strands or fine hyphae, influenced the soil-root contact and the water relations of an inoculated host plant. When water stress was not limiting, the architecture of the extramatrical phase did not have a large effect on Psi(s). It is suggested that the architecture of the extramatrical phase influences the resistance to water flow through the soil-root interface and that large mycelial strands increase the water flow by bridging the gap between the soil and the root. These changes in physiology indicate that dikaryons can improve the survival of Pinus pinaster under dry conditions.

Journal Article↗
PubMed1997

Efficiency of indigenous and inoculated cold-adapted soil microorganisms for biodegradation of diesel oil in alpine soils.

Biodegradation of diesel oil (5 g(middot)kg [soil dry weight](sup-1)) was investigated in five alpine subsoils, differing in soil type and bedrock, in laboratory experiments during 20 days at 10(deg)C. The biodegradation activities of the indigenous soil microorganisms and of a psychrotrophic diesel oil-degrading inoculum and the effect of biostimulation by inorganic fertilization (C/N/P ratio = 100:10:2) were determined. Fertilization significantly enhanced diesel oil biodegradation activity of the indigenous soil microorganisms. Biostimulation by fertilization enhanced diesel oil biodegradation to a significantly greater degree than bioaugmentation with the psychrotrophic inoculum. In none of the five soils did fertilization plus inoculation result in a higher decontamination than fertilization alone. A total of 16 to 23% of the added diesel oil contamination was lost by abiotic processes. Total decontamination without and with fertilization was in the range of 16 to 31 and 27 to 53%, respectively.

Journal Article↗
PubMed2001

Influence of topsoil tilth and soil moisture status on losses of pesticide to drains from a heavy clay soil.

Twelve lysimeters with a surface area of 0.5 m2 and a length of 60 cm were taken over mole drains from a Denchworth heavy clay soil and divided into two groups with either a standard agricultural tilth or a finer topsoil tilth. The influence of topsoil tilth on leaching of the herbicide isoproturon and a bromide tracer was evaluated over a winter season. The effect of variations in soil moisture status in the immediate topsoil on leaching of isoproturon, chlorotoluron and linuron was investigated in the following winter season. Here, water inputs were controlled such that lysimeters received 50 mm at a maximum intensity of 2 mm h-1 over a 4-week period with herbicides applied on day 15. Three treatments received the water either all prior to application, all after application, or evenly spread over the 4-week period. Leaching losses of the three herbicides were monitored for a subsequently drainage event. Analysis of covariance showed a significant effect of topsoil tilth and total flow on both the maximum concentrations (P = 0.034) and total losses (P = 0.012) of isoproturon in drainflow. Both concentrations and losses were c 35% smaller from lysimeters with the finer tilth. However, generation of the fine tilth in the field was restricted by a wet autumn and this is not considered a reliable management option for reducing pesticide losses from heavy clay soils. In the second experiment, variation in soil moisture content prior to and after application did not have any significant effect (P < 0.05) upon subsequent losses of the three herbicides to drains.

Aluminum Silicates↗