ABSTRACT
Fenton oxidation and coagulation-flocculation-sedimentation (CFS) were both effective in removing many organic constituents of the biotreated coking plant effluent before the final treatment in an activated carbon adsorber. Fenton oxidation broke down most persistent organic pollutants and complex cyanides present in the feed stream and caused the eventual biodegradation of the organic residues in the adsorber. The results of Fenton oxidation followed by adsorption and biodegradation in two biological activated carbon (BAC) adsorbers show that the combined treatment consistently produced a high quality final effluent of <50mg/L in COD(Cr) and <0.5mg/L in total cyanide during the 70-d study without replacing any activated carbon. The BAC function of the adsorber substantially reduced the need for replacing activated carbon making the combined Fenton oxidation-BAC treatment process a cost effective treatment process to recycle the final effluent for many beneficial reuses while meeting the much more stringent discharge limits of the future.
Subject(s)
Biodegradation, Environmental , Charcoal/chemistry , Coke , Hydrogen Peroxide/chemistry , Industrial Waste/prevention & control , Iron/chemistry , Adsorption , Cyanides/chemistry , Cyanides/metabolism , Organic Chemicals/chemistry , Organic Chemicals/metabolism , RecyclingABSTRACT
In this paper, the effects of the electrical proper- ties of CuO-doped (Na(0.5)K(0.5))NbO(3) (NKN) ceramics prepared separately using the B-site oxide precursor method (BO method) and conventional mixed-oxide method (MO method) on high-power piezoelectric transformers (PTs) were investigated. The performances of PTs made with these two substrates were compared. Experimental results showed that the output power and temperature stability of PTs could be enhanced because of the lower resonant impedance of the ceramics prepared using the BO method. In addition, the output power of PTs was more affected by the resonant impedance than by the mechanical quality factor (Q(m)) of the ceramics. The PTs fabricated with ceramics prepared using the BO method showed a high efficiency of more than 94% and a maximum output power of 8.98 W (power density: 18.3 W/cm(3)) with temperature increase of 3°C under the optimum load resistance (5 kΩ) and an input voltage of 150 V(pp). This output power of the lead-free disk-type PTs is the best reported so far.
Subject(s)
Ceramics/chemistry , Copper/chemistry , Micro-Electrical-Mechanical Systems/instrumentation , Energy Transfer , Equipment Design , Equipment Failure Analysis , LeadABSTRACT
A textile-based ECG system for sleeper is presented. The electrode in the system is supported by a foam pad to ensure good contact as well as comfort to the wearer, and a flexible rubber to ensure that the electrode will electrically connect to the wearer only when pressed. Eight electrodes are multiplexed such that exactly two electrodes are pressed to connect the wearer no matter how the wearer lies. When the wearer lies in different positions, he/she will press different two electrodes, and then the morphology of the output ECG signal will be different accordingly. By this feature, the system can not only detect ECG but also determine the position of the sleeper.
