Valorization of algal biomass to synthesize heterogeneous gC3N4-Biochar photocatalyst for the treatment of industrial wastewater using photocatalysis-persulfate oxidation process.

Textile wastewater, heavily contaminated with organic dyes, is generating severe problems to environment and human health. The implementation of gC3N4 with biochar (gC3N4-BC) for the treatment of textile wastewater is less effective due to the limited adsorption capacity and slower degradation kinetics. To tackle these problems, peroxydisulfate (PDS) is integrated with gC3N4-BC photocatalyst to enhance the process efficiency and kinetics. The synthesized gC3N4-BC-5 composite shows higher separation of charge carriers, light absorbance, and lower energy bandgap (2.62 eV). The results of photocatalytic degradation and rate constant are enhanced up to 99.9 % and 0.041 min-1 using gC3N4-BC-5 with PDS as compared to without PDS (96.8 % and 0.028 min-1, respectively). The radicals (SO4-•,O2-•, and OH•) are responsible to improve the degradation process efficiency and kinetics. The reusability of optimized sample indicates that gC3N4-BC-5 is stable and effective up to five cycles. The gC3N4-BC-5 composite attains highest adsorption (70.9 %) when compared to BC (62.3 %) and pure gC3N4 (27.1 %). The well-fitted models of adsorption (Pseudo-Second-Order and Freundlich) confirm the favorable, chemical, and multilayered adsorption process. The coupling of gC3N4-BC-5 with PDS is effective, efficient, and stable process to enhance the kinetics and degradation of textile wastewater.

Evaluation on microalgae for the production of bio-chemicals and electricity.

Recent advancement in biophotovoltaic systems using microalgae, coupled with biorefinery approach, would improve economy-feasibility in production. The major concern is its commercial strength in terms of scalability, strain selection and extraction procedure cost. It must compete with conventional feedstocks such as fossil fuels. This project proposes to enhance the economic feasibility of microalgae-based biorefinery by evaluating their performance for bio-electricity, bio-diesel and carotenoids production in a single cycle. The first part of the study was to construct and select a Bio-bottle Voltaic (BBV) device that would allow microalgae to grow and produce bioproducts, as well as generate the maximum current output reading derived from the microalgae's photosynthesis process. The second phase consisted of a 25-day investigation into the biorefinery performance of six different microalgal species in producing bio-electricity, bio-diesel and carotenoid in a prototype BBV device. The prototype BBV device with aluminium foil and pencil lead as its anode and cathode produced the highest carotenoid and biodiesel component production from the two microalgae tested, according to the results of the first phase of the experiment. In the second portion of the study, Scenedesmus dimorphus and Chlorella vulgaris were identified as the two microalgae most capable of maintaining their growth throughout the experiment. The maximum current reading observed for C. vulgaris was 653 mV. High Performance Liquid Chromatography analysis showed four major carotenoid compounds found which were Neoxanthin, Cantaxanthin, Astaxanthin and 9-cis antheraxanthin, and the highest carotenoid producer was C. vulgaris which recorded at 1.73 µg/mL. C. vulgaris recorded as the most alkanes producer with 22 compounds detected and Heptacosane and Heneicosane as the two major biodiesel compounds found in the extracts. Evaluation of C. vulgaris data showed that it has enormous potential for microalgal biorefinery candidates. Further ongoing research and development efforts for C. vulgaris will improve the economic viability of microalgae-based industries and reduce reliance on depleted fossil fuels.

Enhancing coastal ecosystem resilience: Investigating the interplay between safety criteria and ferry employee's perceptions to address climate change impacts.

Coastal ecosystems play an important part in mitigating the effects of climate change. Coastal ecosystems are becoming more susceptible to climate change impacts due to human activities and maritime accidents. The global shipping industry, especially in Southeast Asia, has witnessed numerous accidents, particularly involving passenger ferries, resulting in injuries and fatalities in recent years. In order to mitigate the impact of climate change on coastal ecosystems, this study aimed to evaluate the relationship between employees' perceptions of safety criteria and their own safety behaviour on Langkawi Island, Malaysia. A straightforward random sampling technique was employed to collect data from 112 ferry employees aboard Malaysian-registered passenger boats by administering questionnaires. The findings shed light on the strong connection between providing safety instructions for passengers and safety behaviour among ferry workers. Safety instructions should contain climate-related information to successfully address the effects of climate change. The instructions might include guidance on responding to extreme weather events and understanding the potential consequences of sea-level rise on coastal communities. The ferry company staff should also expand their safe behaviour concept to include training and preparation for climate-related incidents. The need to recognise the interconnectedness between climate change, ferry safety and the protection of coastal ecosystems is emphasised in this study. The findings can be utilised by policymakers, regulatory agencies and ferry operators to design holistic policies that improve safety behaviour, minimise maritime mishaps and preserve the long-term sustainability of coastal ecosystems in the face of difficulties posed by climate change.

