Lithium, together with hydrogen and helium, were the only elements formed duringthe big bang. Lithium today, is a component in various products, some examples aregrease, ceramics, lithium-ion batteries and medication for bipolar disorder. Eventhough the knowledge of lithium’s interactions with biota and our environment islimited, the use of lithium is increasing. In humans, lithium is primarily absorbed in thesmall intestine through Na-channels. The average daily intake varies a lot, but in1985 it was estimated to range from 650 to 3100 μg for a 70 kg adult, according tointernational studies. However, it is not considered as a micronutrient and does nothave a recommended daily intake. Levels in some drinking waters are estimated toreach 170 μg L-1but no definite limit values are set. Humic substances are omnipresent in soil and freshwaters and is well known to formcomplexes with various cations such as most metals. In plants, the complexation ofcadmium and zinc with humic substances decreases their toxicity. However,currently, no studies have been published regarding if this is valid for animal cells aswell. To investigate if this is the case, in vitro tests were performed on Caco-2 cells,which originate from a colon carcinoma. These cells were exposed to a lithium concentration of 10 μg L-1in a nutrient medium for 2 hours. To a series of thesamples, humic acid was added to give a final concentration of 9.86 μg L-1 in thesolution to investigate if that would influence the lithium uptake. The study also includes a methodological evaluation if the performance of microplasma atomic emission spectroscopy (MP-AES) is suitable for the analyses of heavymatrices, e.g. nutrient medium and 1% Triton X solution. After optimization of instrumental parameters, it was concluded that MP-AES can beused for analysis of heavy and complex matrices. It requires, however, the use ofmatrix matched calibration solutions and addition of caesium as ionization buffer incombination with lithium signal correction using internal standards. It is alsoconcluded that lithium is absorbed by Caco-2 cells and that there was no indicationthat humic acid altered this uptake. / Litium är en viktig komponent in många produkter, bland annat smörjmedel, keramik,litium-jonbatterier och medicin mot bipolär sjukdom. Även fast dagens kunskap omlitium och dess interaktioner med miljö och organismer är begränsad, ökaranvändandet av litium. I människor absorberas litium primärt i tunntarmen genomNa-kanaler. Det dagliga intaget av litium varierar geografiskt och med livsstil och detfinnas inga bestämda gränsvärden. I USA var det dagliga intaget av litium 1985uppskattat att ligga kring 650 till 3100 μg hos en vuxen som väger 70 kg. Humusämnen är väl kända för att bilda komplex med flertalet metaller. I växter hardet påvisats att humusämnen kan bilda komplex med kadmium och zink vilketminskar toxiciteten av dessa för växten. Inga studier har dock hittats gällandehumusämnens eventuella möjligheter att minska toxiciteten av litium, eller andrametaller, hos djur eller människor. För att undersöka detta närmare har denna studiegjorts för att få ökad förståelse kring absorptionen av litium till Caco-2 celler samt föratt se om närvaro av humussyra kan påverka ett eventuellt upptag. Vidare presenteras resultat från en metodologisk utvärdering om MP-AES kananvändas för att kvantifiera litium i tyngre matriser, såsom näringsmedium för celleroch Triton X-100. Resultaten visar att MP-AES kan användas för dessa matriser genom att användamatrismatchade kalibreringslösningar och cesium som jonisationshämmare ikombination med korrigering av litiumsignalen med hjälp av signalen från internstandard. Sammanfattningsvis så absorberar Caco-2 celler litium och ingenindikation på att humusämnen påverkar detta upptag kunde hittas.

