What will be the biggest change in life in 2020? In addition to the new crown outbreak so that we are used to wearing masks to travel, garbage sorting also really affects the daily lives of each of us. From July 2019, Shanghai introduced the “most stringent” regulations on household waste, becoming the first city in the country to enforce the implementation of garbage classification, major cities are also implementing garbage classification.
On May 1, 2020, the new edition of the Beijing Municipal Waste Management Regulations was officially implemented, and Beijing’s garbage classification ushered in a major examination. And as garbage sorting progresses, and the impact of the new crown outbreak, garbage processors are starting to catch fire. According to JD.com statistics, the search volume and turnover of food waste disposal devices increased nearly threefold in the three days from April 22-24, 2020 alone.
What is a garbage processor?
The waste processor, also known as the kitchen food waste processor, is installed under the kitchen sink and connected to the drain pipe. Drive the cutter disc with an AC or DC motor and use centrifugal force to crush the food waste in the crushing chamber and into the sewer. It can be understood that under the sink installed a wall-breaking machine, the difference is that the waste processor uses centrifugal force in the crushing of grinding food waste, its knife plate has no sharp edge, so relatively safe, and durable, clean-free and maintenance.
Waste processors can handle the vast majority of food waste, such as small bones, chicken bones, fish bones, eggshells, corn stick cores, peel kernels, vegetable leaf stalks, nut shells, leftover rice and so on. Smash them into 4mm particles and wash them into the sewage pipe sewage pipes with the water flow. However, garbage processor is not a kitchen waste can be disposed of, like a large piece of bone can not be disposed of, and heavy oil soup is not recommended to pour directly into the waste processor.
Why does the garbage processor fire?
The most difficult thing to deal with is the kitchen waste. Although the kitchen waste is our food, but these originally delicious food, after eating leftovers, all kinds of residue mixed together, become abnormally disgusting. It’s certainly unrealistic to flush the kitchen waste into the sewers without handling it, but stacking it in the trash can sits in the trash, not only to fill the kitchen with an unpleasant smell, but also to attract cockroaches. So we usually dispose of the waste quickly and then throw it at the dump.
Before there was no garbage classification, a brain and other garbage packed piece slot lost, and now in addition to a separate bag, in order to facilitate the follow-up treatment of kitchen waste, need to break the bag and then throw the trash can.
And by this year’s new crown epidemic, we are all in the minimize travel time, especially in the peak of the outbreak has not yet resumed work, relying on the takeaway service, we can basically stay at home for a week without going out. At this time, the disposal of household kitchen waste is particularly troublesome.
The waste processor solves all the pain points of kitchen waste disposal. Kitchen waste through the waste disposal machine grinding treatment, into powder and rushed directly into the sewer, eliminating the need to collect kitchen waste against strong odors, but also let the kitchen less odor and cockroaches.
In fact, the prevalence of waste disposal devices abroad has been quite high, the United States has even reached more than 95% of the penetration rate. With the advance of garbage classification, food waste processors are also gradually recognized, but the popularity of food waste processors, in addition to its more expensive price, its impact on the city’s sewage treatment system and household sewage system, is also the biggest impact on the popularity of a factor.
Effect of waste processor on urban sewage treatment system
More than half of modern household waste is food waste, every year the government has to invest a lot of manpower and resources to deal with waste, but it is difficult to meet the increasing emissions. Food waste processors can crush kitchen waste into sewage pipes, which does reduce the pressure on kitchen waste disposal. However, the waste processor is not to reduce the waste of kitchen waste, it just replaces the waste of kitchen waste discharge way.
Part of the view is that food waste processors discharge waste directly into sewage pipes, which will greatly increase the burden on municipal sewage treatment plants.
Research shows that a small range of popular food waste processors, not only will not increase the burden of sewage treatment plants, but also effectively improve the efficiency of sewage treatment plants.
The treatment of domestic sewage, the most important is the removal of nitrogen and phosphorus in the sewage, both of which will cause eutrophication of the water body, leading to the outbreak of water algae. The denitrogen removal of sewage and phosphorus are mainly achieved through biotechnology and by microorganisms. Microbes, like humans, need to eat, and organic matter in sewage (i.e. carbon sources) is the food of microbes. The increase of carbon source in sewage can effectively improve the biological removal rate of nitrogen and phosphorus. However, for most wastewater treatment plants in China, the low carbon source in the water is usually required to increase the availability of additional carbon sources. And the use of food waste processor, can provide enough carbon source for sewage, there are surveys show that the use of food waste disposal device seisped community, the increase of its carbon source is about 10% to 30%, can meet the requirements of sewage bio-nitrogen removal phosphorus.
