High Efficiency Water Softening Process Using Carbonate Alkalinity
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Solution Overview
Problem
Conventional water-softening processes are inefficient in removing a broad range of contaminants, particularly at high levels, and often require expensive materials, high energy consumption, and complex pretreatment processes, while also generating significant waste and requiring frequent regeneration of ion exchange systems.
Innovation Solution
A novel water-softening process that uses carbon dioxide and/or carbon monoxide in an alkaline solution to create bicarbonate or carbonate ions, operating at elevated pH levels (10.5 to 14), which effectively removes contaminants like calcium, magnesium, barium, strontium, and other impurities without the need for expensive materials or high energy, and produces a minimal waste stream.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional water-softening processes use lime and soda ash as primary chemical agents, then bicarbonate and carbonate alkalinities are delivered, but the process is limited to relatively low levels of hardness (mostly Ca and Mg) and cannot effectively remove a broad range of contaminants
Solution Approach 1:
The patent raises the pH level parameter to 10.5-14.0 (above conventional processes that operate below pH 10.5) and uses carbonate/bicarbonate chemicals to create conditions where a broad spectrum of contaminants (Ca, Mg, Ba, Sr, Cu, Zn, Fe, Mn, Al, silica, TOC, oil, grease, TDS, TSS) precipitate effectively, achieving both high versatility and reliability across diverse contaminant types and concentrations
Solution Approach 2:
The softening process is designed to simultaneously remove multiple types of contaminants (metal cations, non-metallic ions, organics, suspended solids) through a single integrated high-pH precipitation mechanism, making the process universally applicable to various water types including surface waters, well waters, waste waters, produced waters, and process effluents with different contaminant profiles
2Reliability
If conventional processes operate at pH levels below 10.5, then the process is simpler to control, but contaminant removal efficiency is significantly reduced
Solution Approach 1:
The patent deliberately changes the pH parameter to the high range of 10.5-14.0, which thermodynamically favors the precipitation of diverse contaminants. The use of carbonate and bicarbonate chemicals provides buffer capacity that helps maintain stable pH conditions, and the high-pH environment enhances the solubility product expressions for multiple metal hydroxides and carbonates, achieving superior removal efficiency despite the increased pH control complexity
3Reliability
If conventional lime softening processes are used, then the process can handle high hardness levels, but it is difficult to ensure that lime goes effectively into solution
Solution Approach 1:
The patent replaces lime (CaO) with carbonate and bicarbonate chemicals (such as sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate) that have superior solubility characteristics. These chemicals dissolve readily in water without the operational difficulties associated with lime, providing reliable hardness removal through precipitation reactions while eliminating the dissolution problems that plague conventional lime softening processes
4Reliability
If hot lime softening processes are used, then effectiveness is improved, but the process must be conducted at elevated temperatures increasing energy consumption
Solution Approach 1:
The patent changes the temperature parameter from elevated (required for hot lime softening) to ambient or near-ambient conditions. The high-pH precipitation mechanism using carbonate/bicarbonate chemicals is effective at lower temperatures because the chemical reactions are driven by pH and solubility product relationships rather than thermal energy, significantly reducing the energy input required while maintaining softening effectiveness
5Reliability
If conventional processes are used, then treatment is achieved, but significant waste streams are generated requiring disposal
Solution Approach 1:
The patent minimizes waste generation by using carbonate and bicarbonate chemicals that form soluble sodium or potassium salts as byproducts (rather than calcium salts that precipitate as waste). The precipitation process concentrates contaminants into minimal sludge volumes, and the soluble salt byproducts remain in the treated water, reducing the volume of waste requiring disposal while maintaining effective contaminant removal
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 process achieves high-efficiency removal of contaminants, reducing them to negligible levels, with minimal energy consumption and using inexpensive materials, and allows for the recovery of treated water, making it suitable for zero liquid discharge applications.
Implementation Method 1
adding at least one of carbonate or bicarbonate to the quantity of the water stream in an amount at least equivalent to the contaminants in the quantity of the water stream
Implementation Method 2
separating the solids from the quantity of the water stream
Implementation Method 3
separating the solids from the quantity of the water stream
Data Source
AI summary
A high-efficiency water softening process is disclosed. The softening-process is particularly effective for the treatment of water process streams containing a broad array of contaminants, such as Ca, Mg, Ba, Sr, iron, aluminum, manganese, copper, zinc, silica, TOC, oil, and grease. The softening-process includes steps of: (a) adding carbonate ions and hydroxide ions to said water process stream until the process stream pH is raised to between at or about 10.5 and at or about 14.0; (b) optionally adding a coagulation aid so as to facilitate the creation of separated solids comprising a substantial portion of the contaminants; (c) optionally adding a polyelectrolyte so as to facilitate the creation of separated solids comprising a substantial portion of the contaminants; and (d) phase-separating the separated solids so as to remove the contaminants and produce a highly purified water process stream.