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This paper presents the results of bench-scale research into the efficiency of NOM removal by integrated processes-alum coagulation and PAC-adsorption. Experiments were conducted using riverine water samples (collected from the Odra River, Poland) and commercial powdered activated carbon. It has been shown that a PAC-enhanced coagulation process reduces the coagulant dose required and increases the process efficiency at the same time. For example, a coagulant dose of 2.0 mgAl/L and a PAC dose of 5 mg/L have produced results comparable to those of a coagulation process with no adsorbent aid but with a coagulant dose increased by 54%. The coagulation-adsorption tests were carried out at a pH of 6.0, which was lower than the pH(IEP) of the adsorbent. This procedure yielded a high extent of DOC and UV-254 removal, at 90% and 77%, respectively. The drop observed in the SUVA value after the process implied a decrease in reactive DOC forms and consequently a diminished risk that disinfection by-products might form. HPSEC analyses made it possible to describe the changes in the molecular weight distribution for the organic substances persisting in the water both after coagulation and after PAC-aided coagulation, and to evaluate their propensity to removal by the two methods. The coagulation process was effective as far as the removal of high-molecular-weight fractions is concerned. An increase in the removal of the low molecular weight NOM was achieved when the PAC-adsorption process had been combined with coagulation.

Abstract. The dependence between individual water quality indicators and the UV254 was presented in the paper. Derived dependences allow to calculate values for these indicators using only the absorbance measurement, which could be easily on-line monitored. This approach make possible to reduce number of performed laboratory analyzes, used for the efficient controlling of water purification process. Identified relations are not universally applicable even for individual specific water source. These could be described with sufficient precise only for water samples from particular treatment step. Presented methodology can be helpful for exploitation of real water treatment systems to quick and efficient evaluation of individual purifying processes.

Abstract.A non-adaptive controller for a class of vehicles is proposed in this paper. The velocity tracking controller is expressed in terms of the transformed equations of motion in which the obtained inertia matrix is diagonal. The control algorithm takes into account the dynamics of the system, which is included into the velocity gain matrix, and it can be applied for fully actuated vehicles. The considered class of systems includes underwater vehicles, fully actuated hovercrafts, and indoor airship moving with low velocity (below 3 m/s) and under assumption that the external disturbances are weak. The stability of the system under the designed controller is demonstrated by means of a Lyapunov-based argument. Some advantages arising from the use of the controller as well as the robustness to parameters uncertainty are also considered. The performance of the proposed controller is validated via simulation on a 6 DOF robotic indoor airship as well as for underwater vehicle model.