Q. What does the Blue Spring PrecipROTM Waste Water Recycling system do ?
A. It does three things. (1) It treats waste water to recover metal ions and other precipitable impurities in a compact form of a solid cake (2) It purifies treated waste water by a reverse osmosis membrane process (3) It recycles the purified water for re-use.
Q. What are the unique features features of Blue Spring PrecipROTM Waste Water Recycling system ?
A. (1) It is all-in-one waste water treatment system, water recycling system, and water purification system (2) It is a continuous, closed-loop system. That means the flow of waste water into the system and the flow of purified water out of the system are continuous. That also means no water is added or removed from the system, at least in the ideal situation (3) It is an ideal separation system for water and certain kinds of impurities which can be converted to a different phase. Most common phase is solid-phase but a distinct liquid-phase and gaseous phase can be used for the separation of impurities from water. Ideal means the separation is 100%. Both water and the impurities can be recovered with 100% efficiency, at least in the ideal situation (4) It is the most economical process of separation of impurities from water, when it is applicable (5) it is the most environmentally friendly system available for waste water recycling because of its extra-ordinary efficiency of separation of impurities from water and because of its extra-ordinary energy-efficiency.
Q. How close is Blue Spring PrecipROTM Waste Water Recycling system close to ideality?
A. (1) Regarding conservation of water: Generally, water is lost by evaporation and by way of disposal of solid cake which is wet. Also, small amounts of water is inevitably lost in some cleanup operations. Typical water conservation efficiencies run close to 98%-99.5%, ac\after accounting for the inevitable losses (2) Regarding purity of recycled water: The recycled water is typically of the same purity or better better than the source water used in the open-loop process. (3) Regarding the ideality of separation: Impurities that are precipitable are removed almost 100%. Impurities that are not precipitable accumulate in the system, in a tank. They must be purged out of the system either periodically or continuously.
Q. What does the Blue Spring PrecipRO water recycling system NOT do ?
A. (1) It does not make chemicals disappear. It only separates them from water (2) It does not handle waste water concentrated in non-precipitable impurities such as salts of alkali-metals, acids or alkali. This limitation is placed by the osmotic pressure limitation of reverse osmosis processes (2) It does not handle air-pollution problems (3) It does not recover soluble salts of alkali metals, acids, or alkali, although they are recovered as concentrated liquor which may be further processed by conventional methods to recover these salts, acids, alkali, if required.
Q. How does the Blue Spring PrecipROTM waste water recycling system work ?
A. The system is based on a patented process (U.S. Patent No. 5403490). It operates in a working cycle which consists of the following basic steps. Water picks up contamination generated by the target process operation. The contaminated waste water enters the Blue Spring PrecipROTM system. The waste water is treated in a process vessel, so that the precipitable contaminants form a precipitate. The precipitate is removed by a suitable liquid-solid separation device if it is in a solid form, or by liquid-liquid separation device if it is in a liquid form, or a liquid-gas separation device if it is in gaseous form. The water is then purified by reverse osmosis and the purified water is recycled to the original process.
Q. What happens to the impurities separated in the PrecipROTM waste water recycling system ?
A. This depends on their toxicity, their value and their amount. For example, in electro-plating rinse water recycling applications, the impurities are separated in the form of a solid cake which contains metal hydroxides. Most metal hydroxides in the solid form are not considered highly toxic. They can be usually disposed of in ordinary designated disposal sites. Or, if they contain valuable metals, they can be sent to the metal refinery for metal recovery. Cake containing gold, silver, platinum, palladium are valuable and they are best sold to refineries. Cake containing chromium, nickel or copper are not highly valuable but if they are available in large quantity, they may be sold to refiners. Cake containing iron or zinc or aluminum generally do not have salvage value. If the metal hydroxide cake is designated by EPA as toxic, then it must be disposed of in designated disposal sites.
In chemical processing applications, certain valuable industrial chemicals may be recovered in a pure form as the result of the PrecipROTM waste water recycling process. They may be recycled back to the original process or they may be sold as a byproduct. The salts of alkali metals which are present in the concentrated liquor are generally do not have commercial value and they are not toxic. They can be discharged either to the industrial sewer by EPA permit, or they can be hauled away to designated disposal sites, which would be the zero-discharge implementation of the PrecipROTM system.
Q. Is Blue Spring PrecipROTM process a zero-discharge process ?
A.Yes. In the standard implementation of the process, there is no discharge to the public sewer anytime during operating cycle of the system. The impurities which are separated from waste water are hauled away to a different location such as disposal site or metal refinery.
