厌氧污泥无载体颗粒化技术

高效上流式厌氧污泥床(UASB)反应器能否成功运行的关键在于颗粒污泥的培养。作者对在(UASB)反应器中颗粒污泥的培养技术、营养条件和环境因素进行了较为详细的研究,并从物理学和生物学的角度对颗粒污泥的特性进行了分析和探讨,最后进行了颗粒污泥(UASB)反应器运行性能的研究。研究结果表明,实验室可在65天的时间内培养得到具有良好沉降性能和高活性的颗粒污泥,这种颗粒污泥其内部结构极为合理;装有颗粒污泥的UASB反应器是一种非常高效稳定的废水厌氧处理装置。     

Development of catalysts for anaerobic processing of liquid organic waste

In the work, the development of a catalyst carrier of biomaterial for anaerobic processing of liquid organic waste was carried out. A highly porous cellular material (НPСM) made of high-alumina ceramics obtained by thermal destruction of a polymer matrix impregnated with a high-alumina ceramic slip was used as the carrier base. The catalyst coating was applied by blowing a conductive powder through a carrier pre-coated with an adhesive composition or by impregnating the carrier with a suspension of conductive glaze followed by firing. The conductive powder was the product of milling grinding ferromagnetic bodies in a vortex layer apparatus. An experimental setup has been developed and manufactured, including a vortex layer apparatus, a blower, and a chamber with a catalyst carrier. The plant operation was optimized using the response surface methodology. It has been established that it is rational to vary the mass of working bodies to obtain the required concentration while reducing the power consumption of the plant by minimizing the duration of its operation. The next steps are to study the efficiency of an anaerobic bioreactor with an integrated HPCM with a catalyst coating formed by sputtering and glazing to produce biohydrogen and biomethane during anaerobic bioconversion of organic matter of various wastes.     

Anaerobic co-digestion of sewage sludge,wine vinasse and poultry manure for bio-hydrogen production

The influence of the addition of poultry manure on the thermophilic acid co-fermentation of sewage sludge and wine vinasse was studied. For this, discontinuous tests were carried out to determine the potential for hydrogen production (BHP tests) of 50:50 mixtures of sludge and wine vinasse with different amounts of poultry manure (10  g/L, 20  g/L and 30  g/L). The hydrogen production performance was determined under the tested conditions. The experimental results revealed performance values of TCOD and SCOD, TS and VS, similar in all tests, with removal efficiencies lower than 25%. Likewise, an increase in the production of volatile fatty acids was observed. Regarding the yield, the best results were obtained for the mixture with 10 g/L of poultry manure (with a C/N ratio: 27). Thus, the H₂ production and the yield expressed as mL H₂/gVS_added was 18.20% and 27.57% higher in the test with 10  g/L of poultry manure compared to the test with 20  g/L. Furthermore, from 20 g/L of poultry manure, the mixtures showed poorer purification behavior and performance.     

Kinetic analysis of biohydrogen production from complex dairy wastewater under optimized condition

Present work describes a kinetic analysis of various aspects of biohydrogen production in batch test using optimized conditions obtained previously. Monod model and Logistic equation have been used to find growth kinetic parameters in batch test under uncontrolled pH. The values of μ_m, K_s, and X_m were 0.64 h⁻¹, 15.89 g-COD L⁻¹, and 7.26 g-VSS L⁻¹, respectively. Modified Leudeking-Piret and Michaelis–Menten equation corroborates a flux of energy to hydrogen production pathway and energy sufficiency in the system. Modified Gompertz equation illustrates that the overall rate and hydrogen yield at 15 g-COD L⁻¹ was higher compared to a dark fermentation of other wastewaters. Besides, Andrew's equation also suggests that since the higher value of K_I (19.95 g-COD L⁻¹), k (255 mL h⁻¹ L⁻¹) was not inhibited at high S. The experimental results implied that the entire products during the fermentation process were growth and substrate degradation associated. The result also confirms that the acetate and butyrate were substantially used for hydrogen production in acidogenic metabolism under uncontrolled pH.     

The use of a non-motorized treadmill for analysing sprint performance

The measurement of human power output and anaerobic capacity in high-intensity exercise has traditionally been made using cycle ergometers. The assessment of power output during running has proved difficult because previous approaches have limited themselves to using motorized treadmills. In the present study the problems associated with motorized treadmills were overcome by using a non-motorized treadmill which was instrumented so as to allow the measurement of power output during sprint running. A non-motorized treadmill (Woodway model AB) was used because it allows rapid changes in running velocity normally found in sprinting to be monitored. In order to calculate the horizontal component of the applied power the instantaneous values of both the horizontal component of applied force and the treadmill belt speed were measured, and their product determined. A harness, attached to a force transducer, was passed around the waist securing the subject to the crossbar without restricting the movement of the limbs. The force measured was assumed to be the same as that horizontally applied to the treadmill belt.

The outputs from the speed detector, force transducer and heart rate monitor were continuously monitored by a microcomputer.

