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Biochar from sewage sludge is a low-cost sorbent that may be used for several environmental functions. This study evaluates the induced effects of pyrolysis temperature on the physicochemical characteristics of sewage sludge (SS) biochar produced at 350 (SSB350), 450 (SSB450) and 600 (SSB600), based on the metal enrichment index, metal mobility index (MMI), and potential ecological risk index (PERI) of Cd, Cu, Pb, and Zn. Increased pyrolysis temperature reduced the biochar concentration of elements that are lost as volatile compounds (C, N, H, O, and S), while the concentration of stable aromatic carbon, ash, alkalinity, some macro (Ca, Mg, P2O5, and K2O) and micronutrients (Cu and Zn), and toxic elements such as Pb and Cd increased. Increasing the pyrolysis temperature is also important in the transformation of metals from toxic and available forms into more stable potentially available and non-available forms. Based on the individual potential ecological risk index, Cd in the SS and SSB450 were in the moderate and considerable contamination ranges, respectively. For all pyrolysis temperature biochar Cd was the highest metal contributor to the PERI. Despite this, the potential ecological risk index of the SS and SSBs was graded as low.

In 1997, 500,000 MG of mine tailing materials containing 3% lead (Pb), 21% cadmium (Cd), and 13% zinc (Zn) were buried at a site in Santo Amaro, Bahia, Brazil. The present study evaluated the dispersion of contaminants in a toposequence classified by the FAO system: Pellic Vertisol (hilltop, P1), Leptic Vertisol (upper third of the slope, P2), Leptic Endospolic Technosol (middle third, P3), Haplic Vertisol (lower third, P4), and Eutric Fluvisol (footslope, P5). The P1, P2, and P3 soil profiles were located within the processing plant boundary, whereas P4 and P5 were located outside the plant. According to the Brazilian Environmental Agency, the maximum concentrations of Pb and Cd were detected to be 26.4 and 2.6 times higher than the industrial intervention value, respectively, whereas Zn concentration was 1.9 times higher than the residential intervention limit. In the Technosol P3 region, the concentrations of Pb and Cd were above or around the industrial value, whereas Zn concentration ranged from agricultural to industrial values. The metal concentration in the Fluvisol (P5) region was lowest among all soil profiles; however, the concentration of Pb remained above the agricultural intervention limit. The high concentrations of metals, especially Pb, in the P4 and P5 regions are an evidence that after almost two decades, the contaminants still continue to sediment from the top to the lowland area of the toposequence.

In a previous study, a high concentration of Pb, Zn, Cr, and Mn in soil profiles located in the semiarid region of Brazil were found in areas used for decades by small family farmers for the production of the crops and raising small animals. This question motivated the current study to evaluate the soil variability spatial dependence on trace elements to quantify and map its occurrence in this area, comparing their concentration with reference values set by the Brazilian environmental agencies. Soil samples were collected at 0-0.20 and 0.20-0.40 m depths and 25, 50, 100, 200, and 400 m from the center and to both sides of five transects spaced from 1,000 m, forming a grid. The concentration of the trace elements As, Cd, Pb, Cu, Cr, Fe, Mn, Ni, Ti, and Zn was obtained in SW-846 3050B USEPA soil extract by ICP-OES. Spatial dependence for all evaluated elements allowed the elaboration of dispersion maps in the area, except for Cd. Trace elements concentrations were below the investigation values (limit value of a trace element in the soil with risk potential to humans and the environment) of the Brazilian environmental legislation (Conama). Pb and As concentrations were above the prevention values (limit value of a trace element in the soil that can sustain its primary functions), but, still, they presented low dispersion in the area. Zn concentration was above the prevention value, and dispersion was higher, regardless sampling point, which requires a major concern. Cr, Cu, Ni, Fe, Mn, and Ti concentrations were below the Conama reference values, and the dispersion was also low. Fortunately, except for Fe, it was observed that trace elements were concentrated around the central point of the "gossan", instead of distributed throughout in the agricultural area around it.

