Global Research in Environment and Sustainability

Spatial Anaysis and Modelling to Mappping Priorities Areas for Restauration: Study Case: Natural Protected Area Montes Azules, Chiapas, Mexico

M. Lopez L. Daniel — 2024-10-13

Natural Protected Areas play a fundamental role in the conservation of biodiversity and ecosystems throughout the world and are designated and managed with the purpose of preserving biological and cultural capital, ensuring the sustainable use of natural resources, and maintaining ecosystem services. The Montes Azules Biosphere Reserve, like other Natural Protected in Mexico, faces significant challenges such as deforestation, illegal logging, and loss of vegetation cover, as well as socio-environmental conflicts, factors that hinder the biological and cultural conservation of the area. Likewise, despite their importance, many Natural Protected face significant challenges in terms of effective monitoring and planning. The lack of adequate monitoring and planning strategies, as well as staff and budget, makes it difficult to assess the conservation status of these areas and to implement appropriate management measures. Therefore, creating specific monitoring tools is essential to periodically evaluate their conservation status and identify threats and pressures on ecosystems in order to design adaptive and effective management strategies. The objective of this study is to offer a first methodological approach to identify priority areas for restoration within the Montes Azules Biosphere Reserve, which will allow decision-makers to design and apply conservation strategies in the area. The determination of the priority areas for restoration was based on an environmental management process, where the Land suitability is the base for the territorial arrangement, which was modeled together with the current land use and land cover through rules of decision and having the natural protected area as a frame. For land suitability, the land classification system was used according to its use capacity or American system of the 8 classes developed by the Soil Conservation Service of the United States; for mapping land use land cover, an object base classification method was used. The total transformed area in 2023 occupies an extension of 39,475.38 ha, approximately 50% of this lands corresponds to sloping and very steep land and in some cases with shallow to very shallow soils, not suitable for agriculture. The area identified as priority zones for restoration corresponds to an extension of 19,514.5 ha, which represents nearly 50% of the transformed area, and 6% of the total of study area, from which 6,860.5 ha are top priority for restoration. As main conclusion can be said that the methodological proposal described here serves as a first approximation to identify priority zones for restoration in the Montes Azules Biosphere Reserve, allowing for a more detailed identification of these areas at the local level, which will allow decision-makers to design and apply conservation strategies in the area.

Degradation of Azo-dye (Disperse Red) Using Rhizosphere Bacterial Consortium

Aigere Sandra Patrick — 2024-09-12

This study investigates the degradation of the azo dye (Disperse Red) using a rhizosphere bacterial consortium. Standard microbiological and molecular techniques were employed to isolate and identify organisms from rhizosphere soil. Degradation of azodye was carried out in a fabricated anoxic and oxic chambers with hydraulic retention time of 40hrs. Initial identification of the bacterial isolates through Gram’s reaction and biochemical tests revealed the presence of organisms belonging to the genera Pseudomonas, Lysinibacillus, and Citrobacter. Molecular and phylogenetic analyses confirmed the isolates as Pseudomonas aeruginosa, Lysinibacillus sphaericus, Pseudomonas chengduensis, and Citrobacter freundii. During the preliminary testing, the degradation efficiency was assessed under varying glucose concentrations. Higher decolorization rate of 56.17% was observed in the medium with 10% glucose after 72 hours, while the medium with 5% glucose achieved a 44.17% colour reduction. Notably, lower degradation rates recorded were 11.96% and 12.85% for the 5% and 10% dye enhance glucose mineral salt media, respectively. However, During the actual degradation testing in a double-chamber system enhanced with biochar, the first anaerobic cycle achieved a maximum decolorization of 71.95% after 94 hours, with the first aerobic cycle further enhancing degradation to 90.51%. The second anaerobic cycle increased degradation to 94.78%, and the final aerobic cycle achieved a decolorization of 98.47%. These results show that the rate of Disperse Red degradation is highly dependent on glucose levels and alternating anaerobic-aerobic conditions. This study demonstrates the potential of using rhizosphere bacterial consortia to bioremediate wastewater contaminated with azo dyes, offering an efficient and sustainable method of environmental management. The results underline the need of optimizing ambient conditions to increase microbial degradation processes.

Process Performance and Nutrient Removal in Fish Processing Wastewater Using a Membrane Bioreactor (MBR) Unit for Reuse for Irrigation

Jane Mburu — 2024-09-12

This study investigated the removal of nitrogen and phosphates in fish processing wastewater through process optimization of a membrane bioreactor (MBR) treatment unit. Raw process wastewater was collected from the Makindi fish farm and was pre-filtered through a mesh of 0.8 mm. The experiment was conducted at a lab scale using commercial Polyethersulfone (PES) membranes submerged in the MBR unit. The pre-filtered wastewater sample was added into a denitrification (anoxic) tank. The process was conducted through continuous recirculation between the aeration and the anoxic tank to enhance the removal of nitrogenous compounds. The recirculation flow rate was 10L/h. A hydraulic residence time (HRT) of approximately 22-25h was maintained, and the aeration rate in the aerobic tank was 100L/min. Aluminum sulphate AI₂(SO₄)₃18H₂O was added continually into the anoxic tank and with constant stirring to enhance the removal of phosphates. A removal rate of 85±2% for NH₄⁺-N, 84±1% for NO₃^--N, and 69±3% for PO₄^3--P was obtained. The nutrient concentration in the effluent was successfully reduced to an acceptable level with both nitrogenous compounds and phosphate concentrations obtained within the range of < 30 mg/L and ≤ 5 mg/L as per the WHO guidelines for wastewater reuse for irrigation. The results showed a successful process optimization that can be applied to ensure optimized performance of the MBR unit thus improve its effectiveness for the treatment of fish processing wastewater. The study therefore recommends process optimization as a tool for effective removal of nutrients in the MBR system thus making it a potential recycling approach for treatment of fish processing wastewater for reuse for irrigation purposes.