New era, new opportunities, new journey
1、 Preface
Friends in the solid waste industry and colleagues in the leachate treatment industry. hello everyone! On July 23, 2024, the Ministry of Ecology and Environment of China issued GB16889-2024 "Pollution Control Standards for Landfills of Municipal Solid Waste". This standard will be implemented on September 1, 2024. The news quickly sparked a heated discussion within the solid waste community. After studying and comparing the content of the three standards set by the Ministry of Environmental Protection, I would like to conduct an in-depth analysis of the new standards with everyone. The following views represent personal opinions only. Please understand and forgive any inaccuracies.
2、 Comparison of Changes in Pollution Control Standards for Three Municipal Solid Waste Landfills
To standardize the management of the entire lifecycle of construction, operation, and closure of municipal solid waste landfill projects. The Ministry of Environmental Protection has formulated and upgraded control standards for pollutants in domestic waste landfills three times in 1997, 2008, and 2024. Based on the updates and upgrades of these three standards, let's interpret the context of several changes.
2.1 Requirements for landfill site selection
Compared to the 2008 standard, the 2024 standard has improved the criteria for landfill site selection and provided a more comprehensive basis for site selection; Revised the requirement that landfill sites should not be located in designated areas; The selection of landfill sites should avoid key areas for groundwater pollution prevention and control.
2.2 Requirements for landfill design, construction, and acceptance
Compared to the 2008 standard, the 2024 standard has the following changes:
1. Improved the content of landfill facilities, such as measuring facilities, garbage dams, flood control systems, flood monitoring facilities, and emergency response facilities.
2. The distance between the bottom of the foundation layer in the landfill area and the annual highest groundwater level should be changed to 3m (1m according to the 2008 standard).
3. Removed the conditions and applications for using natural clay anti-seepage lining layer; Specific requirements should be made for the artificial synthetic material of the single artificial composite lining layer, which should use high-density polyethylene film with a thickness of not less than 2.0mm; The application scenarios and specific designs of the dual artificial composite lining are specified; At the same time, it has been clarified that double artificial composite lining should be used for anti-seepage in the designated landfill areas for household waste incineration fly ash and medical waste incineration residue.
4. Added anti-seepage requirements for leachate regulating tanks that are not lower than those for landfill areas; Requirements for closed design of leachate regulating tank and odor suction and treatment process.
5. New requirements have been put forward for the treatment and utilization of landfill gas. Landfills with a designed landfill capacity of no less than 2.5 million tons and a thickness of over 20 meters for domestic waste landfill should be equipped with landfill gas utilization or torch combustion facilities, with priority given to high-efficiency utilization methods; When a landfill site with a capacity of less than 2.5 million tons and a thickness of no more than 20 meters for domestic waste landfill does not have the conditions for landfill gas utilization, a quasi aerobic landfill process that reduces methane production and emissions can be used, or landfill gas treatment methods such as torch combustion and biological filters can be used; Added requirements for the design of quasi aerobic landfill technology and its leachate drainage pipes.
2.3 Requirements for garbage entering the venue
In the 1997 standard, it is explicitly required that only household waste can be disposed of, and other waste cannot be disposed of in landfills. In 2008, the standard added solid residues generated from incineration slag, fly ash, composting of household waste, general industrial solid waste similar to household waste (such as clothing processing, food processing, etc.), treated medical waste, sewage plant sludge, anaerobic sludge, etc. In 2024, the new standards have further refined and added requirements for the entry of landfill waste:
1. Added: Solid waste generated from the recycling of decoration waste and demolition waste.
2. Added: Medical waste that meets the exemption management regulations for disposal links in the national hazardous waste list can be disposed of in landfills after disinfection, crushing and shaping treatment.
3. Added: Fly ash from household waste incineration and residues from medical waste incineration (including fly ash and bottom slag) can only be disposed of in independent landfill zones of the landfill site. The requirement for its moisture content to be less than 30% has been removed.
4. Added: except for general industrial solid waste similar to household waste, the landfill requirements for waste require that only independent landfill zones can be entered into the landfill site for landfill disposal.
5. Added: When mixing and landfilling sludge from domestic sewage treatment plants, it should also comply with the provisions of GB/T 23485 regarding mixed landfilling.
6. Waste not allowed to enter landfills: Hazardous waste exempted from management on the national hazardous waste list; Untreated food waste is converted into untreated kitchen waste.
This is equivalent to expanding the list of solid waste entering landfills on one hand, and on the other hand, providing clearer entry and landfill operation requirements for solid waste entering landfills, making the standards more in line with practical demands.