Preservation of mangroves, a very significant ecosystem from a social, economic, and environmental viewpoint, requires knowledge on soil composition, genesis, morphology, and classification. These aspects are of paramount importance to understand the dynamics of sustainability and preservation of this natural resource. In this study mangrove soils in the Subaé river basin were described and classified and inorganic waste concentrations evaluated. Seven pedons of mangrove soil were chosen, five under fluvial influence and two under marine influence and analyzed for morphology. Samples of horizons and layers were collected for physical and chemical analyses, including heavy metals (Pb, Cd, Mn, Zn, and Fe). The moist soils were suboxidic, with Eh values below 350 mV. The pH level of the pedons under fluvial influence ranged from moderately acid to alkaline, while the pH in pedons under marine influence was around 7.0 throughout the profile. The concentration of cations in the sorting complex for all pedons, independent of fluvial or marine influence, indicated the following order: Na+>Mg2+>Ca2+>K+. Mangrove soils from the Subaé river basin under fluvial and marine influence had different morphological, physical, and chemical characteristics. The highest Pb and Cd concentrations were found in the pedons under fluvial influence, perhaps due to their closeness to the mining company Plumbum, while the concentrations in pedon P7 were lowest, due to greater distance from the factory. For containing at least one metal above the reference levels established by the National Oceanic and Atmospheric Administration (United States Environmental Protection Agency), the pedons were classified as potentially toxic. The soils were classified as Gleissolos Tiomórficos Órticos (sálicos) sódico neofluvissólico in according to the Brazilian Soil Classification System, indicating potential toxicity and very poor drainage, except for pedon P7, which was classified in the same subgroup as the others, but different in that the metal concentrations met acceptable standards. A preservação de manguezais, ecossistema de elevada importância social, econômica e ambiental, requer conhecimento da composição, gênese, morfologia e classificação de seus solos, aspectos de fundamental importância para o entendimento da dinâmica e conservação sustentável desse recurso natural. Dessa forma, buscaram-se caracterizar e classificar solos de manguezais na bacia do Subaé e avaliar as concentrações dos poluentes inorgânicos. Foram escolhidos sete pedons representativos de manguezais, cinco sob influência fluvial e dois sob influência marítima, cujos perfis foram analisados quanto à morfologia e coletadas amostras de horizontes e camadas para posterior análise física e química, inclusive de metais pesados (Pb, Cd, Mn, Zn e Fe). Os solos em condições úmidas apresentaram-se subóxidos, com valores de Eh Mg2+>Ca2+>K+. Os solos dos manguezais da bacia do rio Subaé apresentaram características morfológicas, físicas e químicas distintas quando sob influência fluvial e marítima. As maiores concentrações de Pb e Cd foram identificadas nos pedons sob influência fluvial, possivelmente pela proximidade à Plumbum Mineração, e as menores concentrações encontravam-se no pedon P7, em razão da maior distância da fábrica. Por apresentar pelo menos um metal acima dos valores de referência indicados pela National Oceanic and Atmospheric (EPA), os pedons foram classificados como potencialmente tóxicos. Os solos foram classificados como Gleissolos Tiomórficos Órticos (sálicos) sódico neofluvissólicos de acordo com o Sistema Brasileiro de Classificação, apresentando-se potencialmente tóxicos, muito mal-drenados, exceto o pedon 7, que foi enquadrado no mesmo subgrupo dos demais, mas diferenciado deles por apresentar concentração de metal dentro dos limites tolerados. SI

RESUMOA contaminação de solos por chumbo no município de Santo Amaro da Purificação-BA se originou a partir da instalação na cidade de uma metalúrgica na década de 60 e representa um sério risco à população local. A determinação dos teores disponíveis de Pb no solo é uma ferramenta importante para monitorar os riscos desta contaminação. No entanto, diferentes métodos são utilizados para determinar os teores disponíveis de Pb no solo, o que gera valores distintos entre os extratores. O objetivo do presente trabalho foi comparar a eficiência das extrações feitas com solução Mehlich 1, DTPA e CaCl2, na avaliação da disponibilidade Pb em solo tratado com diferentes amenizantes. A amostra de solo utilizada no experimento foi coletada próximo à metalúrgica. As doses de amenizantes foram estabelecidas com base no teor de carbono dos materiais (ácido húmico de compostagem, ácido húmico comercial e carvão vegetal) e corresponderam a 0; 0,75; 1,5; 3 e 7,5 g kg-1 de C. O conteúdo de Pb disponível foi extraído por Mehlich 1, DTPA pH 7,3 e CaCl210 mmol L-1. Foi realizado um