A simple flow injection analytical system for an automatic determination of phosphate in water samples using the molybdenum blue method was developed. Samples were injected and mixed with ascorbic acid used as a reducing agent. The absorbance of the resulting molybdenum blue complex was measured at 880 nm by a spectrophotometer. The optimal conditions of this system were 2 mL/min of carrier flow rate 1000 μL of sample volume 60 centimeters of mixing tube length and 0.020 mol/L of ascorbic acid. The proposed method showed reliability high sensitivity spend small amount of reagents and samples and fast sample throughput (52 samples/hour). The limit of detection (LOD) was 0.015 mg P/L of phosphate. Precision obtained injecting a phosphate standard solution of 0.50 mg P/L (n=10) was 1.81%. This system can be applied to determination of phosphate content in surface water samples in Lopburi province by comparing with a standard method. It was found that obtained from the developed system agreed well with the standard method using the pair t-test (tstat 0.04 < tcrit 2.36). This flow injection analysis system has no effect from arsenate and silicate interference for the analysis of natural water samples.

Water became an important factor for propelling production process of any industries or factories and groundwater was option for production cost reduction especially in areas where had no surfacewater. B.Foods Product International Company Limited an affiliate of Betagro Group was located in Lop Buri Province to daily consume huge quantity of groundwater for production process in its factory. Measuring and recording levels of groundwater in 2 ground tanks related to volume of the water at time point of every 3 hours must continually be done every day in order to prevent lack of water fed into the factory that may impact of its production process. The main problem was caused of unexpected non-working of pumps. Knowing fluctuation of water levels could provide their immediate improvement and recover to avoid serious impacts. A microcontroller board could be employed to control groundwater volume in order that the company could closely follow up levels of groundwater in the ground tanks in real time and continuity. This study went on designing the microcontroller board for managing utility system and maintenance by using with level meter and wireless receiver and transmitter for testing working efficiency every 3 hours of each everyday during 1 February 2016 till 11 March 2016 totally 40 days. It was compared with those of same duration done manually. The findings revealed that the figured from 2 methods became similar and had very close relationship with each other. This could indicate that the simulated microcontroller board could be employed to automatically control groundwater volume efficiently. The company could bring it to appropriately trace levels of groundwater in the tanks in accordance with water usage behavior in each period of time for disruption of production process caused of insufficient quantity of groundwater. And this could be adaptable benefits for improvement of any organizations and also for any further studies