Nanomaterials as a sustainable choice for treating wastewater

Wastewater containing toxic substances is a major threat to the health of both aquatic and terrestrial ecosystems. In order to treat wastewater, nanomaterials are currently being studied intensively due to their unprecedented properties. The unique features of nanoparticles are prompting an increasing number of studies into their use in wastewater treatment. Although several studies have been undertaken in recent years, most of them did not focus on some of the nanomaterials that are now often utilized for wastewater treatment. It is essential to investigate the most recent advances in all the types of nanomaterials that are now frequently employed for wastewater treatment. The recent advancements in common nanomaterials used for sustainable wastewater treatment is comprehensively reviewed in this paper. This paper also thoroughly assesses unique features, proper utilization, future prospects, and current limitations of green nanotechnology in wastewater treatment. Zero-valent metal and metal oxide nanoparticles, especially iron oxides were shown to be more effective than traditional carbon nanotubes (CNTs) for recovering heavy metals in wastewater. Iron oxide achieved 75.9% COD (chemical oxygen demand) removal efficiency while titanium oxide (TiO₂) achieved 75.5% COD. Iron nanoparticles attained 72.1% methyl blue removal efficiency. However, since only a few types of nanomaterials have been commercialized, it is important to also focus on the economic feasibility of each nanomaterial. This study found that the large surface area, high reactivity, and strong mechanical properties of nanoparticles means they can be considered as a promising option for successful wastewater treatment.

Strategies to improve membrane performance in wastewater treatment

Membrane technology has rapidly gained popularity in wastewater treatment due to its cost-effectiveness, environmentally friendly tools, and elevated productivity. Although membrane performance in wastewater treatment has been reviewed in several past studies, the key techniques for improving membrane performance, as well as their challenges, and solutions associated with the membrane process, were not sufficiently highlighted in those studies. Also, very few studies have addressed hybrid techniques to improve membrane performance. The present review aims to fill those gaps and achieve public health benefits through safe water processing. Despite its higher cost, membrane performance can result in a 36% reduction in flux degradation. The issue with fouling has been identified as one of the key challenges of membrane technology. Chemical cleaning is quite effective in removing accumulated foulant. Fouling mitigation techniques have also been shown to have a positive effect on membrane photobioreactors that handle wastewater effluent, resulting in a 50% and 60% reduction in fouling rates for backwash and nitrogen bubble scouring techniques. Membrane hybrid approaches such as hybrid forward-reverse osmosis show promise in removing high concentrations of phosphorus, ammonium, and salt from wastewater. The incorporation of the forward osmosis process can reject 99% of phosphorus and 97% of ammonium, and the reverse osmosis approach can achieve a 99% salt rejection rate. The control strategies for membrane fouling have not been successfully optimized yet and more research is needed to achieve a realistic, long-term direct membrane filtering operation.

Knowledge and perception of breast cancer among women of reproductive age in Chattogram, Bangladesh: A cross‐sectional survey

Background and Aims

Breast cancer is the second leading cause of cancer death in women worldwide. The significantly higher mortality rate has been considered due to poor knowledge of women, delay in diagnosis, and initiation of treatment. Therefore, this hospital‐based cross‐sectional study aimed to understand the knowledge and perception of women with breast cancer in Bangladesh.

Methods

Data was collected using a questionnaire‐based interview from 357 women aged 15–49 years attending two tertiary care hospitals in Chattogram city of Bangladesh.

Results

Neighbors (18.6%) and relatives (18.1%) were the leading sources of information on breast cancer. Among the total, 69.5% knew about breast cancer however, only 14% of them knew about screening tests and 61.5% were unaware of risk factors for developing breast cancer. Pain in the breast, painless lump, and nipple discharge were the most recognized clinical symptoms by the participants. Exercise and weight control, the practice of breastfeeding, and taking medicine were the three most known prevention practices. Women perceived wrong conceptions that Breast cancer is only found in older age (42.3%) and women (15.7%) and that it causes losing one's breast (3.1%). A significant correlation was found between the education level of participants and their knowledge of risk factors related to breast cancer.

Conclusion

Although the majority of the participants have heard about breast cancer, they do not possess enough knowledge regarding the risk factor, symptoms, and preventive methods of breast cancer. We suggest interventions targeting a community‐based awareness program

A case-control study to determine the risk factors of dengue fever in Chattogram, Bangladesh

Objectives

In a tropical country like Bangladesh, where the climatic condition favors the growth of Aedes mosquito vectors, the success of dengue prevention depends largely on the proper identification and control of risk factors. Therefore this study was aimed to explore the potential risk factors and their association with dengue infection.

Study design

A case-control study including 150 cases and 150 controls was conducted in Chattogram district of Bangladesh. Cases were confirmed dengue patients admitted in Chattogram medical college hospital and Bangladesh institute of tropical and infectious diseases during August and September 2019. On the other hand, controls were non-dengue patients admitted in other departments of the same hospitals through gender, age, and location matching.

Methods

The questionnaire data were collected through telephone-based interviews, which included general demography, daily life activities, housing and surrounding environment of participants. Chi-square and binary logistic regression were performed to identify potential risk factors.

Results

The study found that travel history to the high incidence area, staying most of the daytime in office (AOR = 18.10), living in 21-40 years old houses (AOR = 9.74), and the temporary residency in the city (AOR = 10.20) were statistically significant risk factors for getting dengue infection. However, day time sleep, house type and structure, number of family members, morning and evening walk, plant in resident, and junk yard around 250 m of the house were also showed a significant effect in chi square test.

Conclusions

Results strengthen our understanding regarding the role of factors associated with daily lifestyle and living environment of people in the development of dengue and hence support the dengue control program in Bangladesh. The study will provide a basis for future extended research covering different parts of the country.