Salinity-induced changes in the microbial use of sugarcane filter cake added to soil

Five laboratory incubation experiments were carried out to assess the salinity-induced changes in the microbial use of sugarcane filter cake added to soil. The first laboratory experiment was carried out to prove the hypothesis that the lower content of fungal biomass in a saline soil reduces the decomposition of a complex organic substrate in comparison to a non-saline soil under acidic conditions. Three different rates (0.5, 1.0, and 2.0%) of sugarcane filter cake were added to both soils and incubated for 63 days at 30°C. In the saline control soil without amendment, cumulative CO2 production was 70% greater than in the corresponding non-saline control soil, but the formation of inorganic N did not differ between these two soils. However, nitrification was inhibited in the saline soil. The increase in cumulative CO2 production by adding filter cake was similar in both soils, corresponding to 29% of the filter cake C at all three addition rates. Also the increases in microbial biomass C and biomass N were linearly related to the amount of filter cake added, but this increase was slightly higher for both properties in the saline soil. In contrast to microbial biomass, the absolute increase in ergosterol content in the saline soil was on average only half that in the non-saline soil and it showed also strong temporal changes during the incubation: A strong initial increase after adding the filter cake was followed by a rapid decline. The addition of filter cake led to immobilisation of inorganic N in both soils. This immobilisation was not expected, because the total C-to-total N ratio of the filter cake was below 13 and the organic C-to-organic N ratio in the 0.5 M K2SO4 extract of this material was even lower at 9.2. The immobilisation was considerably higher in the saline soil than in the non-saline soil. The N immobilisation capacity of sugarcane filter cake should be considered when this material is applied to arable sites at high rations. The second incubation experiment was carried out to examine the N immobilizing effect of sugarcane filter cake (C/N ratio of 12.4) and to investigate whether mixing it with compost (C/N ratio of 10.5) has any synergistic effects on C and N mineralization after incorporation into the soil. Approximately 19% of the compost C added and 37% of the filter cake C were evolved as CO2, assuming that the amendments had no effects on the decomposition of soil organic C. However, only 28% of the added filter cake was lost according to the total C and d13C values. Filter cake and compost contained initially significant concentrations of inorganic N, which was nearly completely immobilized between day 7 and 14 of the incubation in most cases. After day 14, N re-mineralization occurred at an average rate of 0.73 µg N g-1 soil d-1 in most amendment treatments, paralleling the N mineralization rate of the non-amended control without significant difference. No significant net N mineralization from the amendment N occurred in any of the amendment treatments in comparison to the control. The addition of compost and filter cake resulted in a linear increase in microbial biomass C with increasing amounts of C added. This increase was not affected by differences in substrate quality, especially the three times larger content of K2SO4 extractable organic C in the sugarcane filter cake. In most amendment treatments, microbial biomass C and biomass N increased until the end of the incubation. No synergistic effects could be observed in the mixture treatments of compost and sugarcane filter cake. The third 42-day incubation experiment was conducted to answer the questions whether the decomposition of sugarcane filter cake also result in immobilization of nitrogen in a saline alkaline soil and whether the mixing of sugarcane filter cake with glucose (adjusted to a C/N ratio of 12.5 with (NH4)2SO4) change its decomposition. The relative percentage CO2 evolved increased from 35% of the added C in the pure 0.5% filter cake treatment to 41% in the 0.5% filter cake +0.25% glucose treatment to 48% in the 0.5% filter cake +0.5% glucose treatment. The three different amendment treatments led to immediate increases in microbial biomass C and biomass N within 6 h that persisted only in the pure filter cake treatment until the end of the incubation. The fungal cell-membrane component ergosterol showed initially an over-proportionate increase in relation to microbial biomass C that fully disappeared at the end of the incubation. The cellulase activity showed a 5-fold increase after filter cake addition, which was not further increased by the additional glucose amendment. The cellulase activity showed an exponential decline to values around 4% of the initial value in all treatments. The amount of inorganic N immobilized from day 0 to day 14 increased with increasing amount of C added in comparison to the control treatment. Since day 14, the immobilized N was re-mineralized at rates between 1.31 and 1.51 µg N g-1 soil d-1 in the amendment treatments and was thus more than doubled in comparison with the control treatment. This means that the re-mineralization rate is independent from the actual size of the microbial residues pool and also independent from the size of the soil microbial biomass. Other unknown soil properties seem to form a soil-specific gate for the release of inorganic N. The fourth incubation experiment was carried out with the objective of assessing the effects of salt additions containing different anions (Cl-, SO42-, HCO3-) on the microbial use of sugarcane filter cake and dhancha leaves amended to inoculated sterile quartz sand. In the subsequent fifth experiment, the objective was to assess the effects of inoculum and temperature on the decomposition of sugar cane filter cake. In the fourth experiment, sugarcane filter cake led to significantly lower respiration rates, lower contents of extractable C and N, and lower contents of microbial biomass C and N than dhancha leaves, but to a higher respiratory quotient RQ and to a higher content of the fungal biomarker ergosterol. The RQ was significantly increased after salt addition, when comparing the average of all salinity treatments with the control. Differences in anion composition had no clear effects on the RQ values. In experiment 2, the rise in temperature from 20 to 40°C increased the CO2 production rate by a factor of 1.6, the O2 consumption rate by a factor of 1.9 and the ergosterol content by 60%. In contrast, the contents of microbial biomass N decreased by 60% and the RQ by 13%. The effects of the inoculation with a saline soil were in most cases negative and did not indicate a better adaptation of these organisms to salinity. The general effects of anion composition on microbial biomass and activity indices were small and inconsistent. Only the fraction of 0.5 M K2SO4 extractable C and N in non-fumigated soil was consistently increased in the 1.2 M NaHCO3 treatment of both experiments. In contrast to the small salinity effects, the quality of the substrate has overwhelming effects on microbial biomass and activity indices, especially on the fungal part of the microbial community.