However, the use of food waste processor, not only increase the organic matter in sewage, but also sewage sewage SS (solid suspension), COD (chemical oxygen demand), BOD (biooxygen demand), etc. , the higher the value of these indicators, representing the higher the concentration of pollutants in the water body, the more serious water pollution. Sewage treatment plant can withstand SS, COD, BOD, etc. is limited, exceed the standard will greatly increase the burden of sewage treatment plant.
So how much of a burden does the use of food waste processors place on sewage treatment plants? The author consults an analysis of the tolerance of Shenzhen sewage treatment plant to the crushing inline row of household kitchen waste processor. The survey divided Shenzhen into the former Special Zone, Bao’an District and Longgang District, of which the former Special Administrative Region’s sewage treatment plant service population of 408.85 million, Bao’an Area for 5.1273 million, Longgang District of 2.6926 million.
The data show that, in the absence of universal food waste processors, the total pollutant load of sewage treatment plants in the rest of the region is still in excess, except for the SS (solid-state suspension) in the original Special Zone.
(Data source: Liu Rongjie, Deng Zhou, Liang Weikun, etc. Analysis of the tolerance of the Shenzhen Municipal Sewage Plant to the household kitchen waste crushing straight discharge. Environmental Health Engineering, 2018 (4): 43-47. )
By calculation, it can be found that as the prevalence of food waste disposal devices gradually increases, so does the variety of pollutants. When the popularity rate of food waste processors reached 100%, it has greatly exceeded the pollutant load of sewage treatment plants.
COD (chemical oxygen demand) and SS (solid suspension) in sewage are two important indicators affecting food waste disposal devices.
SS (solid-state suspension) is already over-standard when food waste processors are not widely used in the original SAR, while COD (chemical oxygen demand) can provide a penetration rate of 25.2% at full load;
Simply put, the small-scale popularization of food waste processor, not only can reduce the pressure of waste disposal, but also help to improve the nutritional structure of sewage, is conducive to improve the efficiency of biological denitrification of sewage treatment plant seispher removal phosphorus. However, the large-scale popularization of food waste processors may place a significant burden on sewage treatment plants, although population density and sewage treatment plant pollutant load margins vary from place to place, and acceptable penetration rates vary.
Effect sewage systems of food waste processors
Putting aside the impact of food waste processors on municipal sewage treatment plants, people are more concerned about whether food waste processors will clog sewage pipes. As we all know, when we wash the dishes and cook, all kinds of grease will flow into the sewage pipe, the grease will solidify and adhere to the pipe wall, especially the old house metal pipe, over time will block the sewage pipe. And the use of food waste processors, in addition to grease, there is a large amount of particulate matter, these will increase the risk of pipe blockage?
Studies have shown that the diameter of particulate matter treated with food waste processor is usually less than 5mm, while the current home drainage pipe diameter is usually greater than 50mm, not only does not block the risk of blocking the drain pipe, but also can absorb grease, reduce the attachment of grease.
(Photo source: Environmental Economic Profit and Loss Study Report on the Popularity of Food Waste Processors in Shanghai)
Of course, there are also studies that show that food waste processors increase the risk of blockage of sewage pipe grease and increase pipe maintenance costs.
For some older neighborhoods with older sewage systems, it is generally believed that food waste processors will increase the risk of blockage in sewage pipes, and that their homes may not be blocked, but they are blocked to the neighbors downstairs. And many old neighborhood municipal water pipes do not divert, rain and sewage are walking the same pipe, garbage processor let sewage contain more grease, if the storm caused flooding, floating oil sewage will pour onto the road, the scene is very disgusting.
However, for some new neighborhoods, sewage system is also more advanced, for food waste processor will not increase the risk of blockage, there is no conclusion, but it is still recommended to buy, try to choose a higher degree of crushing food waste processor.
Write at the end
From a country that has made food waste processors widely available on a large scale, food waste processors do make a significant contribution to the environmental cause. However, the author believes that the food waste processor in the domestic in a short period of time will not be large-scale popularity, first of all, its price and strong installation properties have decided the difficulty of large-scale popularization, and most of China’s urban sewage system in the design did not take into account the waste disposal load, which is also an important factor hindering the popularity of waste processor.
However, the impact of the outbreak, increased consumer health awareness and the introduction of waste classification, food waste processors in the more developed regions of small-scale popularity, should not be a problem. Given our country’s population base, small-scale popularization will also bring huge markets. This is a no small opportunity for the domestic just start-up waste processor industry, it can be foreseen that, with the steady implementation of garbage sorting in the country, food waste processor will be further developed, there will be more and more enterprises to join this market, when the existing product standards will not be able to meet the needs of consumers, the industry will certainly establish a higher standard, and consumers will also use better use of waste processors.