fracionamento do solo, determinando-se o metal ligado às frações trocável e matéria orgânica do solo. A adição do AHv reduziu o teor de Pb no solo em 60; 89 e 47% para extrações realizadas com Mehlich 1, CaCl2 e DTPA, respectivamente. O teor de Pb na fração matéria orgânica foi diretamente proporcional às doses dos amenizantes. Os três extratores avaliados foram eficientes na predição dos teores de Pb disponíveis. ABSTRACTSoil contamination by lead in the town of Santo Amaro, in the state of Bahia, Brazil, originated with the installation of a metal plant in the city in the 1960s, and poses a serious risk to the local population. Determination of the available Pb levels in the soil is an important tool in monitoring the risks of this contamination. However, different methods are used to determine the available Pb content of the soil, resulting in differing values for the extractants. The aim of the present work was to compare the efficiency of extraction using Mehlich 1, DTPA and CaCl2solutions in the evaluation of Pb availability in soil treated with different soil amendments. The soil sample used in the experiment was collected near the metal plant. The dosages of soil amendments were set up based on the carbon content of the materials (compost humic acid, commercial humic acid and charcoal), being: 0, 0.75, 1.5, 3 and 7.5 g C kg-1. The available Pb content was extracted by Mehlich 1, DTPA pH 7.3 and CaCl2 10 mmol L-1. Soil fractionation was carried out to determine the metal attached to the exchangeable and organic matter fractions of the soil. The addition of AHv reduced the Pb content of the soil by 60, 89 and 47% for extractions carried out with Mehlich 1, CaCl2 and DTPA respectively. The Pb content of the organic matter fraction was directly proportional to the dosages of soil amendments. The three extractants under evaluation were efficient in predicting the available Pb content.

In recent decades, organic and/or inorganic nonconventional waste such as sewage sludge, agro-industrial or industrial waste, inorganic waste, steel slag, etc., have become some of the most promising alternatives to commercial fertilizer shortages or rising prices. Hence, the aim was to evaluate morphological changes in corn plants and variations in chemical properties of cohesive Yellow Latosol (Oxisol), after the incorporation of sewage sludge doses from domestic waste and the dairy industry. The experimental units were randomised blocks designed with four repetitions. The treatments consisted of five doses of each sewage sludge incorporated into the soil, that is: Domestic Sewage Sludge (DSS) in doses of 0.0; 3.1; 4.6; 6.1 and 9.2 Mg ha-1 (on a dry basis ), and Industrial Sewage Sludge (ISS) in doses of 0.0; 5.2; 7.8; 10.4 e 15.6 Mg ha-1 (on a dry basis), all equivalent to 0; 100; 150; 200 and 300 kg of total N ha-1. Doses equivalent to 150 - 300 kg total N ha-1 led to greater gains in stem diameter, number of leaves, fresh and dry mass of leaves. Increasing doses of both sewage sludges enable gains in the morphological variables studied, except for root length. Positive linear increments occur in the pH and phosphorus content of soils when the doses of sewage sludge are increased. The exchangeable aluminium and potential acidity are reduced, from the first dose of industrial sewage sludge, with no significant difference for domestic sewage sludge. Nas últimas décadas a utilização de resíduos orgânicos e/ou inorgânicos não convencionais, como lodo de esgoto, resíduos agroindustriais ou industriais, rejeitos inorgânicos, escórias siderúrgicas, dentre outros, surgem como alternativas promissoras a escassez ou encarecimento dos fertilizantes comerciais. Diante do exposto, objetivou-se avaliar alterações morfológicas em plantas de milho e alterações nos atributos químicos de um Latossolo Amarelo coeso, após a incorporação de doses de lodos esgoto doméstico e da indústria de laticínios. Os experimentos foram instalados em um delineamento em blocos casualizados, com quatro repetições. Os tratamentos consistiram de cinco doses de cada lodo incorporadas ao solo, sendo: Lodo de esgoto doméstico (LD) nas doses de 0,0; 3,1; 4,6; 6,1 e 9,2 Mg ha-1 (em base seca) e Lodo de esgoto industrial (LI) nas doses de 0,0; 5,2; 7,8; 10,4 e 15,6 Mg ha-1 (em base seca), equivalentes a 0; 100; 150; 200 e 300 kg de nitrogênio total ha-1. As doses equivalentes de 150 a 300 kg de N ha-1 propiciaram maiores ganhos de diâmetro de colmo, número de folhas, massa fresca e massa seca de folhas. Aumentos nas doses de ambos os lodos de esgotos propiciam ganhos nas variáveis morfológicas estudadas, exceto para o comprimento de raízes. Incrementos lineares positivos ocorrem no pH e no teor de fósforo dos solos com o aumento das doses de lodos. O alumínio trocável e a acidez potencial são reduzidos, a partir da primeira dose de lodo de esgoto industrial, não havendo diferença significativa para o lodo doméstico.

