... what does and does not work in remediating the presence of drugs in drinking water There is no question that subtherapeutic doses of these compounds are finding their way into the surface and groundwaters ... chlorine to form N-chloroamines that can further decompose The kinetics and mechanisms of sulfamethoxazole, trimethoprim, and three fluoroquinolone antibiotics (ciprofloxacin, enrofloxacin, and ... after ingestion, and inconsistencies inthe way they are disposed make their presence inthe aquatic environment inevitable Their sources in natural waters are not limited to excretion of parent...
... cadmium in drinking water The study involved exposure of male and female rats to cadmium chloride in drinking water, from the beginning of gestation, through postnatal growth and maturation and one ... (Hutton, 1987) The earliest indication of kidney damage is the presence of low molecular weight proteins (alpha, beta, and gamma globulins) inthe urine These appear inthe urine because of failure ... appearance of small proteins and other chemicals inthe urine To ensure that cadmium levels inthe kidney will not reach the critical level during the course of a lifetime, the intake of cadmium must...
... the sample into the solvent reservoir The water sample will drain into the cartridge, and from the exit into the suction flask Maintain the packing material inthe cartridge immersed in water at ... part ofthe performance test The correct setting ofthe baseline threshold, as indicated by the presence of low intensity ions, is the next most important part ofthe performance test Finally, the ... acetate and elute the cartridge with this rinse into the collection tube Wash the inside ofthe separatory funnel andthe sample jar with mL methylene chloride and elute the cartridge, collecting the...
... inthe northern regions ofthe country, nestled against China and Nepal The region of Uttarakhand is the origin of many ofthe two major rivers of India, the Ganga andthe Yamuna from the snow-capped ... filtration since the beginning of written history In Exodus 7.24 ofthe Bible states And all the Egyptians dug round about the Nile for water to drink, for they could not drink ofthe water ofthe Nile. ... scraping the name can be misleading unless the scraper is automated In remote locations, the filter can be cleaned by draining the water, drying the sand, and scraping the Schmutzdecke off the...
... overview of particle counting, including the basic principles of operation, applications inthe treatment process, andthe fundamentals of installation, operation, maintenance, data collection, and ... Instrumentation and Design, Inc., for assistance in clarifying some ofthe issues with software and SCADA integration Most ofthe manufacturers have been generous in providing materials and information ... overview of particle counting, including the basic principles of operation, application inthe treatment process, andthe fundamentals of installation, operation, maintenance, data collection, and...
... without the need for chemical additives In these applications, the integrity ofthe membrane is all that stands between the source water andthe finished product, with the exception ofthe chlorine ... less, andthe particle counter affords a simple way of measuring how well the task is being accomplished The most basic application is that of determining whether the filters are performing properly ... win every time I’ve only got to win once.” Cryptosporidium and Giardia are parasites that live inthe intestinal tracts of cattle and other mammals They are spread into source waters by runoff...
... PARTICLE COUNTING Most clogs of this type can be removed by reversing the sample flow through the flow cell Remove the inlet and outlet tubing, and connect the inlet tubing to the outlet port ofthe particle ... variations and their effects on the tubing The only way to determine if the particle buildup inthe tubing is causing problems is to make note of changes inthe data output when the tubing is replaced ... understand particle counters or how they are used The best way to keep particle counters maintained and operating properly is to provide the staff the training to understand the importance of the...
... provide a broad overview ofthe available options, andthe rationale behind each Technical information for these approaches are covered in Parts II and III ofthe book Determining the best approach ... necessary to gauge the commitment of plant management andofthe operations and maintenance staff to particle counting If minimal interest is shown inthe technology, then the simplest, lowest-cost ... preparing for the last war, and, when it comes to streamlining for SCADA interface, most ofthe particle counter manufacturers seem to be awaiting the invention of gunpowder Whatever the reasons, their...
... piece of flexible synthetic tubing Particles from previous samples can collect on the outside and inside of this tubing, skewing the resulting data The outside of this tubing should be rinsed ... manageable The following guidelines are presented to offer an example, and can be adjusted to meet the needs ofthe particular situation Operator Training The first step is proper training ofthe operators ... determine the practical concentration limit ofthe particle counter grab sampler, and then back off that number another 25% or so This concentration then becomes the cutoff point for diluting the...
... structure ofthe flow cell windows cause minute scattering and blurring ofthe laser light source The combination of all these factors results in a noise level that can be observed and measured ... phenomenon Inthe case ofthe particle counter, noise is produced by the electronic detector circuit, the laser light source, the power supply, and is induced by other devices The imperfections inthe ... Basically, it is the “coincidence” of two or more particles inthe sensor view volume at the same time, which is a function ofthe concentration of particles inthe sample There are other factors...
