US 20080290033A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2008/0290033 A1 Kimball et al. (43) Pub. Date: Nov. 27, 2008 (54) METHOD AND APPARATUS FOR RECOVERY Publication Classification OF WATER CONTAINING SILCA (51) Int. Cl. (75) Inventors: Robert J. Kimball, Helena, MT CO2F I/44 (2006.01) (US); Kenneth A. Klinko, San CO2F I/72 (2006.01) Diego, CA (US) CO2F L/70 (2006.01) gO, CO2F I/68 (2006.01) Correspondence Address: (52) U.S. Cl. ....................... 210/652; 210/639; 210/198.1 JOHN J. BROOKS, III 2O WYSTERAWAY (57) ABSTRACT WRENTHAM, MA 02093 (US) Disclosed are embodiments of a method and apparatus for the treatment of water containing silica in order to recover as (73) Assignee: CAMP DRESSER & MCKEE, much treated water from a water source as possible while INC., Cambridge, MA (US) minimizing the generation of waste products. Other embodi ments include removing specific elements from the water (21) Appl. No.: 12/126,326 Source and utilizing those elements. Embodiments of the method and apparatus uses in-line physical and physio (22) Filed: May 23, 2008 chemical treatment methods to remove potential biological, colloidal and hardness foulants continually so that there is Related U.S. Application Data minimal loss of water from the water source stream and (60) Provisional application No. 60/940,386, filed on May minimal addition of chemicals to accomplish removal or 25, 2007. reduction of these potential recovery-limiting foulants. 2 O 2O 2. High Pressure RO A" Stage Receive EnsureWater Hi'g Pressure Recover Water eWese Wat Receive High Pressure Characteristics Osmosis e Water Reverse Osmosis Permeate 7 Stream Permeate Stream Reject Reject Stream Patent Application Publication Nov. 27, 2008 Sheet 1 of 11 US 2008/0290033 A1 oll // ||| // Patent Application Publication Nov. 27, 2008 Sheet 2 of 11 US 2008/0290033 A1 Patent Application Publication Nov. 27, 2008 Sheet 3 of 11 US 2008/0290033 A1 Q~~· |ZZ Patent Application Publication Nov. 27, 2008 Sheet 4 of 11 US 2008/0290033A1 MOT3.Inssºud) J???OSXI Patent Application Publication Nov. 27, 2008 Sheet 5 of 11 US 2008/0290033A1 MOT?InSS3J&ON q6?Heunsseld ORI }} Patent Application Publication Nov. 27, 2008 Sheet 6 of 11 US 2008/0290033 A1 J??eNA Patent Application Publication Nov. 27, 2008 Sheet 7 of 11 US 2008/0290033 A1 2C2 Oxaeeunsseud XIOVWA Jau??JOS Je?eNA 30InOS Patent Application Publication Nov. 27, 2008 Sheet 8 of 11 US 2008/0290033A1 Patent Application Publication Nov. 27, 2008 Sheet 9 of 11 US 2008/0290033 A1 <!----yJe?eNW eunsseldub?H 36e?SOXI XIOVWA Jeu???OS 30InOS uue3.J?S ·H···H··· Patent Application Publication Nov. 27, 2008 Sheet 10 of 11 US 2008/0290033A1 Patent Application Publication Nov. 27, 2008 Sheet 11 of 11 US 2008/0290033A1 V Cd cdoo con-dw-Nv cN v cy co Od O V OO cy s O C O H US 2008/0290033 A1 Nov. 27, 2008 METHOD AND APPARATUS FOR RECOVERY In (b) the availability and costs of the wells and transmission OF WATER CONTAINING SILCA lines to a suitable well site meeting environmental regulations must be considered. In (c) existing wastewater facilities must CROSS-REFERENCE TO RELATED be nearby and may require capacity increases or unit process APPLICATIONS modifications to handle the flows. In (d) the costs of evapo 0001. This application claims the benefit of U.S. Appl. No. ration can increase the cost of treated water significantly. 60/940,386 filed on May 25, 2007 and entitled “Method and Currently, individual treatment technologies are typically Apparatus for Recovery of Water Containing Silica” the applied and the resulting processes either do not operate at entire contents of which is incorporated herein by reference. high enough efficiency, or still result in a significant amount of concentrated liquid waste stream that must be disposed of. STATEMENT REGARDING FEDERALLY 0011. As increased efficiencies have been pursued, solu SPONSORED RESEARCH ORDEVELOPMENT: tions are available that create additional issues. For example, 0002. Not Applicable it is well understood that a major obstacle for increased water recovery utilizing RO solutions is the presence of silica in the REFERENCE TO SEQUENCE LISTING, A water that creates Scaling problems as its concentration TABLE, ORACOMPUTER PROGRAM LISTING increases through more efficient recovery processes. One COMPACT DISC APPENDIX solution meant to address the silica problem to date involves continuously using acid and/or caustic additions to adjust the 0003) Not Applicable natural pH of the process stream to reduce the risk of scaling and allow higher water recoveries. One such solution is dis BACKGROUND OF THE INVENTION closed by U.S. Pat. No. 5,925.255, Mukhopadhyay, filed Aug. 0004. 