Visit Dongguan Haixinsha Resource Recycling Base to consolidate the green background for "Made in the Bay Area"

Source: Economic Daily

"Do you know how much garbage is in the pit in front of you?" Nearly 15,000 tons! Do you smell anything? "At the Public Environmental Protection Open Day, at the Haixinsha Resource Recycling Base on a small island in Jiangxin, Mayong Town, Dongguan City, Guangdong Province, teacher Doudou, a missionary, asked questions to the primary school students who came to explore. This "garbage island" that deals with massive amounts of domestic garbage, kitchen waste and industrial solid waste every day, the water is clear and green, the birds are singing, and the children are playing in the garden-style factory area...

Land of 716 acres, investment of more than 5 billion yuan, the small desert island into a super intensive garbage recycling "treasure island", for the trillion yuan GDP, tens of millions of people of the "double ten thousand" city of the manufacturing city of Dongguan, how to calculate this account how to calculate how to calculate -

Megacities with a population of 10.47 million will gradually get rid of the "garbage siege" problem by entering the era of zero domestic waste landfill; the "world factory" that has risen due to manufacturing for more than 40 years has since been able to rely on itself to solve the problem of hazardous waste treatment and move towards green development more confidently; and the unique model of coordinated disposal of three types of garbage and four types of resource recycling on the island has explored a new way for the Guangdong-Hong Kong-Macao Greater Bay Area to solve the solid waste disposal problems faced by the development of large cities.

The "garbage siege" will become history

Just like sitting in front of a huge doll-catching machine, the operator controls the grapple outside the garbage bin, grabs 8 tons of garbage with one claw, and accurately puts it into the incinerator... There are two advanced domestic waste incineration power generation facilities in Haixinsha Island, namely the Ma Chung Environmental Protection Thermal Power Plant, which was put into commercial operation in 2017, and the Haixinsha Environmental Protection Thermal Power Plant, which was put into operation this year. Every day, 3750 tons of domestic waste are incinerated here, in what form will they be utilized?

People first wonder where the stink has gone. "Stink is an energy source here, and it can't be leaked out and wasted." Teacher Bean said. In the garbage unloading hall, the reporter saw a fully loaded garbage truck waiting for unloading in front of a closed door. Inside the sealed bin, negative pressure technology ensures that odors do not spill out. The garbage will be fermented in the warehouse for 5 to 7 days, and the water will be filtered out to fully burn to generate electricity; the odors such as biogas produced by the fermentation will be pumped into the furnace by the extraction system to help ignite.

"Dongguan has a developed manufacturing industry, a high urban living standard, a high calorific value of domestic waste, and a ton of domestic waste can generate more than 500 kWh of electricity." Teacher Bean said. The Ma Chung Thermal Power Plant has been running for 4 years, which not only solves the problem of "garbage siege" in the surrounding water towns, but also achieves an annual power generation capacity of 200 million kWh, which can meet the annual electricity demand of 300,000 urban residents. The Haixinsha Thermal Power Plant generates more than 500 million kWh of electricity per year.

Where are the dioxins and slag from landfill leachate and incineration? Teacher Doudou held up a bottle of brown-red "five-year-old" garbage water and said: "Look, garbage water cannot be naturally decomposed and cleared, but after deep treatment by the wastewater center, it can reach the standard recycling of urban miscellaneous water." The reporter saw that the clear landscape ponds and the condensate water of the thermal power plant on the island were "transformed" from garbage water. Slag is even more "precious", which is processed into environmentally friendly bricks after harmless treatment and appears on the promenades of various scenic spots. And the dioxin that makes people smell discolored, the "death hole" is not resistant to high temperatures, and the high temperature of 850 degrees Celsius in the incinerator is enough to "kill it in a second".

The Haixinsha Environmental Protection Thermal Power Plant, which invested nearly 1.4 billion yuan and was put into operation this year, has a special significance for Dongguan, which enables Dongguan to achieve full incineration of new domestic waste and zero landfill. "Previously, about thousands of tons of domestic garbage in Dongguan could not be incinerated every day, and could only be buried in the ground. The plant handles 2,250 tons per day, and half of its capacity is used to burn stale garbage, dig out all the waste from the past stock landfill, and release valuable land. Zhao Haipeng, head of the Haixinsha environmental protection thermal power plant and deputy general manager of Dongshi New Energy Company, said.

The Haixinsha thermal power plant has been in operation for several months and has burned more than 40,000 tons of stale garbage. In the Greater Bay Area, where land is scarce, this account is particularly exciting. "After digging and backfilling, it is a good piece of land that can be used to build parks and make industrial land." Zhao Haipeng smiled: "With the garbage classification deeply rooted in the hearts of the people, the future of domestic garbage will be less and less. ”

Kitchen waste "eat dry and squeeze out"

When it comes to kitchen waste recycling, Cantonese people will think of an ancient profession "water litter". Nowadays, the illegal collection and transportation of kitchen waste has been prohibited due to the risk of gutter oil and cross-infection between humans and animals, but the unified collection and transportation and centralized disposal system of kitchen waste has not yet been established in Dongguan. It is estimated that Dongguan produces about 1500 tons of kitchen waste every day, which was mainly mixed with general household garbage or purchased by farmers in the past. The Mayong Kitchen Waste Treatment Plant on the island is the first project in Dongguan as the fourth batch of pilot cities for the resource utilization and harmless treatment of kitchen waste in China, filling the gap in resource treatment.

