Activated Sludge Recirculation for Zero Excess Sludge
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Solution Overview
Problem
Conventional activated sludge treatment methods face challenges such as excessive sludge production, pH regulation issues, toxicity damage to sludge, fluctuations in contaminant substance levels, and inefficiencies in treating waste water with high oil content, leading to increased construction costs and operational inconsistencies.
Innovation Solution
The method involves a bioreactor system with a circulation process where sludge is recycled between a waste water aeration-conditioning tank and the bioreactor, maintaining a specific sludge concentration and controlling oxidation-reduction potential to minimize excess sludge production and enhance treatment efficiency, using aerobic and anaerobic microorganism treatments to break down contaminants effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If conventional activated sludge treatment methods are used, then waste water treatment is achieved, but excessive sludge production occurs leading to increased disposal costs and operational complexity
Solution Approach 1:
The patent changes the operational parameters by introducing a recirculation system that maintains specific sludge concentration ranges (500-8000 mg/L) and controls oxidation-reduction potential to positive values, transforming the treatment process to minimize sludge production while maintaining effectiveness
Solution Approach 2:
The patent implements feedback control by monitoring and adjusting sludge recirculation rates based on measured parameters such as mixed liquor suspended solids concentration and oxidation-reduction potential, creating a self-regulating system that optimizes treatment while minimizing sludge
2Adaptability or versatility
If chemicals are added to neutralize pH, then waste water treatment is enabled, but equipment corrosion accelerates and construction costs increase
Solution Approach 1:
The patent employs self-service by utilizing the natural buffering capacity of the activated sludge system itself to regulate pH, eliminating the need for external chemical additives and thereby preventing equipment corrosion from chemical exposure
3Manufacturing precision
If aeration time is prolonged to treat persistent substances, then treatment completeness improves, but treatment duration increases and operational complexity rises
Solution Approach 1:
The patent applies continuity of useful action through the recirculation system that continuously processes sludge through the aeration tank multiple times, ensuring complete treatment of persistent substances without requiring prolonged single-pass aeration time
4Reliability
If toxic substances are present in waste water, then treatment process is disrupted, but complete elimination of harmful substances is not achievable
Solution Approach 1:
The patent converts the harmful effect of toxic substances into a beneficial selection mechanism, where the recirculation system naturally concentrates and removes toxic substances through differential survival of microorganisms, making the treatment process more reliable by eliminating harmful factors rather than just managing them
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
This approach significantly reduces excess sludge production to near zero, stabilizes treatment processes, and maintains efficient waste water treatment with minimal site requirements and operational costs, effectively handling fluctuations in contaminant loads and eliminating foul odors.
Implementation Method 1
after aeration treatment with activated sludge
Implementation Method 2
utilizing the natural food chain, various microbes, from soil bacteria to large protozoa, are utilized
Implementation Method 3
after aeration treatment with activated sludge, the waste water for treatment is separated from the activated sludge
Implementation Method 4
contaminant substances contained in the waste water are removed through adhesion to the inorganic flocculant, forming floating scum
Data Source
AI summary
The object is to provide an activated sludge treatment method whereby production of excess sludge is brought substantially to zero; and a method for upgrading existing waste water treatment equipment, employing this method. The method includes a step (1) in which sludge 1 produced in a bioreactor is supplied to a waste water aeration-conditioning tank for activated sludge treatment; a step (2) in which waste water into which the sludge 1 has been mixed is subjected to aeration-conditioning to bring the oxidation-reduction potential to a positive value, and the conditioning treated waste water 1 supplied to the bioreactor; a step (3) in which released water from the bioreactor is considered to release water.