Identification of lift-off mechanism failure for salt drill-in drilling fluid containing polymer filter cake through adsorption/desorption studies

Drilling fluid`s contact with the productive zone of horizontal or complex wells can reduce well productivity by fluid invasion in the borehole wall. Salted drilling drill-in fluid containing polymers has often been applied in horizontal or complex petroleum wells in the poorly consolidated sandstone reservoirs of the Campos basin, Rio de Janeiro, Brazil. This fluid usually consists of natural polymers such as starch and xanthan gum, which are deposited as a filter cake on the wellbore wall during the drilling. Therefore, the identification of a lift-off mechanism failure, which can be detachment or blistering and pinholing, will enable formulation improvements. increasing the chances of success during filter cake removal in open hole operations. Likewise, knowledge of drill-in drilling fluid adsorption/desorption onto sand can help understand the filter cake-rock adhesion mechanism and consequently filter cake lift-off mechanism failures. The present study aimed to identify the lift-off failure mechanism for this type of fluid filter cake studying adsorption/desorption onto SiO(2) using solutions of natural polymers, lubricants, besides the fluid itself. Ellipsometry was employed to measure this process. The adsorption/desorption studies showed that the adsorbed layer of drilling fluid onto the walls of the rock pores is made up of clusters of polymers, linked by hydrogen bonds, which results in a force of lower cohesion compared to the electrostatic interaction between silica and polymers. Consequently, it was found that the most probable filter cake failure mechanism is rupture (blistering and pinholing), which results in the formation of ducts within the filter cake. (C) 2009 Elsevier B.V. All rights reserved.

Filter cake and vinasse as fertilizers contributing to conservation agriculture

Utilising organic residues in agriculture contributes to the conservation of natural resources by recycling carbon and mineral elements. Organic residues produced by the sugar and alcohol agroindustries have great potential for use in conservation agriculture. The production of sugar and alcohol generates large quantities of byproducts, such as filter cake and vinasse, which can be used as soil improvers and substitutes for inorganic phosphorus and potassium fertilizers. However, the use of these residues in agriculture requires specific recommendations for each pedoclimatic condition to prevent environmental damage. © 2013 Renato de Mello Prado et al.

