Análise e redução do impacto dos produtos químicos de acabamento molhado na carga poluente dos efluentes líquidos de processo

A transformação da pele em couro acabado requer adições sequenciais de produtos químicos em meio aquoso, intercaladas por lavagens e operações mecânicas. Os produtos químicos adicionados são parcialmente retidos pelo couro, sendo as frações remanescentes nos banhos de processo descartadas nos efluentes líquidos. Os efluentes líquidos gerados no processo de acabamento molhado encontram-se caracterizados na literatura. No entanto, poucos estudos avaliam como as classes de produtos químicos e suas dosagens individuais aplicadas ao couro impactam na qualidade dos efluentes líquidos do processo. Desta forma, o presente estudo tem por objetivo avaliar o impacto dos produtos químicos utilizados no processo de acabamento molhado do couro nos principais parâmetros de poluição dos efluentes líquidos gerados nesta etapa de processamento. Este estudo foi realizado em quatro partes: (i) estudo de formulações de acabamento molhado publicadas em artigos científicos, (ii) avaliação do impacto dos produtos químicos na carga poluente dos efluentes gerados no acabamento molhado, em um estudo de caso, (iii) ajuste da formulação de acabamento molhado, visando reduzir a carga poluente dos efluentes líquidos gerados, e (iv) revisão sistemática de tecnologias aplicadas para o tratamento dos efluentes líquidos de acabamento molhado. O estudo de formulações de acabamento molhado mostrou um consumo médio de 360,2 kg de produtos químicos por tonelada de couro processado e o consumo médio de água encontrado foi de 8,6 m³/t. Os resultados da avaliação do impacto dos produtos químicos na carga poluente dos efluentes demonstraram que os agentes de recurtimento (taninos vegetais e sintéticos) foram responsáveis pela maior carga de poluição inorgânica nos efluentes, e que os taninos sintéticos foram mais tóxicos que os vegetais. Os óleos foram responsáveis pela maior carga de demanda química de oxigênio nas águas residuais e foram o grupo químico que apresentou a maior citotoxicidade. O agente de fixação e o corante contribuíram com a carga inorgânica dos efluentes líquidos, e a carga de nitrogênio foi relacionada principalmente ao recurtente neutralizante e ao corante. Os resultados do ajuste da formulação, reduzindo a oferta de produtos químicos, mostraram redução da carga poluente dos efluentes líquidos. O couro obtido mostrou qualidade dentro das especificações requeridas e o custo da formulação foi reduzido em 24%. Por fim, a revisão sistemática apresentou as principais condições de operação, inovações e desafios das tecnologias aplicadas ao tratamento de efluentes de acabamento molhado.The transformation of the hide into finished leather requires sequential additions of chemicals in an aqueous medium, alternated with washing and mechanical operations. These chemicals are partially retained by the leather, and the fractions remaining in the process floats are discharged with the wastewater. Current literature has an extensive number of studies aimed at characterizing tannery effluents. However, few studies have evaluated how groups of chemicals applied to the leather impact the quality of wastewater generated in the process. Thus, this study aims to evaluate the impact of chemicals used in the wet-finishing process of the leather on the main quality parameters of the wastewater generated by this processing step. This study was carried out in four parts: (i) study of wet-finishing formulations published in scientific articles, (ii) evaluation of the impact of chemicals on the pollution load of wet-finishing wastewater, using a case study, (iii) adjustment of the wet-finishing formulation, aiming to reduce the pollution load of the wastewater, and (iv) systematic review of technologies applied to the wetfinishing wastewater treatment. The study of wet-finishing formulations showed an average consumption of 360.2 kg of chemicals per ton of wet-blue leather, and the average water consumption of 8.6 m³/t was found. The results of the analysis of chemicals impact on the pollution load of wet-finishing wastewater showed that the retanning agents (natural and synthetic tannins) were responsible for the highest inorganic pollution load in the wastewater, and the synthetic tannins were more toxic than the natural ones. The fatliquoring agents were responsible for the highest chemical oxygen demand load in the wastewater and were the chemical group that presented the highest cytotoxicity. The fixing agent and the dye contributed to the inorganic pollution load of the wastewater, and the nitrogen load of the wastewater was mainly related to the neutralizing retanner and the dye. The results of adjusting the formulation, reducing the supply of chemicals, showed a reduction in the pollution load of wastewater. The obtained leather showed quality within the required specifications of the tannery and the formulation cost was reduced by 24%. Finally, the systematic review presented the main operational conditions, novelty, and challenges of the technologies applied to the wet-finishing wastewater treatment

