Chemical changes and heavy metal partitioning in an oxisol cultivated with maize (Zea mays, L.) after 5 years disposal of a domestic and an industrial sewage sludge.

The need for solutions to minimize the negative environmental impacts of anthropogenic activities Fhas increased. Sewage sludge is composed of predominantly organic matter and can be used to improve soil characteristics, such as fertility. Therefore, its application in agriculture is an adequate alternative for its final disposal. However, there is a lack of information on its long-term effects on soil changes in tropical areas. Thus, the objectives of this study were to determine (i) the effect of sewage sludge application on heavy metal build-up in soil and maize grains and leaves, and (ii) the effects of soil amendment with sewage sludge on the chemical properties of a Brazilian oxisol. Besides the increasing levels of Zn, Cu, Ni, and Cr, amending soil with sewage sludge also alters the distribution of these metals by increasing the mobile Phases, which correlated significantly with the increase in metal extraction with two single extractants, Mehlich 1 and DTPA (Diethylene triamine pentaacetic acid). The levels of Fe, Mn, Zn, and Cu in maize grains and leaves increased with the type and rate of sewage sludge application. Nevertheless, metal build-up in soil and plants was within the allowed limits. Significant differences were also found in soil characteristics like humic fractionation with the applied sewage doses. The data obtained does not indicate any expressive drawbacks in the use of sewage sludge as a soil amendment, as the heavy metal concentrations observed are unlikely to cause any environmental or health problems, even overestimated loadings, and are in accordance with the Brazilian regulations on farming land biosolid disposal.

Effect of sewage sludge metals on Daphnia similis acid phosphatase.

2009

Assessing the risk of groundwater contamination from organic substances in sewage sludge.

In this work, the risk of groundwater contamination from organic substances in sewage sludge from wastewater treatment stations was evaluated in its worst case. The sewage sludge was applied as fertilizer in corn culture, prioritizing the substances for monitoring. The assessing risk took place in a Typic Distrophic Red Latossol (TDRL) area, in the county district of Jaguariúna, SP. The simulators CMLS-94 and WGEN were used to evaluate the risk of twenty-eight organic substances in sewage sludge to leach to groundwater. The risk of groundwater contamination was accomplished for a single sludge dose application in a thousand independent and equally probable years, simulated to esteem the substances leaching in one year after the application date of the sludge. It is presented the substances that should be priorly monitored in groundwater.

Control of Fusarium in Chrysanthemum with sewage sludge, biofertilizer, hydrolyzed fish, chitosan and Trichoderma.

2008

Combined effects of soil biotic and abiotic factors, influenced by sewage sludge incorporation, on the incidence of corn stalk rot.

Abstract: The objectives of this study were to evaluate the combined effects of soil bioticand abiotic factors on the incidence of Fusarium corn stalk rot, during four annual incorporations of two typesofsewagesludge intosoil ina 5-years field assay under tropical conditions and topredict the effectsof these variables on the disease. For each type of sewage sludge, the following treatments were included: control with mineral fertilization recommended for corn; control without fertilization; sewage sludge based on the nitrogen concentration that provided the same amount of nitrogen as in the mineral fertilizer treatment; and sewage sludge that provided two, four and eight times the nitrogen concentration recommended for corn. Increasing dosages of both types of sewage sludge incorporated into soil resulted in increased corn stalk rot incidence, being negatively correlated with corn yield. A global analysis highlighted the effect of the year of the experiment, followed by the sewage sludge dosages. The type of sewage sludge did not affect the disease incidence. Amultiple logistic model using a stepwise procedure was fitted based on the selection of a model that included the three explanatory parameters for disease incidence: electrical conductivity, magnesium and Fusarium population. In the selected model, the probability of higher disease incidence increased with an increase of these three explanatory parameters. When the explanatory parameters were compared, electrical conductivity presented a dominant effect and was the main variable to predict the probability distribution curves of Fusarium corn stalk rot, after sewage sludge application into the soil.