Lead is a toxic metal that affects plant growth and the ecosystem. This study evaluated the lead (Pb) bioaccumulation potential of vetiver (Vetiveria zizanioides L.), sunflower (Helianthus annuus L.), elephant ear (Alocasia macrorrhiza) and ‘embaúba’ (Cecropia sp.). The plant species were tested in a 50% nutrient solution - Hoagland and Arnon, constantly aerated, containing five Pb concentrations: 0, 50, 100, 200 and 400 mg L-1). The treatments were arranged in a completely randomized design in a 4 x 5 factorial scheme, with four replicates. The Pb contents in the plants increased linearly with the Pb exposure concentration. Vetiver was the species with the highest Pb content in the shoots (260.24 mg kg-1) and sunflower, in the roots (44925.20 mg kg-1). Pb concentration of up to 100 and 50.9 mg L-1 stimulated sunflower biomass and root length, respectively. None of the evaluated species met the hyperaccumulator criterion; however, sunflower and vetiver have the potential to be tested for phytostabilization purposes. RESUMO O chumbo é um metal tóxico que impacta o crescimento de plantas e os ecossistemas. Avaliou-se o potencial de bioacumulação de Pb nas espécies vetiver (Vetiveria zizanioides L.), girassol (Helianthus annuus L.), orelha de elefante (Alocasia macrorrhiza) e embaúba (Cecropia sp.) em cinco concentrações de Pb (0, 50, 100, 200 e 400 mg L-1) em solução nutritiva Hoagland e Arnon, meia força, constantemente aerada. Os tratamentos foram dispostos em delineamento experimental inteiramente casualizado em esquema fatorial 4 x 5, com 4 repetições. Durante 21 dias, a concentração do metal nas plantas aumentou linearmente com a concentração de exposição ao Pb. O vetiver foi a espécie com maior concentração de Pb na parte aérea (260,24 mg kg-1) e girassol na raiz (44.925,20 mg kg-1). A biomassa e o comprimento radicular de girassol foram estimulados até a concentração de 100 e 50,9 mg L-1 de Pb, respectivamente. Nenhuma das espécies atendeu aos critérios de hiperacumulação; entretanto, girassol e vetiver devem ser testados como espécies fitoestabilizadoras.

This study looks at the ability of organic wastes from different sources to efficiently promote chemical attributes and enhance nitrogen (N) concentrations in an Oxisol Ustox with a sandy texture. This experiment was performed in a randomized design using wastes from pulp mill sludge, petrochemical complex, sewage treatment plant, dairy factory sewage treatment plant, and pulp fruit industry, on 10 different days. Results showed that addition of the wastes to the soil amended their chemical attributes. The different characteristics of the organic wastes seem to have influenced the N mineralization rates during the 112 days. There was a close relationship between the N mineralization and organic waste C/N ratio: blank soil (SP) (Nma = 3.17) < Treated pulp mill sludge (PMS) (Nma = 30.49, C/N 63.6:1) < Organic compost from the fruit pulp industry (FPW) (Nma = 67.6, C/N 11.9:1) < Treated urban sewage sludge (USS) (Nma = 76.22, C/N 7.2:1) = Petrochemical complex sludge (PS) (Nma = 84.0, C/N 7.7:1) < Treated da...

