Science & Technology Development Journal - Science of The Earth & Environment

The intergrated model of industry – agriculture towards sustainable development: A pilot model in Cho Moi district, An Giang province

Tran Thi Hieu — 2020-11-10

The objective of this study is to apply the AIZES: Agro – Industrial zero emission system (including components such as garden - livestock - biogas - household- treatment) for households whose main livelihoods are mango and pig farming to minimize environmental pollution and creating livelihoods for farmers in rural areas in the Mekong Delta. The results show that the amount of waste generated from the main components of the model is circulated and reused optimally. In this model, the biological componentsc (B: composting và Biogas) are important in converting the organic waste generated in the model into other useful products to re-serve the model. The T component (Biochar wastewater treatment station) is also important in the treatment of wastewater after biogas tanks to achieve standards and reuse in garden water supply, the remaining components play a role in contributing waste to the model for the best operation of the model (V: gaeden provide leaves, broken branches to burn to form Biochar, ....). In addition, the AIZES model has created a sustainable livelihood and contributed to an increase in household income of 77.100.000 VND after 1 year of application.

Application of sustainable livelihood framework for the assessment of living for rural people in Tan Phuoc District, Tien Giang Province

Vĩ Quốc Lê — 2020-11-09

In this study, the approach of a sustainable livelihood framework following the guidance of the Department for International Development (DFID) is used to assess the livelihoods of people in rural areas of Tan Phuoc district, Tien Giang province. This is one of the acid sulphate soil areas of the Mekong Delta. Sustainable livelihood framework according to Department for International Development in the study will consider the assets of Tan Phuoc district people to ensure livelihoods including human capital, physical capital, financial capital, natural capital, and social capital. The results show that most of the capital for developing livelihoods of people in this area is poor (natural capital, human capital, social capital, financial capital), only physical capital is considered to meet the current development needs. They are the basis for proposing development orientations for Tan Phuoc district in the future, including socio-economic development, labor quality improvement and the number of professionally trained people. Besides, there are specific s upport policies for people and there are many sources of capital to help people access policies easily. To solve this problem, first of all, it is necessary to develop development plans of regions according to natural conditions, continue to improve the skills of local communities and provide specific support policies for livelihood activities. Attract many different sources of investment capital for the locality so that people can easily access, improve the income of local people in the future, especially need a population development strategy corresponding to the development conditions of the district. The analysis is based on aggregate collected data on the different types of livelihoods in the province, so they are of great overall value. However, this is also the basis for conducting detailed studies and investigations for further studies with the aim of having accurate information and correct assessment of the current livelihood status of each district and livelihood group.

Using inverse analysis to estimate hydraulic properties for unsaturated layered sand

Tô Viết Nam — 2020-11-13

In order to better evaluate the applicability of the inverse analysis method for calculation and evaluation of hydraulic properties of unsaturated soil in more realistic conditions, a transient one – step outflow experiment for layered sands was applied in the desaturation process with the purpose to attain the profiles of suction, saturation and flow rate with time. In this study, the fine sand and medium sand were used with the same thickness of 40cm for each layer. The sand grains were mixed under water and scooped into the plexiglas column (H = 80cm, D = 28cm, wall thickness = 1cm) to prepare a fully saturated sample. For homogeneity within each sand layer, the density of two sands must be controlled during soil column construction. For numerical study, the inverse simulation and one straightforward calculation were carried out to determine the unsaturated hydraulic properties of sands. Unsaturated hydraulic parameters in the van Genuchten model were estimated using soil suction measurements at 10cm intervals and an outflow rate at the bottom of a layered sand column. To reduce the quantity of data for analysis and simulation but still keep enough typical information for the experiment, four data sets of soil suction and saturation at four locations (L2, L4, L5 and L8) were selected out of eight to compile the Soil Water Characteristic Curve. The comparison between predicted unsaturated hydraulic properties and the experimental unsaturated hydraulic properties shows good agreement in the case of the fine sand was overlaid with medium sand. The results concluded that besides the homogeneous sand, the inverse analysis based on the 1-D outflow experiment promises to be a useful method in determining the hydraulic properties for unsaturated heterogeneous sand.