1. Field of the Invention 12, 1997, which is herein incorporated by reference in its 0005. The present invention relates to a method and appa entirety. The required addition of chemicals to the water ratus for the treatment of water containing silica. More par treatment process increases the cost and complexity of this ticularly, the invention relates to a method and apparatus to particular Solution. treat water utilizing a novel combination of pretreatment and 0012 Solutions such as adding antiscalants to prevent pre reverse osmosis (RO) processes that result in a high percent cipitation of hardness ions and/or silica have also helped age of treated water output while lowering the amount of increase the recovery rate of some treatment processes. How chemical additions used in the process and lowering the ever, it has not been the general practice in the industry to amount of process waste. operate RO systems on brackish water sources at greater than 0006 2. Background of the Invention 90% recovery even with the addition of acid oran antiscalant/ 0007 Increasing demand for fresh water supplies has led sequestriant because of the scaling potential risks, thus lim to an increasing need to utilize brackish water sources. At the iting the water sources that can be recovered. same time, industries extracting inland groundwater must 0013 Because of these issues and other reasons, the com meet strict limitations prior to discharging that water. mercial viability of extremely high RO system recoveries 0008. These brackish waters usually contain silica at con where the concentration of solutes in the final reject is 10 to centrations that limit to the recovery of treated water for use 100 times the water source stream therefore has not been or discharge. When these brackish waters are used as a water established in practice. supply, it is beneficial to provide a treatment method that recovers as much treated water as possible. When brackish 0014. Because the RO process concentrates and separates water sources are proposed for use or discharged as a by simultaneously, the common teachings in the art are to adjust product of an industrial process, the cost of disposal of the pH of the feed stream to an RO system so that the ions, when concentrated waste stream is a primary consideration, as the concentrated by the process, remain in Solution and prevent purification technologies employed all generate a waste Scaling of the membrane. The teaching is also that the water stream. Maximizing the treated water and minimizing the recovery of the RO system is limited by the ion solubility waste stream are common goals of many treatment methods. product (Ksp) of the sparingly soluble ion pairs in the system, 0009. Depending on the treatment technology employed, and that reducing water recovery is a mitigating design the treated water quality desired and the location of the source response if pH adjustment is not sufficient. Given these chal and options for waste stream disposal, treatment methods lenges, chemical adjustment of the feed stream has been such as ultra-violet (UV) oxidation, micron filtration (MF), taught as the least expensive way to keep feed stream con ion exchange (IX), reverse osmosis (RO), evaporation and stituents in Solution. Some combinations thereof have been employed. 0015 Consistent with these approaches, popular water 0010. One issue related to addressing current solutions to treatment system modeling programs, such as those offered this problem is the Volume of the waste stream being gener by Dow and Hydranautics, put an upper limit of 1.5 times ated by the conventional treatment methods. Because the silica solubility as the upper limit of an aggressive water current processes are Volumetrically inefficient, a significant treatment method. At 25°C., this represents a silica concen waste stream is usually generated. Various disposal options tration of somewhere around 120-130 mg/L. In systems for the waste stream exist. Disposal options are generally where silica is considered to be more than 1.5 times the limited to (a) discharges to surface waters, (b) deep-well solubility, lowering RO system recovery is recommended by disposal, (c) discharges to existing wastewater treatment the major membrane manufactures. plants, or (d) natural or mechanical evaporation. All of these 0016. As water is becoming increasingly expensive, in disposal options are either not feasible or are costly for rea short supply, or both, it is desirable to further increase the Sons specific to that option. In (a) a Suitable receiving water ratio of the recovered water stream to the water source stream must be nearby and environmental regulations must be met. treated by RO systems. US 2008/0290033 A1 Nov. 27, 2008 0017. Therefore, there exists a need for a cost-effective feed water further includes an IX softener capable of pretreat water treatment process that operates at the highest efficiency ing the water source stream from the water source to create of water recovery possible, maximizing the efficiencies of the feed water. several processes to minimize the process waste stream Vol 0026.