Impacts of trace element pollution on sewage sludge and soil-plant systems: developing remediation techniques and assessing plant uptake prevention measures

Trace Elements (TEs) pollution is a significant environmental concern due to its toxic effects on human and ecosystem health and its potential to bioaccumulate in the food chain and to threaten species survival, leading to a decline in biodiversity. Urban areas, industrial and mining activities, agricultural practices, all contribute to the release of TEs into the environment posing a significant risk to human health and ecosystems. Several techniques have been developed to control TEs into the environment. This work presents the findings of three-year PhD program that focused on research on TEs pollution. The study discusses three fundamental aspects related to this topic from the perspective of sustainable development, environmental and human health. (1) High levels of TEs contamination prevent the use of sewage sludge (SS) as a fertilizer in agriculture, despite its potential as a soil amendment. Developing effective techniques to manage TEs contamination in SS is critical to ensure its safe use in agriculture and promote resource efficiency through sludge reuse. Another purpose of the study was to evaluate different strategies to limit the TEs uptake by horticultural crops (specifically, Cucumis Melo L.). This study addressed the effect of seasonality, Trichoderma inoculation and clinoptilolite application on chromium (Cr), copper (Cu) and lead (Pb) content of early- and late-ripening cultivars of Cucumis Melo L.. Finally, the accumulation of copper and the effect of its bioavailable fraction on bacterial and fungal communities in the rhizosphere soil of two vineyards, featuring two different varieties of Vitis vinifera grown for varying lengths of time, were evaluated.

Sewage sludge as organic fertilizer in agriculture. A study of physico-chemical properties, agronomic efficiency and environmental safety, with a specific focus on tannery sludge

In recent decades, the use of organic fertilizers has gained increasing interest mainly for two reasons: their ability to improve soil fertility and the need to find a sustainable alternative to mineral and synthetic fertilizers. In this context, sewage sludge is a useful organic matrix that can be successfully used in agriculture, due to its chemical composition rich in organic matter, nitrogen, phosphorus and other micronutrients necessary for plant growth. This work investigated three indispensable aspects (i.e., physico-chemical properties, agronomic efficiency and environmental safety) of sewage sludge application as organic fertilizer, emphasizing the role of tannery sludge. In a comparison study with municipal sewage sludge, results showed that the targeted analyses applied (total carbon and nitrogen content, isotope ratio of carbon and nitrogen, infrared spectroscopy and thermal analysis) were able to discriminate tannery sludge from municipal ones, highlighting differences in composition due to the origin of the wastewater and the treatment processes used in the plants. Regarding agronomic efficiency, N bioavailability was tested in a selection of organic fertilizers, including tannery sludge and tannery sludge-based fertilizers. Specifically, the hot-water extractable N has proven to be a good chemical indicator, providing a rapid and reliable indication of N bioavailability in soil. Finally, the behavior of oxybenzone (an emerging organic contaminant detected in sewage sludge) in soils with different physico-chemical properties was studied. Through adsorption and desorption experiments, it was found that the mobility of oxybenzone is reduced in soils rich in organic matter. Furthermore, through spectroscopic methods (e.g., infrared spectroscopy and surface-enhanced Raman spectroscopy) the mechanisms of oxybenzone-humic acids interaction were studied, finding that H-bonds and π-π stacking were predominantly present.

Avaliação da biodegradabilidade anaeróbia de resíduos da bovinocultura e da suinocultura

The biodegradability of animal wastes production was evaluated through a simplified methodology that allowed the verification of the applicability of anaerobic processes. The experiments were performed in bath reactors, with granular sludge of three origins: UASB reactor treating dairy effluent, UASB reactor treating swine effluent and UASB reactor treating effluent of slaughterhouse of poultry. The experiments (1) - dairy effluent and poultry slaughterhouse non-adapted sludge; (2) -swine effluent and poultry slaughterhouse non-adapted sludge; (3) - dairy effluent and poultry slaughterhouse adapted sludge; (4) - swine effluent and poultry slaughterhouse adapted sludge; (5) - dairy effluent and dairy sludge, and (6) - swine effluent and swine sludge were performed in Incubator Shaker, at a temperature of 35 °C, under agitation at a 150 rpm, for 5 minutes, every 1 hour. A substrat:biomass relationship of 0.5 was used. Kinetic models of Monod, Zero Order, First and Second Order were tested and it was verified that the First Order model provided the best adjustment. The apparent First Order kinetic parameter (k1) was estimated for the experiments 1; 2; 3; 4; 5, and 6, as 2.51 x 10-2; 2.49 x 10-2; 1.90 x 10-2; 3.09 x 10-2; 2.54 x 10-2; 4.09 x 10-2 h-1, respectively.

