Electrochemical behavior and the determination of furan in beverage samples using glassy carbon electrode

Furan is a possible human carcinogen in many types of foods. A new and sensitive electro analytical method for determination of furan has been developed and validated. The best condition for electrochemical response was obtained with 0.1 M britton-rabinson buffer solution [pH=5] a glassy carbon electrode [GCE] was used as the working electrode, a Ag/AgCl/ KCl[sat.] electrode served as the reference electrode, and a platinum wire as the auxiliary electrode under the Differential Pulse Voltammetry [DPV] mode. The peak current obtained from DPV was linearly dependent on the Furan concentration in the range 12-360 Micro M [0.81-24.5 ppm] with correlation coefficients of 0.999 and a limit of detection [LOD] of 3 Micro M [0.2 ppm] and limit of quantification [LOQ] of 10 Micro M [0.68 ppm] were calculated, respectively. The values of the electron-transfer coefficient [Alpha] involved in the rate determining step calculated from the linear plots of Ep against ln [v] in the pH range investigated were 0.8 confirming the irreversible nature of the oxidation peak. The reproducibility of the method was tested by analyzing 10 samples containing 30 Micro M of Furan. The RSD% of the method thus obtained was 3.0% which showed excellent reproducibility for this developed methods

Evaluating the efficiency of Plantago ovata and starch in water turbidity removal

In. the current study, the efficiency of starch and Plantago ovata extract as coagulant aids is compared in water turbidity removal. The coagulant is ferric chloride and the experiments are run in two ranges of pH 7 and 8. The achieved results of turbidity removal in different turbidity levels of 100, 50 and 20 NTU caused by different concentrations of starch and P.ovata as coagulant aids besides ferric chloride as the main coagulant are compared. According to the achieved results, the use of P.ovata or starch as the coagulant aid may play a key role in reducing the amount of FeCl[3] as the main coagulant and consequently decreasing the generated sludge. Furthermore, the remarkable turbidity removal efficiency gained when these coagulant aids are used in comparison with the case when no coagulant aid is introduced is also of interest. Generally, the both coagulant aids seem to be more efficient in pH value of 7 rather than 8. Although both coagulant aids used in this study manifested acceptable turbidity removal efficiencies, P.ovata showed higher capabilities of removal in different turbidity levels and pH values in comparison with starch

Investigation of intermittent chlorination system in biological excess sludge reduction by sequencing batch reactors

The excessive biological sludge production is one of the disadvantages of aerobic wastewater treatment processes such as sequencing batch reactors. To solve the problem of excess sludge production, oxidizing some of the sludge by chlorine, thus reducing the biomass coefficient as well as the sewage sludge disposal may be a suitable idea. In this study, two sequencing batch reactors, each with 20 L volume and controlled by on-line system were used. After providing the steady state conditions in the reactors, sampling and testing of parameters were done during 8 months. The results showed that during the solid retention time of 10 days the kinetic coefficient of Y and Kd were 0.58 mg biomass/mg COD and 0.058/day, respectively. At the next stage, different concentrations of chlorine were used in the reactors intermittently. Results showed that 15 mg chlorine/gMLSS in the reactor was able to reduce the yield coefficient from 0.58 to 0.3 mg biomass/mg COD. In other words, the biological excess sludge was reduced about 48%. But the soluble chemical oxygen demand increased slightly in the effluent and the removal percentage decreased from 95% in the blank reactor to 55% in the test reactor