Resource recovery has become essential to compensate for costly and complex technical requirements to implement zero-liquid discharge (ZLD) policies. Antiscalant removal, especially phosphonate-based antiscalants, is a clear example of resource and potential subsequent valorization. The global market for phosphonate-based antiscalants is expected to grow in the coming years along with increasing membrane desalination projects. It implies the disposal in surface waters of tons of phosphonates and trace elements, present in wastewater and concentrates, every day. Removing the phosphonates and trace elements allows their subsequent recovery and valorization, minimizing squeezing produc-tion/extraction procedures and saving the environment from suffering any im-pact because of them. The first part of this thesis focuses on phosphonate removal with iron and aluminum-based adsorbents. Porous iron and aluminum (oxi)hydroxides can remove phosphonates from concentrates completely. The main limitation of this process is the diffusion of the phosphonates through adsorbent particles. As proved in this thesis, temperature significantly improves the adsorption kinetics of the phosphonates on both adsorbents as a result of the variation of the diffusion coefficient. The presence of calcium also plays an important role, since accelerates the adsorption at the first stages of the process, but limits and saturates the capacity of the adsorbent surface for further adsorption. More research on the role of calcium is needed in this regard to better understand how the adsorption/diffusion of the phosphonates is affected by this common element present in concentrates. Electrocoagulation was studied in the second part of this thesis as a potential approach for phosphonate removal. Using pure iron electrodes, the applied current density can be easily optimized. As a result, dissolved phosphonates are quickly removed from a large concentrate volume at a relatively low cost and minimal sludge production. The benefits of this technique lie in the possibility of producing the substrate (adsorbent) in situ for the phosphonate to be adsorbed. Furthermore, the time required to completely remove the phosphonates is remarkably shorter compared to adsorption, which, as pointed out above, is limited by diffusion phenomena. Alkaline washing was relatively successful at recovering the phosphorus from the sludge, depending on the dissolved phosphonate in the concentrate. Although experimental results may look promising, further research on finding the optimum working conditions has to be addressed. The process is open to improvement in terms of new electrode materials, reactor design, phosphorus recovery, or optimal working temperature. In the third part of the thesis, the adsorption potential of previously tested adsorbents for the removal of elements at trace levels. The iron-based adsorbent, commercialized for phosphate and arsenic removal, turned out to be excellent at removing transition metals (TM) and rare earth elements (REE). The study was carried out in parallel with the exploration of the capabilities of a high-resolution inductively coupled plasma mass spectrometry (HR ICP-MS) instrument. The potential of this analytical procedure allows the detection and quantification of all the isotopes at the ultra-trace level (in the range of a few ng·L-1) and in only one measurement round. Furthermore, interferences from polyatomic species, formed during the ionization in the plasma, are easily resolved due to the high-resolution mode. As a result, the detection of the targeted element is easily discriminated from the potential interferences. This feature makes a remarkable difference regarding ordinary ICP-MS, which requires different analytical procedures to properly resolve overlapping signals. This analytical procedure opens new possibilities to test the adsorbents in new conditions and develop analytical methods for water speciation.

Made available in DSpace on 2014-12-17T14:08:40Z (GMT). No. of bitstreams: 1 VilsineiaAF_DISSERT.pdf: 2438653 bytes, checksum: 9241425e98a35008922b9e1dd051a3af (MD5) Previous issue date: 2010-08-02 / The acceleration of industrial growth in recent decades on all continents aroused the interest of the companies to counter the impacts produced on the environment, spurred primarily by major disasters in the petroleum industry. In this context, the water produced is responsible for the largest volume of effluent from the production and extraction of oil and natural gas. This effluent has in its composition some critical components such as inorganic salts, heavy metals (Fe, Cu, Zn, Pb, Cd, ), presence of oil and chemicals added in the various production processes. In response to impact, have been triggered by research alternative adsorbent materials for water treatment and water produced, in order to removing oils and acids and heavy metals. Many surveys of diatomaceous earth (diatomite) in Brazil involve studies on the physico-chemical, mineral deposits, extraction, processing and applications. The official estimated Jazi are around 2.5 million tonnes, the main located in the states of Bahia (44%) and Rio Grande