Design of integrated farming system for sustainable livelihoods within an acidic soil in Long An province

Nguyen Thi Thu Thao — 2020-12-03

Long An province, located in the Mekong Delta, has a large area of acid sulfate soils, of which tremendously high acidic soil of Thanh Hoa ward. Due to the toxic factors in the high acid sulfate soil, the area suffers the harsh natural conditions that leading to livelihoods limitation in terms of freshwater supply, drainage, agricultural cultivation, and environmental sanitation as well. The study approach is to build an integrated farming system based on the close loop of material and energy flows for a typical small-scale farm in acidic areas in Long An province for sustainable agriculture. Therefore, the potential systems meet the objectives of recycling waste by the energy efficiency analysis based on energy conversion and by the economic analysis. The results show that pig production and cultivated orchard obtain high profits. Energy efficiency from raising pigs accounts for a high proportion (50%) whereas the ratio of fish production and orchard has not reached 10%. Energy efficiency analysis implies the potential options with optimal efficiencies tend to biogas treatment and composting. In addition, the three-year lifetime system is more efficient than the one-year system. However, the household financial capacity plays the most important role in selecting for the suitable farming system as well as installation of treatment systems.

Researching carbon varieties from season-caused shell for use of H2O2 properties to treat lead

Dao Minh Trung — 2020-12-13

The study assumes lead wastewater treatment with initial concentration fixed at 30 ppm and research material, denatured coal prepared from macadamia seed shell activated by heating, and finally variable Coal calculation with H2O2 agent. The coal was modified by soaking coal in 25% H2O2 solution for 48 hours. Coal after denatured for adsorption results reached 266.26 mg/g, the research results show similarities with some previous studies. On the other hand, when analyzing the infrared spectrum of coal, the FT-IR spectroscopic results showed that after denatured coal, there were some functional groups such as OH-, C-O, C=O, C-N, functional groups capable of participating in the adsorption of heavy metals in wastewater. When observing the SEM image, the photo results of the material show that the surface of the material is rough, with many pores and different sizes evenly distributed on the surface. From SEM image results and FT-IR spectroscopy results show that the material has the ability to adsorb heavy metals by many physical and chemical mechanisms. Indeed, when researching the application of materials to the treatment of lead heavy metals in presumptive wastewater, the research results show that lead treatment efficiency reaches 94.05% when surveyed at the same optimal conditions at pH = 6 with dose of 0.4 g/L and duration of 60 minutes. The control shows that the study results are similar to some previous research results, from which it can be confirmed that the modified coal material is capable of Pb (II) treatment in wastewater.

The study on the proposal an integrated ecological model directed to zero emissions of households whose livelihood is planted rice in the Mekong delta

Thu Hong Anh Nguyen — 2020-12-13

The research has proposed the model of integrated farming production towards zero - emissions based on the foundation of rice farming cultivation. The model of application of ecological solutions, the turnaround, and self-contained energy flow solutions with taking advantage of the existing ecological and environmental conditions of the locality help to maintain livelihoods for the people. Model of a typical application for the household cluster in Dinh Thanh, Thoai Son, An Giang province. The result shows that a straw volume used for the planting of straw mushrooms brings new sources of income to increase the 7.000.000 VND mushroom crop in 40 days, in addition, the rotting medium for growing straw mushrooms, which can be used the flowers to bring effectively revenues in the idle time. At the same time, 2m3/day of livestock and wastewater is processed and reused for agriculture, 39.065,31 tons/year collected in the form of biological gases serving cooking and the amount of straw 6-7 tons of straw/ha is reused by producing Biochar for agriculture, improve the land, improve the efficiency of fertilizer use for households to ensure the requirements of environmental protection, reduce the dependence of existing livelihoods on external factors such as prices, food, human,…. After using Biochar combined with manure for rice fields, helping people reduce 50% of the cost of using chemical fertilizers/ha, equivalent to 5,000,000 VND/ha. This can be seen as the best-integrated model for households whóe the main inheritance is rice cultivation combining livestock, the ability to apply long-term and can easily develop on a wide area, as well as increasing the likelihood of linking for many households to create mutual support in the case of a residential cluster with other livelihood activities besides rice cultivation.