Centrifuging rotary vacuum filter mud at Tully Mill

Disposal of mud and ash, particularly in wet weather conditions, is a significant expense for mills. This paper reports on one part of a process to pelletise mud and ash, aimed at making mud and ash more attractive to growers across entire mill districts. The full process is described in a separate paper. The part described in this paper involves re-constituting mud cake from the filter station at Tully Mill and processing it in a decanter centrifuge. The material produced by re-constituting and centrifuging is drier and made up of separate particles. The material needs to mix easily with boiler ash, and the mixture needs to be fed easily into a flue gas drier to be dried to low moisture. The results achieved with the particular characteristics of Tully Mill rotary vacuum filter cake are presented. It was found that an internal rotor with a 20º beach was not adequate to process re-constituted rotary vacuum filter mud. A rotor with a 10º beach worked much more successfully. A total of four tonnes of centrifuged mud with a moisture content ranging from 60% to 65% was produced. It was found that the torque, flocculant rate and dose rate had a statistically significant effect on the moisture content. Feed rate did not have a noticeable impact on the moisture content by itself but torque had a much larger impact on the moisture content at the low feed rate than at the high feed rate. These results indicated that the moisture content of the mud can most likely be reduced with low feed rate, low flocculant rate, high dose rate and high torque. One issue that is believed to affect the operation of a decanter centrifuge was the large quantity of long bagasse fibres in the rotary vacuum filter mud. It is likely that the long fibres limited the throughput of the centrifuge and the moisture achieved.

The effect of filter cakes enriched with soluble phosphorus used as a fertilizer on the sugarcane ratoons

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Measurement of the Mechanical Properties of Filtercakes

In order to improve drilling mud design to cater for specific well situations, a more comprehensive knowledge and understanding of filter cake failure is needed. This paper describes experimental techniques aimed at directly probing the mechanical properties of filter cakes, without having to take into account artefacts due to fluid flow in the substrate. The use of rheometers allows us to determine shear yield stress and dynamic shear modulii of cakes grown on filter paper. A new scraping technique measures the strength and moisture profiles of typical filter cakes with a 0.1 mm resolution. This technique also allows us to probe the adhesion between the filter cake and its rock substrate. In addition, œdometer drained consolidation and unloading of a filter cake give us compression parameters useful for Cam Clay modelling. These independent measurements give similar results as to the elastic modulus of different filter cakes, showing an order of magnitude difference between water based and oil based cakes. We find that these standard cakes behave predominantly as purely elastic materials, with a sharp transition into plastic flow, allowing for the determination of a well-defined yield stress. The effect ofsolids loading on a given type of mud is also studied.

A geotechnical description of fresh cement grout - filtration and consolidation behaviour

The removal of water from three Portland cement grouts by pressure filtration is examined, and the consolidation behaviour of the filtered material clarified. The filtration takes place by the laying down of a very stiff filter cake through the removal of excess water. The behaviour due to further loading resembles that of a re-constituted silt. For stress levels above the filtration pressure the calculated permeability values are similar to those from the filtration phase only if the data sampling rate was sufficiently rapid to discriminate the first portion of the observed primary consolidation curve. The change in void ratio for incremental loading is roughly linear with the change in the logarithm of the vertical effective stress. The characterisation of fresh cement paste using standard soil mechanics models is both appropriate and useful, at least during the first few hours after mixing.