A contaminação de solos por chumbo representa importante risco à saúde humana, sendo o município de Santo Amaro da Purificação, BA, um dos mais graves casos de contaminação do metal. O objetivo deste trabalho foi avaliar o efeito de ácidos húmicos e carvão vegetal ativado como amenizantes da toxidez de Pb para plantas de milho cultivadas em solo contaminado, coletado próximo à área da metalúrgica responsável pela contaminação. As doses foram estabelecidas com base no teor de C dos materiais (ácidos húmicos de compostagem, ácidos húmicos comerciais e carvão vegetal) e corresponderam a 0; 0,75; 1,5; 3; e 7,5 g kg-1 de C no solo. Ao final de 43 dias de cultivo, as plantas foram coletadas rente ao solo, separadas em parte aérea e raízes e submetidas à digestão nítrico perclórica para determinação de Pb. A fim de avaliar o efeito do metal sobre o aparato fotossintético, os teores de clorofilas a e b foram também avaliados. Os amenizantes aplicados no solo contaminado foram eficientes em diminuir o estresse provocado por Pb nas plantas de milho, sendo a maior eficiência obtida para os ácidos húmicos de compostagem, seguida pelo carvão vegetal e pelos ácidos húmicos comerciais. Todos os amenizantes testados diminuíram a translocação de Pb para a parte aérea das plantas, o que implica em maior fixação do metal no solo, com consequente diminuição dos riscos de transferência à cadeia trófica. Por essa razão, esses amenizantes podem ser recomendados para programas de fitoestabilização de Pb em solos. Soil contamination by Pb poses a significant risk to human health. The municipality of Santo Amaro da Purificação, Bahia, Brazil, has one of the most severe cases of contamination of this metal in the world. The objective of this study was to evaluate the effect of humic acids and activated charcoal as soil amendments for reducing the toxicity of Pb to corn plants grown in contaminated soil collected near the area of the company responsible for the contamination. Application rates were based on the C content of the materials (humic acid from composting -AHv, commercial humic acid - AHc, and charcoal - CV) and corresponded to 0, 0.75, 1.5, 3 and 7.5 g kg-1 of C in the soil. At 43 days of growth, the plants were cut at ground level, separated into shoots and roots, and Pb contents were determined by nitro-perchloric digestion. The concentrations of chlorophyll a and b were also evaluated to evaluate the effect of the metal on the photosynthetic apparatus. The soil amendments applied to contaminated soil were effective in reducing the stress of Pb in corn plants. The highest efficiency was obtained from AHv, followed by CV and AHc. All the soil amendments tested decreased translocation of Pb to the shoots. This implies a greater fixation of the metal in the soil and, consequently, a reduction in the risk of transfer to the food chain. For this reason, these materials can be recommended as soil amendments for Pb phytostabilization in soils.

Na região Nordeste do país o pinhão-manso surge como uma planta promissora para a produção de biodiesel devido ao alto teor de óleo nas sementes. O presente trabalho objetivou avaliar o comportamento e a qualidade de mudas do pinhão-manso, em função de doses de lodos de esgoto doméstico e industrial. Os experimentos foram conduzidos em casa de vegetação com cinco tratamentos, consistindo de cinco doses de ambos os lodos de esgoto (equivalentes a 0, 100, 150, 200 e 300 kg N total ha-1), no delineamento em blocos casualizados, com quatro repetições. As variáveis analisadas foram: comprimento da parte aérea, comprimento da raiz, número de folhas, diâmetro do caule, massa fresca da parte aérea, massa fresca da raiz, massa seca da parte aérea, massa seca da raiz e índice de qualidade de mudas de Dickson (IQD). O lodo de esgoto industrial favorece as variáveis relacionadas à raiz até a dose de 200 kg N total ha-1 e o lodo de esgoto doméstico as variáveis relacionadas à parte aérea na dose de 200 kg N total ha-1, exceto para a massa seca da parte aérea e raiz de mudas de pinhão-manso. O lodo de esgoto industrial não alterou a quantidade de massa seca da parte aérea de mudas de pinhão-manso. O índice de qualidade de Dickson caracteriza as mudas de pinhão-manso como de boa qualidade, contudo não apresenta diferença significativa entre os tratamentos.

