Depleting Tropical Forest at a Landscape Scale: Finding Solutions for Bangladesh

Drastic deforestation is a major problem of Bangladesh which is contributing to negative downstream impacts on the environment. To address this problem various measures should be taken at different scales. The main objective of this paper is to suggest the possible steps that Bangladesh could take and reverse the trend of deforestation. An extensive literature review and interviews with government officials, professionals and NGO workers have been used to collect relevant information on the agents of deforestation in the country. Based on the information gathered, this paper presents the reasons for the extent of deforestation, and suggests some positive steps where the Government could be the main mitigating actor by implementing integrated programmes, which will also ensure mass awareness and wider impact. Local NGOs and international bodies must also formulate adequate plans to protect valuable areas of remaining forest

Extent and Consequences of Tropical Forest Degradation: Successive Policy Options for Bangladesh

This paper is conceived at a time when new paradigms are sought for the development of a framework to deal with the problem of forest resources degradation. Deforestation in Bangladesh, has reached an alarming rate in recent years. The forest coverage of Bangladesh is one of the lowest and the deforestation rate is the highest of any country in the world. Coupled with the process of deforestation, flawed afforestration programmes have seriously exposed Bangladesh to environmental vulnerability. Considering this situation various strategies should be taken at different levels. The main objective of this paper is to suggest the possible steps that Bangladesh could halt and reverse the trend of deforestation. An extensive literature review and structured interviews of key informants have been used to collect relevant information to understand the reasons and consequences of forest degradation in the country. Based on the information gathered, this paper suggests some positive steps where the Government could be the main mitigating actor by implementing integrated programmes, which will also ensure mass awareness and wider impact

Initiatives of Tropical Agroforestry to Sustainable Agriculture: A Case Study of Capasia Village, Northern Bangladesh

A relatively large percentage of the population in Bangladesh lives under the poverty line and is affected by the country's degrading natural resources. Agroforestry has been seen as one of the few options to lift people out of poverty. Research into the costs and benefits of agroforestry was undertaken in Capasia Village in Northern Bangladesh. Initial results indicate that agroforestry may not only be an optimal livelihood solution for poor farmers, biodiversity conservation and environmental sustainability but agroforestry systems also provide good economic rates of return. Thus the farmers who engage in agroforestry are benefited in different ways

Modelling of struvite chemistry

This paper shows the simulation results of struvite thermodynamics. The thermodynamic simulation shows the complex solution chemistry of struvite. Based on the thermodynamic simulation results, the complexes and ions present in struvite solution system are MgOH+, +, MgHPO4, MgPO4-, H3PO4, H2PO4-, HPO42-, NH3, NH4+, Mg2+ and PO43-. The thermodynamic simulation results also show that the supersaturation of struvite system is a function of reactant concentration (concentration of total magnesium, ammonium and phosphate) and solution pH. The paper also includes the validation the developed thermodynamic model using Minteq (a specialized thermodynamic modeling package)

Development and commissioning of controlled struvite crystallization in pilot scale

This paper focuses on the design of a nutrient recovery scheme, conducted in a fed-batch controlled crystallization technique, leading to the formation of struvite (Magnesium Ammonium Phosphate). The controlled crystallization technique included the control of solution pH and concentration during each experiment. Characterization of struvite crystal growth was conducted by CSD (crystal size distribution) analysis of growing struvite. Controlled crystallization showed significant growth of struvite crystals by surface diffusion, whereas faulty control initiated significant amount of fines

Nutrient recovery from piggery effluents

The present study aims to evaluate struvite precipitation potential, using the Visual MINTEQ modelling package. A solution speciation model of struvite precipitation in different phases has been developed. This model indicates that across a wide range of pH (6-14) various other crystals are formed along with struvite, whereas struvite formation is dominant in the pH range of 7.75-9.27. Solution speciation modelling indicates that a Magnesium Ion Selective Electrode can be used to infer struvite supersaturation, enabling better modelling and control of crystal growth kinetics. A brief thermodynamic investigation of the piggery wastewater collection pond will be performed using this model

Thermodynamic and solution chemistry of struvite

The key feature of this paper is the combined removal of magnesium, ammonium and phosphate from a representative\ud synthetic solution of piggery effluent. The byproduct of this recovery process is struvite, commercially used as slow-release fertiliser. A thermodynamic model was developed relating to all the complexes of magnesium, ammonium and phosphate using gPROMS process software. A laboratory-based batch experiment confirmed 80% recovery of phosphate using this crystallization technique. The batch experiment was conducted at constant pH using synthetic solution made up of analytical-grade MgCl2 and NH4H2PO4. Borosilicate glass grindings of 5 g were used as seeds in this batch experiment. Basic solution characteristics of piggery effluent are reported in this paper