2.4 Requirements for landfill operation
Addition: An emergency plan for sudden environmental incidents should be prepared when the landfill site is put into use, and corresponding requirements should be made for the content of the emergency plan for sudden environmental incidents; Requirements for transportation and disposal of household waste within the site; Requirements for reducing the impact of odorous gases; Requirements for treating leachate through reinjection method; Requirements have been made for maintaining slope stability; Requirements have been made for integrity testing of the anti-seepage layer, environmental risk assessment, and emergency response measures at different stages of the landfill site; Proposed emergency response measures for groundwater and pollution prevention measures; Corresponding modifications and adjustments have been made to the operation period and post closure maintenance and management of the landfill site.
2.5 Requirements for site closure and post maintenance and management
Added requirements for site closure and environmental status investigation after landfill operations reach the design elevation; Propose requirements for integrity testing after the completion of the anti-seepage layer construction of the sealing and covering system; Requirements for land use and stabilization of landfill sites; All archive requirements for landfill sites.
2.6 Standards for leachate discharge
2.6.1. The 1997 standard is divided into Level 1, Level 2, and Level 3 standards. The third level is the standard for receiving pipes into the sewage treatment plant.
2.6.2. The 2008 standard has been significantly improved by eliminating the three-level management standard and upgrading the first and second level standards to Table 2 and Table 3 standards. Added chromaticity, TN, TP, and six heavy metal indicators. The strict requirements for chromaticity and COD basically equate the membrane based deep treatment process with leachate treatment, while also cutting off the back path to discharge into the sewage treatment plant.
2.6.3. The 2024 new standard has undergone significant changes once again, with a considerable amount of information. I will explain it to you one by one:
2.6.3.1 Added indirect discharge standards for entering sewage treatment plants and industrial sewage treatment plants. Require a written contract to be signed with the operating unit of the centralized sewage treatment facility, specifying the discharge method, collection point, indirect discharge standards, etc. There is no limit on the discharge ratio of indirectly discharged urban sewage treatment plants and industrial sewage treatment plants after pretreatment of leachate relative to centralized sewage treatment facilities. This means that as long as the receiving unit has sufficient capacity to treat this wastewater, it can enter. This is equivalent to basically alleviating the biggest and most troublesome problem for local homeowners regarding the discharge of leachate. This also basically blocks all the current simple treatment methods using DTRO and similar processes, including the dual membrane process and evaporation treatment, which will become increasingly difficult. It's not that it can't be done, but compared to external discharge, the cost-effectiveness is too low. Most owners will consider process routes with high cost-effectiveness, unless there are a few sensitive area projects and concentrated liquid treatment projects with extremely high conductivity.
2.6.3.2 The monitoring content in Tables 2 and 3 has increased from 14 to 18 items, with the addition of 4 items (total copper, total zinc, total beryllium, and total lead) as pollutant control indicators for landfill incineration fly ash; Except for the added pollutant monitoring indicators, the limits in Tables 2 and 3 have not changed; The monitoring location remains the same as the discharge outlet of the leachate treatment facility. The monitoring content of Table 4 has increased from 14 items to 17 items, with fewer monitoring items for fecal Escherichia coli compared to Tables 2 and 3.
2.6.3.3, Article 7.5 of the standard specifies that leachate can be disposed of through reinjection, but it should not have adverse effects on the stability of the landfill site; When the leachate drainage pipe is not smooth and cannot meet the stability requirements, the leachate recharge should be stopped immediately. And it is stipulated that the impact of odorous gases should be reduced during reinjection.
3、 Interpreting the Logic Behind Standard Changes
3.1. While adhering to the concept of green mountains and clear waters, it is also necessary to align with the dual carbon emission reduction targets
Especially increasing the requirements for landfill site details and water quality standards is very precise and accurate. A bigger consideration for the revision of this standard is to actively respond to the dual carbon goals (peak carbon emissions, carbon neutrality) mentioned by the General Secretary, which means that all processes, technologies, products, etc. that deviate from dual carbon should be abandoned as soon as possible.
For example, taking the operating cost of leachate as an example, the removal cost of 1 kilogram of COD per ton of water using a fully quantified process is around 30 yuan, while the removal cost of 1 kilogram of COD per ton of water in a sewage plant is around 3.5 yuan, a difference of up to 7.5 times between the two.
The difference in operating costs for treating pollutants with the same unit equivalent is astonishing. The main reason is that the leachate uses high energy consuming and consumable membranes and evaporation processes, which is contrary to the dual carbon economy. If these pollutants are treated in sewage treatment plants, especially compared to ultrafiltration water, using full process technology to meet the direct discharge standards in Table 2 and indirect discharge standards in Table 4, the cost and energy consumption of the two differ by more than four times.
