This study was carried out to characterize the biogeochemical and physicochemical properties of landfill leachate from Matuail Sanitary landfill site, Dhaka, Bangladesh. In addition, the study also aimed to identify the photodegradation of landfill leachate under natural sunlight. The leachate pH was slightly alkaline (7.87–8.07) with a minimum level of dissolved oxygen, and low BOD 5 /COD ratio that are indicators of the matured methanogenic phase. Ca, Fe, Br, Rb, Cu was present in a considerable amount. A trace amount of Sr, Co, As, Pb, Cr was found in the leachate sample. Fourier Transform - infrared (FTIR) spectra of all three samples had five major peak regions notably at 3440–3450 cm −1 (O–H groups of water), 1638 cm −1 (C=O Amide I, carboxylates C=C, aromatic ring modes, or alkenes), 1385–1390 cm −1 (deformation of the C–H bond in CH 2 and CH 3 , or the asymmetric stretching of COO¯), 1115 cm −1 (stretching of the C–O bond in phenol ethers and phenols) and 605 cm −1 (S–O bends of sulfates). In addition to the appearance of new peak, peak shifting on the 2 nd -day and 5 th -day phototreatment are in compliance with the 34% TOC reduction. From analyzing three-dimensional excitation/emission (3D-EEM) spectra of the raw sample pyrene-like or humic-like peak A (Ex 255/Em 465), soil fulvic-like peak M p (Ex 315/Em 450), and humic-like peak C (Ex 370/Em 455) was found indicating more humified characteristics of the mature landfill site. From 1-hour to 6-hours phototreatment, all three substances slightly lost fluorescence intensity. From the 2 nd day to the 5 th day of photo-treatment, two unknown photo-product was identified within Ex 210/Em 457 and Ex 205/Em 408 at peak A region. Fluorescence intensity lost was 65% for peak A and 44% for peak C. Soil fulvic-like peak M p was absent on the 5 th day of photo-treatment.

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Urban green spaces and urban forest covers are a significant component of urban planning which is critically ignored in Bangladesh. This study aims to identify the prospects and challenges of achieving sustainable urban green spaces in Dhaka North City Corporation (DNCC), Bangladesh which is a significant indicator of the sustainable development goal (SDG11). We have analyzed the historical land use and land cover change (LULC) from 1992, 2002, 2012, and 2022 using Landsat 4–5 Thematic Mapper (TM), Landsat 7 Enhanced Thematic Mapper Plus (ETM+), and Landsat 8 Operational Land Imager (OLI) images by ArcGIS 10.8 and Google Earth-pro software. The use of the Normalized Difference Vegetation Index (NDVI) primarily indicates vegetation greenness as well as determining other land uses such as waterbody, settlements and barren land. The calculated kappa values varied from 80% to 86.7% for all the years and fit the current research. A strength-weakness-opportunity-threat (SWOT) analysis reviewed and analyzed existing sectoral policy and plans to identify challenges to achieve sustainable urban forestry. Fifteen key informant interviews (KII) from Dhaka North City Corporation (DNCC), Department of Environment (DOE), Bangladesh Forest Department (BFD), and Department of Social Forestry Department (DSF) wing under BFD were taken to identify the status of urban forestry, its problems, opportunities, and threats. The responses were drawn using a Driver-Pressure-State-Impact-Response (DPSIR) framework. Of the total measurements of 194.2sq km (2022), normal vegetation cover has decreased significantly from 1992 to 2022 by approximately 65.9%, while urban areas increased by almost 95% simultaneously. From 1992 to 2022, areas of water bodies decreased by more than 32.4%. The vegetation coverage in DNCC is only 16.17%, inferior in meeting sustainable urban greening to fulfil the criteria of sustainable cities and communities. From the KII, it is found that despite some relevant forestry policy and plans, limited lands, institutional corruption, and weak governance are the major institutional drawbacks. In the DNCC, unplanned and rapid megacity expansion, roads and utility service expansion weak institutional policy, plan, and program implementation for urban green space protection are some of the driving forces of green cover loss. Introducing strategic environmental assessment of urban forestry policy, plans, and programs, removing inter-institutional conflicts, strategic sectoral plans, and programs for increased green spaces through the bioeconomy concept is required. In addition, increased participation from urban stakeholders is some of the significant responses identified for strategic urban green space and forest cover improvement in DNCC.