Analyze and Evaluate the Relationship Between City Ctr Management and Treatment Plant Production.

Can handle large fluctuations between the rainy and dry seasons, accompanied by different characteristics of input wastewater. For each certain type of wastewater, the treatment steps and sequence of treatment steps can be flexibly changed accordingly.

The proposed treatment line below is used to treat urban waste leachate.

diagram 3.5 - leachate treatment process - preliminary treatment: leachate from the landfill is 1

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Diagram 3.5 - Leachate treatment process

- Preliminary treatment: Leachate from the landfill is collected into the waste reservoir. At the garbage reservoir, there is a suspended aeration system to regulate the dosage and concentration of leachate. In addition, the leachate reservoir is also biodegradable. Leachate from the reservoir is pumped to a trash separator to remove trash larger than 2mm in size and flows into a lime mixing tank equipped with a lime stirrer system (or

aeration system).

The mixed lime tank is supplied with intermittently aerated lime to avoid lime sedimentation and increase the effectiveness of raising pH. The tank has the role of removing some heavy metal ions in leachate and decolorizing the leachate.

Wastewater after the mixing tank continues to be led into the equalization tank. In the conditioning tank, a mixer is arranged to increase mixing ability and at the same time reduce odors arising from the anaerobic process. Wastewater from the equalization tank is pumped to the lime settling tank to separate lime residue before entering the next stage.

The wastewater flow is automatically measured, the received signal will then be transmitted to the PLC - SCADA control system to then control the wastewater pump to easily operate at the required flow.

- Calcium treatment tank: Calcium reduction + physical and chemical pretreatment

Wastewater after lime deposition is led into the pump pit. Wastewater is continued to be passed through the Calcium treatment tank to remove Ca2+ ions before entering the biological treatment stage. Here, wastewater is mixed with a chemical on the pipe, the precipitated Ca2+ will settle in the sedimentation compartment, the water will overflow through the collection trough to the biological treatment tank.

On the wastewater pipeline to the Calcium treatment tank, there is an additional chemical filling system (FeCl3, H2SO4, polymer). At this time, the Calcium tank acts as a physicochemical pretreatment tank (flocculation - flocculation - sedimentation) to increase stable conditions and increase treatment efficiency for the biological treatment system.

Leachate after physicochemical pretreatment has a low pH value, so the pipeline leading to the UASB tank is filled with NaOH solution to raise the pH = 7 - 7.5, which is a favorable condition for biological treatment.

- Biological treatment: Biological treatment is the integrated working process of many treatment tanks. The process is based on the activity, life and growth of microorganisms to assimilate organic substances in wastewater, turning organic substances into gases and cell shells of microorganisms to remove from water.

UASB reactor

It is a type of anaerobic reactor. They use the activated sludge method for anaerobic treatment of wastewater with the influent flowing backward from the bottom up.

Rare gas reactor

Used to settle and decompose sediments using natural biochemical methods based on the life and activity of anaerobic microorganisms. The combined work of the UASB tank and the rare gas tank is to remove nitrogen, phosphorus and reduce BOD5 and COD index.

Aerobic reaction tank (Aeroten tank).

Aerobic tanks are very effective for organic carbon removal. Adding Bioerg is to stabilize bacterial density and increase the efficiency of the biochemical treatment process. A gas distribution system with a fine-grained gas distribution disc is installed to agitate the mixed liquid sludge solution and provide adequate oxygen for the biochemical reaction in the aerobic tank. Oxygen is provided by an air blower.

- Physical and chemical treatment: Wastewater after biological treatment will be pumped to a physical and chemical treatment tank to remove suspended residues in the leachate and a color element. The flow of wastewater pumped to the physical and chemical treatment tank is automatically controlled by a flow measuring device installed on the pipeline. The physicochemical treatment tank consists of 3 compartments that act as flocculation tanks, FeCl3 and H2SO4 alum solutions are poured into this compartment. The flocculating compartment is supplemented with polymer to bind the flocs together to form flocs that are larger in size and easier to settle before flowing to the third compartment, the settling compartment. The process of flocculation and flocculation with Fe2+ alum takes place at pH=3-3.5.

- Water filtration and disinfection: Filter tank with a layer of quartz sand filter material has the function of removing remaining residue after the secondary sedimentation tank.

After passing through the filter tank, the waste water is directed to the disinfection tank. In the first compartment of the disinfection tank, a metering pump will supply a chemical solution to disinfect the wastewater to meet the required standards and flow into the ecological lake.