I think this is the first logic of this standard change, which requires both green mountains and clear waters, as well as achieving dual carbon standards; We need to balance both, not just one. This is also a concrete manifestation of the Scientific Outlook on Development. We are developing countries, and we cannot focus a large amount of funds on one point, set unscientific standards, and invest endlessly. This is not advisable. For example, in many developed countries abroad, the emission standards for leachate from garbage only require BOD and not COD. In fact, it is known that that part of COD is humic acid, which is the most stable chemical substance in nature and has little harm. It is just that its sensory properties are not good, so no requirements are made. This is a very pragmatic spirit.
At present, there are still a large number of pollution sources in the country that have not been rectified in a timely manner, and environmental protection governance should be comprehensively considered. This is a very correct logical thinking.
3.2. Excessive correction will inevitably lead to a pullback
As we all know, the original intention of the 2008 standard was good. To change the chaos, we must first rectify it. Therefore, compared with the 1997 standard, the strict standards for leachate discharge in the 2008 standard are revolutionary. As a result, there was a clear industry watershed around 2008. The old established leachate treatment companies gradually faded out of sight, and new companies mainly based on membrane methods began to take the lead on the stage. But this standard does have much to complain about.
3.2.1 At the beginning of the standard setting, there was insufficient evaluation of the subsequent impacts and hazards caused by the membrane concentration solution. Resulting in a series of subsequent problems.
3.2.2 At the beginning of the standard setting, only the discharge standards for treated water were required, and there were no clear requirements for the disposal of concentrated liquid. This has led to the emergence of many Western style treatment techniques. Even within the industry, there have been grandiose claims that devices can produce water within 3 to 5 days. Can giving a terminally ill person a booster shot of 120 every day solve the problem? Relying solely on simple interception and concentration does not solve the fundamental problem of pollutants, and the behavior of treating symptoms without addressing the root cause seems to be coming to an end.
3.2.3. A one size fits all ban on the discharge of wastewater into sewage treatment plants has been implemented, and relevant discharge standards have been removed. Little did they know that China's regional development is very uneven, especially in many economically underdeveloped areas. In order to cope with environmental inspections from higher authorities, they have to tighten their belts and participate in projects to avoid any accidents. Heavy investment and light operation, coupled with membrane technology hijacking, how can it possibly operate healthily and sustainably. It is very good if 2-3 out of ten games can operate normally and stably without any problems for a long time.
I think the experts at the top of the country have also seen this real contradiction, and the problems that arise during development should be resolved in the process of development. Since the overly strict standards set in history are difficult for everyone to meet, it indicates that the formulation is not scientific enough. Reform is like crossing a river by feeling the stones, which requires a certain degree of adjustment. Making the standards more in line with the reality and relatively able to meet the standards is more reasonable.
Multiple options to avoid a one size fits all approach
We can see that this standard reform for leachate provides more options for government property owners. Compared to before, first of all, he has an additional passage to the urban sewage treatment plant; Secondly, he also stipulated that it can be discharged into industrial wastewater treatment plants, which greatly increases the choice of treatment process ideas. Allowing property owners to determine whether to directly discharge water bodies or treat them through pipelines based on their actual conditions avoids a one size fits all approach, thereby reducing the environmental and economic pressure on property owners.
4、 There are still some issues in the standards that need to be improved
4.1 Standards should consider the demands of leachate operation in small and micro landfill sites
We believe that specialized treatment processes and standards should be added to the standards for the treatment of leachate from micro landfills.
For example, it is highly inappropriate to execute a project in northern China with a daily production of less than 20 tons of leachate according to current standards. Whether it is a full-scale process or a pipe feeding process, it may not be appropriate in terms of investment, temperature conditions, operational level, human resources, and so on. Therefore, this aspect should be taken seriously. It is suggested to increase the number of micro sites for processing garbage below a certain tonnage, which can be transported for centralized disposal, and stricter protection and management measures should be taken for collection and transportation along the way, which is also more in line with the scientific development concept.
4.2. When implementing this standard for existing leachate facilities, a certain buffer time should be set (following the approach of the 2008 standard)
Suggest setting a buffer period of 1 year. Set a renovation time for the processing stations currently utilizing the two-stage AOUF process (or related processes), as this involves land acquisition, design, construction, commissioning, and connecting discharge joints, and cannot be completed in a short period of time.
