Conly L. Hansen

Antioxidant Capacity, Phenolic Content, and Polysaccharide Content of Lentinus edodes Grown in Whey Permeate-Based Submerged Culture

Total antioxidant capacity (TAC), phenolic content, and crude water-soluble polysaccharide (WSP) were determined for Lentinus edodes mycelia grown on both whey permeate (WP)-based medium with lactose content of 4.5% and controlled medium, and harvested after 5, 10, 15, or 20 d of fermentation at 25 degrees C. Both methanol extracts and water extracts of L. edodes in this study were found to exhibit high free radical scavenging capacity. The harvesting time was found to contribute to most of the variability in the free radical scavenging capacity. High levels of antioxidant capacities (0.28 +/- 0.03 and 0.29 +/- 0.06 mmol TAE/g dry weight for methanol and water extracts, respectively) were observed in mycelia grown on whey permeate and harvested on day 10. Harvesting time and the type of media can interact to alter the chemical content of mycelia. Mycelia grown in whey permeate had greater (P < 0.05) WSP than mycelia grown in the synthetic media. High levels of WSP (4.1 x 10(2)+/- 71 mg polysaccharide/g dried mycelia) were found in mycelia grown in whey permeate and harvested on day 10. Whey permeate grown mycelia had phenolic compounds ranging from 4.2 +/- 0.1 to 8.0 +/- 0.8 mg GAE/g dried mycelia. The overall means of total phenolic contents of mycelia grown in whey permeate were 5.9 +/- 0.5 and 6.2 +/- 0.6 mg GAE/g dried mycelia for methanol and water extracts, respectively.

Sodic soil reclamation using cottage cheese (acid) whey

Abstract Cottage cheese production in the United States yielded approximately 3 × 106 Mg of cottage cheese (acid) whey in 1991. Unmarketable whey is disposed of in sewage treatment facilities or on land. Environmental concerns and new laws make disposal even more costly and difficult. While much whey is applied to land for fertilizer or disposal purposes, acid whey has recently been used as a sodic soil amendment. The objectives of this research were to determine the effects of whey application on chemical properties and infiltration rates of sodic soils. Four treatments of acid whey (0, 25, 50, and 100 mm) were applied to Freedom silt loam (fine‐silty, mixed, mesic, Xerollic Calciorthids) in greenhouse lysimeters and to De‐clo loam (coarse‐loamy, mixed, mesic, Xerollic Calciorthids) in field basins. Accumulative sodium removal at 0.5 pore volumes of leachate was 1.0, 1.1, 1.2, and 1.7 mol for the 0‐, 25‐, 50‐, and 100‐mm lysimeter treatments, respectively. Whey applications lowered sodium adsorption rati...

Modeling and optimization in anaerobic bioconversion of complex substrates to acetic and butyric acids

Cheese-processing wastewater was biologically treated to produce short-chain organic acids in laboratory scale continuously stirred tank reactors. A constant inoculum system was used to mimimize the experimental error due to the use of inconsistent inoculum. The inoculum system was operated with dilute cheese-processing wastewater with 5000 mg soluble chemical oxygen demand/L at pH 6.5 and 35 degrees C at 0.5 days hydraulic retention time. Response surface methodology was successfully applied to determine the optimum physiological conditions where the maximum rates of acetic and butyric acid production occurred. These were pH 7.01 at 36.2 degrees C and pH 7.26 at 36.2 degrees C, respectively. The lack of overall predictability for butyric acid production meant that the response surface was much more complicated than that of acetic acid; therefore, a small change in pH or temperature could cause large variations in the response of butyric acid production.

Biokinetics of an upflow anaerobic sludge blanket reactor treating whey permeate

Abstract A laboratory study was performed to determine the kinetic model and to evaluate kinetic coefficients of continuous upflow anaerobic sludge blanket (UASB) reactors treating whey permeate. Eight hydraulic retention times (5·-0·4 day) were investigated at fixed influent substrate concentration (10·4 ± 0·2 g COD/litre). The maximum substrate utilization rate, k, and half saturation coefficient, K L , were determined to be 0·941 kg COD rmvd /kg VSS/day and 0·773 kg COD/kg VSS/day. The yield coefficient, Y, and sludge decay rate coefficient, K d , were also determined to be 0·153 kg VSS/kg COD and 0·022/day, respectively.