Acompanhamento químico da vermicompostagem de lodo de esgoto doméstico

This research aims to monitor the humification process of domestic sewage sludge resulted from the vermicomposting, evaluating, also, the possibility of using the final product (vermicompost) in agricultural soils. The monitored chemical variables during the 90 days of vermicomposting were: humidity rate, organic matter content, nitrogen and phosphorus content, pathogenic organisms concentration, total organic carbon, acidity, CEC, C/N ratio, CEC/TOC ratio, and humic and fulvic acids content. The change in these variables during the vermicomposting process showed that this technique is effective for use in the maturation of the residue.

Disponibilidade de metais pesados em Latossolo com aplicação superficial de escória, lama cal, lodos de esgoto e calcário

O objetivo deste trabalho foi avaliar alguns atributos químicos do solo e a disponibilidade de cádmio (Cd), cromo (Cr), níquel (Ni), mercúrio (Hg), chumbo (Pb) e arsênio (As), por meio da extração pelo DTPA,em conseqüência da aplicação superficial de escória de aciaria, lama cal e lodos de esgoto centrifugados e de biodigestores, nas doses 0 (testemunha), 2, 4 e 8 Mg ha-1 e um tratamento adicional composto pela calagem superficial na dose 2 Mg ha-1. O experimento foi conduzido em delineamento de blocos ao acaso, em condições de campo, em área sob sistema plantio direto, durante 2003 e 2004. A aplicação superficial de escória de aciaria,lama cal, lodo de esgoto centrifugado e de biodigestor, até a dose 8 Mg ha-1, assim como o calcário na dose 2 Mg ha-1, não trazem problemas de disponibilidade ao ambiente, com relação aos metais pesados Cd, Cr, Hg, Pb, Ni e As, quando aplicados sobre a superfície em Latossolo Vermelho distrófico, no sistema plantio direto. A fitodisponibilidade de metais pesados às culturas da soja e aveia-preta foi nula, quando foram aplicadas doses de até 8 Mg ha-1 de lodo de esgoto, escória e lama cal sobre a superfície do solo, no sistema plantio direto

Produção de óleo essencial e balanço nutricional em Corymbia citriodora adubado com lodo de esgoto em diferentes espaçamentos

The Corymbia citriodora is one of the most cultivated species in Brazil for wood and essential oil production. The oil is obtained by the leaves distillation and the yield is around 2%. For the sustainability of leaves extraction is necessary a good nutritional replacement, because the leaves contain a large quantity of nutrients. The sewage sludge application in Corymbia plantations is a way to apply organic fertilizer and is also a good alternative for the final disposal of this residue. In this context, the objective of this study was to evaluate the sewage sludge use as fertilizer for the essential oil production in two different Spacing. The experiment was constituted by 4 blocks and the treatments were: i) Close spacing (1m x 1m) with sewage sludge + K and B; ii) Close spacing with mineral fertilization: iii) Regular spacing (3m x 1m) with sewage sludge + K and B; and iv) Regular spacing with mineral fertilization. When the C. citriodora plots were 12, 18, 24 and 30 months old, leaves and branches biomass and also essential oil production were quantified. It was observed that the system of close planting totalized a higher biomass, 3.8 times more than the conventional system, providing 3 times more essential oil production (363 l ha(-1) at the close spacing and 116 l ha(-1) at the regular Spacing during 30 months). No difference was found in the leaves or oil production with the use of sewage sludge or mineral fertilizer any of spacing studied The use of sewage sludge as fertilizer for Corymbia citriodora plantations may be an interesting alternative. because it supplies large quantities of nutrients and ensures a positive budget of nutrients in the ecosystem.

Efeito da aplicação de fertilização nitrogenada e lodo de esgoto nas características da madeira juvenil de árvores de Eucalyptus grandis

This work evaluated the wood anatomical and physical characteristics of 24 months-old Eucalyptus grandis trees, planted in 3x2m spacing and fertilized with nitrogen (6, 12, 18 month old) and sewage sludge (planting, 8 month old). For each treatment 10 eucalypts trees were cut according to the distribution of basal area. Wood samples were collected in different percentages of the total height to analyze the anatomical (vessels and fibers) and physical (wood density) characteristics. The results showed that the wood apparent density and wood basic density of the eucalypt trees in the nitrogen and sewage sludge were larger in comparison to the control. Radial profiles of wood apparent density, were similar in the three treatments, presenting the exected characteristics of juvenile wood of 24 months-old eucalypt trees. Fiber and vessel dimensions were not affected by fertilization.