Book of abstracts of the 10th International Chemical and Biological Engineering Conference: CHEMPOR 2008

This book contains the extended abstracts presented at the 10th International Chemical and Biological Engineering Conference - CHEMPOR 2008, held in Braga, Portugal, over 3 days, from the 4th to the 6th of September, 2008. Previous editions took place in Lisboa (1975, 1889, 1998), Braga (1978), Póvoa de Varzim (1981), Coimbra (1985, 2005), Porto (1993), and Aveiro (2001). The conference was jointly organized by the University of Minho, “Ordem dos Engenheiros”, and the IBB - Institute for Biotechnology and Bioengineering with the usual support of the “Sociedade Portuguesa de Química” and, by the first time, of the “Sociedade Portuguesa de Biotecnologia”. Thirty years elapsed since CHEMPOR was held at the University of Minho, organized by T.R. Bott, D. Allen, A. Bridgwater, J.J.B. Romero, L.J.S. Soares and J.D.R.S. Pinheiro. We are fortunate to have Profs. Bott, Soares and Pinheiro in the Honor Committee of this 10th edition, under the high Patronage of his Excellency the President of the Portuguese Republic, Prof. Aníbal Cavaco Silva. The opening ceremony will confer Prof. Bott with a “Long Term Achievement” award acknowledging the important contribution Prof. Bott brought along more than 30 years to the development of the Chemical Engineering science, to the launch of CHEMPOR series and specially to the University of Minho. Prof. Bott’s inaugural lecture will address the importance of effective energy management in processing operations, particularly in the effectiveness of heat recovery and the associated reduction in greenhouse gas emission from combustion processes. The CHEMPOR series traditionally brings together both young and established researchers and end users to discuss recent developments in different areas of Chemical Engineering. The scope of this edition is broadening out by including the Biological Engineering research. One of the major core areas of the conference program is life quality, due to the importance that Chemical and Biological Engineering plays in this area. “Integration of Life Sciences & Engineering” and “Sustainable Process-Product Development through Green Chemistry” are two of the leading themes with papers addressing such important issues. This is complemented with additional leading themes including “Advancing the Chemical and Biological Engineering Fundamentals”, “Multi-Scale and/or Multi-Disciplinary Approach to Process-Product Innovation”, “Systematic Methods and Tools for Managing the Complexity”, and “Educating Chemical and Biological Engineers for Coming Challenges” which define the extended abstracts arrangements along this book. A total of 516 extended abstracts are included in the book, consisting of 7 invited lecturers, 15 keynote, 105 short oral presentations given in 5 parallel sessions, along with 6 slots for viewing 389 poster presentations. Full papers are jointly included in the companion Proceedings in CD-ROM. All papers have been reviewed and we are grateful to the members of scientific and organizing committees for their evaluations. It was an intensive task since 610 submitted abstracts from 45 countries were received. It has been an honor for us to contribute to setting up CHEMPOR 2008 during almost two years. We wish to thank the authors who have contributed to yield a high scientific standard to the program. We are thankful to the sponsors who have contributed decisively to this event. We also extend our gratefulness to all those who, through their dedicated efforts, have assisted us in this task. On behalf of the Scientific and Organizing Committees we wish you that together with an interesting reading, the scientific program and the social moments organized will be memorable for all.Fundação para a Ciência e a Tecnologia (FCT

Proceedings of the 10th International Chemical and Biological Engineering Conference - CHEMPOR 2008

This volume contains full papers presented at the 10th International Chemical and Biological Engineering Conference - CHEMPOR 2008, held in Braga, Portugal, between September 4th and 6th, 2008.FC