In some situations, it may be more economical to discharge the concentrated waste liquor to the industrial sewer and haul away the solid impurities. in this case, it is not a zero-discharge process. The amounts of these by-products are very small in comparison with the amount of waste water.
Q. How does PrecipROTM system differ from a conventional waste water treatment system?
A. First of all, the goal of a conventional waste water treatment system is to assure that the water discharged from the facility meets the applicable environmental regulations. The goal of Blue Spring PrecipRO system is three-fold: (1) to recover and recycle water thereby saving operating costs (2) to recover valuable impurity chemicals for recycling or sales thereby improving profitability (3) Eliminate or reduce discharge to the environment thereby avoiding environment pollution.
The conventional waste water treatment processes consider water as a disposable commodity. Blue Spring PrecipROTM process treats water as a valuable working fluid that should not be dumped down the sewer.
Blue Spring PrecipROTM is capable of precipitating out impurities (or valuable chemicals) with 100% efficiency which no other waste water treatment process or chemical separation process is capable of.
In a regular separation processes, process control is critical because the efficiency of separation is dependant on the exact value of the process parameter. For example, in precipitation of metal ions in the form of hydroxides the pH control is critical because the residual metal ion concentration is a function of the operating pH. In the Blue Spring PrecipROTM process control is not critical. Non-optimum value of the separation parameter has very little effect on the final separation efficiency, which is always 100%. There are practical reasons for controlling parameters such as pH in the PrecipROTM process, but they are not related to the fear of violation of EPA regulations.
Blue Spring PrecipROTM speeds up the separation process by a factor of 5 or more compared with conventional waste water treatment processes and conventional separation processes because the PrecipROTM process is carried out under highly concentrated conditions.
In the Blue Spring PrecipROTM process, the total amount of metal ions leaking out of the facility into the environment is reduced by a factor of 10 - 40 compared with conventional metal ion precipitation processes. Another advantage of the PrecipRO system is that the final liquid sludge being very small in volume, it can be batch-treated for further precipitation of metal ions, if it is required to do so. In the conventional precipitation system, such batch treatment system is not practical because of the large volumes of waste involved.
The second technical advantage is reduced consumption of certain chemicals. In regular precipitation systems, excess quantities of chemicals are invariably used to speed up precipitation and to prevent particles of metal hydroxides from leaking out in the overflow. These chemicals include neutralizing agents, oxidizing/reducing agents, Coagulating agents and flocculating agents. These excess chemicals are lost in the waste stream and they can present additional environmental hazard. In the PrecipRO system, the excess chemicals are retained in the system at all times. That means the consumption of chemicals is almost quantitative. reduced chemical consumption means less operating cost and better environmental protection. Typical reduction in the chemical consumption is 50% - 80%.
The operating cost of PrecipROTM system is about the same as the operating cost of the regular waste water treatment system, or slightly higher. While the reverse osmosis stage adds to the operating cost, the reduction in chemical consumption saves on the operating cost. If the savings in water bill, sewage charges, permit fees, analysis fees and violations are taken into account, then the overall economics of the PrecipROTM system is unquestionably favorable to that of a typical waste water treatment system.
The equipment cost of PrecipROTM system is higher than the conventional waste water treatment system because of the additional RO unit and other equipment requirements. The difference in equipment cost may not be much because conventional systems require multi-stage reactors and precise pH controllers.
In summary, as a waste water treatment system, a PrecipROTM system is more economical to operate, is far less sensitive to pH control, results in a couple of orders of magnitude (1/10 to 1/40) less discharge and is far more environmentally friendly. While conventional waste water treatment systems show negative cash flow, the Blue Spring PrecipROTM system shows positive cash-flow. That means it is worthwhile to install the PrecipROTM system even if there were no environmental regulations in force simply on business-economics grounds.
Perhaps the biggest advantage of Blue Spring PrecipROTM system over the conventional waste water treatment system is the freedom from environmental liquid discharge regulations for now and in the future.
Q. How does the Blue Spring PrecipROTM system differ from chemical precipitation system ?
A. The Blue Spring system overcomes the limitations and uncertainties of the conventional chemical precipitation system and it enhances the efficiency of the chemical precipitation system. The conventional precipitation system requires a huge reaction tank to reduce the concentration of the metal ions to an acceptable level. The Blue Spring system can use a tank about one quarter the size of the tank required by the conventional system. The conventional chemical precipitation leaves a discharge. The Blue Spring system has no discharge. Different metal ions precipitate best under different pH conditions. The conventional precipitation system is extremely sensitive to the pH conditions inside the precipitation tank so much so that it is impossible to remove different metal ions efficiently within one tank. The Blue Spring system is not critically sensitive to pH and it removes all metal ions with 100% efficiency using a single tank.