Mirosław Krzemieniewski

Effect of magneto-active filling on the effectiveness of methane fermentation of dairy wastewaters

AbstractThe goal of this study was to determine the effectiveness of methane fermentation of dairy wastewaters in terms of the volume and qualitative composition of biogas produced in an anaerobic reactor with magneto-active filling (MAF) mounted in the zone of hydrolysis and acidogenesis. Experiments were conducted in the fractional-technical scale in a vertical fermentation reactor with a labyrinth flow. Synthetic dairy wastewaters prepared based on milk powder were used as a substrate. The analyzed filling was made of plastic covered with iron and copper powders and was additionally equipped in fluid magnetizers (FM) in the form of neodymium magnets. The study demonstrated that MAF incorporation into the technological system significantly improved effectiveness of biogas production, increased methane concentration and lowered content of hydrogen sulfide in gaseous metabolites of fermentative bacteria. A significant increase was also observed in the effectiveness of COD removal from dairy wastewaters. R...

Respirometric studies on the effectiveness of biogas production from wastewaters originating from dairy, sugar and tanning industry

The objective of the present study was to determine the effectiveness of biogas production during methane fermentation of wastewaters originating from the dairy, tanning and sugar industries, by means of respirometric measurements conducted at a temperature of 35°C. Experiments were carried out with the use of model tanks of volume 0.5 dm3. A high production yield of biogas, with methane content exceeding 60%, was achieved in the case of the anaerobic treatment of wastewaters from the dairy and sugar industries. A significantly lower effect was observed in the case of tanning wastewaters. The effectiveness of the fermentation process decreased with increasing loading of the tanks with a feedstock of organic compounds. By loading a model tank with this feedstock, the effectiveness of treatment ranged from 62.8% to 71.4% residual chemical oxygen demand for dairy wastewaters and from 57.9% to 64.1% for sugar industry wastewaters. The efficiency of organic compound removal from tanning wastewaters was below 50%, regardless of the method applied.

Effect of corrosion of steel elements on the treatment of dairy wastewater in a UASB reactor.

Experiments were performed in parallel using two laboratory upflow anaerobic sludge blanket (UASB) reactors. One of the two reactors was packed with spiral elements made of steel wire with 48% iron content in order to examine the influence of the steel elements on the chemical oxygen demand (COD) and efficiency of phosphorus removal from synthetically prepared dairy wastewater. A strong relationship was found between anaerobic corrosion and efficiency of phosphorus removal. Phosphorus removal in the reactor packed with steel elements was between 16.4% and 64.4% higher than without the steel elements present. The anaerobic corrosion process improved COD removal efficiency by 1.0–3.1%, which was statistically significant. When steel elements were present the methane content of the biogas was increased by 6.7%. Increasing the organic loading rate had a strong effect on the anaerobic efficiency of the dairy wastewater treatment.

Effectiveness of dairy wastewater treatment in a bioreactor based on the integrated technology of activated sludge and hydrophyte system

The aim of this study was to determine the effectiveness of dairy wastewater treatment in the integrated technology based on the simultaneous use of the activated sludge method (AS) and a hydrophyte system (HS) (AS–HS), in this case, common reed (Phragmites australis) or common cattail (Typha latifolia). Experiments were conducted in an innovative reactor exploited in the fractional-technical scale at the loads of 0.05 mg BOD5/mg.d.m. d (biochemical oxygen demand) and 0.10 mg BOD5/mg.d.m d. The AS–HS enabled improving the removal effectiveness of biogenes characterized by concentrations of Ntot., N-NH4 and Ptot.. In contrast, the integrated system had no significant reducing effect either on concentrations of organic compounds characterized by BOD5 and chemical oxygen demand parameters or on the structure of AS in the sequencing batch-type reactors.

Phosphorus removal in anaerobic fluidized bed reactor with active microporous filling produced by extrusion technology

Methane fermentation leads to the formation of biogas in the process of wastewater treatment, but a limitation to its use is the low effectiveness of the removal of phosphorous compounds under anaerobic conditions. The study demonstrates a method to solve this problem through the use of a magneto-active microporous filling, produced by extrusion technology from polyvinyl chloride. This has increased the effectiveness of dairy wastewater treatment by stimulating the selective development of specific groups of microorganisms and the chemical binding of the phosphorous compounds in biological processes as well as chemical sorption on the metal surface of the filling. Regardless of the used organic loading rate, the efficiency of phosphorous removal from the wastewaters was about 85%. Achieving low concentrations of phosphorous in the effluent was directly influenced by the method of the wastewater operation and disposal by magneto-active filling layer.

Nitrogen compounds transformation in the biological filter by means of direct energy supply to the biofilm

The aim of the research was to determine the effect that direct energy supply to the biofilm, which was attached to the packing with its temperature raised, exerts on the course of nitric compounds changes. The experiment was conducted in a laboratory scale. A model reactor which allowed smooth regulations of the packing temperature was used in the experiment. The energy supply was based on the emission of thermal radiation through the reactors packing to the biofilm. On the basis of the conducted tests it has been found that such a technological solution improves the efficiency of wastewater treatment, nitrification processes in particular. The temperature range between 20 °C and 25 °C appeared to be optimal for nitrification. At temperatures higher than 25 °C anoxic spheres were generated in the deeper layers of the biofilm, which is proved by denitrification.

Application of an Innovative Ultrasound Disintegrator for Sewage Sludge Conditioning Before Methane Fermentation

Ultrasonic disintegration is one of the most interesting technologies among all known and described technologies for sewage sludge pre-treatment before the process of methane fermentation. This study was aimed at determining the effects of an innovative ultrasonic string disintegrator used for sewage sludge pre-treatment on the effectiveness of methane fermentation process. In this experiment, we used a device for disintegration of organic substrates, including sewage sludge, with the use ultrasonic waves. Its technical solution is protected by a patent no. P. 391477 – Device for destruction of tissue and cell structures of organic substrate. The volume of biogas produced ranged from 0.194±0.089 dm3/g o.d.m. at loading of 5.0 g o.d.m./dm3 and power of 50 W to 0.315±0.087 dm3/g o.d.m. at loading of 4.0 g o.d.m./dm3 and ultrasounds power of 125 W. The study demonstrated a positive effect of sewage sludge sonication on the percentage content of methane in biogas. Sewage sludge exposure to 125 W ultrasounds increased methane content in biogas to 68.3±2.5 % at tank loading of 3.0 g o.d.m./dm3.

DAIRY WASTEWATER TREATMENT IN ANAEROBIC REACTOR WITH ACTIVE FILLING

The aim of this study was to determine the effect of magneto-active microporous filling, manufactured by extrusion technology and modified by the addition of relevant amounts of metal catalysts and magnetic activation, on the effectiveness of dairy wastewater treatment and biogas productivity in a magneto-active anaerobic fluidised bed reactor (MA-AFBR) with full mixing. The best performance of the system was found at organic loading rate (OLR) in the range of 5.0–7.0 kg COD/m3·d. The effectiveness of COD removal was about 80%, and the biogas production 320 dm3/kg CODremoved, with methane content of 67%.