Raising insects to eat garbage, raising fish with battery wastewater... these waste treatments are eye-opening
HANGZHOU, June 4 (Xinhua) -- How can waste gas and wastewater not affect the ecological environment? How to make "misplaced resources" produce value? How to solve the "garbage siege" dilemma? June 5 is the World Environment Day, waste disposal has once again become one of the focus of attention. A few days ago, the reporter learned in an interview that at present, some new technologies and new methods of waste treatment are being used, becoming a new force to protect the world's blue sky and clear water.
Biodegradation is the "new blue ocean" of waste treatment technology. In Chongxian Street, Hangzhou, Zhejiang Province, there is a magical "insect farm" that can "eat" more than 3,400 tons of kitchen waste a year. The farm is run by Zhang Zhijian, an associate professor at the School of Environment and Resources at Zhejiang University. Nearby residents have given him the nickname "Professor of Insects".
Entering Zhang Zhijian's farm, a row of neat greenhouses came into view. Inside is a huge black tabanus breeding tank, which is lined with a layer of processed kitchen waste. Swarms of wriggling white worms are clearing away the food waste that has been brought in from nearby.
The "white worm" is the larval form of the black water fly. In early spring, the larvae hatch from the eggs and grow into pupae in 12 to 14 days. In less than two weeks, the larvae gain more than 2,000 times their weight, and this 2,000-fold increase is all due to the food waste they eat. For every kilogram of Black fly larvae, they can convert 4 kilograms of food waste. A reduction of more than 80 percent of waste at a time. The larvae and their excrement can also be made into green organic fertilizer and sold in the market.
Zhang Zhijian said that although the adult black water fly and fly grow somewhat similar, but it is neither sedentary nor eat, the adult life cycle of about two weeks, will not carry pathogenic microorganisms.This "insects eat garbage" technology, Zhang Zhijian has been exploring for many years. Today, this small farm with only a few acres of land can handle about 12 tons of food and kitchen waste every day, basically solving the problem of food and kitchen waste disposal for the entire population of 180,000 people in Chongxian Street.
Rockery, grass, green trees, koi carp -- Walking into the circular Economy Industrial Park in Changxing County, Zhejiang Province, the vibrant scenery makes it hard to believe that this is part of the lead battery recycling and processing park.
From the recycling of waste batteries, to crushing, sorting, melting, refining, and then reassembly into batteries, the park staff will operate each step separately: from the waste batteries to separate lead-containing substances, re smelting into lead; Separate out the waste plastic and re-manufacture the battery shell; The waste acid is separated and purified to produce concentrated sulfuric acid, which is used to make battery acid.
"A nearly 10 pounds of waste lead battery after multiple processes, can be decomposed and refined to recover 6 pounds of recycled lead, 2 pounds of sodium polysulfate and 0.6 pounds of plastic, these substances can be recycled, produced into a new battery put on the market." The person in charge of the park said that compared with the traditional primary lead production method, each ton of recycled lead produced can reduce solid waste by 60% and reduce sulfur dioxide by 66%. "The treated water meets the national secondary drinking water standard and can be used to water flowers and raise fish."
Located in the hinterland of the Yangtze River Delta, Changxing's lead battery industry started in the 1970s and is one of the local pillar industries. A responsible comrade in the county introduced that since 2005, Changxing County has carried out the transformation and renovation of the green development of the lead battery industry, the number of lead battery enterprises has been reduced, the technical equipment has shifted from manual operation to mechanical equipment, and the pollution control equipment has achieved full coverage.
"Battery wastewater is done well, we are closer to the beautiful China of blue sky, green ground and clear water." The responsible comrade said. (Writing reporters: Gu Xiaoli, Zheng Jianghua, Wei Yijun, Liu Fang, Liang Youchang; Video Production: Gu Xiaoli, Zheng Jianghua, Song Lifeng)