... mounting the laser and other optical lenses on a single block or in a tube This “subassembly” is then bolted to the flow cell The detector electronics assembly is mounted to the opposite side ofthe ... Different grades of sapphire are available The entrance window (the side where the laser enters before passing through the flow cell) must be of a higher grade than the exit window The beam must ... contacts the particles Since the detector is measuring total light energy, it is not greatly affected by some diffusion inthe exit window The entrance window is covered with an antireflective coating...
... in amplitude in proportion to the size ofthe particle The counting electronics then sorts these pulses and counts them according to size To achieve this, the counter must be able to discriminate ... being reduced at the standard flow rate C COUNTING ELECTRONICS Several types of counting electronics are found inthe particle counter industry All of them serve the same end, which is to sort and ... available with the simplest, and move up in complexity from there The output ofthe counter electronics will either be inthe form of a to 20 mA signal or a digital output designed for computer interface...
... ANALOG INPUTS One ofthe most useful features ofthe more-advanced models of particle counters are the auxiliary analog inputs These provide a means for trending the outputs from other instruments ... FEATURES 95 As outlined above, the number and location ofthe analog inputs should be sufficient for all required instruments, and convenient for installation A spare input can come in handy for future ... means of scaling the count output to conform to the limitations ofthe to 20 mA signal Some ofthe units provide a selectable sample time period The counter counts continuously during the sample...
... “protocol.” These protocols are not standardized, and a lot of effort can be expended in “translating” the data into usable form Many laypeople are confused by the distinction between the industry standard ... be supported Most ofthe signals will be inthe form of to 20 mA current loops Serial interfaces are becoming more common, with the growing complexity of newer instruments andthe need for greater ... inhibiting the rest ofthe tasks required ofthe SCADA system The ever-increasing speed of available computer hardware will make this easier to achieve F SORTING OUT THE OPTIONS As mentioned in Part...
... the “pizzazz” into particle counting The software is what the operator sees and interacts with, so it will naturally be the most appealing part ofthe system Now that the importance ofthe software ... motherboard b Mouse and Keyboard The mouse and keyboard are the means of controlling and inputting data into the computer Several types of mice and keyboards are available, most providing different ... selection Some of them maintain good records of each machine sold, and can quickly access that information The small shops will not be able to maintain such records, placing the burden on the user...
... from the standpoint of mounting space Most filter galleries provide plenty of room to mount instruments The size ofthe enclosure is more important from the standpoint of access to wiring terminals, ... simplified if the AC power does not have to be handled When the enclosure must be opened for cleaning the sensor, the time and effort required is increased This makes the task of maintaining the sensor ... good deal inthe last few years That said, many of them still run the sample into the NEMA enclosure, providing the greatest potential for leaks and hazards Passing the sample into the enclosure...
... more often As was the case for the online units, cell cleaning involves removing and reinstalling sample tubing to the sensor, which increases the likelihood of leaks The pump, strainer, and battery ... particles into the sample The pressure forces the sample up into a stainless steel tube, which is connected to the inlet ofthe particle sensor The sample passes through the particle sensor, and into ... to form, affecting the optical clarity ofthe cell With many different types of samples being run through the same sensor, it becomes easier to contaminate the cell windows The tubing may need...
... time These sizes should include the lower sensitivity ofthe particle counter (usually µm) and or 10 more sizes covering the full sizing range ofthe particle counter These standards are introduced ... ofthe brightly displayed pulse, and reading its value from the oscilloscope grid The PHA, on the other hand, provides a complete histogram ofthe pulses, allowing the amplitude to be determined ... a significant increase inthe cost ofthe units F FIELD VERIFICATION OF CALIBRATION One area of increasing relevance is that of field verification Although the cost and complexity of in- house calibration...
... currently marketing drinking water systems through US Filter in North America At the time of writing, the current manufacturers offering particle counting equipment inthe drinking water industry are ... particle counting product line to another manufacturer, to prevent a “monopoly” inthe drinking water industry This despite the presence of Hach and Chemtrac and somehow in ignorance ofthe virtually ... PMS As part of this agreement, PMS ceased any direct marketing inthe water treatment industry Inthe biggest “off-field” development inthe particle counting industry, around the end of 1995, Pacific...
... tubing are then run from the sensor inlet and outlet to nylon quick-disconnect fittings mounted on the walls ofthe NEMA box The external sample tubing is then connected to these fittings IBR uses ... to synthetic sapphire C SAMPLE FITTINGS Sample fittings vary among the different manufacturers, with the simplest being the nylon barb fittings found on the Chemtrac particle counters Since the Chemtrac ... altered, affecting the sizing accuracy ofthe sensor If the mechanical alignment is altered or loosened, the calibration will be affected, and leaks could occur The directions for replacing the flow...