Graphene-grafted bimetallic MOF membranes for hazardous & toxic contaminants treatment.

Development of membrane with improved carbon dioxide (CO2) gas separation capability is a significant challenge. However, the fabrication of membrane that efficiently separate and purification CO2-containing gases has been the focus of global attention. Cellulose Acetate (CA) has robust reinforcing characteristics when incorporated within a suitable polymer matrix. This work focus on the synthesis of novel mixed matrix membranes (MMMs) by introducing Graphene-grafted bimetallic MOFs in Cellulose Acetate polymer. The graphene-grafted bimetallic MOF (GG-BM MOFs) was prepared by a hydrothermal technique. Whereas, the solution casting approach used to fabricate membranes. The 1-5 wt% of GG-BM MOFs incorporated into the CA matrix. The mechanical, hydrophilicity and adsorption characteristics of fabricated MMMs were investigated. The crystallinity of MMM enhanced after the addition of GG-BM MOFs. In addition, the mechanical characteristics of MMMs were improved with the incorporation of GG-BM MOFs inside the polymer matrix. Maximum stress and strain was obtained for 2 wt% MMM (36.4 N/mm2 and 11% respectively). The CO2 adsorption performance was evaluated at 10 bar and 45 °C. The FTIR results represent insignificant bond shifting with the addition GG-BM MOFs at these conditions. The overall results showed that MMMs containing 2 wt% GG-BM MOFs have good adsorption properties for CO2 i.e 3.15 wt% of CO2. The MMMs have shown a decrease in the mechanical properties and CO2 adsorption at the higher GG-BM MOFs loading due to the presence of agglomeration which was confirmed through SEM. Thus, the addition of GG-BM MOFs in the CA matrix positively altered the physicochemical characteristics of the resulting MMMs, which could assist them in achieving remarkable CO2 adsorption at 2 wt%.

Sustainable remediation of dye-contaminated wastewater using novel cross-linked Hex-CCP-co-PPT microspheres.

The presence of dyes in contaminated water poses substantial dangers to the health of both humans and aquatic life. A process called precipitation polymerization was used to create unique cross-linked hexa-chlorocyclotriphosphazene-co-phenolphthalein (Hex-CCP-co-PPT) microspheres for the purpose of this research. Advanced methods such as X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential thermogravimetry (DTG) were used to characterise these microspheres. In a simulated solution, the performance of Hex-CCP-co-PPTs as a sorbent for removing MB dye was investigated, and the results showed an unprecedentedly high removal rate of 88.4% for MB. Temperature of 25 °C, a Hex-CCP-co-PPTs dose of 40 mg, an MB concentration of 20 ppm, an MB solution volume of 20 mL, a contact time of 40 min, and a pH of 9 were found to be the optimal experimental conditions. According to the results of the kinetic and adsorption analyses, the PSO and Langmuir adsorption models are the best ones to use. These models favour the chemi-sorption nature and mono-layered adsorption of MB in comparison to Hex-CCP-co-PPTs. Importantly, the thermodynamic analysis demonstrated that the process of removing MB by utilizing Hex-CCP-co-PPTs was endothermic and occurred spontaneously. These findings highlight the potential application of Hex-CCP-co-PPT microspheres in Algal Membrane Bioreactors (AMBRs) for the efficient and sustainable removal of dye from wastewater. This would contribute to the protection of ecosystems as well as the public's health.

Development of sodium alginate-pectin biodegradable active food packaging film containing cinnamic acid.

Plastics are still the most popular food packaging material and many of them end up in the environment for a long period. Due to packaging material's inability to inhibit microbial growth, beef often contains microorganisms that affect its aroma, colour and texture. Cinnamic acid is categorized as generally recognised as safe and is permitted for use in food. The development of biodegradable food packaging film with cinnamic acid has never been conducted before. This present study was aimed to develop a biodegradable active packaging material for fresh beef using sodium alginate and pectin. The film was successfully developed with solution casting method. The films' thickness, colour, moisture level, dissolution, water vapour permeability, bending strength and elongation at break were comparable to those of polyethylene plastic film in terms of these attributes. The developed film also showed the degradability in soil of 43.26% in a duration of 15 days. Fourier Transform Infrared (FTIR) spectra showed that cinnamic acid was successfully incorporated with the film. The developed film showed significant inhibitory activity on all test foodborne bacteria. On Hohenstein challenge test, a 51.28-70.45% reduction on bacterial growth was also observed. The antibacterial efficacy of the established film by using fresh beef as food model. The meats wrapped with the film showed significant reduction in bacterial load throughout the experimental period by 84.09%. The colour of the beef also showed significant different between control film and edible film during 5 days test. Beef with control film turned into dark brownish and beef with cinnamic acid turn into light brownish. Sodium alginate and pectin film with cinnamic acid showed good biodegradability and antibacterial activity. Further studies can be conducted to investigate the scalability and commercial viability of this environmental-friendly food packaging materials.

