Pulp and paper mill effluent toxicity before and after treatment with engineered nanomaterials and ash

• Autor(a) principal: Mostafaie, Amid
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/28998
• topic: Effluent; Effluent treatment; Nanomaterials; Ecotoxicity; Ash; Daphnia magna

The continued growth of the population and industrialization results in the production of large quantities of toxic effluents containing various contaminants. This type of wastewater is often discharged into aquatic systems after being treated. Unless efficient treatment is applied, treated wastewater can pose a threat to aquatic organisms, flora, fauna and human health. Consequently, the application of an effective treatment technique in the treatment of wastewater is of great importance. In order to assess the growth of research in the field of toxicity of industrial effluents and biosolids, a scientometric analysis was carried out using the relevant keywords in the main collection of the Web of Science. In this analysis, the analyzed documents were evaluated according to their scientometric criteria. The results obtained in this regard demonstrate that, despite a relatively long investigation carried out in this field between 1951 and 2018, only 944 documents were published, denoting the need for greater collaboration between industries and scientific communities to reduce uncertainties and risks, and barriers that hinder the growth of research in this area. In addition, the scarcity of relevant regulations and legislation to minimize the negative impacts of industrial effluents was also marked by this analysis. In addition, within the scope of this dissertation, the toxicity assessment of an effluent from a paper and cellulose factory supplied by a Portuguese industry was carried out before and after treatment, using Daphnia magna as a model species and the acute immobilization test. The analysis previously carried out on this effluent revealed extreme toxicity and, therefore, several treatments were applied with iron-based nanomaterials and ashes supplied by the effluent producing industry. Before the effluent toxicity analysis, the treatment additives were analyzed for their toxicity through their application to the ASTM medium, the culture solution used in the cultures and as a negative control in D. magna. Then, the best sequence of additives was applied to the effluent and the toxicity of the treated effluent was evaluated. The results obtained in this regard showed that, although the treatment can effectively reduce environmental impacts by inducing chemical corrections, the treatment did not produce a considerable reduction in the effluent toxicity for D. magna. Therefore, further research is needed on a possible effective treatment for these industrial wastewaters, both from a chemical and ecotoxicological point of view. This study is in line with the 2030 Sustainable Development Goals assigned by the United Nations in relation to waste reduction, pollution and the need to achieve a sustainable environment.