- Sludge treatment: During the wastewater treatment process, suspended substances, organic, inorganic, and dissolved organic colloids are transformed into sludge and separated from the wastewater. Sludge will be stabilized and concentrated to reduce weight and volume. The thickened sludge is transferred to the sludge tank using a sludge pump. At the sludge tank, the sludge will be transferred to a water separator to minimize the amount of water remaining in the concentrated sludge or transferred to the sludge truck by a sludge pump. After that, the sludge is safely brought to the receiving place and no longer has toxic effects on the environment .

- Odor and exhaust gas treatment technology: High-speed aerobic biological composting technology, during the process of decomposing H 2 O and CO 2 , CO 2 gas does not produce bad odors like anaerobic composting technology and composting as other countries are doing today. However, Co 2 gas according to the Kyoto Protocol is a gas prohibited from being released into the environment, increasing its concentration (GHG).

According to some experiments in the United States, on average, 1 kg of waste produces 6mol/l of Co 2 gas (about 276mg), so with a factory capacity of 180,00 tons/year, organic waste can be classified (90,000 tons). x [12+(17x2) ] = 46 x 6mol/l) about 24,840 tons of CO 2 , according to the Kyoto Protocol, if 01 ton of CO 2 gas into the environment is reduced, the emission standard price will be 14 USD.

The waste treatment process using aerobic biotechnology in the automated Bioreactor system, according to Patel of High Technology Transfer Joint Stock Company, is capable of recovering 100% of CO 2 gas, using these solutions . Useful as CO 2 recovery combined with lime (CaO) to create CaCO 3 light powder as raw material for many chemical industries.

(3) Capacity and development orientation of the factory:

Through the interview process, the representative of Eastern Waste Treatment Joint Stock Company (Comrade Phong) learned:

- When the plant comes into operation, the average solid waste treatment capacity is 150 tons/shift/day including two equipment lines. During peak days, the factory can run at maximum capacity of 300 tons/day.

- Expanded capacity: Phase 2 of the factory will install an additional equipment transmission system to increase the factory capacity to 300 tons/shift/day. With 3 equipment transmission systems, the maximum capacity of the factory can reach 500 tons/day (02 shifts)

.In the future, it is possible to expand to 4 equipment lines, increasing capacity to 500 tons/day - 1,000 tons/day. The fact that the equipment line is structured into modules will help the factory have unlimited expansion if land needs are met.

+ Average waste treatment plant capacity 150 tons x 360 days = 54,000 tons/year

+ Production of high-quality organic microbial compost = 6,500 tons/year

+ Collect Co2 gas, produce CaCo3 light powder = 300 tons/year

+ Recycling scrap, creating nylon granules = 540 tons/year

+ Recovery and recycling of inorganic scrap into construction bricks = 10,000 m 3 /year

+ Hazardous waste and other medical waste > 720 tons/year

+ The proportion of non-recyclable waste that must be buried is about < 10%

(4) Labor use plan:

- When the factory goes into production, it will create regular jobs for over 150 workers. It is expected that the factory will also have the ability to double overtime once production has stabilized, thus the number of workers will increase. 250 people.

- Labor use plan: Management staff: 20 people Technical staff: 20 people Unskilled workers: 110 people

- Employing workers in Management departments: 20 people

Waste treatment and high-quality organic microbial compost production department: 50 people Scrap recycling and nylon granulation department: 20 people

Department of recovery and recycling of inorganic scrap into construction bricks: 20 people Other departments: 20 people

3.6. Analyze and evaluate the relationship between the City's solid waste management and the treatment plant's production.

The solid waste treatment plant at km 26, village 5, Quang Nghia commune uses high-speed aerobic biotechnology in an automatic, closed equipment system to produce high-quality organic biofertilizers and supplies. Designed waste capacity is 150 tons/shift/day. During peak days, the plant can run at maximum capacity of 300 tons/day.

Regarding the current status of collection and treatment of domestic solid waste in the city, generating about 82 tons/day, it is expected that in June 2014 the plant will be completed and put into operation, so domestic solid waste in Mong Cai will meet the demand. meets 54.7% of the supply according to the factory's design.

In addition, when the factory comes into operation, it will also be a favorable condition to treat solid waste at Hai Hoa area 6 landfill (closed in 2007). Because according to the general planning, Bac Luan II bridge (border bridge) will pass through this location, currently the Bac Luan II bridge project is in the process of site clearance compensation and is expected to start construction in 2014. Relocating the landfill to km26 for treatment will fully meet the treatment needs according to the plant's design.

