Amounts of Cu and Fe in MCF-Cu and NSM/MCF-Cu particles were confirmed again by using ICP-AES analysis and are presented in Table 2. The amount of Fe in NSM/MCF-Cu was 8.62 × 104 ppm. Therefore, the NSM/MCF-Cu particles could be easily recovered by magnetic separation. The amount of Cu in NSM/MCF-Cu was about 5 times higher than that Ezatiostat in MCF-Cu.
ICP analysis of the MCF-Cu and NSM/MCF-Cu.Sample IDCu (ppm)Fe (ppm)MCF-Cu6.05 × 103–NSM/MCF-Cu3.46 × 1048.62 × 104Full-size tableTable optionsView in workspaceDownload as CSV
If the organosilane ligand of Cu complex with pyridine nitrogen were grafted to the silica surface in the same manner as the MCF-Cu, more significant decrease of surface area in NSM/MCF-Cu was expected due to larger amount of Cu. However, it was noted that the decreased surface area of NSM/MCF-Cu (272 m2/g, 0.33 cm3/g) from that of NSM/MCF was similar to the difference observed between MCF-Cu and MCF, as shown in Table 1. It indicates that a certain amount of organosilane ligand can be grafted on the surface of NSM and MCF because NSMs bound by TSBN were positioned at the pores in the MCF.
In Eq. (2), Q is the vinasse flow rate, and Vw is the working volume of the reactor.
The concentration of tsa inhibitor throughout the experimental period (Cxn/t) was estimated using the biomass yield (Yx/s) and the carbohydrate concentration converted throughout the experimental time (Ctc/t), as show in Eq. (3):equation(3)Cxn/t=Yx/s·Ctc/tCxn/t=Yx/s·Ctc/t
The biomass yield (Yx/s) was calculated with data obtained for biomass concentration in respect to the total carbohydrate concentration converted throughout the experimental time, as shown in Eq. (4):equation(4)Yxs=Cxa+Cxs+CxwCtc
In Eq. (4), Cxa is the attached biomass concentration (g), Cxs is the concentration of biomass suspended in the liquid, which was drained at the end of the APBR operation (g), Cxw is the concentration of biomass that was washed out naturally by the system (g), and Ctc is the concentration of total carbohydrates consumed during the entire APBR operation.
The value of Cxw was estimated based on the mass flow of biomass (Wxn; units, g-VSS h−1), which was washed throughout the experimental time (Eq. (5)):equation(5)Cxw=1Vw∫Wxn·dt
Generally, AMD composed of many chemicals which are toxic; these may be removed from AMD adsorbed on the surface of the MNPs or in some cases incorporated into preformed MNPs. The presence of toxic trace impurities that NHS Biotin are being adsorbed on the surface of produced MNPs can be reduced or removed through proper cleaning with both deionized water and organic solvents several times until none of the chemicals leached out. Any other volatile toxicants also can be removed during heating for drying purpose. However, immovable joint is inevitable to eliminate completely; therefore, before fully commercialization of synthesized MNPs produced from AMD, proper attention should be given to their stability, purity, and area of application. After the qualities of these MNPs synthesized from AMD are carefully considered; they can be used as additives to ceramics and paints, for manufacturing electronic materials and wastewater treatment directly or after modification, which means forming their corresponding composites.
Batch growth on both synthetic VFA and the sterilized VFA stream from the P 22077 food-waste fermenter resulted in similar biomass concentration (p = 0.11, Table 3). However, the intracellular lipid concentration (14.9 ± 0.1%) and the maximum specific growth rate (0.021 ± 0.00 h−1) were statistically lower for fermentate VFA (p = 0.02, Table 3). Similarly, in a previous study, the oleaginous yeast C. curvatus also showed poor cell growth and a decrease in the intracellular lipid content (13.5%) when using food waste fermentation effluent as the growth medium ( Chi et al., 2011), pointing to the presence of as yet unknown inhibitors in the fermentate. Another possible cause of lower lipid yield could be the high protein content of the food waste, which can effectively lower the COD:N ratio below the favorable range (COD:N ? 25). Based on our previous results, food waste fermentate TKN concentrations were in the range 1410.8 ± 516.2 mg-N/L ( Ljupka Arsova, 2010) resulting in an effective feed COD:N ratio in our C. albidus batch cultures of 2.87:1. Although not attempted in nektonic organisms study, the observed differences in the kinetics (μm) and extent of lipid accumulation between synthetic VFA and VFA present in fermentate point to the necessity for independent optimization of lipid production from different waste streams, which is not entirely unexpected.
