Abstract: Urban agriculture is a highly concerned issue during the period of rapid urbanization in Vietnam. Research aims to propose a cultivation process for cultivating oyster mushrooms, utilizing coffee grounds from coffee businesses as a resource. This approach promotes circular economy principles, generating economic benefits for households while protecting the environment and being suitable for urban areas. The study conducted experiments on grey oyster mushrooms using different mixtures of coffee grounds and rubber wood sawdust at the following ratios: 0%, 25%, 50%, 75%, and 100% coffee grounds/rubber wood sawdust, filled into bags with a weight of 1.2kg. The research results showed that disease infection rates were mild in the 0% and 25% mixture ratios, while the remaining ratios exhibited moderate to severe infection levels. The highest mushroom yield was observed in the mixture ratio of 25% coffee grounds, with an average number of mushroom ears per bag reaching 29.7grams/bag, the dry weight is 63.8 grams/bag, with an average size ranging from 3 to 14 cm and a moisture content of 79.5%. The fastest colonization speed on the substrate is achieved by 25%, 50% coffee grounds blend, which fully colonizes the bag in a period of 25 to 35 days, the shortest time compared to the 75% and 100% coffee grounds blends, which take 40 to 45 days. The experimental results show that the 25% coffee grounds: 75% rubber sawdust blend is suitable for urban mushroom cultivation models and can be expanded on a large-scale farm, contributing to minimizing environmental pollution, utilizing limited urban land area, and providing high economic efficiency.

subjects in many countries and the treatment of breeding waste has to be taken as a priority. Nowadays, biogas technology sets up and operates primarily to treat breeding waste. However, this technology formed a considerable amount of wastewater the effluent quality is still poor and the concentration of pollutants is higher than the required national technical regulation (QCVN 40:2021/BTNMT). Thus, the project aimed to find out an appropriate procedure to reduce environmental pollution from breeding wastewater of the biogas system which then can be applied in the constructed wetlands system. Two units of Horizontal Flow Constructed Wetland (HFCW) and Vertical Flow Constructed Wetland (VFCW) were located and set up in two treatments with three replications. Both of these units were planted with Cyperus involucratus. Wastewater was fed into the wetland units at a mean flow rate of 312 ml/day. Major parameters including COD, BOD5, SS, N-NH3; P-PO43- were measured. The results indicated that vertically Flow Constructed Wetlands exhibited a higher treatment efficiency than horizontally Flow Constructed Wetlands with the average removal efficiency for COD, BOD, SS, N-NH3, and P-PO43- were 55.2 %, 75.3 %, 82.3 %, 75.9 %, and 70.1 %, respectively. Generally, the study demonstrated that the constructed wetlands can be used as an option for improving the quality of biogas wastewater.

The issue of marine pollution in general, as well as pollution brought on by oil spills into the sea, in rivers and lakes, or wastewater from factories, businesses, mechanical repair shops, gas stations, universities, and auto repair shops, is one that the world is currently facing, particularly since when it does, it invariably results in harm to the environment and people. Oil spills result in oil plaques on the ground, in rock crevices, washed up on the coast, a foul smell, a loss of tourism beauty, harm to the ocean's ecosystem, and even equipment damage. equipment, supplies, water transportation, etc. We had to use very expensive oil spill blotting papers at the time. The amount of hair that individuals discard each day is not little, and even when it is burned, it emits unpleasant scents and polluting gases that are harmful to human health. Furthermore, it is very easy to make a hair mat at vehicle wash facilities, school restaurants with big parking lots, and car repair shops. To prevent the majority of the oil from being spilled into the environment, handmade oil-absorbing carpets made of hair materials are laid over the drains in these locations.

Vietnam's economy is operated to serve more than ninety million people so this is a very vivid picture. The large population brings many advantages to the food production sector in general and the production of fresh noodles in particular. Fresh vermicelli is the raw material for processing many dishes of the Vietnamese people for a long time, that's why there are many Vietnamese dishes with indispensable ingredients, which as Noodles in the national culinary books. Vietnam. The production of fresh vermicelli with the main ingredient is fermented and shaped rice with simple steps, but hidden inside there are environmental issues that need to be considered. The production and business associated with environmental protection are the responsibility of most enterprises and production facilities in Vietnam. The fresh noodle food production industry is no exception. Instead of learning about the aspects that affect the environment in the traditional way of collecting information, analyzing, and evaluating the current situation, this time the research team looked at understanding the causes of environmental pollution in terms of consumption. ISO 14001 international standard. ISO 14001 Environmental Management System is an international standard that helps businesses and establishments identify the important role of the environment as well as the risks brought by the environment, thereby realizing the environment as an activity of the Organization. In this standard, the commitment to prevent environmental pollution is a mandatory condition, so determining the environmental aspects to overcome the impacts is a key element of the standard. If a business achieves ISO 14001 Certification, it will have a very good effect in promoting the corporate image of being responsible for the environment and the community. (Lê Huy Bá, 2006), (Lê Thị Hồng Trân, 2008)

