Rapid urbanization is one of the key factors that leads to defragmentation and the shrinking of agricultural land. It further leads to the generation of an ample amount of municipal waste. Several technologies have emerged in the past for its utilization, and in this regard, composting is one of the conventional approaches gaining popularity in modern agriculture. To overcome the possible criticality of intense urbanization, the concept of urban agriculture is taking shape. Municipal solid waste compost (MSWC) has been popularly explored for the soil amendments and nutritional requirements of crops. With this, the assessment of soil pollution (due to the heavy metals presently found in MSWC) is a required step for its safe application in agriculture. The present study aims at assessing the utilization of MSWC (in different ratios) to amend the soil and its impact on the growth and yield of brinjal (Solanum melongena), tomato (Solanum lycopersicum), and okra (Abelmoschus esculentus). The study also explored the uptake of heavy metals by plants and their risk to human consumption. The findings suggested that MSWC amendments upgraded the physio-chemical properties of soil, including organic matter (OM) and micronutrients, and increased the heavy metal concentrations in soil. Heavy metal analysis underlined the presence of several heavy metals both in soil and crops. Total metal concentration in soil increased with increased MSWC dosage. Concerning metal uptake by crop plants, 25% of MSWC was found to impart metal concentrations within permissible values in edible parts of crops. On the contrary, 50%, 75%, and 100% compost showed higher metal concentrations in the crops. A Health Risk Index (HRI) of less than 1 was found to be associated with soil amended with 25% MSWC. Our study implies that MSWC significantly improved the growth and yield of crops, and it can be considered an alternative to chemical fertilizer but only in a safer ratio (≤25%). However, further studies are required, especially on field conditions to validate the findings regarding metal accumulation.

The generation of biomedical waste has increased many times after the SARS Cov2 commencement. The biomedical waste generated from COVID-19 Patients is very infectious and contaminated. Thus, it is a big challenge with all stakeholders to avoid spreading of COVID-19 through it. This requires monitoring the complete cycle to the grave to be monitored from the cradle, if the spreading needs to be controlled. The COVID-19 waste generation, collection, storage, transportation and disposal is a big challenge withall stakeholders including isolation wards, quarantine centres, sample collection centres, laboratories, urban local bodies, and the Common Bio-medical Waste Treatment Facility (CBWTF) respectively. As its a novel virus and WHO has instructed that proper guidelines need to be followed with regards to COVID-19biomedical waste generation and its safe disposal. The Government of India has separately developed the Guidelines for the handling of COVID-19 biomedical waste, which needs to be followed besides BiomedicalRules, 2016 so that Corona spread through this can be controlled. Owing to its novel origin and least information about its behaviour, thus it is extremely important to take all precautions possible till we get some medical treatment.

The iron impregnated fungal bio-filter (IIFB) discs of luffa sponge containing Phanerochaete chrysosporium mycelia have been used for the removal of As(III) from water. Two different forms of same biomass viz. free fungal biomass (FFB) and modified free fungal biomass (chemically modified and iron impregnated; CFB and IIFB) have been simultaneously investigated to compare the performance of immobilization, chemo-tailoring and iron impregnation for remediation of As(III). IIFB showed highest uptake capacity and percentage removal of As(III), 1.32 mg/g and 92.4% respectively among FFB, CFB and IIFB. Further, the application of RSM and ANN-GA based mathematical model showed a substantial increase in removal i.e. 99.2% of As(III) was filtered out from water at optimised conditions i.e. biomass dose 0.72 g/L, pH 7.31, temperature 42 °C, and initial As(III) concentration 1.1 mg/L. Isotherm, kinetic and thermodynamic studies proved that the process followed monolayer sorption pattern in spontaneous and endothermic way through pseudo-second order kinetic pathway. Continuous mode of As(III) removal in IIFB packed bed bioreactor, revealed increased removal of As(III) from 76.40 to 88.23% with increased column height from 5 to 25 cm whereas the removal decreased from 88.23 to 69.45% while increasing flow rate from 1.66 to 8.30 mL/min. Moreover, the IIFB discs was regenerated by using 10% NaOH as eluting agent and evaluated for As(III) removal for four sorption–desorption cycles, showing slight decrease of their efficiency by 1–2%. SEM–EDX, pHzpc, and FTIR analysis, revealed the involvement of hydroxyl and amino surface groups following a non-electrostatic legend exchange sorption mechanism during removal of As(III).

In recent years, studies on phytochemicals, antioxidants, and antibiotics using blue green algae from harsh environments has become increasingly prevalent. The search for novel bioactive molecules exhibiting diverse biological activity is one of the most important strategies for addressing the issue of rising concerns regarding bacterial antibiotic resistance. In present study, the phytochemicals, antioxidant potentiality and antibacterial assessment of organic solvent extracts of blue-green alga isolated from Naini lake water were characterized. From the mass culture of alga, extracts were prepared in MeOH, EtOH, acetone, AcOEt, hexane and DCM and antioxidant potential and antibacterial properties were studied against multiple antibiotic-resistant E. coli, P. aeruginosa, P. fluorescence, S. enteric, S. typhimurium and Sh. dysenteriae. The 16S rRNA gene sequence analysis and phylogenetic tree revealed that blue-green algal isolate belongs to Nostoc sp. A higher extraction yield (5.3%) was recorded for MeOH extract as compared to other solvent extracts. Alkaloids, flavonoids and phenols were present in all extracts. DPPH free radical scavenging activity was determined using various concentrations of extracts (1 to 2048 μg mL-1). Maximum % inhibition (free radical scavenging activity) was observed in MeOH extract (35.23 ± 0.12). The methanolic extract was found to be inhibitory against P. aeruginosa and P. fluorescence. 2048 μg mL-1 MIC value was recorded against P. aeruginosa. In GC-MS profiling, a total of 8 significant peaks showing various compounds were identified among the 21 peaks. Oxirane hexadecyl was reported as the main components in this compound. The results showed that Nostoc sp. HANL07 is a good source of antioxidant and antibacterial compounds and could be used for further study in the field of drug discovery.