5、 Prediction of the Development of the Leachate Industry in the Next Step
After the implementation of this standard, it is a disruptive reform for the leachate treatment industry. Our analysis and prediction are as follows:
5.1 Major Trends
Due to the increased emission requirements and the choice of pipes, we believe that most homeowners will choose this process. The reason is simple: the overall investment and operating costs will be significantly reduced, and the historical backlog of concentrated liquid problems can be completely solved. This greatly reduces the scale of the leachate treatment market, and the complex problems accumulated in history will gradually be thoroughly solved.
5.2 DTRO and Similar Processes
The market for traditional mainstream processes such as DTRO and three-stage membrane rolling will seriously shrink. The reason is simple. Because the concentrated solution produced by DTRO will inevitably need to be processed, the difficulty, investment, and operating costs of subsequent processing will significantly increase, and the cost-effectiveness of this process is the lowest. Owners will almost soon abandon this process, and industry companies that focus on this process should pay attention to the risks it brings.
Evaporation process
The market for processing concentrated liquids through evaporation technology will significantly shrink. Once the indirect discharge to the sewage treatment plant is opened, it will lead most landfills to implement indirect standards. Compared with the evaporation process, which often requires an investment of 70000 to 90000 yuan/ton of water, an operating cost of over 200 yuan/ton of water, and 8-15% salt mud or mother liquor, it often causes pain and embarrassment of blockage and inability to operate continuously and normally. To meet the indirect discharge standards, it does not produce concentrated liquid or produces less concentrated liquid, with lower investment, lower operating costs, easier implementation, strong operability, and good operational stability.
5.4 AOUF+Double Membrane Process
The mainstream process of dual AOUF+dual membrane method will also become very awkward, for reasons similar to Article 5.2. In the future, the market share of such processes is likely to not exceed 20%.
5.5. Membrane free process
The membrane free process based on AOUF+advanced oxidation+secondary biochemistry will become mainstream, mainly due to the lack of headache inducing concentrated solutions. This standard has reduced CODcr from 100 to 500mg/L, TN from 40 to 70mg/L, and chromaticity from 40 to 64 times. Deducting the removal rates of CODcr, TN, and chromaticity by NF and RO, it is actually equivalent to reducing CODcr from 100 to 500mg/L, TN from 40 to 70mg/L, and chromaticity from 40 to 64 times in the past ultrafiltration water production. This will definitely induce the transformation of the process section after UF water production. Low investment and low operating costs ensure the stability of CODcr, total nitrogen, and chromaticity in ultrafiltration water to meet indirect emission standards. Therefore, it is necessary to use processes such as coagulation, advanced oxidation, and biological denitrification for treatment. Future technology is about advanced understanding of oxidation and biochemistry, such as materialization, and lean management.
Please ask companies in the industry to self compare and make up for their shortcomings as soon as possible. This will usher in a major wave of transformation opportunities, with the strengthening and upgrading of biochemical treatment facilities and the addition of advanced oxidation and other physical and chemical facilities.
There is still a market for fully quantitative processing
The new standard has had a certain impact on the full quantification treatment of leachate to meet the emission standards in Table 2, leading to a decrease in market demand. However, some landfills are located in mountainous areas and far from urban areas, making it impractical to discharge into sewage main pipes and industrial sewage plants (due to high transportation costs by tank trucks). They will continue to be plagued by concentrated liquids, and there is still a certain market opportunity for fully quantified treatment to meet the discharge standards in Table 2. At the same time, influenced by indirect emission standards, there will be a significant increase in market demand for fully quantified treatment to meet the indirect emission standards in Table 4. After the implementation of the new standards, there will be a concentrated market explosion period, but it will also accelerate the leachate treatment into the end of the project cycle.
5.7 Impact of Industry Changes on Enterprises
The industry reshuffle is intensifying, as the overall market size is shrinking, profit margins are becoming thinner, and the demand for technology is increasing. A group of enterprises with slow transformation will gradually exit the market and eventually become a mature and niche market. The industry enterprises that will exist in the future will compete in biochemical technology and advanced physical and chemical technology.
epilogue
Colleagues, friends. New era, new opportunities, new journey. The introduction of the 2008 standard has developed and strengthened our industry, and has produced a group of excellent enterprises. The implementation of the new standards in 2024 will also have a significant and profound impact on this industry. Let us bravely embrace change, actively prepare for technological advancements, and find certainty amidst uncertainty. Let us adhere to the concept of true environmental protection and low-carbon environmental protection. Develop new processes and technologies for energy conservation and consumption reduction, and make new contributions to the industry. Thank you all.
