How much does it actually cost to properly dispose of one ton of sludge?

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Recently, a in-depth article in Caixin Weekly titled “Where Has the Sludge Gone?” ”It sparked a lot of discussion within the industry, and quickly filled the social media accounts of those working in the environmental protection sector. Beijing and Beipai became the targets of criticism from the media and industry insiders. Some believed that the funds needed for sludge treatment were not available, while others thought the technical approach was incorrect. Still others argued that there was no proper planning, or that no sites had been designated for building facilities for sludge treatment and disposal... This article will not determine whether it is Beipai’s fault or the fault of Beijing’s authorities; instead, it will focus on the financial aspect – namely, how much money is required to render one ton of sludge harmless I. The total cost of treating and disposing of sludge per ton ranges from 150 to 500 yuan per ton. The \"China Sludge Treatment and Disposal Market Analysis Report (2014 Edition)\」published by the E20 Research Institute conducted various investigations into current sludge treatment and disposal projects in China, primarily those of the BOT type. The cost information obtained from these investigations is as follows: the investment cost for the overall technology approach of anaerobic digestion combined with land use is 500,000 to 600,000 yuan per ton, while the operating cost is 80 to 120 yuan per ton ； The investment cost for the overall technology approach of aerobic fermentation plus land use is 300,000–500,000 yuan per ton, while the operating cost is 100–120 yuan per ton ； The investment cost for sludge drying and incineration is 300,000–500,000 yuan per ton, while the operating cost is 200–350 yuan per ton ； The investment cost for using sludge in construction materials is 300,000–500,000 yuan per ton, while the operating cost is 250–350 yuan per ton ； The total cost of the whole process for extracting microbial protein from sludge is 180–220 yuan per ton. Based on the findings of the report, due to various factors such as differences in statistical methods and regional price levels, there are significant variations in the costs associated with different disposal methods. From the perspective of BOT projects, the overall cost range for sludge treatment and disposal, as indicated in the report, is between 150 and 500 yuan per ton, with an average cost of 270 yuan per ton. This translates to approximately 0.2 yuan per ton when included in the wastewater treatment fees (assuming that 7 tons of sludge with an 80% moisture content are generated per 10,000 tons of water). However, due to the relative sensitivity of cost data, E20 Research Institute also encountered reluctance on the part of various parties to disclose and share such data during its research, which resulted in some discrepancies between the survey data and the actual figures. Taking dry incineration as an example, according to research, the operational costs of several publicly available dry incineration projects in China currently range between 200 and 300, a figure that has also been questioned by the industry. At present, the operating costs of sludge drying and incineration projects in operation in China range between 400 and 500 yuan per ton. Yang Xinhai, the chief engineer at the Shanghai Environmental Research Institute, told the researchers at the E20 Research Institute that, based on his personal experience, when depreciation and the costs associated with final disposal are taken into account, the total cost is generally over 500 yuan per ton; when converted into a water fee, this amounts to 0.35 yuan per ton. At the current level, it is practically impossible to carry out the entire commercial operation at a cost of less than 300 yuan per ton in developed regions. The cost of collaborative processing is often slightly lower; for example, in the case of waste incineration plants working together, the total cost including profits is around 400 yuan per ton. Regarding the costs associated with sludge treatment and disposal in Beijing, several experts and senior officials from sludge-related companies have stated that to treat and dispose of Beijing’s sludge to high standards and render it harmless, the cost per ton must be no less than 500 yuan. Compared to foreign countries, the cost of sludge treatment and disposal in our country is relatively low. According to research on international costs associated with sludge treatment and disposal, in Japan where the proportion of sludge incineration exceeds 70%, the cost of drying and incinerating sludge is between 500–600 yuan per ton, while the cost of using melting techniques for sludge is even higher, at over 1000 yuan per ton. Of course, due to differences in national conditions, living habits of the population, drainage systems, prices, and so on, there are significant variations in aspects such as the heavy metal content and moisture content of sludge. Therefore, the methods used abroad for sludge treatment may not be suitable for China, and the cost figures provided are only for reference within China. Overall, however, the cost of sludge treatment and disposal in our country remains relatively low. II. The proportion of sludge treatment and disposal costs in the total sewage treatment costs is relatively small. According to the water price database maintained by the E20 Research Institute, the average cost of sewage treatment in 36 provincial capitals and cities with separate planning status across the country is 0.82 yuan per ton, which is still somewhat below the required level for sewage treatment costs. Rising sewage treatment fees in key cities are already a problem, not to mention other prefecture-level cities and county towns. The costs associated with sludge treatment and disposal should be included in the sewage treatment fees, as further clarified by the Regulations on Urban Sewage Discharge and Treatment, which came into effect on January 1, 2014. However, according to research conducted by the E20 Research Institute, at present, only a few areas include the costs associated with sludge treatment and disposal within the overall wastewater treatment costs, such as Beijing, the Taihu Lake region in Jiangsu Province, Changzhou City in Jiangsu Province, and Guangzhou City. The wastewater treatment costs in Jiangsu Province are relatively high; the cost of sludge disposal there is 0.2 yuan per ton, accounting for only about 15% of the total wastewater treatment costs. Guangzhou has only 4 cents. With the current nationwide lack of funding for sewage treatment fees, it is even more difficult to secure funds for sludge treatment and disposal. III. **Willing to pay 100–150 yuan per ton** – In terms of their attitude toward sludge treatment and disposal and their willingness to pay, according to the author’s investigations, this is reflected in two main aspects: firstly, a desire for the sludge to disappear completely, and secondly, a wish to resolve the sludge problem at a cost of 100–150 yuan per ton. It is precisely the lack of attention to sludge treatment and disposal issues, as well as the use of the lowest price as the criterion for project bidding rather than focusing on the quality of disposal, that has created a negative atmosphere in the market. The mismatch between supply and demand ultimately leads either to an inability to properly deal with the sludge, or to its disposal through landfilling, or to illegal discharge ； Either win the bid at a low price and then find ways to provide basic services in order to cover the costs. Either one of them does not meet the current situation and requirements of environmental governance in China, hinders the healthy development of the market, and may cause even greater negative impacts. According to available information, the resource-based disposal method of using sludge in construction materials was once implemented in China at low costs (with BOT prices below 100), but it soon faced setbacks due to widespread issues of poor quality and secondary pollution in practical applications. This hindered the development of this technology and also significantly constrained the growth of the related market. The phenomenon of winning bids at low prices is also severe in the waste disposal sector at present. Reading this article, some people might ask: Just by having the funds available, can the sludge problem definitely be solved? Yes, money doesn’t necessarily solve the problem of sludge, and Beijing is probably a typical example of this. However, without the necessary funds, the sludge problem certainly cannot be resolved properly. Of course, in addition to the availability of funds, **adequate supervision is a primary and essential condition; moreover, this supervision must cover the entire process – including how to handle the biogas sludge after it has been processed, and whether the products resulting from aerobic fermentation can be used legally. All these aspects need to fall under regulatory oversight.