Anthropogenic activities such as uranium mining and milling, nuclear weapons production, and nuclear reprocessing have left a legacy of groundwater and soil contaminated with uranium that needs to be addressed. Therefore, developing new remediation technologies to sequester uranium in situ is crucial. The objective of the study was to determine if low-cost commercially available unrefined humic substances, such as Huma-K, can be used to facilitate uranium sorption to minerals in soil and sediment. Sediments from the saturated zone beneath the F-Area seepage basins at the Savannah River Site (SRS) in South Carolina were used for the present study. The SRS site is analogous to many contaminated locations where groundwater acidity enhances uranium and other contaminants mobility. First, a variety of techniques were applied to characterize Huma-K and SRS sediment. Characterization studies showed that Huma-K possesses functional groups that have an acidic nature such as carboxyl and phenol groups. For SRS sediment, a mineral composition of mainly quartz (93.2%), kaolinite (5.1%), and goethite (1.1%) was identified. Second, the interactions between Huma-K and SRS sediment were investigated through batch experiments. Sorption, homogeneous precipitation, and surfaced-induced precipitation were observed to be enhanced at pH 4. However, Huma-K removal from solution decreased with an increase of pH. The sorption behavior was not able to be described by any of the models employed (pseudo-first, pseudo-second, Langmuir, and Freundlich). Third, the interactions between uranium and SRS sediment with and without Huma-K amendment were investigated. In acidic conditions (pH 3-5), the sorption capacity of SRS sediment amended with Huma-K was significantly increased compared to plain sediment. At circumneutral conditions, uranium removal from solution decreased for SRS sediment amended with Huma-K, compared with plain sediments, likely as a result of the formation of aqueous uranium-humic complexes. In summary, the results from the present study suggest that Huma-K, and likely other unrefined humate products, has the characteristics and effects necessary to be suitable for subsurface injection to remediate uranium in acidic groundwater conditions. The treatment zone will persist as long as the pH does not increase sufficiently to cause soil-bound Huma-K to be released, remobilizing uranium.

For this study 14 lambs were obtained, which were split into two groups; a control group (CON) and a group that was supplemented Reed Sedge Peat (RSP). We wanted to test whether RSP could decrease stress at weaning, increase immune response and also increase digestibility of the animal. Lambs were subjected to an ACTH challenge 48 hours post weaning. After weaning (d 28 of study) 10 of the lambs (5 CON; 5 RSP) also underwent a digestibility challenge. We found that there was no difference (P = 0.8764) within cortisol concentration during the weaning portion of the study between the two treatment groups. During the ACTH challenger there was a difference between RSP group and CON, where RSP had a decrease in cortisol concentration (P = 0.0892). There was no difference in blood cell parameters, except for SEG, % (P = 0.0890) where RSP had greater % of SEG than CON group. Within the digestibility trail there was a decrease in digestibility within the RSP group compared to CON, within DM, OM, NDF and ADF (P = 0.0458; P = 0.0430; P = 0.0509; P = 0.0786; respectively).

Aqueous silica is present in all natural waters and exhibits a high affinity for the surfaces of iron oxides. Therefore, it is expected to play an important role in environmental systems. Experiments were conducted to investigate the fundamentals of silica sorption onto pre-formed ferric hydroxide at pH 5.0-9.5 and silica concentrations of 0-200 mg/L as SiO₂. Over the entire pH range studied, sorption densities exceeding monolayer sorption were observed at silica levels typical of natural waters. Under some circumstances, sorption exceeded a monolayer while the particle zeta potential remained positive, a phenomenon which is inconsistent with available models. To address this deficiency, an extended surface complexation model was formulated in which soluble dimeric silica sorbs directly to iron surface sites. This model fits sorption density data up to 0.40 mol SiO₂/mol Fe, and it accurately predicts trends in zeta potential and the observed H⁺ release during silica sorption to ferric hydroxide at pH 5.0 and 6.0. A second phase of research was aimed at identifying the practical implications of silica sorption to iron hydroxide in natural and engineered systems. Two types of surfaces were prepared by exposing pre-formed Fe(OH)₃ to aqueous silica (0-200 mg/L as SiO₂) for periods of 1.5 hours or 50 days. The concentration of pre-formed iron passing through a 0.45 micron pore size filter at pH 6.0-9.5 increased as the solids aged in the presence of silica. Consistent with formation of small, stable colloids, "soluble" iron concentrations exceeded 0.2 mg/L only at zeta potentials <span style="text-decoration:underline"><</span> -15 mV. When arsenate was added to iron hydroxide particles equilibrated with silica for 1.5 hours, percentage arsenate removals were high. In contrast, arsenate removals decreased markedly as pH and silica concentrations increased if silica was pre-equilibrated with the iron for 50 days. Trends in percentage removal of humic substances were similar. Competition for sorption sites was the main cause of hindered anionic contaminant removal. However, interference with hydrolysis and precipitation are expected to be important under some circumstances, particularly during water treatment. / Master of Science

The purpose the diploma thesis was to determine main fluorophores of soil and lignite humic substances using methods of 2D synchronous fluorescence spectroscopy (SFS) and 3D SFS. These fluorescence methods are frequently used for characterization multifluorophore systems. Measured synchronous spectra were compared with standards IHSS. Next to that the aim was to find differences between chosen samples of humic and fulvic acids.

