Investigation of the Environmental Transport of Human Pharmaceuticals to Surface Water: A Case Study of Persistence of Pharmaceuticals in Effluent of Sewage Treatment Plants and Hospitals in Malaysia

Removal of caffeine from aqueous solution by indirect electrochemical oxidation using a graphite-PVC composite electrode: A role of hypochlorite ion as an oxidising agent

“…Malaysia for the first time, caffeine was detected in influent, effluent STP and surface water as reported by our previous studies [4][5][6]. Because conventional treatments of waste water cannot degrade caffeine and other pollutants efficiently, it is necessary to look for alternatives.…”

“…We conclude that removal efficiency and rate of reaction have same principal of kinetics. 6 Page 14 COMMENT: However, in page 14 the authors indicate that the actual computed rate constants do depend on the volume of the solution, which is an unreasonable conclusion. From the data in figure 1 it seems that in the 500 mL solution there is a concentration reduction of about 0.1, while in the 50 mL solution there is "only" a reduction of 0.8 -this would imply by a simple mass balance that the rate of reaction is actually a bit higher in the 500 mL solution than in the 50 mL solution, as it might expected from a kinetic point of viewthis is issue should be clarified.…”

“…because it could reduce caffeine almost to zero although high concentration of caffeine was used in this study compared with its low concentration in natural water [4][5][6]. Compared to the conventional methods for caffeine removal from municipal wastewater, this method seems to be more feasible with the following reasons: easy operation, fast caffeine removal rate and reliable treatment efficiency.…”

“…Yes, the authors agree with the reviewer that OCl − is the responsible oxidising agent for the removal of caffeine. However, we would like to explain why we did not add 6 directly OCl − , the reason may related to two points: First point, OCl − species produced already in the electrochemical reactor spontaneously as shown in equations (2-4) so unnecessary to add OCl − directly. Second point, sodium chloride is the main source to produce OCl − in solution which is cheaper than HOCl (source of OCl − ) so it is important to used cheap and active materials in terms of cost.…”

Determination of Caffeine in Surface Water Using Solid Phase Extraction and High Performance Liquid Chromatography

“…In groundwater environment, the septic system failure could be the main source of pollution with pharmaceuticals [6]. The residue of caffeine in surface water usually traced at low level concentrations within the range of ng/L to µg/L [7,8]. Nevertheless, it is still threatening to aquatic ecosystem especially living organism likes coral, which is highly sensitive to caffeine [9].…”