Occurrence of Sexual Hormones in Sediments of Mangrove in Brazil

The presence of sexual hormones (female estrogens) was assessed in sediments of a mangrove located in the urban region of southern Brazil. The estrogens are involved in human sexual reproduction. They act as the chemical messengers, and they are classified as natural and synthetic. The estrogens inputs in the environment are from treated and untreated sewage. The presence of estrogens in sewage is excretion from the female due to natural production and use of contraceptives (synthetic estrogens). With the indiscriminate release of sewage into the environment, estrogens can be found in rivers, lakes, and even in oceans. In this work, the presence of estrone (E1), 17-beta-estradiol (E2), and 17-alpha-ethynilestradiol (EE2) in eight sedimentary stations in Itacorubi mangrove located on Santa Catarina Island, south Brazil, was investigated. Historically, the Itacorubi mangrove has been impacted by anthropogenic activities because the mangrove is inserted in the urban area of the Florianopolis. The estrogen EE2, used as contraceptive, had the highest concentration in mangrove sediment, 129.75 +/- 3.89 ng/g. E2 was also found, with its concentration ranging from 0.90 +/- 0.03 to 39.77 +/- 1.19 ng/g. Following the mechanism, under aerobic or anaerobic conditions, E2 will first be oxidized to E1, which is further oxidized to unknown metabolites and finally to CO(2) and water (mineralized). EE2 is oxidized to unknown metabolites and also finally mineralized. Theoretically, under anaerobic conditions, EE2 can be reduced to E1 even in environments such as mangrove which is essentially anaerobic.

Performance evaluation and phylogenetic characterization of anaerobic fluidized bed reactors using ground tire and pet as support materials for biohydrogen production

This study evaluated two different support materials (ground tire and polyethylene terephthalate [PET]) for biohydrogen production in an anaerobic fluidized bed reactor (AFBR) treating synthetic wastewater containing glucose (4000 mg L(-1)). The AFBR, which contained either ground tire (R1) or PET (R2) as support materials, were inoculated with thermally pretreated anaerobic sludge and operated at a temperature of 30 degrees C. The AFBR were operated with a range of hydraulic retention times (HRT) between 1 and 8 h. The reactor R1 operating with a HRT of 2 h showed better performance than reactor R2, reaching a maximum hydrogen yield of 2.25 mol H(2) mol(-1) glucose with 1.3 mg of biomass (as the total volatile solids) attached to each gram of ground tire. Subsequent 16S rRNA gene sequencing and phylogenetic analysis of particle samples revealed that reactor R1 favored the presence of hydrogen-producing bacteria such as Clostridium, Bacillus, and Enterobacter. (C) 2010 Elsevier Ltd. All rights reserved.

Anaerobic degradation of linear alkylbenzene sulfonate (LAS) in fluidized bed reactor by microbial consortia in different support materials

Four anaerobic fluidized bed reactors filled with activated carbon (R1), expanded clay (R2), glass beads (R3) and sand (R4) were tested for anaerobic degradation of LAS. All reactors were inoculated with sludge from a UASB reactor treating swine wastewater and were fed with a synthetic substrate supplemented with approximately 20 mg l(-1) of LAS, on average. To 560 mg l(-1) COD influent, the maximum COD and LAS removal efficiencies were mean values of 97 +/- 2% and 99 +/- 2%, respectively, to all reactors demonstrating the potential applicability of this reactor configuration for treating LAS. The reactors were kept at 30 degrees C and operated with a hydraulic retention time (HRT) of 18 h. The use of glass beads and sand appear attractive because they favor the development of biofilms capable of supporting LAS degradation. Subsequent 16S rRNA gene sequencing and phylogenetic analysis of samples from reactors R3 and R4 revealed that these reactors gave rise to broad microbial diversity, with microorganisms belonging to the phyla Bacteroidetes, Firmicutes, Actinobacteria and Proteobacteria, indicating the role of microbial consortia in degrading the surfactant LAS. (C) 2010 Elsevier Ltd. All rights reserved.