do Norte (37,4%). Moreover, these two states appear as large offshore producers, earning a prominent role in research of adsorbents such as diatomite for treatment of water produced. Its main applications are as an agent of filtration, adsorption of oils and greases, industrial load and thermal insulator. The objective of this work was the processing and characterization of diatomite diatomaceous earth obtained from the municipality of Maca?ba-RN (known locally as tabatinga) as a low cost regenerative adsorbent for removal of heavy metals in the application of water produced treatment. In this work we adopted a methodology for batch processing, practiced by small businesses located in producing regions of Brazil. The characterization was made by X-ray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area (BET). Research conducted showed that the improvement process used was effective for small volume production of diatomite concentrated. The diatomite obtained was treated by calcination at temperature of 900 oC for 2 hours, with and without fluxing Na2CO3 (4%), according to optimal results in the literature. Column adsorption experiments were conducted to percolation of the in nature, calcined and calcined fluxing diatomites. Effluent was used as a saline solution containing ions of Cu, Zn, Na, Ca and Mg simulating the composition of produced waters in the state of Rio Grande do Norte, Brazil. The breakthrough curves for simultaneous removal of copper ions and zinc as a result, 84.3% for calcined diatomite and diatomite with 97.3 % for fluxing. The calcined fluxing diatomite was more efficient permeability through the bed and removal of copper and zinc ions. The fresh diatomite had trouble with the permeability through the bed under the conditions tested, compared with the other obtained diatomite. The results are presented as promising for application in the petroleum industry / A acelera??o do crescimento industrial nas ?ltimas d?cadas despertou em todos os continentes o interesse das empresas em se contrapor aos impactos produzidos sobre o meio ambiente, incentivadas principalmente pelas grandes cat?strofes ocorridas na ind?stria do petr?leo. Nesse contexto, a ?gua produzida ? respons?vel pelo maior volume de efluentes provenientes de processos de produ??o e extra??o de petr?leo e g?s natural. Este efluente tem em sua composi??o alguns componentes cr?ticos como sais inorg?nicos, metais pesados (Fe, Cu, Zn, Pb, Cd,...), presen?a de ?leo e de produtos qu?micos adicionados nos diversos processos de produ??o. Como resposta a estes problemas foram desencadeadas pesquisas com materiais adsorventes alternativos para o tratamento de ?guas produzidas e ?guas residuais, com a finalidade de remo??o de ?leos e graxos e de metais pesados. Muitas pesquisas feitas com terras de diatom?ceas (diatomita) no Brasil envolvem estudos sobre as caracter?sticas f?sico-qu?micas, jazidas, extra??o, beneficiamento e aplica??es. As jaziadas oficiais estimadas s?o da ordem de 2,5 milh?es de toneladas, sendo as principais localizadas nos estados da Bahia (44%) e Rio Grande do Norte (37,4%). Por outro lado, esses dois estados apresentam-se como grandes produtores de petr?leo em terra, merecendo um destaque importante nas pesquisas de adsorventes como a diatomita para tratamento de ?gua produzida. Suas principais aplica??es s?o como agente de filtra??o, adsor??o de ?leos e graxas, carga industrial e isolante t?rmico. Esse trabalho tem como objetivo o beneficiamento e a caracteriza??o da diatomita do munic?pio de Maca?ba-RN (conhecida na regi?o como tabatinga) como um adsorvente regenerativo de baixo custo para fins de remo??o de metais pesados na aplica??o do tratamento de ?guas produzidas. No presente trabalho adotou-se uma metodologia de beneficiamento por batelada, praticada por pequenas empresas estabelecidas nas regi?es produtoras do Brasil. A caracteriza??o foi feita por difra??o de raios-X (DRX), microscopia eletr?nica de varredura (MEV) e ?rea superficial espec?fica (BET). A investiga??o conduzida mostrou que o processo de beneficiamento utilizado foi eficaz para produ??o em pequena escala de diatomita concentrada. A diatomita obtida foi tratada por calcina??o na temperatura de 900 oC por 2 horas, sem e com fluxante carbonato de s?dio (Na2CO3, 4 %), de acordo com resultados otimizados na literatura. Ensaios de adsor??o em coluna de percola??o foram realizados para as diatomitas in natura, calcinada, e calcinada com fluxante. Como efluente foi utilizado uma solu??o sint?tica contendo ?ons de Cu, Zn, Na, Ca e Mg, simulando a composi??o de ?guas produzidas no estado do Rio Grande do Norte-Brasil. As curvas de ruptura para remo??o simult?nea dos ?ons de cobre e zinco apresentaram como resultados, 84,3 % para diatomita calcinada e 97,3 % para diatomita com fluxante. A diatomita calcinada com fluxante apresentou maior efici?ncia na permeabilidade atrav?s do leito e na remo??o dos ions de cobre e zinco. A diatomita in natura teve dificuldade com a permeabilidade atrav?s do leito nas condi??es testadas, comparada com as outras diatomitas. Os resultados obtidos apresentam-se como promissores para aplica??o na ind?stria do petr?leo