The use of organic wastes in agricultural soils is one of the possible ways to employ these materials. The aims of this study were to evaluate the effectiveness of organic wastes and Fermented Bokashi Compost (FBC), to establish the most efficient use of organic wastes for a soil, changing the net nitrogen mineralization and soil chemical properties. The experimental design was completely randomized in a 6 x 2 x 5 factorial, being five organic wastes plus an control (soil without waste), with or without FBC, evaluated at 0, 7, 42, 70 and 91 days of incubation, with three replicates, under laboratory conditions. The organic wastes enhanced the soil chemical properties and increased nitrogen concentration in soil. However, the net nitrogen mineralization was affected by C/N ratio of wastes and incubation time. The FBC mixed with the wastes accelerated and enhanced organic matter degradation, resulting in quickly available quantity of net nitrogen. The wastes can be considered potentially useful as organic fertilizer but their usefulness appears to depend on knowing the C/N ratio of each one. The FBC can be used when one wants a more accelerated degradation, resulting in a quicker quantity of available nutrients to the plants. O uso de resíduos orgânicos nos solos é uma das maneiras possíveis para empregar estes materiais. Os objetivos deste estudo foram avaliar a eficácia de resíduos orgânicos e do composto fermentado Bokashi (FBC) e estabelecer o uso mais eficiente dos resíduos, alterando a mineralização líquida de nitrogênio e as propriedades químicas do solo. O delineamento experimental foi inteiramente casualizado, em fatorial 6 x 2 x 5, sendo cinco resíduos mais um controle (solo sem resíduo), com ou sem FBC, avaliados aos 0, 7, 42, 70 e 91 dias de incubação, com três repetições, em condições de laboratório. Os resíduos orgânicos melhoraram as propriedades químicas e aumentaram a concentração de nitrogênio no solo. No entanto, a mineralização líquida do nitrogênio foi afetada pela relação C/N dos resíduos e o tempo de incubação. A mistura do FBC com os resíduos acelera e melhora a degradação da matéria orgânica, resultando em uma quantidade de nitrogênio líquido rapidamente disponível. Os resíduos estudados podem ser considerados potenciais adubos orgânicos, contudo sua utilidade parece depender do conhecimento da relação C/N de cada um. O FBC pode ser usado quando se deseja uma degradação mais acelerada, resultando em rápida quantidade de nutrientes disponíveis para as plantas.

Ever since the government began providing incentives for biofuel production, physic nut has appeared to be a promising plant, due to the high oil content of the seeds. The purpose of this study was to evaluate the nutrition of physic nut seedlings and changes in the chemical attributes of soil, based on the doses of domestic and industrial sewage sludge. Two experiments were conducted in a design with casualized blocks with four repetitions using samples of a “Latossolo Amarelo” that received five doses of each sludge, equivalent to 0; 100; 150; 200 and 300 kg N total ha -1 . The domestic sewage sludge raised the calcium and magnesium contents in the dry mass of the aerial part and root, and nitrogen and phosphorus in the dry mass of the aerial part of physic nut seedlings, whereas the industrial sludge raised the calcium and nitrogen in the dry mass of the aerial part and root of the physic seedlings, but did not affect the phosphorus, nitrogen, magnesium and potassium contents in the dry mass of the aerial part and root. The domestic sludge did not alter the soil pH but raised the amounts of phosphorus, calcium + magnesium, cation exchange capacity, organic matter and reduced the exchangeable aluminum, while the industrial one raised the pH and the cation exchange capacity of the soil, increased the amounts of phosphorus, calcium + magnesium, and organic matter and reduced the exchangeable aluminum present in the soil. The domestic and industrial sludges may be used to produce physic nut seedlings; however is necessary studies to evaluate the presence of heavy metals or potentially pathogenic microorganisms.