Batch acidogenesis was performed at 37 °C and at pH 8 as the optimum conditions. Culture immobilization on kissiris increased the OAs yield in most of the tested sucrose/raffinose mixtures as compared with free cells. The highest improvement was observed in the case of 100% raffinose and the 30% sucrose–70% raffinose mixture. Table 1 shows the results of the batch acidogenesis of sucrose and raffinose mixtures with and without the use of kissiris. Bioconversion of sucrose and raffinose occurred in all fermentation batches indicating the capability of the mixed ABT-737 culture to ferment this type of sugars. The OAs yield factor varied from 0.38 to 0.62 g/g for an initial sugar concentration of 20 g/L. OAs concentration ranged from 5.9 to 13.4 g/L, while ethanol formation did not exceed 0.5 mL/L. Without kissiris the OAs concentrations and yield factors were lower, while higher concentrations of ethanol were observed. OAs that were formed were lactic, valeric, acetic, propionic, succinic, and butyric acids, and in few cases isovaleric acid. Lactic acid and valeric acid were the predominant acids in most cases. These results encouraged the subsequent study of continuous acidogenesis using immobilized cells in order to achieve the aforementioned objectives.
The rheological properties of an SCC mixture containing a certain type and amount of SCC can be affected by the test methods (such as rheometer type) and material characteristics. Therefore, it should be kept in mind that the following conclusions were derived for the materials used and tests applied in this study:(1)SCC mixtures containing various mineral admixtures were highly stable and moderately stable (VSI between 0 and 1) at 0 min according to ASTM C 1611. However, mixtures containing FAC, FAF and BFS exhibited some bleeding and Rapamycin at 50 min while there was no significant change in the stability of SF and MK blended mixtures after 50 min of rest.(2)T50 flow time of almost all mixtures after 50 min of rest (except 18BFS and 8SF18FAC18BFS mixtures) increased approximately 2 times compared to 0 min. MK and FAC were the two mineral admixtures that had most significant effect on T50 with time especially when they were incorporated at high replacement levels.(3)Mixtures containing MK and FAC, showed significant increase in torque plastic viscosity with time. Torque plastic viscosity of the mixtures incorporating SF displayed comparable behavior to that of the control mixtures with time. Moreover, torque plastic viscosity was reduced in time when BFS was incorporated in binary and quaternary systems. In addition, FAF did not show significant effect on plastic viscosity values as function of time.(4)Good correlations were established between T50 flow time and torque plastic viscosity values, irrespective of the duration of rest period.(5)In contrast to torque plastic viscosity values, apparent yield stress values increased with time for all SCC mixtures; however, no clear trend was depicted with the replacement level of the mineral admixtures. Similar to torque plastic viscosity values, MK and FAC blended mixtures had significant influence on yield stress with elapsing time. Increase in yield values were more pronounced in comparison with torque plastic viscosity values after 50 min of elapsing time.(6)Increase in thixotropy with time for the SF and MK blended mixtures were higher when compared to the control mixtures and the mixtures containing other mineral admixtures (FAC, FAF and BFS). The highest increase was observed in 36MK mixture whose thixotropy at 50–80 min time period was approximately 32% greater than the thixotropy of the same mixture at 0–30 min.(7)SF and MK significantly increased the compressive strength of the mixtures. The highest compressive strength was observed in 8SF18BFS mixture whose compressive strength was approximately 52% greater than of the control mixture. The partial replacement of PC by FAF decreased compressive strength of control mixtures while the compressive strength of FAC mixtures was found to be higher than control mixtures.
2.5. Analytical methods
3. Results and discussion
3.1. Comparison between different DZNep reagents for efficacy of quenching total chlorine
Fig. 1. Lab tap water quenched with different reducing agents (initial residual chlorine concentration = 0.60 mg/L as Cl2; quenching condition pH = 7.0, phosphate buffer concentration = 5 mM, temperature = 25 ± 1 °C).Figure optionsDownload full-size imageDownload as PowerPoint slide
3.2. Reactions of NaAsO2 with free chlorine, NH2Cl and NHCl2
In order to investigate the quenching ability of NaAsO2 in finished water from DWTPs, the individual reaction of NaAsO2 to free chlorine, NH2Cl and NHCl2, respectively, should be considered first. Based on previous studies, the reducing power of NaAsO2 can be controlled by adjusting its dose and solution pH, and the reactions to free chlorine and NH2Cl are sedimentary rock shown in Eqs. (1) and (2).equation(1)NaOCl+AsO2-→AsO3-+Na++Cl-equation(2)NH2Cl+AsO2-+H2O→NH4++Cl-+AsO3-