This study analyzed the influencing factors of implementing environmental impact assessment (EIA) reports on the efficiency of using commercial and service land in Cai Rang district, Can Tho City. Descriptive statistics and SWOT analysis methods were used in this study. The results presented that the investor’s financial ability; compensation, resettlement support and suitable location were the influencing factors in the exploitation and management of land (66.67%; 51.52%, and 93.94%, respectively). For the investors, the suitability of the location, consistent infrastructure, and legal suitability significantly influenced EIA and land management. Implementing an environmental impact EIA reports influenced land use efficiency by 63% (for experts) and 85% (for investors). Annual land use planning is the biggest challenge (63.64%) with land management and use. In addition, EIA that contributes to environmental protection is also identified in this study. Finally, this study recommended solutions to improve land use efficiency.

This study assessed the effects of the stirring frequency of super-intensive shrimp sludge on biogas production. A batch anaerobic digestion was conducted, comprising five treatments: non-stirring (NS), and stirring at one (1T), two (2T), four (4T), and eight (8T) times per day, with a stirring time of 2 minutes. The shrimp sludge loading rate was the same for each treatment at 20g volatile solid/L. The findings revealed that the methane yield (CH4) in the 1T, 2T, and 4T treatments were significantly higher by 10.01%, 5.99%, and 4.2%, respectively, compared to the NS treatment. The study also reported negative correlation between CH4 yield and the number of stirring times. Notably, the highest stirring frequency (8T/day) resulted in a methane yield (CH4) similar to non-stirring.

The research evaluated the greenhouse gases (GHGs) emission tradeoff for financial efficiency gained from chili and green mustard cultivation based on the emissions and the cultivation models’ profit. The life cycle assessment methodology with an approach defined as “cradle-to-gate” and a 100-year framework as the assessment period for all calculations through MiLCA software was used to estimate total GHGs emission through agricultural inputs production. Green mustard cultivation emitted 11,249.7 kg-CO2e ha-1 yr-1 which was higher than the emission from chili cultivation (7,455.5 kg-CO2e ha-1 yr-1). However, base-on the fresh commercial products’ weight, chili fruit’s emission calculation was higher than commercial green mustard ones (246.5 kg-CO2e t-1 and 107.4 kg-CO2e t-1, respectively). In the research period and estimated for the year 2022, the profit from chili cultivation (535.676 ± 101.118 million VND ha-1 yr-1) was 1.37 times higher than green mustard cultivation’s profit (392.386 ± 124.570 million VND ha-1 yr-1). In the current cultivation, to achieve a profit of 1.000 VND, green mustard cultivation must trade off 28.67 g-CO2e, which was 2.1 times higher than chili cultivation (13.92 g-CO2e).

A study on water quality and phosphate and phosphate loads of intensively cultured snakehead (Channa sp.) was conducted in Tam Nong district, Dong Thap province. Input water, pond water, and wastewater samples of snakehead ponds were collected after 45, 95, and 135 days. The results showed that the surveyed snakehead ponds' water supply parameters met the national standard QCVN:08-MT/2015/BTNMT (column A1). pH and DO of pond water and wastewater tended to decrease, while EC and TDS increased. The inorganic nitrogen and phosphorus concentrations of the snakehead ponds reduced and were lower than those in input water. However, most of them were still within the appropriate limits for the growth of snakeheads. The concentrations of NH4+-N, NO2--N, and PO43--P of wastewater were higher than those in input water (p

Fresh water is the basic life demand, but this resource is unevenly distributed lacking, and polluted in many places. Sea water is a great potential resource to produce fresh water, especially in the context of increasing drought and saline intrusion. This study performed experiments on various types of nanofiltration (NF) and reverse osmosis (RO) membranes to evaluate their desalination efficiency. Therefore, the adequate type of filter was used as a core item in a solar-powered desalination system was assessed the treatment efficiency. Finding results showed that the desalination efficiency of RO membrane was very high, approximately 99.6%. A complete desalination system was built and operated to evaluate the desalination efficiency. The quality of treated water met the threshold value of QCVN 01-1:2018/BYT, a regulation on domestic water quality. The technology could be applied widely in saline intrusion zones and areas without access to hygienic water supply sources.