Addition of alkalinity to acid mine drainage (AMD) results in the neutralisation of acidity and precipitation of dissolved metals as insoluble hydroxides. Two aspects of the current AMD treatment practice at the Stockton Mine could be enhanced. Firstly, residual water quality may be poor due to unreacted alkalinity reagents, particularly CaCO3, resulting in poor water clarity and elevated suspended solids (SS). Secondly, neutralisation to circum-neutral pH may not avoid the discharge of residual metals (Ni and Zn) due to incomplete adsorption and hydroxide precipitation. The aim of this project was to enhance the conventional neutralisation of AMD through addition of humic substances (HS) to reduce residual SS and trace metal concentrations. Humic substances are organically derived and have a high molecular weight. Functional groups on the surface of HS are capable of binding dissolved metals, forming HS-metal complexes. Incorporation of HS complexed metals into settling floc could result in increased metal removal from the dissolved phase. Modified jar testing was used to investigate the effects of HS addition before, after and during (pH 4.5) neutralisation of AMD in two treatment scenarios at the Stockton Mine; the Blackwater Treatment Plant (BTP) using NaOH and Ca(OH)2 and the Mangatini Stream-sump System (MSS) using CaCO3. Supernatant samples collected during the sedimentation period were analysed for basic water quality parameters (turbidity and suspended solids) and dissolved (< 0.45 µm) metal concentrations. The addition of HS to the BTP process before (pH 2.8) and during (pH 4.5) neutralisation resulted in HS precipitation. Precipitated HS subsequently acted as a nucleation site, triggering flocculation of precipitating metal hydroxides, resulting in low turbidity and suspended solids (SS) of less than 2 NTU and 5 mg/L, respectively. The addition of HS after neutralisation (pH 7) did not result in HS precipitation. Intermolecular bridging of HS by the divalent Ca resulted in incorporation of HS into floc when neutralised by Ca(OH)2, resulting in low turbidity and SS. However, in NaOH neutralised conditions, the monovalent Na was unable to bridge HS molecules, resulting in HS remaining dissolved and contributing to elevated turbidity and SS of up to 24.4 NTU and 18.4, respectively. The neutralisation efficiency of CaCO3 is relatively low, thus approximately 1000 mg/L CaCO3 remained unreacted in MSS scenarios, resulting in elevated turbidity and SS. When added after neutralisation, dissolved Solid Energy Humic Acid (SEHA) facilitated flocculation of residual CaCO3 SS, resulting in an up to 75% lower suspended solids than CaCO3 neutralisation alone conditions. Although the results are good, the efficiency of SEHA as a polymer compared unfavorably in a cost: benefit analysis to two commercially available polymers for the removal of residual CaCO3. Neutralisation of AMD in control samples resulted in decreased concentrations of the target metal group (Ni, Zn, Cu, Cd, and Pb) by hydroxide precipitation, co-precipitation, and adsorption. Equilibrium speciation modeling showed that the HS-metal binding affinity controlled the effectiveness of HS addition for metal removal. The low HS complexation affinity of Ni and Zn resulted in no additional metal removal by HS dosing. The removal of Cu was enhanced by over 50% for SEHA 20 during-neutralisation conditions neutralised by both NaOH and Ca(OH)2. Up to 80% lower Cd concentrations were observed for all HS dose conditions when neutralised by Ca(OH)2. Data for CaCO3 HS dosed metal removal was statistically indeterminate. The high detection limit for Pb made any HS dosed removal enhancement difficult to identify, which was unfortunate as Pb has a high HS complexation affinity (Čežı́ková, Kozler et al. 2001; Milne, Kinniburgh et al. 2003). A simple cost: benefit analysis showed that the additional removal of metals by HS dosing was less efficient than conventional neutralisation alone, on a cost basis. Overall, incorporation of HS into AMD treatment results in improved water quality for CaCO3 neutralisation and lower concentrations of metals with a high HS binding affinity, for some conditions. However, further investigation is required to improve the feasibility of HS incorporation into the AMD neutralisation process.

