Trickling Filter with Reverse Washing for Sewage Treatment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing sewage treatment systems, such as the standard activated sludge method and anaerobic lagoon method, face issues like high operational costs, energy consumption, sludge bulking, and contamination of rivers or seas due to inadequate biochemical oxygen demand (BOD) reduction, while the trickling filter method requires significant space and is prone to nozzle clogging and bad smells.
Innovation Solution
A sewage treatment system incorporating a solid-liquid separating apparatus with a filtering medium packed layer that separates sewage into solid components and filtered water, followed by a trickling filter with a second filtering medium packed layer for biotreatment, and a latter-stage solid-liquid separating apparatus for additional treatment, which includes a reverse washing function to prevent clogging and maintain system efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a trickling filter is used for sewage treatment, then BOD removal is effective and maintenance is simple, but the system occupies large space and is prone to nozzle clogging
Solution Approach 1:
The system divides the trickling filter into multiple stages with different filtering media layers. The first layer uses large-sized media for coarse filtration and anaerobic treatment, while the second layer uses small-sized media for fine filtration and aerobic treatment. This segmentation allows compact design while maintaining high BOD removal efficiency and preventing nozzle clogging through progressive filtration.
2Reliability
If a standard activated sludge method is used, then stable treated water quality is achieved, but high power consumption and operational costs occur
Solution Approach 1:
The system employs natural ventilation through the trickling filter structure, where air flows through the filtering media layers without mechanical assistance. The anaerobic layer generates gas that rises through the aerobic layer, creating natural airflow for oxygen supply. This eliminates the need for energy-consuming aeration equipment while maintaining stable treated water quality.
3Use of energy by moving object
If an anaerobic lagoon method is used, then low power consumption and easy maintenance are achieved, but BOD reduction is insufficient and sludge deposition occurs
Solution Approach 1:
The system merges anaerobic and aerobic treatment processes into a single compact trickling filter structure. The first filtering media layer provides anaerobic treatment, while the second layer provides aerobic treatment. This combination achieves high BOD reduction efficiency similar to activated sludge methods but with the low power consumption and simple maintenance characteristics of anaerobic systems.
4Area of stationary object
If filtering media is packed densely to reduce space, then space requirements are minimized, but nozzle clogging and bad smells increase
Solution Approach 1:
The system applies different local qualities to different layers of the filtering media. The first layer uses large-sized media with high void ratio to prevent clogging and allow gas flow, while the second layer uses small-sized media for fine filtration. This local differentiation allows compact overall design while preventing clogging and odors in each specific zone through appropriate media selection.
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 configuration reduces the load on the trickling filter, minimizes space requirements, prevents nozzle clogging, suppresses bad smells, and enhances the removal rate of suspended solids, resulting in a more efficient and compact sewage treatment system with improved water quality.
Implementation Method 1
a solid-liquid separating apparatus having a first filtering medium packed layer packed with a predetermined filtering medium, configured to separate sewage to be treated into solid components and filtered water by passing the sewage through the first filtering medium packed layer upward
Implementation Method 2
configured to reversely wash the first filtering medium packed layer by passing the filtered water through the first filtering medium packed layer downward
Implementation Method 3
a trickling filter installed on a latter stage of the solid-liquid separating apparatus, having a second filtering medium packed layer packed with a filtering medium attached with microorganisms, and configured to allow the filtered water to fall into the second filtering medium packed layer by trickling the filtered water onto an upper part of the second filtering medium packed layer to flow out treated water acquired by biotreating the filtered water by the microorganisms
Data Source
AI summary
A sewage treatment system, includes a solid-liquid separating apparatus having a first filtering medium packed layer packed with a predetermined filtering medium, configured to separate sewage to be treated into solid components and filtered water by passing the sewage through the first filtering medium packed layer upward, and configured to reversely wash the first filtering medium packed layer by passing the filtered water through the first filtering medium packed layer downward at a predetermining timing; and a trickling filter installed on a latter stage of the solid-liquid separating apparatus, having a second filtering medium packed layer packed with a filtering medium attached with microorganisms, and configured to allow the filtered water to fall into the second filtering medium packed layer by trickling the filtered water onto an upper part of the second filtering medium packed layer to flow out treated water acquired by biotreating the filtered water by the microorganisms.