Boron (B): Boron is generally present in seawater at levels up to 5 mg/L. It is lower in inland lagoons. Boron is not a source of pollution, but it must be removed in the electronics industry due to its adverse effects in certain environments. Boron chemical
Similar to silicon, the pH is higher than 10, it exists in the form of a monovalent borate anion, and the pH is lower than 10, it
In the form of non-ionized boric acid B(OH)3, the removal rate of borate is related to pH value, and when the pH value is high, the removal rate is also high.
Silica (SiO2): Silica is an anion in some cases. Its chemical nature is very complicated,
Even unpredictable. TOC (in terms of carbon) indicates the total amount of organic matter and does not indicate the composition of organic matter. Similarly, the concentration of silicon
Only the total concentration of silicon is shown, but the concentration of various constituents of silicon is not indicated. The total amount of silicon in the water includes active silicon and colloid
silicon. Active silicon is soluble silicon that is weakly ionized and not polymerized into long chains. Active silicon is desirable in RO and ion exchange processes
The form is also the form of silica used by the IMSDesign software. Although active silica has anionic properties,
In the water quality analysis, it is not counted as an anion and anion balance, but is counted as TDS in the form of salt. Colloidal silicon is polymerized
Silicon or colloidal, closer to solids in terms of its properties. Colloidal silicon can be removed by the RO system, but may be caused at the front end of the RO
Colloidal pollution. The diameter of colloidal silicon can be as small as 0.008 microns, but only parts greater than or equal to 0.45 microns can be measured with SDI. Particulate silicon mixtures such as clay, silt, sand, etc. typically have a diameter of 1 micron or larger and can be measured by an SDI meter. The solubility limit of activated silicon is 100-150% under the conditions of using a silicon dispersant. When the temperature is raised and the pH is below 7.0 or above 7.8, the solubility of silicon increases, and in the presence of iron ions which catalyze the polymerization of silicon, the solubility of activated silicon decreases. In the RO system, the removal rate of silicon is closely related to the pH value of the raw water. As the pH value increases, the removal rate also increases.
More active silicon is present in the form of a salt rather than an acid.
Carbon dioxide (CO2): Carbon dioxide is a gas that reacts with water to form weakly carbonic acid (H2CO3) when dissolved in water.
If the carbon dioxide in pure water is saturated, its concentration is about 1600 mg / L, and the pH is about 4.0. Dioxane in natural waters
The source of carbon is based on the pH balance of bicarbonate. The concentration of carbon dioxide in a water body is indirectly determined by the correspondence between pH and bicarbonate concentration. Carbon dioxide and bicarbonate ions are in equilibrium between pH 4.4 and 8.2. Carbon dioxide was obtained at a pH of 4.4 and bicarbonate at a pH of 8.2. The IMSDesign program calculates the concentration of carbon dioxide in water using bicarbonate concentration and pH. Since carbon dioxide is a gas, the RO membrane does not have the effect of removing or concentrating it, and its concentration is the same in the water supply, the produced water and the concentrated water. The addition of acid to the feed water converts the bicarbonate to carbon dioxide, so the pH drops.
Hydrogen sulfide (H2S): Hydrogen sulfide is in a gaseous state, giving the water a smell of a foul egg. Its 0.1mg/L concentration is the odor of Pro
The cut-off value has a strong odor at a concentration of 3-5 mg/L. Hydrogen sulfide is easily oxidized by air, chlorine and potassium permanganate
Turn into sulfur. Sulfur acts like colloidal contamination and cannot be removed with conventional media filters. In the system design, it is recommended
The hydrogen sulfide remains in a gaseous state, allowing it to pass through the RO system into the produced water, which is then treated and removed.