Estudo da Aptidão ao Desaguamento e do Potencial de Lixiviação Em Diferentes Tipos de Lodos Produzidos na Estação de Tratamento de Águas Residuárias da Coqueria da Companhia Siderúrgica de Tubarão

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

The coke oven production in steel industry generates a solid waste denominated coke sludge or coke mud. The large production of this material presenting substances with high environmental toxicity, demands a consolidated management comprising the processes of thickening, stabilization, conditioning, dewatering, sanitization and final disposition. Literature data about these materials and processes are scarce and very specific. The overall objective of this research is the characterization, assessment of dewatering ability and lixiviation process of coke oven sludge, searching for best alternatives for management practices of this sludge. The characterization process was performed by analysis of COD, solids content, phenol, cyanide, oil and grease, total nitrogen (NTK), total phosphorous, heavy metals and pH by Standard Methods for Examination of Water and Wastewater (1995). The dewatering ability was evaluated by classical methods such as Capillary Suction Time (CST), Specific Resistance to Filtration (SFR), bench centrifugation and dilatometry tests of raw sludge and conditioned sludge with anionic, cationic and non-ionic polymers. The lixiviation process was performed according to NBR 10005 ( solid waste lixiviation standard test). The characterization results showed high levels of phenol concentration exceeding the upper limit of NBR 10004/87 and placing this residue as dangerous. The other analyzed parameters showed levels below the legislation. The dewatering ability results of biologic sludge showed higher levels of free water (73,9%) than chemical sludge (71,1%), indicating higher dewatering ability of biologic sludge than chemical one. The results of bench centrifugation were correlated with the dilatometry data gathered from the coke sludge evaluation. The results from the capillary suction time and specific resistance to filtration tests were opposite to dilatometry data as a result of media viscosity due to polyelectrolyte added to the sludge. The conditioning process increased the sludge free water content and base don these results it was possible to establish the polymer type and efficiency range for each evaluated sludge. The heavy metal content in the those referential values of NBR lixiviation extracts showed values below 10004/87.

ASSUNTO(S)

lixiviação companhia siderúrgica de tubarao engenharia sanitaria cianetos coqueria lodo - desidratação águas residuárias, estações de tratamento

ACESSO AO ARTIGO

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