This research aims to evaluate the differences in physicochemical characteristics, including pH, electrical conductivity (EC), cation exchange capacity (CEC), and carbon content of biochar from durian husk and jackfruit peel. At the same pyrolysis temperature, physicochemical properties expressed through parameters such as moisture, pH, EC, CEC, and carbon content of the two types of biochar were different. The results show that durian husk (85%) has higher moisture content than jackfruit peel (81.7%). The biochar yield obtained from durian husk and jackfruit peel was 39% and 39.7%, respectively. Biochar from durian husk (has lower pH and EC values than from jackfruit peel, 10.36 vs. 10.43 and 630 µS/cm vs. 884 µS/cm, respectively. However, durian husk-derived biochar had higher CEC value and carbon contents than jackfruit peel-derived biochar, 23.2 cmolc/kg vs 21.75 cmolc/kg and 55.3% vs 53.4%, respectively. The results implied that durian husk and jackfruit peel can beconverted into biochar which can be used for environmental treatment and soil improvement.

Cartap is one of the active ingredients of plant protection drugs allowed in Vietnam and is used quite popular in rice cultivation in the Mekong Delta. Cyprinus carpio is a common fish species culturing in rice – fish system, so they are often exposed to pesticides used for rice. This study aimed: (1) to determine the value of LC50-96 hours of Cartap on the carp, (2) to check cholinesterase activity in the carp flipped abdomen, muscle convulsion, and death after exposure to the pesticide, (3) to determine the effect of Cartap on oxygen consumption and oxygen threshold of carp. The research showed that the LC50-96 hours of the Cartap active ingredient on the carp was 1.343 ppm. The ChE rate of carp was inhibited by about 30% to contract a fish muscle, and when the cover was inhibited by about 50% to flip fish. Dead fish at lethal concentrations had low inhibition of ChE (50%), and the cause of death could be damaged gills not getting enough oxygen. Cartap hydrochloride tended to increase the respiratory rate of carp. The effects of Cartap on carp gill structure should be investigated in depth to explain why fish exposed to lethal concentrations have low rates of ChE inhibition.

The subject was done to determine pollutant load and propose solutions to reduce pollution from main waste sources. The study was conducted in Vinh Long province from June 2021 to March 2022. The study uses the rapid assessment method based on the emission factor and the pollutant load calculation method based on the flow and concentration to calculate the pollutant load for the emission sources. The research results show that domestic wastewater plays a significant role in generating BOD5 and COD loads into rivers and canals with 6,450 and 11,198 (tons/year) respectively, followed by runoff from agricultural land with 3,185 and 4,954 (tons/year). The load of T-N and T-P discharged into canals is quite high. Agricultural land contributes the most to this load, with 6,712 and 1,492 (ton/year), followed by livestock, with 45.4 and 13.9 (tons/year).

The study aimed to assess the relationship between water quality and distribution of zoobenthos at E canal, Can Tho city. The zoobenthos and water samples were collected twice (Dec 2018 and Apr 2019) at three locations on the canal. The zoobenthos quantitative and qualitative results showed that 8 species belonging to 4 families and 4 classes. The density and biomass of zoobenthos greatly vary between survey points and survey times. Based on species composition, the calculated values of H’, RBP III, and ASPT indicated the heavy pollution of a water body. From analyzed physio-chemical parameters, the water quality index VN_WQI showed that the water source at E canal reaches a medium pollution level. The VN_WQI values had a close correlation to ASPT, and RBP III values but a weak correlation to H’ values. The results showed that the ASPT, RBP III index could be used to evaluate the surface water quality for saving cost.

This research aims to analyze the impact of saline intrusion on land use/land cover (LULC) and assess the vulnerability of agricultural land in Tien Giang province in 2020. The methodology applied an Object-Based Image Analysis (OBIA) on Landsat 8 images and an unsupervised classification on MODIS images to create land use/land cover and rice crops maps in Tien Giang province in 2020. The assessment is evaluated based on 2 parameters, including overall accuracy (T) at 85.6% and Kappa coefficient at 0.79. The LULC distribution consists of seven groups: triple-rice crops, double-rice crops, single rice crop and aquaculture combination, perennial land, aquaculture, construction land, and rivers. The highest total area of rice cultivation accounts for 47.5%, and the lowest is aquaculture with 4.7%. The study estimated vulnerability based on three main components, including exposure (E), susceptibility (S), and adaptive capability (AC). The vulnerability impacts LULC in the salinity intrusion areas with the highest on triple-rice crops and perennial lands; and the lowest on aquaculture in Tien Giang province.