O presente estudo trata da investigação sobre o uso de um produto inovador, classificado como substâncias húmicas, as quais têm sido estudadas como aditivo alternativo na dieta de bovinos de corte. Assim, o objetivo deste estudo foi avaliar o uso de substâncias húmicas como aditivo na dieta de bovinos Nelore e sua influência no metabolismo ruminal e na síntese de proteína microbiana. Utilizou-se 8 machos canulados e castrados, alocados em baias individuais, com peso vivo de 549 kg (± 45 kg). Os animais foram divididos aleatoriamente em delineamento quadrado latino 4x4 replicado, recebendo tratamentos com níveis crescentes de substâncias húmicas na MS da dieta (0%, 0,45%, 0,9% e 1,35%). Avaliou-se o consumo de matéria seca, pH ruminal, ácidos graxos de cadeia curta, nitrogênio amoniacal, contagem de protozoários, síntese de proteína microbiana e níveis de ureia plasmática no sangue. Não houve efeito (p > 0,05) entre os tratamentos para o consumo de matéria seca, pH ruminal, nitrogênio amoniacal, população de protozoários e níveis de ureia plasmática no sangue. Quanto aos ácidos graxos de cadeia curta, ocorreu efeito linear decrescente nas concentrações de isobutírico e valérico e não houve efeito de tratamento para ácido acético, propiônico, butírico e isovalérico. Obteve-se efeito quadrático na excreção urinária de alantoína, purinas microbianas absorvidas e nos compostos nitrogenados microbianos. A adição de substâncias húmicas até o nível de 1,35% na matéria seca não influenciou os parâmetros ruminais dos animais recebendo uma dieta com 50% de concentrado. Estudos adicionais sobre o uso do produto em maior quantidade na dieta, com maior proporção de concentrados, influência de raças, idade e categoria animal podem contribuir para elucidar os efeitos desse produto como aditivo alimentar. / The present study explore the use of an innovative product, classified as humic substance, which has been studied as an alternative additive for beef cattle diet. Therefore, the objective of this study was to evaluate the use of humic substances as an additive in the diet of Nellore cattle and their influence on ruminal metabolism. Eight cannulated and castrated males were used in individual pens with a live weight of 549 kg (± 45 kg). The animals were randomly allotted into a replicated 4x4 latin square design, receiving treatments with increasing levels of humic substances in the diet (0%, 0.45%, 0.9% e 1.35%). The dry matter intake, ruminal pH, short chain fatty acids, ammoniacal nitrogen, protozoan count, microbial protein synthesis and blood urea levels were evaluated. There was no effect (p> 0.05) between treatments for dry matter intake, ruminal pH, ammoniacal nitrogen, protozoan population and plasma urea levels in the blood. As for short chain fatty acids, there was no treatment effect for acetic, propionic, butyric and isovaleric acid, but it was observed linear decreasing effects on isobutyric and valeric concentrations. There was a quadratic effect on urinary excretion of allantoin, absorbed microbial purines and microbial nitrogen compounds. The addition of humic substances up to the level of 1.35% in DM did not influence the ruminal parameters of the animals receiving diet with 50% of concentrate. Additional studies on the product use considering more challenging ration, with a greater concentrated:forage ratios, animal age and other variations can contribute to clarify the effects of this product as additive.

