ABSTRACT
Adsorption in biomass has proven to be a cost-effective option for treatment of wastewater containing dyes and other pollutants, as it is a simple and low cost technique and does not require high initial investments. The present work aimed to study the adsorption of methylene blue dye (MB) using sugarcane bagasse (SCB). The biomass was characterized by scanning electron microscopy (SEM). Adsorption studies were conducted batchwise. Kinetics, adsorption isotherms, and thermodynamics were studied. The results showed that SCB presented a maximum adsorption capacity of 9.41 mg g-1 at 45 °C after 24 h of contact time. Adsorption kinetics data better fitted the pseudo-second order model, indicating a chemical process was involved. The Sips's three-parameter isotherm model was better for adjusting the data obtained for the adsorption isotherms, indicating a heterogeneous adsorption process. The process showed to be endothermic, spontaneous, and feasible. Therefore, it was concluded that SCB presented as a potential biosorbent material for the treatment of MB-contaminated waters.
Subject(s)
Cellulose/chemistry , Methylene Blue/chemistry , Saccharum , Water Pollutants, Chemical/chemistry , Adsorption , Biomass , Coloring Agents , Hydrogen-Ion Concentration , Kinetics , Microscopy, Electron, Scanning , Thermodynamics , Wastewater/chemistryABSTRACT
Achatina fulica, known as Giant African Snail (GAS), was introduced in Brazil as a substitute for the European escargot, Helix aspersa maxima. However, its cultivation was abandoned and the mollusk became an invasive species, found throughout Brazil and causing damage to health and the environment. In this context, this study analyzed the knowledge of the population about the damage caused by GAS, seeking to reveal a regional scenario on this issue. This exploratory and cross-sectional study was conducted by means of a questionnaire applied to 150 people, which obtained sociodemographic characteristics of respondents and specific responses about the knowledge and handling of GAS. The results showed that most of the respondents know the snail and are concerned about the transmission of diseases and losses in agricultural crops, but few recognize this pest as the basis of environmental imbalance. It is suggested to implement actions seeking the dissemination of such knowledge and the awareness of the population about the impact of this mollusk on the environment.
Achatina fulica, conhecida como caramujo gigante africano, foi introduzida no Brasil como um substituto do escargot europeu, Helix aspersa maxima. Contudo, seu cultivo foi abandonado e o molusco transformou-se numa espécie invasora, presente em todo o território brasileiro, provocando danos à saúde e ao meio ambiente. Assim, objetivou-se, com este trabalho, analisar o conhecimento da população sobre os danos causados pelo caramujo gigante africano, buscando evidenciar um cenário regional sobre esta problemática. A pesquisa teve caráter exploratório e transversal e foi realizada por meio da aplicação de um questionário para 150 pessoas, por meio do qual foram obtidas as características sociodemográficas dos respondentes e respostas específicas sobre o conhecimento e o manuseio do caramujo africano. Os resultados deste estudo mostraram que a maioria dos respondentes conhece o caramujo africano e se preocupa com a transmissão de doenças e com os prejuízos em culturas agrícolas, porém poucos reconhecem essa praga como base de desequilíbrios ambientais. Sugere-se que ações sejam implementadas, buscando a disseminação desses conhecimentos e a conscientização da população sobre o impacto desse molusco no meio ambiente.