This study aims to analyze greenhouse gas (GHG) emissions from domestic activities, industrial activities, and post-harvest burning of straw. Three main types of emissions including Carbon dioxide (CO2), methane (CH4), and nitrous oxide (NO2) were selected for evaluating GHG which was calculated by multiplying of the fuel consumption and emission factor corresponding to each source. The total amount of GHG emissions in the study area is 3,343,145.1 tons of CO2eq/year. In which, Binh Thuy district emits the highest with 2,529,732.4 tons of CO2eq/year (accounting for 75.7% of total emissions), followed by Ninh Kieu district, which emits 589,178.8 tons of CO2eq/year (accounting for 17.6%), and Cai Rang district has the lowest emission with 224,233.9 tons of CO2eq/year (6.7%). Research outcomes provide an overview of current GHG emissions to support environmental management, and land use plan orientation in the future.

The study was conducted on intensive algae tanks to determine the possibility of using domestic wastewater to produce Spirulina sp. biomass, and evaluate the efficiency of domestic wastewater treatment. Experiments were implemented at a laboratory scale on two models of intensive algae tanks added with HCO3- and without HCO3-. The results showed that at the hydraulic retention time of 1.5 days, loaded water of 2,000 m3.ha-1.day-1 and loaded organic matter of 343 kg.ha-1.day-1; the algae tank added HCO3- had higher biomass than the algae tank without added HCO3- (258 and 178 kg.ha-1.day-1) and there was a significant difference. Regarding treatment efficiency, outflow wastewater from two intensive algae tanks reached column A of both QCVN 14:2008/BTNMT and QCVN 40:2011/ BTNMT, and there was no significant difference between the two models.

In the design of urban drainage systems, the water level in the sewer and the degree of flooding in the drainage area depend on the rainfall in the region and the water level at the outlet. In the case of urban areas situated in lowland regions and influenced by tides, like Ho Chi Minh City (HCMC), the boundary conditions of rainfall and water level at the drainage are considered as random variables.The calculation and design of the surface drainage system and the design of the ground elevation require determining the combinations of rainfall-water level (I-H) at repeated cycles. From there, using compound pairs (I-H) as boundary conditions, not just determining the amount of precipitation at repeated cycles as before.  The purpose of this paper is to introduce the method and results of constructing repeating co-periodic curves of the combination of precipitation-water level (I-H) for design and application cycles in HCMC. Using these curves, the calculation and design of the surface water drainage system as well as the design of the foundation elevation of Ho Chi Minh City will ensure compliance with the National Technical Regulations on the cycle of sewer overflow as well as flooding.

This study aimed to investigate the potential of co-digestion of food waste (FW) and water hyacinth (WH) to improve biogas yield compared to only digestion of FW. Semi-continuous anaerobic incubation with different ratios of FW and WH was conducted. The results showed that the daily produced biogas and biogas yield were higher with increasing mixed WH ratios. Specifically, the volumes of daily produced biogas were 0.37±0.03L/day, 0.51±0.03L/day, 1.03±0.03L/day, 1.31±0.04L/day, and 1.71±0.08L/day for the treatments of 100%FW, 75%FW+25%WH, 50%FW+ 50%WH, 25%FW+75%WH, and 100%WH, respectively, while the biogas yields were 1.08±0.10L/(kgTS×day), 1.50±0.10L/(kgTS×day),3.01±0.09L/(kgTS×day),3.81±0.11L/(kgTS×day), 5.01±0.24L/(kgTS×day) for the same treatments. The percentage concentration of CH4 was also lowest for the 100%FW treatment (28.25 ± 17.48%) compared to the 75%FW+25%WH treatment (30.25 ± 18.62%), the 50%FW+ 50%WH treatment (33.25 ± 17.59%), the 25%FW+75%WH treatment (40.15 ± 19.19%), and the 100%FW treatment (44.51 ± 18.71%). These results suggest that co-digestion of FW with WH has the potential to significantly increase biogas yield, providing a promising solution for the treatment of food waste by the biogas production method.

This study aimed to assess the potential use of Jmat as a carrier in aerobic submerged biofilter systems for domestic wastewater treatment. The triplicated experimental models were designed with a media height of 0.9 m and completely submerged in feeding wastewater. The filter columns were fed with wastewater by using a peristaltic pump with 2 loading rates of 2 m3/m2.day and 4 m3/m2.day, respectively. The results showed that the concentration of pollutants in treated wastewater met the technical regulation QCVN 14:2008/BTNMT (column A). Using Jmat as biofilter media in aerobic submerged biofiltration provides high pollutant removal rates. The removal efficiencies for SS are 95.8%, COD: 92.5%, BOD5: 93.5%, TKN: 94.0%. The effluent concentration of NO3- is higher than the influent, indicating that the nitrification process was taking place. When doubling the loading load, the performance of removing substances decreases, but the targets SS, PO43-, COD, BOD5, TKN still meet the technical regulation QCVN 14-MT:2008/BTNMT (type A). This research shows that Jmat can be used as a carrier in biological filtration systems to treat domestic wastewater.