Orientador: Altair Benedito Moreira / Coorientador: Ademir dos Santos / Banca: César Ricardo Teixeira Tarley / Banca: Eduardo Alves de Almeida / Resumo: Este trabalho teve como objetivo estudar a interações das Substâncias Húmicas (SH) com os metais cobre(II), cromo(III) e cromo(VI) por meio de dois métodos, o da supressão da fluorescência molecular e o sistema de ultrafiltração com fluxo tangencial (SUFT). As SH foram caracterizadas por técnicas espectroscópicas na região do infravermelho e do ultravioleta-visível e por fluorescência molecular. Foram realizadas duas coletas de sedimentos, uma no período de chuva e outra no de seca, sendo coletados em três rios da Bacia Hidrográfica do Turvo/Grande, Rio Preto, Rio Turvo e Rio Grande. O sedimento foi coletado com o auxilio de uma draga manual do tipo Van Veen. As SH foram extraídas de acordo com metodologia oficial sugerida pela Sociedade Internacional de Substâncias Húmicas (SISH). A constante de estabilidade condicional (Kc) foi determinada por meio da supressão da fluorescência e variou de 5,6x10-3 - 1,23 em período chuvoso para o íons cobre, e de 5,5x10-3 - 8,7x10-2 para o período de seca. Quando a Kc foi determinada para o complexo SH-Cr(III) valores de 1,9x10-1-5,2x10-1 e 2,1x10-1-3,5x10-1, foram determinados para o período de chuva e de seca, respectivamente. Por fim a Kc foi determinada para a interação das SH com Cr(VI), de forma geral os valores de Kc foram maiores para o período de chuva. A capacidade complexante (CC) determinada por meio do SUFT para a interação das SH com cobre(II) teve valores que variaram de 4,0x10-1 - 6,3x10-1 mmol Cu g-1 SH e de 1,4x10-1 - 5,3x10-1 mmol Cu g-1 SH para período de chuva e seca, respectivamente. Para o Cr(III) a CC variou de 2,1x10-1 - 9,7x10-1 e de 2,6x10-1 - 8,4x10-1 mmol Cr g-1 SH para o período de chuva e seca, respectivamente. Quando a interação das SH com o Cr(VI) foi estudada por meio do SUFT só foi possível calcular a CC para os pontos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work aimed to study the interactions of humic substances (HS) with copper(II), chromium(III) and chromium(VI), using by two methods, the suppression of the molecular fluorescence and tangential flow ultrafiltration sytem (TFUS). The HS were characterized by spectroscopic thecniques in the infrared and ultraviolet/visible region and molecular fluorescence. There were two sediment samples, one during the wet season and another the dry, being these sediments collected from the three Rivers of the Turvo/Grande drainage basin, Preto river, Turvo river and Grande river. The collection of sediment was carried out with the aid of a manual Van Veen type dredge. The HS were extracted according to the official methodology suggested by the International Humic Substances Society (IHSS). The conditional stability constant (Kc) was determined by suppressing fluorescence and ranged from 5,6x10-3 - 1,23 in the wet season for the copper ions, and of the 5,5x10-3 - 8,7x10-2 to the dry season. When Kc was determined for the complex HS-Cr(III) values of 1,9x10-1-5,2x10-1 e 2,1x10-1-3,5x10-1, were determined for the wet and dry seasons, respectively. Finally, the Kc was determined for the interactions oh HS with the Cr(VI) in geral the Kc values were higher for the wet season. Complexant capacity (CC) was determined by means of TFUS for the interactions of the HS with Copper(II) the values ranged from 4,0x10-1 - 6,3x10-1 mmol Cu g-1 HS and of 1,4x10-1 - 5,3x10-1 mmol Cu g-1 HS for a wet and dry season, respectively. For the Cr(III) CC ranged from 2,1x10-1 - 9,7x10-1 and from 2,6x10-1 - 8,4x10-1 mmol Cr g-1 HS for the wet and dry period, respectively. When the interactions oh HS with Cr(VI) was studied by means of TFUS was only possible to calculate the CC for the points NRP and CAPRP, as for others... (Complete abstract click electronic access below) / Mestre