Investigating the crude oil biodegradation performance in bioreactor by using a consortium of symbiotic bacteria.

Crude oil pollution is one of the most serious environmental issues today, and the clean-up procedure is perhaps the most difficult. Within one to three weeks, the vast majority of oil bacteria may degrade approximately 60% of the crude oil, leaving approximately 40% intact. The by-product metabolites produced during the breakdown of oil are essentially organic molecules in nature. These metabolites inhibit its enzymes, preventing the oil bacteria from further degrading the oil. By combining a variety of different oils with heterotrophic bacteria in a bioreactor, the rate of crude oil biodegradation was accelerated. In this study, two strains of oil-resistant, heterotrophic bacteria (OG1 and OG2-Erythrobacter citreus) and a bacterium that uses hydrocarbons (AR3-Pseudomonas pseudoalcaligenes) were used. Gas chromatography-mass spectroscopy was used to investigate the effectiveness of this consortium of symbiotic bacteria in the biodegradation of crude oil. According to gravimetric and gas chromatography analyses, the consortium bacteria digested 69.6% of the crude oil in the bioreactor, while the AR3 single strain was only able to destroy 61.9% of it. Under the same experimental conditions, consortium bacteria degraded approximately 84550.851 ppb (96.3%) of 16 aliphatic hydrocarbons and 9333.178 ppb (70.5%) of 16 aromatic hydrocarbons in the bioreactor. It may be inferred that the novel consortium of symbiotic bacteria accelerated the biodegradation process and had great potential for use in increasing the bioremediation of hydrocarbon-contaminated locations.

A cohesive effort to assess the suitability and disparity of carbon nanotubes for water treatment.

Population growth, industrialization, and the extensive use of chemicals in daily life have all contributed to an increase in waste generation and an intensified release of organic pollutants into the aquatic environment. To ensure the quality of water (including natural resources), the removal of these pollutants from wastewater has become a challenging task for scientific community. Conventional physical, chemical, and biological treatment methods are commonly used in combinations and are not very effective. Recently, carbon nanotubes (CNTs) emerged as the most reliable and adaptable choice for efficient water treatment due to their extraordinary material properties appearing as a single-step solution for water treatment. High surface area, exceptional porosities, hollow and layered structures, and ease of chemical activation and functionalization are some properties which makes it excellent adsorption material. Hence, this review paper discusses the recent advances in the synthesis, purification, and functionalization of CNTs for water and wastewater treatment. In addition, this study also also provides a quick overview of CNTs-based advance technologies employed in water treatment and carefully assesses the benefits versus risks during large-scale water treatment. Furthermore, it concludes that identified risks to the environment and human health cannot be easily ignored and strict regulatory requirements are a must for producing low-cost innoxious CNTs.

Effect of light intensity on survival, growth and physiology of rohu, Labeo rohita (Cyprinidae) fry.

Purpose: Light intensity is one of the important environmental factors that have strong influence on larviculture. Culture of fish at high intensity of light generates harmful radicals in the body that can compromise their health and production. The present study aims to evaluate the effect of various light intensities on the physiology of rohu Labeo rohita fry.Materials and Methods: Rohu fry (13.56 ± 0.4 mg) were exposed at five different light intensities: 0.17 ± 0.005 (Lc, control), 1.45 ± 0.23 (L1), 2.69 ± 0.47 (L2), 3.93 ± 0.72 (L3) and 5.06 ± 0.95 Wm-2 (L4). After 90 days of culture, rohu were harvested.Results and Conclusions: A 2-5% mortality of rohu was recorded in L3 and L4 treatments. The average weight and specific growth rate were significantly (p < .05) higher in Lc treatment compared to others. The light intensity and swimming activity of rohu showed direct relationship, whereas, light intensity showed inverse relation with nitric oxide synthase and reduced glutathione levels. Significantly (p < .05) higher glutathione S-transferase and glutathione peroxidase activies were found in rohu exposed at L4 treatment. Higher light intensities resulted in oxidative stress in the muscles of rohu. Thiobarbituric acid reactive substances, carbonyl protein and heat shock protein 70 were significantly (p < .05) higher in rohu exposed at L4 compared to other treatments. Exposure of rohu fry to intense light resulted into physiological stress and immunosupression.

