MODULAR FLUID FILTRATION SYSTEM

The Multi-functional Modular Fluid Filtration System (MMFFS™) relates to the field of water purification, and in particular concerns a modular mobile water purification system for use by military forces in the field. The water purification system includes a portable multi-functional filtration unit having configurable modules. The modules can be adapted to render environmental water potable or to isolate contaminants from groundwater or water from other sources such as backwash from reverse osmosis water purification units (ROWPU), membrane cleaning chemicals and wastewater from field laundry and shower units. The MMFFS™ permits safe environmental discharge of treated water, or allows the wastewater to be recycled for utility use or reused by the ROWPU as feed water. The MMFFS™ then substantially decreases the need to truck contaminated water away for disposal or for treatment. In addition to the efficient post-treatment of ROWPU discharge, the MMFFS™ can also be used as an effective and economical solution to the problem of pretreatment for the ROWPU when source water is highly contaminated, i.e.; with Nuclear, Chemical and Biological agents.

Background

A large amount of the natural water on the Earth is seawater or brackish water that is not suitable for human consumption due to the presence of salts and sediments. So-called fresh water may likewise be unsuitable for human consumption because it may contain deleterious compounds, such as bacteria or other microorganisms. Furthermore, groundwater and surface can become polluted by the actions of man. In such instances it is known to treat the water by filtration and chemical treatment steps.

Filtration involves passing water through a filter medium that stops pollutants and passes pure water. The filter medium must be cleaned or replaced when its capacity is met. A highly effective mobile filtration and purification apparatus used by the military is the reverse osmosis water purification unit or "ROWPU".

Reverse Osmosis is a method that effects the separation of solutes from a solution by causing the solvent to float through a membrane at pressure higher than the normal osmotic pressure. This is possible because of the phenomenon of osmosis. Osmosis is a phenomenon manifested by the diffusion of a solvent (such as water) through a semi-permeable membrane from an area of greater osmotic pressure (i.e., greater concentration of dissolved substance) to an area of lower osmotic pressure (i.e., lesser concentration of dissolved substance.) In reverse osmosis, the solvent diffuses through a membrane filter leaving dissolved substances, such as salts and other contaminants, behind.

Reverse osmosis purification equipment is readily sized for a particular application simply by providing the requisite area of membrane and a suitable pump. Therefore, reverse osmosis purification units are ideally suited for use at remote sites, and are conveniently transported on trailers.

These units are available in various capacities and typically are carried on trucks having such pumps and conduits as necessary to filter water from available sources. In this apparatus, water is pumped through a multimedia filter and then is forced through a membrane that passes pure water and concentrates pollutants in the water on the upstream side of the membrane. In addition, it is periodically necessary to flush or backwash the ROWPU multimedia filter and or hyper-filtration membranes to release collected contaminants from them. As the concentration of the contaminants in the raw water increases to a given limit, the throughput through the ROWPU decreases for a given pump head pressure. Also, the membrane may become caked with contaminants on the high-pressure side.

As a byproduct of hyper-filtration and/or backwashing, the water on the high-pressure of the membrane, known as the "brine," or "concentrate", carries a higher concentration of contaminants then the source water. Depending on the time used and the extent of contaminants in the source water, the concentration of contaminants in the "concentrate" and/or backwash can be sufficient to render the water unfit for discharge into natural watercourses, which could become polluted. As a result, part of the water carrying capacity of a mobile military unit is devoted to transporting concentrate and backwash to municipal or similar fixed installations for discharge.

Conveniently, during military training operations, the backwash is captured in hard walled water tankers. Once one tanker is filled, the composition of its contents is determined via well-known analytical methods. The contents of the tanker are then chemically treated. The tanker's contents are analyzed a second time. This process continues until the contents in the tanker are brought into compliance with EPA limits (NPDES) for sewer system disposal. Once in compliance, the contents are taken to a sanitation disposal site and discharged. The process of collecting and transporting concentrate (brine) and backwash, and treating and safely discharging it, requires the commitment of time and equipment. For example, it is conceivable that several tankers may need to be staged and available for collection and transport functions, each having at least one associated person on duty, in order to support the continuous operation of a ROWPU. What is needed is a multi-functional modular water filtration unit that can be adapted to treat different concentrations (brine) compositions, and which can be used in the field to render the concentrate (brine) and backwash sufficiently pure to be discharged in the same area where the source water was collected, or at least to meet the minimum environmental protection standards for discharge into municipal sewage systems. By treating the concentrate and backwash in the field, the present invention eliminates the costs of permitting, batch hauling and discharge fees associated with conventional means of treatment; reduces the risks of spillage and substantially decreases the man-hour and equipment requirements associated with current military wastewater handling methods.

The multi-functional modular water filtration unit as described herein may be easily interfaced to optimize throughput capacity versus extent of filtration, using parallel and serial configurations of filtration elements interconnected by reconfigurable fittings. In a similar manner, the filtration media can be conveniently and effectively modified to facilitate operation in a variety of circumstances and for different specific pollutants. In a preferred arrangement, a modular brine/backwash filtration unit coupled to a ROWPU can be configured using the filtration elements to treat backwash from a ROWPU sourced by a natural watercourse or municipal supply; to treat sanitary wastewater from showers, laundry facilities and the like; to treat water containing nuclear, biological and chemical (NBC) contaminants before ROWPU use; to remove chemical contaminants such as oils and fuels; and to pre-treat municipal source water supplies, for example to eliminate chlorine that tends to damage reverse osmosis membranes.

Summary

The purpose of the MMFFS™ is:

• To provide a water filtration unit, which is portable and easily transported to remote locations wherever troops may be deployed.
• To provide a water filtration unit which is modular in design such that multiple units may easily be arrayed together to satisfy the capacity requirements for a given application.
• To provide a water filtration unit which is very flexibly reconfigurable and which easily may be modified to filter from the raw water a wide variety of different contaminants including nuclear, biological and chemical compositions.
• To provide a water filtration unit comprising a bank of water purifying tanks wherein the bank may quickly and easily be removed from the unit and replaced with a fresh bank.
• To provide a water filtration unit wherein the unit may quickly and easily be modified to accommodate changes in the contaminant composition in the raw water fed to the unit.

©1996-2012 TerraGroup Corporation. All rights reserved. TECWAR^® is a registered trademark of TerraGroup Corporation. MULTIFUNCTIONAL MODULAR FLUID FILTRATION SYSTEM™, DRED™ and MMFFS™ are trademarks of TerraGroup Corporation. RECOR^®, MMFFS™, PRO™, and all TECWAR® systems are protected by one or more of the following U.S. Patents: 5,972,216, 5,788,858 and 6,395,168 B1 and other U.S. and foreign Patents pending.