In precipitation process, large volumes of sludge are generated which can present dewatering and disposal problems , as well as re-carbonation of the softened water are needed . Ion-exchange resin have been widely used to remove calcium and magnesium ions due to their many advantages, such as high capacity and fast kinetics [12-14]. However, ion-exchange resins must be regenerated by chemical reagents when they are saturated and the regeneration can cause serious secondary pollution. In large scale, application of resin is expensive . In recent years, various method such as nanofiltration [15, 16], capacitive deionization , electrodialysis , electrochemical treatment  and, adsorption [20, 21] have been widely studied for ions removal from aqueous solution, especially water softening.
The experiment was conducted in the following manner: The test sample placed in the photoreactor and, the glass window was attached. Simultaneously, the flow was stabilised in an empty line that directly connected to the NOx analyser. Next, the test gas was allowed to flow over the sample in darkness and the change in the volume fraction of NO and NOx was recorded. After maintaining of the gas flow, the sample was exposed to ambient light for 60 minutes and the NOx volume fraction was recorded under this conditions; the percent yield of photocatalytic NO oxidation was conducted
CO2 levels were measured using a CO2 sensor. The sensor was given time to warm up then placed in a glass chamber with a sample from one of the treatment groups or a sample of control. CO2 levels in ppm were collected every four seconds for ten minutes by the sensor. The data was divided by the weight of the sample used to generate it, to give the respiration rate per gram of sample. The data was then graphed and the slope of the line of best fit for the data points was found.
Then, we did reflux for 75 minutes. After reflux, we removed the reaction mixture from the apparatus and cooled it for several minutes. We transferred the mixture to the beaker that contained water (30 mL). We cooled the mixture to room temperature and added sodium carbonate to neutralize the mixture. We added sodium carbonate until the pH of the mixture was 8.
By adding the additive, the amount of crack in the coating’s structure decreased; the lowest amount of cracks was observed for sample containing 3g/lit ion cobalt (Figure 1-d). The structure of phosphate crystals based on the obtained results is mainly in the form of plate and mud. Phosphate coatings containing additive have a more plate texture than phosphate coatings without additives, so that the most plate-shaped structure was observed for sample containing 3g/lit ions of cobalt. Therefore, changing the amount of plate-shaped structure based on surface morphology leads to an increase in the size of phosphate crystals for specimens containing cobalt additive . By adding the cobalt additive, the phosphate crystals formed on the zinc get more uniform and contain less porosity.
On the other hand, 132 seconds were needed for the solution with the crushed tablet to stop reacting, which is the one with the reactant having a larger surface area. In a reaction, the absence of fizzing indicates that the chemical process has ended. Average rate of reaction (Whole Tablet) = 100 / 160 = 0,625 Average rate of reaction (Crushed Tablet) = 100 / 132 = 0,757 0,757 > 0,625 All these information signifies that the powdered vitamin C increased the reaction rate by causing the reaction to take place in a decreased amount of time. From the graph it is also clear that the rate of reaction took place with a fairly higher speed when the powdered vitamin C was used. Based on the previous results, the hypothesis was confirmed.
Mixing .20 milligrams of the commercial dye (red dye #3) with 250 ml of distilled water to get the initial concentration, the goal is basically to get the absorbency level below 1. Putting the dye solution in the blank cuvette and observe the absorbance level that it dorms. Repeat the steps five times making different dilutions to maintain multiple absorbance values. The second week was making another commercial dye solution and also testing the food dye brought into class. Calibrate the spectrophotometer the same exact way so that it does not mess up the calculations gathered.
In 10 g dried sediment sample added 7 ml 0.2 M NH4Cl solution. A mixture of 100 ml hexane: acetone (1:1) was used as a solvent to extract pesticides with overnight shaking for 12 h on reciprocal or wrist action shaker at 180 rpm. The extract was carefully decanted through activated florisil column (2-3 cm), giving twice wash with25 ml hexane: acetone (1:1) to the sediments. The elute was then washed with 200 ml water and then again aqueous layer was extracted with 50 ml hexane. Finally the hexane layer was washed with 100 ml water and then evaporated to dryness with a vacuum rotary evaporator.
The drugs were stable for at least three freeze-thaw cycles. No considerable changes were observed for the stability of the spiked urine samples after 2 weeks of storage at -20˚C. 4.8. System suitability test Resolution (Rs) is a measure of the degree of separation between two adjacent peaks. A value of 1.5 for resolution implies a complete separation of the two compounds .
Analysis, Discussion and Interpretation of Findings: As can be seen on the first graph, a general gradual decreasing trend in the concentration of nitrates can be observed in each of the trays excepting the control (with A experiencing a decrease of 8mg/l, B 10mg/l, C being the control remained the same, D 7mg/l and E 9mg/l respectively). Since the nitrate concentration in the control remained unaffected at around 40ml, any possible external causes of nitrate removal, other than the duckweed itself, can be eliminated. Thus, as stated in both the first part of the hypothesis and the literature (Tan 2001, Journey, Skillicorn & Spira 1991, Yang 2013, Skillicorn 2008) duckweed is indeed capable of acting as a nitrate sink. However, as can be seen