Characterization of organic matter from composting of different residues by physicochemical and spectroscopic methods

Chemical and spectroscopic methods were used to characterize organic matter transformations during the composting process. Four different residue mixtures were studied: P1 - garden trimmings (GT) only, P2 - GT plus fresh cattle manure, P3 - GT plus orange pomace and P4 - GT plus filter cake. The thermophilic phase was not reached in PI compost, but the P2, P3 and P4 composts showed all three typical process phases. The thermophilic phase and CEC/C ratio stabilized after 90 days, while C/N ratio and the ash content stabilized after 60 days. The increasing E(4)/E(6) ratio indicated oxidation reactions occurring during the process in the material from P2, P3 and P4. The (13)C NMR and FTIR results suggested extraction of both pectin and lignin in the HA-like fraction. The CEC/C ratio, temperature and E(4)/E(6) ratio showed that within 90 days P2, P3 and P4 composts were humified. However, material from P1 did not show characteristics of humified compost. From these data, it is apparent that C/N ratio and ash content are not reliable methods for monitoring the composting process. (C) 2009 Elsevier Ltd. All rights reserved.

Modelagem e previsão da perda de injetividade em poços canhoneados

Waterflooding is a technique largely applied in the oil industry. The injected water displaces oil to the producer wells and avoid reservoir pressure decline. However, suspended particles in the injected water may cause plugging of pore throats causing formation damage (permeability reduction) and injectivity decline during waterflooding. When injectivity decline occurs it is necessary to increase the injection pressure in order to maintain water flow injection. Therefore, a reliable prediction of injectivity decline is essential in waterflooding projects. In this dissertation, a simulator based on the traditional porous medium filtration model (including deep bed filtration and external filter cake formation) was developed and applied to predict injectivity decline in perforated wells (this prediction was made from history data). Experimental modeling and injectivity decline in open-hole wells is also discussed. The injectivity of modeling showed good agreement with field data, which can be used to support plan stimulation injection wells

Characterization and thermal behavior of residues from industrial sugarcane processing

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desempenho de cultivares de alface americana em resposta a diferentes doses de torta de filtro

Com objetivo de estudar o desempenho de três cultivares de alface americana (Júlia, Tainá e Grandes Lagos) em quatro doses de torta de filtro (0; 10; 20 e 40 ton ha-1), sob cultivo protegido (túnel alto), foi conduzido um experimento na Universidade do Estado de Mato Grosso, em área de Latossolo Vermelho (textura argilosa), nos meses de março a maio de 2009. O delineamento experimental foi em blocos casualizados, distribuídos em esquema fatorial 3 x 4 (cultivares x doses) com quatro repetições. Foram avaliadas as seguintes características agronômicas: circunferência da planta (CP), massa fresca total (MFT), massa fresca comercial (MFCo), massa fresca da cabeça (MFCa), diâmetro do caule (DC), número de folhas comerciais (NFC), comprimento do caule (CC) e número de folhas totais (NFT). As cultivares Júlia e Tainá responderam à adubação com torta de filtro até a dose de 40 ton-1. A cultivar Grandes Lagos respondeu à adubação com torta de filtro até a dose de 35 ton ha-1 para MFT e MFCa e até 40 ton-1 para MFCo. A cultivar Grandes Lagos apresentou melhor desempenho em MFT, MFCo, CC e CP, em relação às demais cultivares, e equiparou-se com a cultivar Tainá em MFCa e NFC e com a cultivar Júlia em DC. Todas as cultivares tiveram comportamentos semelhantes quanto a NFT. A adubação orgânica com torta de filtro aumenta a produtividade de cultivares de alface americana.

Alterações em algumas propriedades de um latossolo degradado com uso de lodo de esgoto e resíduos orgânicos

