RESUMO
Pulp and paper industries are very important for developing the Brazilian economy. During production processes, many effluents are generated with high polluting potential. The objective of this study is to conduct an extensive literature review on the characteristics of effluents and treatment forms adopted by Brazilian mills in this industrial sector. Most consulted studies address raw (without treatment) and secondary (after biological treatment) effluents, considering their main characteristics like pH, chemical and biochemical oxygen demands (COD and BOD, respectively), color, solids, organochlorines, toxicity, estrogenic activity, and phenols. Raw effluents differ considerably in composition, depending on the type of paper produced, the pulping process employed, and other steps, like pulp bleaching. Raw effluent characteristics indicate that this effluent cannot be directly disposed of into water bodies, because it does not comply with federal and state disposal standards. Secondary effluents normally comply with Brazilian legislations, although some studies have reported COD and total phenol concentrations higher than disposal standards, suggesting that additional treatments are necessary. Treated effluent reuse was verified in some Brazilian mills, while its disposal in eucalyptus plantations has been considered a promising alternative for irrigation purposes.
Assuntos
Eliminação de Resíduos Líquidos , Poluentes Químicos da Água , Brasil , Monitoramento Ambiental , Resíduos Industriais/análise , Papel , Fenóis , Poluentes Químicos da Água/análiseRESUMO
This study aimed to evaluate smartphone addiction, sleep quality, quality of life and depression among dental students before and during the first wave COVID-19 pandemic lockdown and explore how smartphone addiction influences the other variables. 57 dental students answered the smartphone addiction inventory, Pittsburg sleep quality index, WHOQOL-bref and research diagnosis criteria for temporomandibular disorders axis II questionnaires before and during lockdown. Statistical analysis was conducted using Wilcoxon test, Mann-Whitney U test, Spearman tests and linear regression models considering the smartphone addiction inventory total score as the independent variable. The high mean scores on smartphone addiction on both times are remarkable. The smartphoneaddictionprevalence was also high on both times (68.66% and 71.92% respectively). Overall sleep quality improved. However, there was no significant change on overall smartphone addiction, quality of life and depression grade during lockdown. Tolerance using smartphones increased during lockdown, especially for women. Smartphone addiction showed negative correlation to quality of life and positive correlation to depression, subjective sleep quality and sleep medication use. Smartphone addiction was apredictor to total WHOQOL-bref score, all WHOQOL-bref domains, sleep medication use and to depression on both times, before and during lockdown. Smartphone addiction was directly affecting quality of life. Despite the growing smartphone use among university students due to the pandemic restrictions, this study showed that the overall smartphone addiction, quality of life and depression grade were not influenced by the lockdown restrictions. However, it was observed an improvement on sleep quality during this period among dental students (AU).
O objetivo deste estudo foi avaliar o vício emsmartphones, qualidade de vida, qualidade de sono e depressão em estudantes de odontologia antes e durante a quarentena daprimeira onda da pandemia por COVID-19. 57 estudantes de odontologia responderam nos dois tempos os questionários validados:smartphone addiction inventory, índice de qualidade de sono de Pittsburg, WHOQOL-bref e critérios para diagnóstico em pesquisa dasdisfunções temporomandibulares eixo II. Foram realizados os testes estatísticos: Wilcoxon, Mann-Whitney U, Spearman e regressões lineares considerando o total do smartphone addiction inventorycomo variável independente. A prevalência de vício em smartphonesfoi elevada nos dois tempos (68.66% e 71.92% respectivamente). Durante a quarentena a qualidade de sono melhorou e não houve diferença estatisticamente significativa no vício em smartphones, qualidade de vida nem depressão. A tolerância no uso dossmartphonesaumentou, especialmente entre as mulheres. O vício em smartphonesapresentou correlação negativa com qualidade de vida e positiva com a depressão, qualidade subjetiva do sono e necessidade de medicação hipnótica. O vício em smartphonesfoi preditor para todos os domínios do WHOQOL-bref e seu escore total, para o uso de medicação e depressão em ambos os tempos. O vício em smartphonesfoi muito elevado nos dois tempos afetando a qualidade de vida dos estudantes. Apesar do aumento do uso desmartphonesem virtude das restrições impostas pela pandemia, esse estudo mostrou que o vício em smartphones, qualidade de vida e depressão não foram influenciados pela quarentena. Entretanto, foi observada melhora na qualidade de sono durante esse período (AU).