This study evaluated the treatment performance of three types of buffer materials in a biofilter system to control odor-causing gases. The anaerobic decomposition of protein-rich organic compounds from fish raw materials and organic waste produces odors. The biofilter adsorbs odorous gases onto a biofilm and is biodegraded by microorganisms into simpler, less toxic compounds. Odor removal efficiency results in about 91-98% for ammonia gas (NH3), from 85% to 95% for hydrogen sulfide (H2S), from 78% to 100% for carbon monoxide (CO), and about 80% for carbon dioxide (CO2) gas. Compost buffer materials with coconut fiber particles have a slower adsorption time to saturation after 45 minutes than compost and compost with activated carbon after 35 minutes, respectively. Biofilter system can handle a wide spectrum of odor-causing gases and is environmentally friendly.

Daxanh pomelo (Citrus maxima Burm. Merr.) is a special fruit product with high economic value, and the cultivated area keeps increasing. Therefore, agricultural inputs were supplied to the cultivation through agricultural activities to achieve fruit productivity. The inputs production depends on natural resources exploitation and greenhouse gases (GHGs) emissions into the atmosphere. The life cycle assessment methodology was used to estimate emitted GHGs through agricultural inputs provided for 55 conventional Daxanh pomelo orchards, and 55 orchards applied the Vietnam Good Agricultural Practices (VietGAP) standards. The results showed that conventional Daxanh pomelo orchards emitted 3,996.1 ± 888.5 kg-CO2e ha–1, higher than VietGAP Daxanh pomelo orchards (2,688.7 ± 994.7 kg-CO2e ha–1). Although, the applied VietGAP standards cultivation will cause lower productivity than conventional practice. However, based on the fresh fruit weight, VietGAP Daxanh pomelo fruit achieves a better value than conventional Daxanh pomelo fruit (174.1 ± 57.8 and 253.8 ± 58.7 kg-CO2e ton–1, respectively).

The study on water quality in the intensive giant freshwater prawn (Macrobrachium rosenbergii) farming in Cao Lanh district, Dong Thap province was carried out in three prawn ponds. Supply water, pond water, and wastewater samples were collected 1 time a month from the stock (4 months). The results showed that the quality of the water supply and pond water were suitable for giant freshwater prawn growth. EC, TDS of pond water, and wastewater tended to increase, while DO concentration decreased compared to input water, especially after the third and fourth months. Inorganic nitrogen and phosphorus concentrations in supply water met A1 column of QCVN 08-MT:2015/BTNMT, the concentrations of these parameters increased in pond water and were highest in wastewater. The concentration of N-NH4+, N-NO2- and P-PO43- of wastewater from prawn farming exceeded QCVN 08-MT: 2015/BTNMT than QCVN 08-MT:2015/BTNMT. The inorganic nitrogen and phosphorus loads of the wastewater are 14,712 g/1000 m2 and 13,263 g/1000 m2, respectively. It is necessary to monitor and control the temperature and pH of the pond water in the last cultivation, especially in the dry season, and treat NO2-, PO43- in wastewater before being discharged into the environment.

This article aims to determine the factors affecting the results of the agricultural land use plan (ALUP) implementation of Phong Dien district, Can Tho city, which is based on proposing solutions to improve the efficiency of ALUP implementation. The data about ALUP, statistics and land inventory were collected in 2016-2021. A participatory rural appraisal was carried out to identify the factors affecting the results of ALUP implementation by SWOT tools. Then, 20 experts were consulted to determine the level of influence of the multi-criteria evaluation method. The results showed that in 2016-2021, the results of ALUP implementation did not meet to many land use plan targets. Thereby, three main factors and 14 sub-factors affecting ALUP implementation were identified. The factors of farming practices, conversion costs, and the weakness of the consulting unit were the factors that affected greatly. Since then, the research has proposed 12 solutions to improve efficiency for the ALUP implementation in the future. In which, priority was given to implementing solutions on changing mindsets on farming practices, policies to support change, and specific mechanism building for the district.

The study was conducted to contribute to the improvement of land use and management in ethnic minority villages. The study used research methods such as collecting secondary information, consulting experts, processing, analyzing, synthesizing data, using the comparison method, and using the map and norm method. Research results showed that Krong Pa district currently has 81 ethnic minority villages and hamlets, using 43.481,28 hectares of land, accounting for 26,78% of the district's area. The land of 13 ethnic minority villages was being studied on 7.198,23 hectares, of which agricultural land was 6.112,58 hectares, accounting for 84,92%. However, there were still some shortcomings: The land has not been measured and marked, the land has not been registered, and the issuance of land use rights certificates still faces many difficulties. Land transfer through land use righted certificates; the situation of people being propagated and disseminated about the law on land is still too low (18.76%). The proposed solutions to improve the efficiency and management of land use in ethnic minority villages include land use and land management solutions.