The study of ameliorative effect of dietary supplementation of vitamin C, vitamin E, and tryptophan on Labeo rohita (Cyprinidae) fry exposed to intense light.

The stress ameliorating effect of dietary supplementation of vitamin C, vitamin E, and tryptophan on rohu Labeo rohita fry was evaluated. Rohu fry (1.1 ± 0.03 g) were cultured under five different feeding regimes: enriched with 0.08% vitamin C (D1), 0.02% vitamin E (D2), 1.42% tryptophan (D3), a combination of these three ingredients at similar doses (D4), and control diet (D5). Rohu fry of D5 were divided into two groups-exposed to experimental light (D5FL) and ambient light (114 ± 4 lx, D5AL). All fry (except D5AL) were exposed at light intensity of 3442 ± 648 lx. Feeding of rohu with enriched diets significantly (P < 0.05) enhanced the survival rate and average weight. A 15-25% higher survival and 1.3-1.8-fold higher average weight were recorded in rohu fed with enriched diet compared to D5FL treatment. Supplementation of vitamin C in diet (D1) of rohu resulted in 4.1-fold and 6.9-fold higher nitric oxide synthase and reduced glutathione (GSH) levels, respectively compared to the D5FL treatment. The tryptophan-enriched diet (D3) showed 5.8-fold higher melatonin and 4.4-fold lower cortisol levels in rohu compared to the D5FL treatment. Significantly (P < 0.05) higher nitric oxide synthase, GSH and melatonin, and lower cortisol, glucose, thiobarbituric acid reactive substances, carbonyl protein, glutathione S-transferase, and glutathione peroxidase levels were found in D4 diet fed rohu compared to the other treatments. Reduced level of stress in D4 treatment resulted in best performance of rohu in terms of less swimming activity and higher survival and growth compared to the other treatments.

HIV in Females: A Clinico-epidemiological Study.

BACKGROUND: Human Immunodeficiency Virusinfected women account for almost half the number of cases of HIV worldwide. Despite reduction in HIV prevalence among the population, the percentage of Indian women contracting the disease seems to have increased. The social implications are also different in females. MATERIALS AND METHODS: This prospective observational study was conducted from September 2009 to July 2011 at tertiary care hospitals attached to the Kasturba Medical College Mangalore, on a group of 200 HIV-positive patients. Patients above 18 years of age diagnosed with HIV as per National AIDS Control Organisation guidelines were included in the study. Clinical profile among women and men was compared with respect to clinical presentation, disease detection, CD4 count and response of family and society. RESULTS: Clinical presentation was similar among both men and women. Eighty-one percent men had promiscual sexual exposure, 19% of women had so. Males were identified to be HIV-positive earlier than their spouse (tested later), time lag being 27.6 weeks. After detection of positivity 77% of females felt being less cared for by the in-laws. CD4 count less than 50 was detected in more number of females as compared to men (11% females and 1% males). Death of spouse was seen more often in females (among 35% of women and 11% of men). CONCLUSION: Most of the females were likely to acquire infection from their spouse. Females tend to seek and get medical attention at the late stage of disease as compared to men. HIV in females has different social implications which includes discrimination within the family.

HIV-Tuberculosis: A Study of Chest X-Ray Patterns in Relation to CD4 Count.

BACKGROUND: Fight against human immunodeficiency virus (HIV) is incomplete without addressing problems associated with difficult diagnosis of tuberculosis in HIV-Tuberculosis coinfected patients. Chest X-ray is a primary tool to evaluate tuberculosis in HIV. AIM: To assess and compare various radiological patterns of pulmonary tuberculosis in HIV patients and compare these patterns in relation to CD4 counts. MATERIALS AND METHODS: Prospective cohort study was conducted in a tertiary hospital in South India from September 2009 to July 2011 with 200 HIV positive patients. WHO guidelines were used for diagnosis of HIV and tuberculosis. RESULTS: 27% of the patients had sputum positive pulmonary tuberculosis, with higher incidence (33%) among CD4 less than 200 as compared to CD4 more than 200 (14%). Infiltration (39%) followed by consolidation (30%), cavity (11%), and lymphadenopathy (9%) seen with CD4 less than 200. Infiltration (37.5%) followed by cavity (25%) and miliary (25%) with CD4 above 200. Bilateral (68.5%) and mid and lower zones or all zone involvement more commonly seen. CONCLUSION: In patients with CD4 lower than 200 noncavitory infiltration and consolidation predominated. Involvement of lungs was atypical; diffuse or mid and lower zone involvement than classical upper lobe involvement. A high index of suspicion is necessary for the accurate and timely diagnosis of tuberculosis in HIV positive patients.