The results of the study showed that:

(1)the peak speed attained on the treadmill is approximately 80% of that achieved in free-sprinting.

(2)peak force is attained earlier than peak power and in turn peak power occurs before peak speed.

(3)the force and power required to propel the treadmill belt at a constant speed increase with body weight.

(4)the power required to propel the treadmill belt increases with speed.

(5)stride length and frequency could be monitored.

(6)elasticity in the tethering system acted as a low pass filter on the force profile.     

Anaerobic Adhesive Cure Mechanism-I

Anaerobic adhesives are single-component acrylic adhesives which cure rapidly at or below room temperature when air is excluded, but they remain in an uncured stage over a long time when they are exposed to an adequate supply of air. Thus, anaerobic adhesives are widely used in retaining compounds for nuts and bolts, in sealants, and for impregnation. Recently, anaerobic adhesives have also been used in electrical and electronic applications because of their fast room temperature cure capability and their convenience.¹     

Internal Purification of Thermomechanical Pulp Clear Filtrate with a Combined Biological and Membrane Filtration Method: A Preliminary Study

Abstract

In this study a combined anaerobic biological-nanofiltration method was studied as a means of internal purification of a thermomechanical pulp (TMP) plant effluent. A TMP plant clear filtrate was first subjected to a thermophilic anaerobic treatment at 55 or 70°C in an up flow anaerobic sludge blanket reactor and then nanofiltered in a flat-sheet laboratory-scale module. The anaerobic treatment removed 55% of the chemical oxygen demand at 70°C and 65% at 55°C. Sugars were removed both at 55 and 70°C while the low molar mass ligneous material was removed only at 55°C. By nanofiltration the remaining low molar mass ligneous material was removed by about 98–99% and the high molar mass ligneous material by 96–99%. Sugar was removed by 88–98% and chemical oxygen demand by 78–81%. It was also shown that most of the pulp-brightness-decreasing substances had been removed. The permeate flux depended on the sample but was at its best [about 38 L/(m²-h) at 8 bar] for the first hour of filtration for the sample anaerobically treated at 55°C. The samples did not cause permanent fouling of the membrane. In this study it was shown that the combined anaerobic biological-nanofiltration method is a competitive internal purification method for TMP plant clear filtrate resulting in a very clean water, which could be reused in the water circulartion system of the plant or in the paper machine white-water system. However, further studies for optimization of the process are needed.     

Inoculum acclimation to oleate promotes the conversion of olive mill wastewater to methane

This work aims at selecting a suitable strategy to accelerate the start-up of the anaerobic treatment of olive mill wastewater (OMW) and to enhance the biogas production. Two anaerobic sludges were tested in toxicity and biodegradability batch experiments: biomass acclimated to oleate (BAO) and biomass non-acclimated (BNA). The results showed that the resistance to OMW toxicity was higher for the BAO than for the BNA. In the presence of OMW, the BNA was inhibited at all concentrations tested, whereas for the BAO no inhibition occurred at 5 and 10 g COD L⁻¹. In fact, even at 25 g COD L⁻¹ both substrates (acetate + OMW) were degraded. The biodegradation rate of OMW was higher in batch vials with the acclimated sludge.The results demonstrate that the use of an acclimated microbial consortium to LCFA compounds is a promising strategy to accelerate the start-up of the digestion process, and to improve the overall anaerobic treatment of a real oily wastewater such as OMW with simultaneous bioenergy production (biogas).     

Relation between power and endurance for treadmill running of short duration

Abstract

An exercise test was devised to investigate the relationship between power and endurance for treadmill running. The subjects were 19 males aged 21-25 yr (11 distance runners and 4 sprinters of provincial grade, and 4 non-competitive runners). Each subject ran to exhaustion on a treadmill at 15kmhr^?1at five different inclinations (31%-9%), giving maximum performance times in the range 10s to 3 min. An iterative least-squares procedure was used to fit the following exponential model to each subject's data: I₁= I_∞+ (I₀?I_∞)exp(?t/τ) where I₁, I₀and 1_∞are inclinations at time t = t, t = 0 and t → ∞, and τ is a time constant. The fit was excellent (r ²= 0.96? 1.00). I₀and 1_∞are interpreted as measures of maximum anaerobic (instantaneous) and maximum aerobic (continuous) power respectively. Inclinations corresponding to performance times of 10-180s (I₁₀?I₁₈₀) were calculated from these parameters. Test-retest reliability was highest for I₀-I₃₀(intraclass r= 0.97?0.94), lower for I₆₀-I_∞(r= 0.89?0.84), and lowest for τ (r= 0.78). Good correlations were observed between I₀-I₃₀and peak power in a 30s all-out test on a cycle ergometer (r= 0.73?0.81), and between I₁₈₀, I_∞and maximum oxygen consumption (r= 0.87, 0.81). The test may be useful for ranking or monitoring running performance for events of up to 1 min duration.