According to forecasts, the total solid waste generated in Mong Cai city in 2020 is 163.8 tons/day. If considered based on the city's administrative boundaries, by 2030 phase I of the plant will still be enough to meet treatment needs without needing to increase capacity. However, according to the goal of the solid waste treatment plant at km26 Quang Nghia, in addition to meeting the solid waste treatment needs of Mong Cai city, it also meets the solid waste treatment needs of Hai Ha District,

With the specific weather and climate conditions, the city's development characteristics are trade and services, so the waste composition of Mong Cai city is typical, organic matter contained in domestic solid waste accounts for 60% of total waste. .7%, so choosing this technology, in addition to saving landfill space, the technology cost is not as expensive as other treatment technologies, also provides an abundant supply of organic fertilizer.

- Waste treatment technology by high-speed aerobic fermentation is an advanced technology that can classify multi-component, high-humidity, unsorted household waste from the source. decomposing organic waste into high-quality microbial organic fertilizer, in a closed process equipment system, within 13-15 days (in advanced countries composting takes 49-60 days). This technology also allows 100/% recovery of Co2 gas to combine with CaO to form CaCO3 light powder and completely reduce greenhouse gas emissions.

The special advantage of biotechnological treatment with thermophilic and thermophilic aerobic microorganisms is the conversion of organic matter into organic fertilizer, carbon dioxide (Co2) and water (H20). ), does not produce CH4 and H2S gas, so it does not cause fire or explosion, and does not have a foul smell that pollutes the environment. Bioreactor equipment system, controls and regulates temperature, humidity, oxygen... during operation, in a closed process is supplemented with heat-resistant and thermophilic microorganisms up to 80 degrees Celsius, so Pathogenic microorganisms are completely destroyed, compounds containing chlorine and heavy metals are transformed and are no longer toxic to the flora, so patted organic fertilizers completely meet the needs of the flora. demand for agricultural production.

The technology for treating household waste by high-speed aerobic fermentation is considered suitable for waste treatment in Vietnam. It can be designed and manufactured domestically, reducing costs by 50-60% compared to with foreign technology and equipment. Because machines and equipment have simple structures, large weight, and slow speed, domestic industries use many similar machines, so Vietnam's mechanical engineering industry produces products easily and without hassle. Passive actions such as importing foreign equipment and technology. In addition, workers do not operate directly with organic waste during the decomposition process, so labor safety is very high; Wastewater from the process of decomposing organic waste is treated with biological technology, filtered and reused, without being discharged into the environment causing pollution.

From the above assessments compared with the actual situation of the nature of solid waste as well as the status of collection, classification, treatment and special use needs related to the City's environmental issues, it shows that the technology selection

The treatment chosen by Mien Dong Waste Treatment Joint Stock Company is suitable for the specific solid waste generated in Mong Cai city.

- About the factory location: The land for the project is located at km26, village 5, Quang Nghia commune, Mong Cai city, on national highway 18A. Located between Hai Ha district and Mong Cai city, about 30 km from the city. The planned land area is located entirely within the administrative boundaries of Quang Nghia commune.

The scope of the investment land to build the factory is 22 hectares, which is a hilly area with uneven terrain, the trees are mainly pine trees, and the research land has almost no people living. The boundaries of the project area, measured, drawn and planned, are adjacent to:

The South borders National Highway 18A. The North borders tree hills

The East borders on tree hills. The West borders on tree hills.

The current planned land is a complex hilly area. Infrastructure systems such as transportation, surface, water supply, and drainage currently do not exist.

Therefore, investing in building a solid waste treatment plant at the above location ensures the standard distance as prescribed in Joint Circular No. 01/2011/TTLT-BKHCNMT-BXD dated January 18, 2011 of the Ministry. Science, Technology and Environment - Ministry of Construction on guidance on environmental protection regulations for selecting construction locations and operating solid waste landfills.

3.7. Propose measures to improve solid waste management to contribute to effective treatment of the factory.

3.7.1. Improve institutions and policies and enhance the effectiveness of supervision and enforcement:

Review the system of policies and laws in environmental management, thereby proposing additions and improvements to the system of environmental policies and laws.

- Overall assessment and lessons learned in implementing strategies and planning for solid waste management in the spirit of Resolutions, directives, and Decision No. 4252/QD-UBND dated December 25, 2009 of the Provincial People's Committee. approval of waste management planning

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