Brazilian Journal of Science

Treatment of effluent from the coconut (Cocos nucifera) processing industry via dissolved air flotation

2026-06-01T15:59:38-03:00

The coconut palm (Cocos nucifera L) is one of the most widespread fruit species worldwide and plays a key role in Brazilian agribusiness, especially in the Northeast, which accounts for over 90% of national production. However, coconut processing generates large volumes of liquid effluents, composed of coconut milk, oil, and mainly washing water, which require proper treatment before disposal. Among the available techniques, dissolved air flotation (DAF) stands out for its efficiency and low operating cost in contaminant removal. This study focused on treating coconut industry effluents using DAF, applying a full 2³ experimental design. The evaluated factors were effluent concentration (0.05% and 0.1%), feed flow rate (100 L/h and 150 L/h), and dilution flow rate (50 L/h and 100 L/h), with initial pH fixed at 10 and saturation pressure between 4.5 and 6 kgf/cm². Aluminum sulfate 1% m/v was used as the coagulant. Results showed that oil and grease reduction increased with higher effluent concentration and lower dilution flow rates, reaching up to 73.75% removal under conditions of 0.1% concentration, 150 L/h feed, and 50 L/h dilution.

The effect of WhatsApp-based leadership communication on neighborhood security

2026-06-01T15:59:31-03:00

This study examines the relationship between WhatsApp-based leadership communication and perceptions of neighborhood safety. This study used a cross-sectoral exploratory quantitative survey of 92 residents of Bojong Lio Village, Cilodong District, Depok City, Indonesia, who are members of a neighborhood WhatsApp group. Respondents were selected using purposive sampling based on their participation in neighborhood-level WhatsApp communication. Data were collected through a structured questionnaire using a five-point Likert scale and analyzed using descriptive statistics and simple linear regression. The results showed a positive and statistically significant relationship between leadership communication and perceptions of neighborhood safety. A correlation coefficient of 0.750 indicates a strong relationship, while a coefficient of determination of 0.562 indicates that 56.2% of the variation in neighborhood safety perceptions can be statistically explained by leadership communication. The regression equation is Y = 11.192 + 0.354X, indicating that higher-quality leadership communication is associated with higher perceptions of neighborhood safety. Descriptive findings also revealed that clarity of information, leader activeness, understandable language, coordination skills, and clear directions were the most prominent aspects of communication. In terms of security, the highest-ranking indicators included residents' response to disturbances, sense of security, rapid dissemination of security information, and cooperation among residents. These findings suggest that WhatsApp-based leadership communication can support neighborhood coordination and perceived preparedness, although the cross-sectional study design limits causal conclusions.

Disability in mass media through children’s eyes: Primary school students’ perceptions of media portrayals of people with disabilities

2026-06-01T15:59:39-03:00

Media representations of people with disabilities often rely on simplified or stereotypical narratives that do not reflect everyday social realities. Such portrayals may reinforce pity-based or charitable perspectives and contribute to the persistence of social distance and misunderstanding. Against this background, the present study explores how primary school students perceive the way disability is presented in mass media. A pilot study was conducted between October and December 2025 with 154 sixth-grade students attending primary schools in the region of Attica, Greece. Data were collected through a structured questionnaire adapted for children aged 11–12 years. The study examined students’ interest in disability-related information, the media sources through which they are informed, their emotional responses to disability-related media content, and their evaluation of media attitudes toward people with disabilities. Findings indicate that the majority of students express a clear interest in being informed about disability-related issues. Television remains the primary source of information, while digital media and social networking platforms are also frequently reported. Students largely perceive media portrayals of people with disabilities as characterized by pity, yet they strongly believe that accurate and objective media coverage could substantially improve their own attitudes and behaviors toward people with disabilities.

Physiological response of weaner pigs fed rice-based indigenous microorganisms in the humid tropics

2026-06-01T15:59:38-03:00

Pig production has strong potential to bridge the protein deficiency gap in the humid tropics. Quality nutrition is essential for increased growth and productivity in any pig farming enterprise. This research examined the effect of rice-based indigenous microorganisms (IMOs) solution on the haematological and serum biochemical indices of weaner pigs in the humid tropics. A total of 24 weaner pigs (Aged 12-weeks) with an average body weight of 10.21 ± 0.4 kg were randomly assigned to three treatments (T) group and four replications each in a completely randomized design (CRD). The treatments comprised three levels of rice IMOs in water: T1 (0 mL/L^-1), T2 (5 mL/L), and T3 (10 mL/L^-1). The weaner pigs were exposed to the rice IMOs for a period of 20 weeks. Data were collected on haematology and serum biochemical parameters. The results showed that rice IMOs significantly (p < 0.05) increased haemoglobin (16.59 ± 0.05 g/dL), packed cell volume (41.80 ± 0.12%), red blood cells (14.50 ± 0.16 x 10⁶/µL), and white blood cells (19.80 ± 0.18 x 10³/µL) concentrations of pigs in T3. Neutrophil (28.00 ± 0.08 %), eosinophil (8.00 ± 0.26 %), and monocyte (6.00 ± 0.10 %) blood concentrations were higher (p < 0.05) at T2, with lowered lymphocyte compared to other treatments. Compared with IMOs-treated pigs, total protein, globulin, alanine aminotransferase, aspartate aminotransferase, and total cholesterol were higher in the control group (T1). Alkaline phosphate (37.12 ± 0.18 µL/L) and urea (45.00 ± 0.18 mg/dL) concentrations were equally higher (p < 0.05) for T3 pigs. However, albumin concentration showed a non-significant effect (p > 0.05) on the pigs. Based on these findings, the study concluded that rice-based IMOs fed at 10 mL/L improved the physiological health status of weaner pigs in the humid tropics.

Integrated application of a commercial biostimulant improves growth, root development, and biomass accumulation in Coffea arabica seedlings

2026-06-01T15:59:25-03:00

The use of plant biostimulants has emerged as a promising strategy to improve seedling quality and sustainability in coffee production systems. This study evaluated the effects of the integrated application of a commercial biostimulant on the growth and biomass accumulation of Coffea arabica seedlings under nursery conditions. The experiment was conducted in a randomized complete block design with two treatments, control and biostimulant application, and twenty replications. The commercial product Enervig Leg^® was applied during seed treatment (6 mL kg^-1 of seeds) and by foliar spraying (150 mL per 200 L of water) during the early vegetative stage. Growth and biomass variables were evaluated at 180 days after emergence. Biostimulant-treated seedlings showed significant increases in plant height, stem diameter, shoot dry mass, and root dry mass compared to the control treatment. Shoot dry mass increased by 37.7%, while root dry mass increased by 104.5% in treated plants. The treatment also promoted greater root system development and more balanced biomass allocation between shoot and root components. The low coefficients of variation observed for all variables indicated high experimental precision and uniformity of responses under nursery conditions. The results demonstrate that the integrated use of plant biostimulants can improve seedling vigor and structural development in Coffea arabica, representing a promising strategy to optimize nursery management and support sustainable coffee production systems.