ACCURATE, LOW-COST DEVICES FOR WATER QUALITY CONTROL

PRESENT TECHNIQUES FOR THE ANALYSIS OF INDUSTRIAL AND AGRICULTURAL WATER USE MODIFIED VERSIONS OF LABORATORY PROCEDURES. THEREFORE, THEY REQUIRE SKILLED LABOR, INSTRUMENTATION AND OFTEN MULTI-STEP SAMPLE PREPARATION WORKOUT. IN PRELIMINARY STUDIES, WHICH STEMMED FROM OUR WORK ON GAS ANALYSIS FOR THE DEPARTMENT OF DEFENSE, WE ESTABLISHED THAT AN ACCURATE ANALYSIS OF WATER CAN BE DONE USING A VERY SIMPLE DEVICE THAT CONTAINS A TITRANT AND A CHROMOPHORE. THE PROTOTYPES THAT WE HAVE BUILT (PHOTOS ARE INCLUDED) ARE 3" X 1" X 1/16" PLASTIC CARDS AND WEIGH APPROXIMATELY 1 GM EACH. TO MEASURE AN ANALYTE, THE USER HAS ONLY TO DIP THE CARD IN THE WATER FOR 10-60 SECONDS AND READ THE CONCENTRATION FROM THE LOCATION OF THE COLOR FRONT THAT DEVELOPS. THE OBJECTIVE OF THE PROPOSED WORK IS TO CONDUCT A SYSTEMATIC STUDY OF DIFFERENT PHYSICAL ARRANGEMENTS THAT CAN BE USED TO CARRY ON THE TESTS, AND TO EVALUATE ALTERNATIVE CHROMOPHORIC MIXTURES THAT CAN BE USED FOR THE ANALYSIS. IN THE PRELIMINARY WORK, DEVICES WILL BE DEVELOPED FOR THE ANALYSIS OF FIVE KEY WATER COMPONENTS: ACIDITY, ALKALINITY, CHLORIDES, SULFATES AND AMMONIA CONCENTRATIONS. DEVICES FOR THE ANALYSIS OF ADDITIONAL COMPONENTS WILL BE DEVELOPED IN SUBSEQUENT STUDIES. FOR EACH DEVICE, WE WILL EVALUATE THE SENSITIVITY,SELECTIVITY, AND THE RATE OF RESPONSE TO THE DESIGN ANALYTE. IN ADDITION, WE WILL CONDUCT PRELIMINARY STUDIES RELATIVE TO THE SHELF LIFE OF THE DEVICE AND THE REPRODUCIBILITY OF THE RESULTS. WE ESTIMATE THAT ABOUT 11,000,000 TESTS ARE CONDUCTED ANNUALLY BY GOVERNMENT LABORATORIES AND ABOUT 17,000,000 ADDITIONAL TESTS ARE CONDUCTED BY PRIVATE LABORATORIES TO DETERMINE THE CONCENTRATION OF DIFFERENT ANALYTES FOR WATER QUALITY ASSESSMENT FOR AGRICULTURAL USE, BOILERS, POLLUTION CONTROL,ETC. THE COST OF CONDUCTING EACH SUCH TEST IS $10-40 AND IT TAKES 20 MINUTES TO 2 HOURS TO COMPLETE EACH TEST. THE COST OF MANUFACTURING ONE TITRASTRIP(TM) TESTING DEVICE USING OUR METHOD IS ABOUT $0.5-1.25 EACH AND WILL TAKE THE USER LESS THAN TWO MINUTES TO OBTAIN THE RESULTS. MOREOVER,BECAUSE OF THEIR SMALL SIZE AND WEIGHT, THEY LEND THEMSELVES TO FIELD USE SINCE THE USER CAN PUT MANY OF THEM IN HIS WALLET. THE USE OF THESE CARDS WILL NOT ONLY REDUCE THE COST OF CONDUCTING WATER ANALYSIS BUT IT WILL ALSO IMPROVE THE QUALITY OF THE RESULTS SINCE IT WILL ELIMINATE THE OPERATOR AS A VARIABLE AND BECAUSE IT WILL ELIMINATE THE NEED FOR SAMPLE HANDLING. THE USERS WILL BE ABLE TO CONDUCT MORE TESTS BECAUSE OF THE LOWER COSTS AND THEREFORE AN OVERALL BETTER WATER QUALITY MANAGEMENT WILL BE ACHIEVABLE.