Contaminated Impound Water Treatment via Ferrous Oxidation and Membrane Filtration
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Solution Overview
Problem
Contaminated impound water, including agricultural, hydraulic fracturing, and anaerobic digested sludge effluent waste, poses challenges due to high levels of selenium, arsenic, and uranium, which traditional methods struggle to treat effectively for environmental discharge or industrial recycling.
Innovation Solution
A process and system involving pretreatment with oxidation, pH adjustment, coagulant, and polymer treatment, followed by microfiltration and reverse osmosis, utilizing ferrous ions for advanced oxidation and specific membrane technologies to reduce contaminants, including the use of low molecular weight cationic polymers and inorganic coagulants, to produce canal-grade quality water.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional treatment methods are used to remove selenium, arsenic, and uranium from impound water, then some contaminant removal is achieved, but the treatment effectiveness is insufficient to meet environmental discharge standards
Solution Approach 1:
The patent changes the chemical parameters of the water by adjusting pH levels and applying oxidation processes to transform contaminants into removable forms. This enables the treatment system to achieve contaminant removal effectiveness that meets environmental discharge standards, resolving the insufficiency of traditional methods
Solution Approach 2:
The patent employs a composite treatment approach combining multiple mechanisms: oxidation chemicals, coagulants, flocculants, and membrane filtration. This composite material strategy achieves comprehensive contaminant removal including selenium, arsenic, and uranium at levels meeting environmental standards
2Manufacturing precision
If advanced oxidation and multiple treatment stages are implemented to achieve high contaminant removal, then treatment effectiveness improves, but system complexity increases
Solution Approach 1:
The patent merges multiple treatment functions into an integrated system where oxidation, coagulation, flocculation, and membrane filtration work in sequence. This combining approach achieves high contaminant removal effectiveness (selenium reduction exceeding 97.5% and uranium reduction of 99%) while managing system complexity through coordinated operation of treatment stages
3Manufacturing precision
If membrane filtration is used to achieve high contaminant removal, then water quality improves, but membrane damage and operational costs increase
Solution Approach 1:
The patent applies preliminary treatment stages including oxidation, coagulation, and flocculation before membrane filtration. This preliminary action removes bulk contaminants and reduces the load on membranes, achieving high water quality (selenium reduction exceeding 97.5% and uranium reduction of 99%) while minimizing membrane damage and operational costs
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 achieves substantial reduction of contaminants, with selenium reduction exceeding 97.5% and uranium reduction of 99%, enabling the production of water suitable for environmental discharge or industrial recycling with minimal membrane damage and low operational costs.
Implementation Method 1
a pretreatment stage wherein the contaminated water is oxidized
Implementation Method 2
treated with a coagulant, and treated with a polymer. The pretreatment to the contaminated water increases the physical size of contaminants and particulates in the contaminated water and to form a flocculent
Implementation Method 3
form a flocculent comprising bulk solids and fine particles
Implementation Method 4
The liquid portion containing fine particles is applied to a low pressure deadhead microfiltration unit to remove the fine particles from the contaminated water
Implementation Method 5
The resulting reacted solution containing the now bound contaminants is low viscosity, low tackiness and highly dewatered
Data Source
AI summary
Systems and methods for treating contaminated impound water are disclosed which include a pretreatment stage wherein contaminated water is oxidized, pH adjusted, treated with a coagulant, and treated with a polymer to form a flocculent comprising bulk solids and fine particles. The oxidizing step may include two or more stages, one of which is a treatment with ferrous iron generated from iron filings or steel wool. Bulk solids are removed, and the liquid portion containing fine particles is applied to a low pressure microfiltration unit to remove the fine particles resulting in a microfilter effluent. The microfilter effluent may be directly fed to a reverse osmosis (R/O) unit. The R/O reject may be recycled to another R/O unit (second pass). The R/O permeate may be blended as needed with the microfiltration effluent to provide the final discharge effluent with reduced contaminant levels and maximized throughput. The R/O second pass reject water is further oxidized and recycled back to the front of the system to be retreated.