Filter Backwash Water Flocculation Using Carboxymethylated Corn Starch
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Solution Overview
Problem
Existing water treatment methods using synthetic polymers like polyacrylamides for flocculation pose safety concerns due to potential secondary pollution with neurotoxic and carcinogenic monomers, and there is a lack of effective use of natural polymers like carboxymethylated corn starch (CMS) in treating filter backwash water.
Innovation Solution
A method utilizing carboxymethylated corn starch (CMS) as a biodegradable flocculant, combined with polyaluminum chloride, is applied in a flocculation process to reduce iron ions in filter backwash water by stirring and sedimentation, achieving nearly 99% reduction of iron ions content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If synthetic polymers like polyacrylamide are used for flocculation, then flocculation efficiency is improved, but safety and environmental pollution worsen due to neurotoxic and carcinogenic monomers
Solution Approach 1:
The patent changes the chemical composition parameter from synthetic polyacrylamide to carboxymethylated starch, transforming the flocculant from a synthetic polymer to a modified natural polymer that eliminates toxic monomer contamination while maintaining flocculation efficiency
Solution Approach 2:
The patent uses carboxymethylated starch, a biodegradable natural polymer derivative, as a safer alternative to persistent synthetic polymers, allowing environmental degradation and elimination of long-term toxic accumulation
2Object-affected harmful factors
If natural polymers like starch are used for flocculation, then environmental safety is improved, but flocculation efficiency worsens compared to synthetic polymers
Solution Approach 1:
The patent uses carboxymethylated starch, a chemically modified natural polymer with introduced carboxymethyl groups, creating a composite structure that combines the environmental safety of natural starch with enhanced flocculation properties similar to synthetic polymers
Solution Approach 2:
The patent modifies the physical and chemical parameters of natural starch through carboxymethylation, changing its molecular structure to improve flocculation efficiency while preserving the biodegradable and non-toxic characteristics of the natural polymer
3Object-affected harmful factors
If carboxymethylated corn starch is used as flocculant, then environmental friendliness and safety are improved, but application complexity increases due to need for aqueous solution preparation
Solution Approach 1:
The patent uses water as an intermediary medium to dissolve carboxymethylated starch and create an aqueous solution, simplifying the application process while maintaining the environmental benefits of the biodegradable polymer
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 CMS-based flocculation process effectively reduces iron ions in filter backwash water, offering a safe and environmentally friendly alternative to synthetic polymers with comparable efficiency.
Implementation Method 1
coagulation and flocculation are used more and more often. The processes allow the destabilization and aggregation of particles suspended in water, which can be further removed from water by sedimentation
Implementation Method 2
The processes allow the destabilization and aggregation of particles suspended in water, which can be further removed from water by sedimentation
Data Source
AI summary
The method of technological water treatment remaining after rinsing filters in the flocculation process with carboxymethylated corn starch is characterized in that 1 mg/dm3 of Al3+ ions in the form of polyaluminum chloride is added to an aqueous suspension containing from 25 to 50 mg/dm3 of iron ions per each 1 dm3 preferably 30.91 mg/dm3 and stirred, next from 0.10 to 2ml preferably 0.20 ml of the 0.10% (w/ w) aqueous solution of carboxymethylated corn starch is added, constituting from 0.10 to 2mg/dm3 preferably 0.20 mg/dm3 in terms of dry weight, and stirred at the rate of 250 rpm for 60 seconds, and stirred again at the rate of 25 rpm for 15 minutes, and the thus prepared suspension is subject to sedimentation for 30 minutes using commonly known methods.