A recuperação de áreas muito impactadas, como as oriundas da construção de hidrelétricas, é um processo lento e, usualmente, requer a adição de resíduos orgânicos, como fonte de matéria orgânica, e de nutrientes, como condicionador das propriedades do solo. O objetivo deste trabalho foi verificar o efeito da adição de lodo de esgoto e resíduos orgânicos (maravalha e torta de filtro de cana-de-açúcar) sobre o crescimento de duas espécies arbóreas de Cerrado na recuperação de um subsolo de uma área degradada pela construção da Usina Hidrelétrica de Ilha Solteira, localizada em Selvíria - MS. O experimento foi conduzido em casa de vegetação em delineamento experimental inteiramente casualizado, com oito tratamentos, seis repetições e uma planta por repetição, para cada planta-teste. Cada repetição (saco plástico) teve 3,3 L e as proporções em volume da mistura de cada resíduo foram de: 30 % de lodo de esgoto, 20 % de torta de filtro e 10 % de maravalha de madeira. Foram mensuradas a fertilidade, a micorrização, a atividade microbiana (C-CO2 liberado) do subsolo, a massa do sistema radicular e parte aérea e a altura de plantas de duas espécies nativas do Cerrado [monjoleiro (Acacia polyphylla DC.) e jatobá-do-Cerrado (Hymenaea stigonocarpa Mart)]. Os tratamentos com lodo de esgoto proporcionaram maior atividade microbiana no substrato e maior crescimento para as duas espécies arbóreas. A presença do lodo de esgoto promoveu melhora na fertilidade do subsolo, com aumento dos teores de matéria orgânica, P, K, Ca e Mg. A matéria orgânica e o P tiveram seus teores elevados nos tratamentos com mistura de lodo de esgoto e demais resíduos. Os resultados permitem concluir que as misturas contendo lodo associado a resíduos promoveram melhores incrementos na qualidade do subsolo, com perspectivas de sua recuperação.

Qualidade tecnológica da cana-de-açúcar sob adubação com torta de filtro enriquecida com fosfato solúvel

The study had the objective to evaluate the effect of the fertilization with filter cake enriched with soluble phosphate on the sugar yield. The experiment carried at Presidente Prudente-SP, used a randomized complete block design, in the factorial scheme 5 x 4, where the first factor consisted of doses of filter cake (0; 0.5; 1.0; 2.0 and 4.0 t ha(-1)) and the second, doses of phosphorus fertilizer (0, 50, 100, 200 kg ha(-1) of P2O5), with 4 replicates, totaling 80 plots. The results indicated that phosphorus applied in planting furrows improves the quality of sugarcane raw matter by increasing the levels of soluble solids, total reducing sugars and sucrose in the stalks. The phosphorus also increases the productivity of sugar. The filter cake applied in planting furrow has the potential to partially replace the chemical fertilization with phosphate aiming to improve the quality and the productivity of sugar. The best combination was filter cake at dose between 2.6 and 2.7 t ha(-1) combined with dose between 160 and 190 kg P2O5 ha(-1) for obtaining best response of soluble solids and productivity of sugar.

Produtividade de cana-de-açúcar sob adubação com torta de filtro enriquecida com fosfato solúvel

Phosphorus is considered an essential element for plants and it is found in small amounts in Brazilian soils. The filter cake residue, composed of a mixture of bagasse and decanting sludge, has high levels of organic matter, phosphorus and calcium. The phosphorus present in the filter cake is organic, and its release, as it happens to the nitrogen, occurs gradually by mineralization and by microorganisms attack in the soil. This study aimed to evaluate sugarcane vegetative growth and yield under fertilization with filter cake enriched with soluble phosphate. The experiment was carried out in Presidente Prudente, São Paulo State, Brazil, by using a randomized complete block design, in a 5x4 factorial scheme, where the first factor consisted of filter cake doses (0 t ha-1, 0.5 t ha-1, 1.0 t ha-1, 2.0 t ha-1, and 4.0 t ha-1) and the second of phosphorus fertilizer doses (0 kg ha-1, 50 kg ha -1, 100 kg ha-1, and 200 kg ha-1 of P 2O5), with 4 repetitions, totalizing 80 plots. The experiment evaluated the tiller number, at 30, 60, 90, and 120 days after planting, oBrix, and yield. The stalk yield and tillering were influenced by the filter cake rates applied to the soil. Filter cake doses and their combination with phosphate did not change the juice quality (Brix) at harvest.