Biosorption is a convenient process for heavy metal remediation. In this study, banana peel was experimented to eliminate lead (Pb2+) from an aqueous solution following batch experiments. The functional groups of banana peel were identified by Fourier-transform infrared spectroscopy (FTIR). The adsorption mechanism was studied by the Langmuir and Freundlich adsorption isotherm model and determined the separation factor from the Langmuir adsorption isotherm. The adsorption of Pb2+ on dried banana peel had been studied at different adsorbent doses, pH, initial concentration of Pb, contact time, temperature, and agitation speed. After adsorption, Pb2+ was measured using atomic absorption spectroscopy (AAS). Maximum adsorption had taken place at pH 5 for adsorbent dose 45 g L-1. The optimum contact time and agitation speed was 30 minutes and 150 rpm, respectively for the initial Pb concentration of 100 ppm at 25°C. Both, Langmuir and Freundlich adsorption isotherm models shows the best fitting (r2 = 0.9978 and 0.9595) for Pb2+ adsorption. The maximum Pb2+ adsorption capacity was 2.1 mg g-1. The findings indicate that the banana peel waste could be a potential adsorbent for heavy metal removal. Moreover, the waste management problem could be solved in an eco-friendly manner by utilizing it for the eradication of Pb2+ from wastewater.

Noakhali Pourashava is an important municipality in southern Bangladesh, faces severe waterlogging problems every year during the monsoon period. The present study aimed to investigate the major causes of waterlogging and its negative effects on life, from the viewpoint of people residing in different areas of Noakhali Pourashava, various government, non-government, development organizations as well as various stakeholders including experts. It has been found that Noakhali Pourashava experienced waterlogging during peak monsoon season in ward no. 1, 2, 4, 5, and 8. Most of the inhabitants/respondents of the Noakhali Pourashava claimed that lack of drainage facility; excessive rainfall; inadequate, low capacity and conventional drainage system; natural siltation; improper waste management; absence of proper inlets and outlets; and blockage and encroachment of existing drainage are responsible for waterlogging. It has ascertained that the water logging becomes a burden for the inhabitants of the Pourashava and creating adverse effects on livelihood, society, infrastructure, economy and environment. Other notable adverse effects of waterlogging are disruption of traffic movement and normal life, structures and infrastructure damage and loss of income potentials with a lot of sufferings. The stagnant water acts as a breeding site for the vectors of various diseases and becomes a health hazard to people residing in the waterlogged area. The current study suggests that close coordination among Pourashava authorities, local government agencies and a strong collaboration between public and private sectors as well as local people participation are essential for solving the waterlogging problem effectively and sustainably.

Untreated wastewater disposal from industries has been a crucial environmental issue for developing countries like Bangladesh. The current study aims to investigate the status of Effluent Treatment Plant (ETP) and the quality of effluents in the Noakhali industrial area, Bangladesh. Total 10 industries were surveyed and the ETP status showed that about 30% of industries do not have ETP facilities and only 30% of industries use their ETP for the treatment of the effluents where the rest of the industry’s ETPs were under construction or exit but not used. Effluent samples were collected from seven locations near the discharge points of various industries. All the physicochemical parameters were determined using standard analytical procedures and analyzed the values comparing with the guideline standard by the Department of Environment (DoE), Bangladesh. The average values of electric conductivity (EC) have exceeded the tolerable limit in maximum effluent samples. On the contrary, the temperature, pH, and total dissolved solids (TDS) values were within the standard limit for all of the collected effluent samples. The chloride concentration of the three effluent samples surpassed the limit. The biological oxygen demand (BOD) and chemical oxygen demand (COD) limit were exceeded for the effluent sampling sites S-6 and S-7 collected near the food and beverage industry. Besides, the maximum dissolved oxygen (DO) values of the effluents were below the standard which indicates poor water quality. Environmental nuisance is producing in Noakhali industrial area as maximum industries have not enough wastewater treatment facilities. Present study demonstrated that it is obvious to operate the ETP regularly for improving the quality of effluents to save our native environment from the harmful effects of wastewater.