Neste trabalho efetuou-se um detalhado estudo metodológico das técnicas empregadas para a caracterização espectroscópica e cromatográfica dos ácidos húmicos. Neste estudo demonstrou-se que outros fatores, além de características intrínsecas dos ácidos húmicos, podem afetar os resultados obtidos pelas diferentes técnicas espectroscópicas utilizadas. Dentre estes fatores o mais importante foi o íon vanadila (VO2+) residual que afetou drasticamente os resultados das análises espectroscópicas levando à supressão: dos sinais de RMN de 13C de grupos hidrofílicos; dos sinais de RPE dos radicais livres orgânicos; e da intensidade de fluorescência. Pela supressão seletiva dos sinais de RMN de 13C dos grupos carboxilas e daqueles associados a carboidratos foi possível inferir que estas estruturas possivelmente estejam diretamente envolvidas na complexação do VO2+, assim como a supressão dos sinais de fluorescência e de RPE dos radicais livres orgânicos indicaram que estes radicais e estruturas fluorescentes também podem estar envolvidas na complexação deste íon ou então o efeito do íon paramagnético pode difundir-se facilmente pela estrutura dos ácidos húmicos. Adicionalmente, os ácidos húmicos com maior conteúdo de VO2+ apresentaram um maior tamanho molecular aparente, indicando um possível efeito agregante deste íon. A análise multivariada dos dados obtidos possibilitou o isolamento destes efeitos do VO2+ e as novas variáveis obtidas pela técnica dos componentes principais, independentes do conteúdo deste íon, indicaram que o cultivo mais intenso do solo levou ao acúmulo relativo de estruturas mais recalcitrantes e com maiores conteúdos de estruturas associadas à lignina e C-Alquila de cadeia longa. Além disto, observou-se que o sinal dos radicais livres orgânicos dos ácidos húmicos era devido à pelo menos dois centros paramagnéticos distintos sendo que o VO2+ suprimiu preferencialmente o sinal com maior valor-g, atribuído a radicais livres orgânicos onde o elétron desemparelhado estaria delocalizado sobre átomos de oxigênio. / In this work it was realized a detailed methodological studies of spectroscopic and chromatographic techniques that were applied in the humic substances characterization. In these studies it was demonstrated that, besides the intrinsic characteristics of humic substances, there are other factors which can affect the results obtained with the different spectroscopic techniques utilized. Among these factors, the residual vanadyl ion (VO2+) affected drastically the spectroscopic results causing the suppression of: 13C NMR signals of hydrophilic groups; EPR signals from organic free radicals; and the fluorescence intensity. By the selective suppression of 13C NMR signals from carbohydrates and carboxyl groups it was proposed that these structures could possibly be directly involved in the VO2+ complexation. The suppression of fluorescence signals and EPR ones from organic free radicals indicated that or these radicals and the fluorescent structures can also be involved in the VO2+ complexation, either the paramagnetic ion effect can diffuse through the humic substances structures. In addition, the increase of VO2+ contents resulted in a higher apparent molecular size indicating a possibly aggregating effect of this ion. The multivariate analysis from the obtained data allowed the isolation of these effects from VO2+. The new variables obtained by the principal components technique, independent from that ion content, indicated that the most intense cultivation of the soil lead to the relative accumulation of more recalcitrant structures associated to lignin and long chain C-alkyl. Besides this, we observed that the organic free radicals signal from humic acids was due to at least two paramagnetic centers. The residual VO2+ suppressed preferentially the signal with the highest g-value. This signal was assignment to organic free radicals where the unpaired electron could be delocalized on oxygen atoms.