Active ingredient Fenobucarb in Excel Basa 50EC is one of the active ingredients in pesticides widely used in the Mekong Delta. Studying the effects of Excel Basa 50EC   on silver barb fish in fingerlings to (1) determine the LC50–96h of Excel Basa 50EC  in fingerling silver barb, (2) determine the ChE threshold in fish exhibiting abnormal behavior when exposed to Excel Basa 50EC, (3) effect of Excel Basa 50EC to the oxygen threshold and oxygen consumption in fish. The results showed that the LC50–96h value of Excel Basa 50EC for silver barb was 25.248 ppm (#12.714 ppm fenobucarb), the medium toxic. ChE in fish with abnormal swimming, belly flipping, and death when exposed to Excel Basa 50EC had inhibition rates of 83.55, 84.45, and 89.47%, respectively, which decreased compared with control. When silver barb was exposed to Excel Basa 50EC  at lethal concentrations, the threshold for oxygen and oxygen consumption increased and was higher than that in the control treatment. Further study on the effects of drugs on the gill histology of silver barb is needed further to explain the effects of drugs on fish respiration.

Wastewater from the preliminary fried chicken after pre-treatment with ozone still contains a large amount of nitrogen and phosphorus that needs to be treated. Research on using common reed (Phragmites australis) planted in horizontal subsurface flow constructed wetland system to absorb nitrogen and phosphorus in this wastewater. The experiment was arranged with 01 experimental treatment and 01 control treatment (each experiment had a repeatability of 03 times). Each experiment was built with concrete bricks with dimensions of length x width x height of 8 m x 0.4 m x 0.5 m, loaded with 330 liters of wastewater with a retention time of 03 days. At the end of the experiment, the common reed grew and developed well, the average height of the reed is 166cm/tree, the average fresh weight and dry weight (dw) are 83 and 23 g/plant, respectively. Nitrogen content in Common reed stems and roots reached 0.611±0.014%dw and 0.333±0.009%dw respectively. Phosphate content in Common reed stems, and roots reached 0.096±0.004%dw and 0.088±0.005%dw. Common reed helps to absorb 11.22% nitrogen and 8.88% phosphorus in input wastewater. After being treated with wetland, wastewater meets the discharge standard of column B – QCVN 40:2011/BTNMT.

The study aimed to find the optimum operating parameters of the lab-scale electro-coagulation unit to pre-treat printing wastewater. The results have recorded the optimal operational parameters, including an electrode angle of 45o, a current density of 240 A/m2, an electrode distance of 1 cm, a hydraulic retention time of 30 minutes, and electric voltage of 12 V. The initial wastewater had the color of 1363 PCU, pH = 6.27, SS = 3187 mg/L, BOD5 = 1275 mg/L, TKN = 35.16 mg/L, TP = 8.73 mg/L, Zn = 5.4 mg/L and Cu = 0.8 mg/L; after treated by the electro-coagulation unit, the wastewater had recorded the color of 50 PCU, pH = 7.33, SS = 149.72 mg/L, BOD5 = 64 mg/L, TKN = 3.42 mg/L, TP = 0.58 mg/L and not recorded any metal residues. The treated wastewater met the QCVN 40:2011/BTNMT (column A) at most monitoring parameters except SS and BOD5. This result showed that electro-coagulation could be applied to pre-treat the printing wastewater.

The study was conducted to map the current land use in Thap Muoi district, Dong Thap province by remote sensing approach. In addition, results were compared to land use maps achieved from the traditional approach to propose the solution to improve the efficiency of land inventory, mapping the current land use in the future in the study area. Specifically, the study used Sentinel-2 imagery achieved on 01/01/2020 to map the current land use throughout the object based classification method, with the joint contribution of Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI). The accuracy of the classified land use map, including 06 classes, was evaluated using 470 ground truth points, the overall accuracy and Kappa were 92.8% and 0.86 respectively. The result showed that applying remote sensing images in determining the difference between the current land use status and the cadastral records is highly effective. Based on consulting experts, who directly carry out the land inventory in the study area, the process of conducting the land inventory and mapping the current land use was proposed by integrating traditional and remote sensing approaches to improve the efficiency of information technology application in land management at the district level.