An adsorbent was developed from agro-industrial residues derived from the seed husks of Moringa oleifera Lam., in which the hydrochar process was used as it is a sustainable, low-cost and easy-to-operate process. In comparison, a commercial adsorbent, activated charcoal from babaçu coconut, was used. Both materials were characterized using SEM, FTIR, zeta potential and BET, showing their morphologies, chemical compositions and textural analyses that proved the adsorption capacity of each material. A cost study was also carried out regarding the production of the materials. For both materials, an equilibrium study was carried out using the following contaminants: metformin, diuron, methylene blue and lead. We aimed to study the use of agro-industrial waste as a new adsorbent material, which was shown to have an average removal for all the contaminants tested of around 84.56–99.13%. The new adsorbent developed had many interactions with the studied contaminants, allowing its use on a large scale since its production cost was low. The main objective of this study was thus to compare a commercial activated charcoal with a biosorbent from agro-industrial waste, prepared by the hydrochar method.

Atrazine (ATZ) is an herbicide used for increased food production due to its weed and pesticide control capacity in different crops. However, ATZ is a chemical compound that is harmful to the environment and human health, and, unfortunately, it has been detected in surface and groundwater. Therefore, the aim of this paper was to perform the adsorption of Atrazine from a synthetically contaminated water sample using a packed-bed column with a low-cost adsorbent prepared from Moringa oleifera Lam. seeds. The synthesized adsorbent presented an increase in the surface specific area (S_BET) of 37% in comparison with the in natura material. The effects of the peristaltic pump flow rate (Q), concentration of the ATZ inlet ([ATZ]_inlet) solution, and bed height (H) were studied, with the highest percentage of ATZ removed through the adsorption column (50, 0%) obtained with a packed-bed column with H = 13 cm bed height, Q = 1 mL/min, [ATZ]_inlet = 2.0 mg/L, pH = 5.0, a breakthrough time of 25 min, and a saturation time of 420 min. The logistic model was used to best fit the experimental data with an R² > 0.99, and the Bohart–Adams, Thomas, and Yoon–Nelson models were used to explain and analyze the obtained effects in the continuous adsorption of ATZ. Therefore, the Moringa oleifera Lam. seeds provided a low-cost adsorbent for the continuous adsorption of the herbicide Atrazine in a packed-bed column.

The major problems related to environmental pollution are increasingly present among us. The uncontrolled use and incorrect disposal of products means that these problems are increasing at frightening rates. In this context, a major related problem is the incorrect disposal of dishwasher sponges that are no longer useful; their material being made up of petroleum derivatives causes this problem to be leveraged in the environment. In the present work, we evaluated and carried out tests in which these dirty sponges that would be discarded were used for the purpose of developing new sustainable adsorbent materials. These materials were washed and dried, crushed and made available for use, by which they were kept in contact with a paracetamol solution, evaluating the effect of mass, pH, kinetics, equilibrium, thermodynamic parameters, and cost analyses. The results demonstrated an adsorptive capacity of approximately 40 mg g⁻¹ and its cost was relatively viable, since this material would otherwise be discarded incorrectly. In conclusion, this material achieved the good removal of this studied contaminant and became an economical, viable, and ecologically viable material.

Regarding groundwater quality, the presence of nitrate is among the main indicators of water pollution. The aim of the present study was to evaluate the presence of nitrate, verify the hydrochemical standard and evaluate the efficiency of the removal process of nitrate ions by activated carbon from groundwater sources of Ribeirao Borba Gato (BHBG). The samples were collected between the period of 08/2014 to 08/2015, in 19 deep tub wells and subjected to some physical-chemical analyzes and treated with activated carbon filter. Our results shows that was possible to know the hydrochemical standard of water collected in the study area, identify possible risks of anthropogenic contamination, through the nitrate concentrations and also the amount of nitrate that the commercial activated carbon filter retains in slow filtration process. Most samples showed nitrate concentrations above the natural value of groundwater. So one can see that the underground sources of BHBG has suffered contamination and other pollutants may have equal or greater hazard to human health and environmental.

O presente estudo busca a reflexão e discussão sobre a importância do uso de dispositivos diferenciais-residuais em instalações elétricas residenciais, possui objetivo despertar os leitores, incluindo os leigos ao assunto, os perigos provocados pela ausência deste meio de proteção nos ambientes domiciliares. A pesquisa bibliográfica foi realizada com base em livros, normas, manuais técnicos e documentos institucionais, buscando demonstrar o atual panorama do Brasil com relação aos acidentes domésticos envolvendo eletricidade. O levanto demonstra que as crianças e adolescentes representam uma parcela significativa das mortes ocorridas por acidente elétrico em residências, sendo o Nordeste a região com os índices mais preocupantes. Concluiu-se que a fiscalização do uso obrigatório desses dispositivos é insuficiente, e também que a falsa sensação de segurança provida pelo ambiente doméstico juntamente com a falta de informação das pessoas contribui para a não utilização do dispositivo DR na maior parte das residências do país.