O avanço industrial e urbano associado ao aumento da produção dos bens de consumo resultou na geração de resíduos que, por muito tempo, foram descartados indiscriminadamente no ambiente, provocando danos quase sempre irreversíveis e de difícil recuperação. Dois experimentos foram conduzidos em solos contaminados por metais pesados, o primeiro devido ao descarte de produtos inorgânicos contendo grande carga de poluentes no solo; no segundo estudo a contaminação deve-se ao uso sucessivo de fungicidas contendo cobre em pomares cítricos do sul da Flórida. O primeiro estudo objetivou avaliar o uso de amenizantes orgânicos como mitigadores da toxicidade de bário, boro, cádmio, chumbo, cobre, níquel e zinco presentes no solo contaminado decorrente da adição de resíduo de sucata automobilística e avaliar o potencial fitoextrator do pinhão-manso (Jatropha curcas L.). Observou-se que o fornecimento da matéria orgânica na forma de turfas não amenizou a contaminação por metais pesados (Ba, Cd, Cu, Ni, Pb,Zn) e B; tal efeito pode ter ocorrido devido ao elevado pH deste solo mantido pelas práticas constantes de calagem. Os elementos apresentaram maior disponibilidade no solo ao longo das avaliações, exceto o boro que não apresentou significância. As plantas apresentaram sintomas de fitotoxicidade causados pelo elevado teor de boro e metais pesados no solo. A maior parte dos elementos metálicos se acumulou nos colmos e o boro nas folhas do pinhão manso, ou seja, a planta foi eficiente em translocar tais elementos para a parte aérea, situação desejável em uma fitoextratora. Ao final do experimento, os teores de Ba, Cd, Cu, Ni, Pb e Zn estavam mais disponíveis às plantas. O que indica que a matéria orgânica presente nas turfas mineralizou e tornou mais disponível estes metais pesados às plantas ao longo das avaliações. Pelos índices de transferência, de translocação e de remoção o pinhão manso foi viável somente para fitoextração de boro da área contaminada; estes índices também apontaram que o pinhão manso apresentou potencial para acumular B, Ba e Cd. O segundo experimento foi desenvolvido em casa de vegetacão com um argissolo coletado em uma área que tem recebido sucessivas aplicações de fungicidas a base de cobre, o que tem promovido o acúmulo significativo deste elemento nos solos sob produção de citros. O objetivo foi avaliar o potencial de fitoextração de cobre pelas plantas chinesas Splendens elsholtzia e Argyi elsholtzia para remover o excesso de cobre em solos contaminados devido a aplicação sucessiva de fungicidas cúpricos em pomares cítricos do sul da Flórida. A produção de massa seca de folhas, colmos e raízes e a concentração de cobre nos tecidos da Splendens elsholtzia foram superiores ao da espécie Argyi elsholtzia, o que indica que a Splendens elsholtzia é mais tolerante aos elevados níveis de cobre no solo. Assim, esta espécie pode ser indicada para programas de fitoextração em solos contaminados com cobre; entretanto, o índice de translocação do cobre indicou que as duas espécies não foram eficientes em translocar o cobre da raíz para parte aérea. The industrial and urban progress associated with increased production of consumer goods has resulted in the generation of waste, which, for a long time, was indiscriminately discarded in the environment, causing damage usually irreversible to recover. Two experiments were conducted in soils contaminated with heavy metals: the first aimed at the disposal of products containing high loads of inorganic pollutants in the soil and the second focused on contamination due to the successive uses of fungicides containing copper in citrus groves of South Florida. The first study aimed to evaluate the use of organic soothers as mitigators of toxicity caused by barium, boron, cadmium, lead, copper, nickel and zinc in soil contaminated with waste resulting from the disposal of automobile scrap and to evaluate the phytoextraction potential of Jatropha (Jatropha curcas L.). It was observed that the supply of organic matter in the form of peat did not alleviate the contamination with heavy metals (Ba, Cd, Cu, Ni, Pb, Zn) and B, which may be attributed to the high pH of the soil due to constant practices of liming. The items showed higher availability in the soil during the evaluations, except for boron which showed no significance. The plants showed symptoms of phytotoxicity caused by high levels of boron and heavy metals in the soil. Most metallic elements are accumulated in the stems and boron in the leaves of Jatropha curcas, thus, the plant was efficient in the translocation of these elements to the shoot, a situation is desirable in phytoextraction. At the end of the experiment, the concentrations of Ba, Cd, Cu, Ni, Pb and Zn were more available to plants. This indicates that the organic matter present in the peat mineralized and made these heavy metals more available to plants. Considering the transfer rates of translocation and removal, the Jatropha was feasible only for phytoextraction of boron in the contaminated area, which shows that Jatropha has the potential to accumulate B, Ba and Cd. The second experiment was conducted in a greenhouse in an alfisol collected in an area that received repeated applications of copper-based fungicides, which promoted significant accumulation of this element in soils under citrus production. The objective was to evaluate the potential for phytoextraction of copper by the Chinese plants Splendens elsholtzia and Argyi elsholtzia to remove excess of copper in contaminated soils due to repeated application of copper-based fungicides in citrus groves of South Florida. The dry weight of leaves, stems and roots and the concentration of copper in the tissues of Splendens elsholtzia were higher than in Argyi elsholtzia, which indicates that the Splendens elsholtzia is more tolerant to high copper levels in the soil. Thus, this species may be indicated for phytoextraction of soils contaminated with copper; however, the rate of copper translocation indicated that the two species were not efficient to translocate copper from root to shoot.