Heavy metals are the most dangerous substances in the environment, have caused deleterious effect not only to the environment but also to the public’s health. Different studies have demonstrated that plants have a high removal capacity for lead ions from pollution sources. However, these plant species were rather limited. Thus, the project aimed to find out plant species that represent its lead removal ability to reduce environmental pollution. The experiment was carried out factorially as a randomized complete design in hydroponic systems with four treatments (0, 100, 200, and 300 mg/l of Pb) and three replications. The results indicated that the growth of the Dracaena sanderiana plant is well in Pb concentration of 100 mg/l, with less growth while the increasing lead concentration of 200 mg/l and 300 mg/l. The amount of lead in the water of three treatments 100 mg/l, 200 mg/l, and 300 mg/l after 30 days of the experiment decreased by 91.5%, 86.8%, and 86.4%, respectively. It was found that Dracaena sanderiana exhibited high lead treatment efficiency in the water. Moreover, results showed that the accumulation of lead in the roots of Dracaena sanderiana is quite large with treatments of 100 mg/l, 200 mg/l, and 300 mg/l lead concentrations were 5073.8 mg/kg, 5134.0 mg/kg, 7054.0 mg/kg, respectively. In contrast, the ability to lead accumulation in plant leaves and stems is lower. cultivated in hydroponic systems with four treatments and three replications. Four levels of Pb(NO3)2 (0, 100, 200, and 300 ppm) were used. The monitoring indicators include the contents of lead in water, the growth target of Dracaena sanderiana, and the accumulation of lead contents in different organs of Dracaena sanderiana. The results indicated that: the growth of the Dracaena sanderiana plant is well in Pb concentration of 100 ppm, with less growth while the increasing lead concentration of 200 ppm and 300 ppm. The amount of lead in the water of three treatments 100 ppm, 200 ppm, and 300 ppm after 30 days of the experiment decreased by 91.5%, 86.8%, and 86.4%, respectively. It was found that Dracaena sanderiana exhibited high lead treatment efficiency in the water. Moreover, results show that the accumulation of lead in the roots of Dracaena sanderiana is quite large with treatments of 100 ppm, 200 ppm, and 300 ppm lead concentrations were 5073.8 mg/kg, 5134.0 mg/kg, 7054.0 mg/kg, respectively. In contrast, the ability to lead accumulation in plant leaves and stems is much lower.

Through analysis of the DPSIR model, combined with research methods such as field surveys, and survey questionnaires, the author has given the following results: The amount of waste is increasing; Not paying attention to the classification at source, Solid waste collection is still limited; Environmental quality is degraded due to the stench caused by domestic waste in some neighborhoods; The soil environment is polluted due to solid waste treatment that is difficult to decompose; Surface water and groundwater are also leaked due to leachate, wastewater from landfills; The polluted environment has, directly and indirectly, affected the health and production and business activities of the people in the ward, degraded the ecosystem, and lost the urban beauty. The author has proposed solutions to reduce environmental pollution caused by domestic waste such as population policy, establishing collection groups, craft village planning, and applying the circular green model in economic development.

Bien Hoa City is an urban area of Dong Nai province located in the Southern key economic region. Currently, Bien Hoa City has 6 industrial parks in operation with large daily wastewater flow, causing environmental risks, especially from organic pollutants. The study applied the Nemerow risk index and the geographic information systems (GIS). The results showed that the industrial parks were mainly organic pollution levels including N-total, P-total, and Ammonium. The level of environmental risk from organic pollution was recorded in range of medium to very high levels, the ranked in descending order: Agtex Long Binh Industrial Park (P = 24)> Amata Industrial Park (P = 16)> Bien Hoa 2 Industrial Park ( P = 10),> Tam Phuoc Industrial Park (P = 5)> Loteco Industrial Park (P = 3). The results of the study provided good information for the management and improvement of wastewater quality in the industrial wastewater treatment plants of the industrial parks in Bien Hoa City.