How does kitchen waste start the magical "journey"? In the kitchen project workshop, only the closed operation of pipelines and equipment, no trace of garbage. Deng Yongjun, project leader and assistant general manager of Dongshi New Energy Company, said: "We provide services for more than 1,200 catering enterprises and unit canteens such as McDonald's and Haidilao, and can process 300 tons of kitchen waste and 10 tons of gutter oil per day. Garbage is crushed, separated, boiled and purified through a series of processes, and the slag, water and oil go to different places to become resources. ”

Food waste is a treasure, and the most valuable output is natural gas and industrial grease. "Biogas purification into natural gas, which can produce more than 10,000 cubic meters per day, is integrated into the urban natural gas pipeline network and sent to thousands of households; gutter oil is purified and converted into biodiesel, which can be used as aviation fuel and chemical raw materials." Deng Yongjun said that in order to achieve high-value utilization, the base is exploring the black water fly farming business. "Black water fly can eat a large amount of residue biogas liquid in a day, and when raised, it can be used as feed for high-quality aquatic products such as hairy crabs and lobsters."

Dongguan's kitchen waste treatment adopts a combination of centralized and decentralized methods, and 32 town streets have established decentralized treatment points, but odors, residues and sewage have always been a problem of terminal treatment, but in Haixinsha Island, full resource recycling can be achieved. "The odor is transported to the thermal power plant to assist in combustion, and the residue is also sent to the thermal power plant to burn and generate electricity, and the sewage is treated and reused on the island." Deng Yongjun said.

Today, the base's kitchen waste intelligent collection and transportation system has been running smoothly in 17 town streets in Dongguan. The reporter saw on the monitoring platform that 50 garbage trucks equipped with the Beidou satellite positioning system were busy at various collection and transportation points, and the garbage in the special bucket was automatically dumped into the car. "The intelligent system not only saves costs, but also allows the people to see each link at a glance and be more assured." He said.

Hazardous waste disposal is also a business environment

Dongguan is an important smartphone production base in the world. "As soon as the phone is taken apart, most of it is hazardous waste containing harmful ingredients. Batteries, circuit boards, blue glass... Must be professionally handled. Coming to the green industrial service project, Gu Sihai, the project leader and assistant general manager of Dongshi New Energy Company, told reporters that Dongguan has been doing the "world factory" for many years, and has been relying on other cities to deal with a large number of industrial hazardous wastes, and invested 1.9 billion yuan to build the project in 2019, which is to make up for the shortcomings of hazardous waste disposal.

The reporter saw in the green industrial service project that the incineration treatment center, the surface waste recycling center and the advanced treatment units such as waste mineral oil, waste water, and waste circuit board treatment center are readily available. "It can dispose of 26 of all 27 categories of hazardous waste in Dongguan, with an annual treatment capacity of 316,100 tons." Gu Sihai said.

With 190,000 industrial enterprises and committed to building an advanced manufacturing center in the Greater Bay Area, Dongguan has no way out of relying on itself to solve the rapid growth of industrial hazardous waste. Data show that in 2017, Dongguan enterprises produced 235,700 tons of hazardous waste. By 2020, the total amount of hazardous waste in Dongguan will be about 619,000 tons, and the disposal gap will be about 406,000 tons. "Relying on outside market treatment will face a huge risk of leakage and theft along the way, and on-site treatment is the perfect solution." Gu Sihai said.

Environmental protection constraints are becoming increasingly stringent, and hazardous waste disposal capacity has become an important business environment. "For example, if mobile phone companies want to invest in new projects, they will definitely consider the cost of hazardous waste disposal." There is no place for garbage to go, and factories and markets will be restricted. He said that the base has now provided many enterprises with integrated services for hazardous waste disposal, transportation, storage, comprehensive utilization, environmental monitoring and technical consulting.

Compared with domestic waste, industrial solid waste utilization value is higher, with advanced treatment facilities, you can find treasure from it. "For example, Dongguan's electronics industry is developed, and large electronics factories can reach tens of thousands of tons of electroplating sludge a year, which can extract copper and nickel metals for resource utilization; for example, Dongguan has 3.5 million cars, and the waste motor oil in 4S stores can cause lubricating oil to return to the market." He introduced that in the circulation of four types of resources of water, electricity, steam and natural gas on the whole island, the project has also become an important part: its wastewater has become the circulating cooling water of the thermal power plant; the electric energy of the thermal power plant is used for the operation of the project, and the steam generated is used for the evaporation of the industrial wastewater workshop...

"The recycling of hazardous waste is the trend of the times, and the current utilization rate is still relatively low." Gu Sihai told reporters that the national key research and development plan "solid waste resources" key special project "Guangdong-Hong Kong-Macao Greater Bay Area megacity resource recycling base integration demonstration" project has been launched in the base recently, the new technology will vigorously promote the high-value utilization of solid waste, for the "Bay Area manufacturing" to build a green background. (Economic Daily reporter Zheng Yang)