Investigou-se a influência de íons metálicos Al(III), Ca(II), Fe(III), Pb(II), Cu(II) e Cr(III) (10-6 a 10 -3 mol L-1 na intensidade relativa de fluorescência (IRF) do ácido húmico (AH, 10 mg L-1). os íons Cu(ii), Pb(II) e Cr (III) produziram um efeito de supressão, enquanto os íons Fe(III), Al(III) e Ca(II) não influenciaram significativamente nos valores de IRF. A partir dos valores de IRF foram calculadas a constante de estabilidade (K) dos complexos e a capacidade complexante do AH com Cu(II), Pb(II) e Cr(III). Os valores de K seguiram a ordem: Cr(III)> Pb(II) > Cu(II) e a capacidade complexante: Cr(III) ~ Pb(II)> Cu(II). Desenvolveu-se um novo método analítico baseado na reação quimiluminescente da oxidação do AH com peroxomonosulfato de potássio (PMS; 0,6 mol L-1</SUP) ) em meio básico (NaOH 1,0 mol L-1 ). A intensidade máxima de radiação emitida (Imáx ) e a área em função do tempo foram lineares com a quantidade de AH em solução na faixa de 0,5 a 20 mg L-1, com o limite de detecção de 0,24 mg L-1 , com limite de detecção de 0,24 mg L-1 . Um estudo comparativo foi realizado utilizando-se H2O2 (0,58 mol L-1 na presença de CH2O (0,44 mol L-1) em meio básico (NaOH 0,16 mol L-1) com limite de detecção de 0,4 mg L-1. As adições dos íons Cl-, NO3- , PO43- , CO32- , Fe(III), Cu(II), Cr(III) e Ca(II) na reação quimiluminescente de AH com PMS, não interferiram significativamente no sinal. Adições de 50 mg L-1 de Co(II) ou Mn(II) à solução de AH Aldrich, na forma de complexos de EDTA ou cloretos, aumentaram o valor Imáx devido à formação de espécies fortemente oxidantes como SO5°-, SO4°- HO° durante a reação de decomposição do PMS. O método foi aplicado para determinar a concentração de AH em amostra de água do Rio Miranda - MS, obtendo-se valores entre 2,9 a 12,3 mg L-1 . As reações de oxidação, com emissão de radiação, de alguns compostos orgânicos com PMS em meio básico foram estudadas. Com os polifenóis obtiveram- se intensidades de radiação mais significativas e os valores de área seguiram a seguinte ordem: floroglucinol >> ácido fúlvico > ácido húmico > resorcinol > ácido pirogálico > catecol > hidroquinona. Desta forma, como polifenóis existem na estrutura de substâncias húmicas, acredita-se que essas porções da molécula devem ser as responsáveis pela produção de quimiluminescência. / The influence of Al(III), Ca(II), Fe(III), Pb(II), Cu(II), and Cr(III) metal ions (10-6 to 10-3 mol L-1) on the relative fluorescence intensity (RFI) of humic acid (HA, 10 mg L-1) was investigated. Cu(II), Pb(II), and Cr(III) ions produced a quenching effect, while Fe(III), Al(III), and Ca(II) ions did not significantly interfere with RFI values. Stability constants (K) and complexing capacities of HA with Cu(II), Pb(II), and Cr(III) were obtained using RFI values. Stability values of complexes followed the order: Cr(III)> Pb(II) > Cu(II) and the complexing capacity values: Cr(III) ~ Pb(II) > Cu(II). A new analytical method was developed based on the chemiluminescent oxidation of HA by peroxymonosulfate (PMS; 0.6 mol L-1) in basic medium (NaOH 1.0 mol L-1). The intensity of radiation emission (Imax) and area vs. time were linear functions of HA concentration range of 0.5-20 mg L-1. The detection limit was 0.24 mg L-1. A comparative study was conducted using H2O2 (0.58 mol L-1) in the presence of CH2O (0.44 mol L-1) in basic medium (NaOH 0.16 mol L-1). The detection limit was 0.4 mg L-1 of HA. The addition of Cl-, NO3-, PO43-, CO32-, Fe(III), Cu(II), Cr(III), and Ca(II) to the chemiluminescent reaction of HA with PMS did not interfere with the signal. The addition of 50 mg L-1 Co(II) or Mn(II) (as EDTA complexes or chloride salts) to the HA sample enhanced radiation emission, due to the formation of strong oxidant species such as SO5o-, SO4o-, and HOo during PMS decomposition reaction. This method was applied to determine HA concentration in a sample of river water (Miranda River - MS), obtaining values between 2.9 and 12.3 mg L-1. Oxidation reactions of some organic compounds by PMS in basic medium were studied, which produced radiation emission. Polyphenols produced the highest emissions and the area values followed the order: phloroglucinol> fulvic acid> humic acid> resorcinol> pyrogalic acid> cathecol> hydroquinone. Since polyphenolic groups are supposed to exist within humic acid structure, those portions of the molecule are most likely to be responsible for that chemiluminescence.