The management, collection and treatment of domestic solid waste in rural areas are of great significance to reduce its amount generated to the environment. The study has determined that the total amount of rural domestic solid waste generated in Nam Dinh province is 660 tons/day with the average amount of 0.31 ÷ 0.35 kg/person/day and the collection rate is 87 % (about 575 tons/day). The amount of organic in the solid waste is about 60% of total solid waste. Currently, the solid waste is not separated at the source. Specifically, 47 % solid waste (about 112,968 tons/year) is treated by landfilling. Besides that, 43 % solid waste in this province is burned in the incinerator. In the areas where the collection conditions face difficulties, local people self-treat domestic solid waste at home by burning, burying, or composting it, which accounts for 10.0 % of the total amount. In this province, one of the well – known private companies, Tan Thien Phu has manufactured incinerators with the LOSHIHO brand having capacity up to 1,000 tons/day. Combustion method can be used at the sanitation landfill to reduce the volume of wastes brought to burial sites and limit the environmental pollution. Therefore, to achieve sustainable development in this province, it is necessary to improve solid waste management with solutions relating to the separation, collection, storage and treatment of domestic solid waste.

Porous MnO2 with a hexagonal crystalline structure was facilely prepared at a low hydrothermal temperature of 90°C, without using any template or capping agent. The as-prepared MnO2 only presented an exceptional electrocatalytic ability by the typical amperometric detection of copper (II) in the presence of super P carbon black as  conducting agent, and Nafion as binder. In the present work, to evaluate the detection ability of copper (II) of the MnO2, the graphite plate electrodes (GPE) were modified with MnO2 microflowers and super P carbon and used as electrochemical electrodes for the determanation of copper (II) present in water sources. From the measured results, the fabricated electrodes with excellent copper detection and rapid response demonstrated has high application potential for electrochemical sensors in detection of copper in water resources.

Heavy metals recovery from Printed Circuit Boards industrial wastewater is crucial because of its cost effectiveness and environmental friendliness. In this study, a copper recovery route combining the sequential processes of acid leaching and LIX 984N extracting with an electrowinning technique from Printed Circuit Boards production's sludge was performed. The used residual sludge was originated from Hanoi Urban Environment One Member Limited Company (URENCO). The extracted solution from the printed circuit boards waste sludge containing a high copper concentration of 19.2 g/L and a small amount of iron (0.575 ppm) was used as electrolyte for the subsequent electrolysis process. By using a simulation model for multi-step current electrolysis, the reasonable current densities for an electrolysis time interval of 30 minutes were determined, to optimize the specific consumption energy for the copper recovery. The mathematical simulation model was built to calculate the important parameters of this process.

Climate change has been affecting the socio-economic life of Quang Ninh province in general, and the coal mining activities of many companies, including Ha Tu Coal Joint Stock Company in particular. By the methods of collection, synthesis, statistics, field survey, and public consultation, this study has evaluated the climate condition of the study region and the impact of climate change on the coal mines in the past. The environmental incident of landslides caused by heavy rain in 2015 has filled rivers and streams and destroyed infrastructure. According to the scenario of climate change for Quang Ninh province by 2100 (B2), the regional temperature will increase by 2.50C, and the rainfall will increase by 7.3% compared to the period 1980÷1999. The study predicted the potential impacts of climate change on mining operations in the future such as the increased risk of landslides, floods, geological hazards, the drawdown of groundwater levels, and subsidence of the ground surface at the mining site. By the forecast results, the larger the mining depth is, the higher the radius affected by the lowering of the groundwater level will become, which can be up to 2.4 km compared to the mining area. In addition, the increase in temperature will be one of the factors that cause difficulties for production activities, affect the health of workers, slow down the process of reclamation and restoration of the mine environment, and increase electricity and water costs, etc. The study also proposed several technical and management solutions to reduce the risk and respond to environmental incidents before the impact of climate change on the Ha Tu coal mine towards sustainable development.