Glass and bottle testing: from laboratory to wastewater treatment plant
Glass and bottle testing: from laboratory to wastewater treatment plant
Jar Test can correctly select and add chemical coagulants to remove suspended solids and pollutants in the treated water of sewage treatment plants. The choice and dosing of chemical coagulants was actually derived from the results of laboratory Jar tests simulating the full operation of a water treatment plant. The most commonly used coagulants are lime (calcium hydroxide), alum (aluminum sulfate) and iron salts (ferric or ferrous).
Coagulation is the basis of every water treatment process, it is the pre-treatment step of sedimentation, filtration and disinfection before residential and industrial water is distributed. Using an aggregator, add the coagulated material to the water sample beaker. The chemical coagulant begins to settle, traps all impurities and forms a coagulate, which settles to the bottom of the beaker. Stir the sample continuously to observe the formation, development and precipitation of condensate, as in a simulated water treatment plant operation.
The operator then runs a series of tests comparing the effect of different amounts of coagulant at different pH values to determine the appropriate size of agglutinate.
The most common analytical conditions using aggregators are:
- 1000 ml glass beaker (jar), tall type, Ø 105 mm
- 600ml wastewater sample + coagulant
- Paddle height: mid-sample height
- Turbulent agitation: 120 rpm, 120 seconds
- Slow flocculation: 30 rpm, 25 minutes
- first evaluation after 5 minutes of settling
Evaluation of results for comprehensive application and optimized performance:
The results of the Jar test can be evaluated according to different criteria:
- Estimate the size of agglutinates numerically
- Time from addition of chemical to first appearance of agglutinate
- Evaluation of residual turbidity by means of a turbidimeter after a defined settling time
- EMF measurements of suspended particles on samples taken immediately after addition and mixing of chemicals
- Evaluation of filterability of clarified water by standardized membrane filters under pressure. The reduction in water flow is related to the degree to which the filter is clogged with residual unsettled suspended matter
VELP Agglutination Special Solutions:
Jar Test helps water treatment plant laboratory operators avoid overdosing, especially with coagulants, to save resources and optimize processes. VELP solutions for Jar Test are robust devices with high resistance to chemical and mechanical corrosion. The illuminated rear panel allows easy and clear observation and evaluation, maximizing reproducibility. The VELP agglomerators of the JLT and FCS series have multiple agitators and reproducible speeds to ensure standard conditions. With independent speeds for each position or a single speed with digital display and timer, the VELP agglutinators meet the requirements of every laboratory. Whenever the need arises, the VELP FP4 is a portable flocculator that can be tested on site.
VELP official text sharing:https://www.velp.com/en-ww/the-importance-of-jar-test-in-water-and-wastewater-analysis.aspx