Circulation Sludge Recycling with Two-Stage Fermentation and Carbonization
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Solution Overview
Problem
Existing sewage sludge recycling systems face challenges in producing usable compost within a reasonable timeframe and maintaining consistent quality, with some materials being discharged in an unripe state.
Innovation Solution
A sewage sludge-to-resource recycling system incorporating a horizontal cylindrical fermentative treatment container with controlled rotation, dehydration, multiple stages of fermentative treatment, and carbonization, utilizing aerobic thermophiles to produce compost and activated carbon, with feedback loops for water content control and resource distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-stage fermentative treatment is used, then the device complexity is reduced, but the productivity and product quality are insufficient due to long treatment time and unripe compost discharge
Solution Approach 1:
The fermentative treatment is divided into two distinct stages: primary fermentative treatment in a horizontal cylindrical container and secondary fermentative treatment in a separate container. This segmentation allows each stage to be optimized independently, with the primary stage handling initial decomposition and the secondary stage completing ripening, thereby resolving the contradiction between structural simplicity and treatment effectiveness.
2Device complexity
If a single-stage fermentative treatment is used, then the device complexity is reduced, but the manufacturing precision of compost quality is insufficient
Solution Approach 1:
By separating the treatment into primary and secondary stages with different functional requirements, the system ensures that compost quality standards are met. The secondary fermentative treatment specifically addresses quality concerns by providing additional processing time and controlled conditions, ensuring consistent, ripe compost output.
Solution Approach 2:
The system incorporates feedback mechanisms where the output of the primary fermentative treatment becomes the input for secondary treatment. This staged feedback approach allows quality control at each stage, ensuring that only properly treated material proceeds to the next stage, thereby maintaining consistent compost quality.
3Productivity
If dehydration is performed to reduce water content, then the productivity of resource production is improved, but the energy consumption increases
Solution Approach 1:
The system utilizes self-heating during the fermentative treatment process, where microbial activity generates heat that naturally drives water evaporation and dehydration. This eliminates the need for external energy input for dehydration, resolving the contradiction between productivity improvement and energy consumption.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system efficiently produces compost and activated carbon, reducing water content and enhancing microbial activity, contributing to sewage treatment and resource utilization, while ensuring consistent product quality and reducing BOD and COD.
Implementation Method 1
configured to rotate the fermentative treatment container about the central axis to cause the raw material within the fermentative treatment container to gradually move from an inlet end side toward a discharge end side... thereby fermentatively treating the raw material by an aerobic microorganism
Implementation Method 2
dehydration means to dehydrate sewage sludge until a water content of the dehydrated sewage sludge becomes a preset given raw material water content value
Implementation Method 3
carbonization means to receive the secondary fermented product from the secondary fermentative treatment means, and subject the received secondary fermented product to carbonization treatment to produce a carbide
Data Source
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AI summary
The sewage sludge-to-resource recycling system of circulation-type according to the present invention comprises: dehydration means to dehydrate sewage sludge to form a raw material; primary fermentative treatment means comprising a horizontal cylindrical shaped fermentative treatment container configured to be rotated about a central axis thereof; raw material supply means configured to receive the raw material from the dehydration means and supply the received raw material into the fermentative treatment container; primary fermented product discharge means configured to discharge the primary fermented product outside the fermentative treatment container: secondary fermentative treatment means to receive the primary fermented product from the primary fermentative treatment means, and additionally ferment the received primary fermented product to produce a secondary fermented product having a second set water content value or less, the second set water content value being less than a water content of the primary fermented product; carbonization means to receive the secondary fermented product from the secondary fermentative treatment means, and subject the received secondary fermented product to carbonization treatment to produce a carbide; mixing means to receive the secondary fermented product from the secondary fermentative treatment means and the carbide from the carbonization means, and mix them together to produce a mixture; wherein the mixing means is connected to third distribute and supply means, the third distribution and supply means being configured to distributively supply at least part of the mixture to the raw material supply means and/or third useful resource processing means to perform processing into a third useful product of a third form.