Performance of Upflow Anaerobic Sludge Blanket (UASB) Reactor Treating Whey Permeate

Whey permeate was anaerobically digested in laboratory scale upflow anaerobic sludge blanket (UASB) reactors. Eight hydraulic retention times (HRT) between 0.4 and 5 days were examined with a fixed influent concentration of 10.4 ± 0.2 g COD/L.

Formation of organic acids and ammonia during acidogenesis of trout-processing wastewater

A set of experiments was carried out to characterize trout-processing wastewater and to investigate biological acidification (acidogenesis) of the wastewater. Based on individual amino acids analysis and stoichiometric calculations, protein was a major organic material which composed 92.9% of chemical oxygen demand (COD) in the wastewater. Three concentrations of COD set up in a ratio of 1:4:9 made by dilution of raw wastewater (11.4, 45.7, and 102.7 g COD/L) were tested for acidogenesis in batch mode. Production of acetate, propionate, isobutyrate, butyrate, methylbutyrate, and valerate was monitored. Acetate production was predominant in all treatments, and amounts of acetate and butyrate were proportional only to the initial wastewater strength. The formation of odd-chain organic acids (propionate, methylbutyrate, and valerate) increased with decreasing initial wastewater strength. Based on stoichiometric calculations, total conversions of organics in the wastewater to short-chain organic acids at initial COD concentrations set up in a ratio of 9:4:1 were respectively 52.1%, 74%, and 79.6%.

Anaerobic digestion of rendering waste in an upflow anaerobic sludge blanket digester

Abstract Rendering wastewater was anaerobically digested in an upflow anaerobic sludge blanket (UASB) digester in 11 trials spanning 11 months. The UASB digester influent was 2% blood/98% condensate for six of the trials (phase one) and 56% wash-up water/44% cooker condensate for the other five trials (phase two). The influent chemical oxygen demand (COD) for both phases was 5300 mg/l. The only parameter varied within phases was hydraulic retention time (HRT) which was varied from 5·2 to 15·6 days; however, changing HRT caused loading rate to change because the influent strength was held constant. COD removal efficiencies for phase one ranged from 28 to 72% and for phase two, from 72 to 87%. The biogas production from all trials contained over 75% methane and had traces of hydrogen sulfide. The production of methane was 0·2–0·25 l/gCOD converted in phase one and 0·28–0·34 l/gCOD converted in phase two.

Chemical oxygen demand fate from cottage cheese (acid) whey applied to a sodic soil

Abstract Cottage cheese (acid) whey is an effective amendment in sodic soil reclamation, but the high chemical oxygen demand (COD) of whey is of concern in land application. The objective of this research was to determine the fate of COD from cottage cheese whey applied to a sodic soil. Treatments of 0, 25, 50, and 100 mm (0, 20, 40, and 80 Mg COD ha‐1) of whey were applied to dry‐unacclimated Freedom silt loam (fine‐silty, mixed, mesic, Xerollic Calciorthids) in greenhouse lysimeters. The COD from lysimeter leachate at 1 m depth was monitored. Ninety days after whey application, total accumulative leachate COD for 0‐, 25‐, and 50‐mm whey applications was not significantly different. Leachate COD concentrations from the 100‐mm application reached 37% (29 400 mg COD L‐1) of the applied whey COD. Twenty‐eight days after whey treatment, infiltration was reduced in all whey‐treated lysimeters, probably as a result of increased microbial activity. Barley (Hordeum vulgare L. cv. Ludd) grain yield was 0.0, 0.0, ...

Evaluating a correlation between volatile suspended solid and adenosine 5′-triphosphate levels in anaerobic treatment of high organic suspended solids wastewater

Abstract Methods were developed to correlate volatile suspended solids (VSS) with adenosine 5′-triphosphate (ATP) concentrations in the treatment of cheese-processing wastewater. Two different physiological conditions where the maximum rates of acetate and butyrate production occurred, which were pH 7·01 at 36·2°C (condition A) and pH 7·26 at 36·2°C (condition B), respectively, were tested in batch mode. The ratios of ATP to volatile suspended solid (VSS) concentration were constant at exponential growth and decay phases for conditions A and B, which were 4·03 mg ATP/g VSS and 3·20 mg ATP/g VSS, respectively.

Method for evaluating anaerobic digester performance

The degradation rate and efficiency of digestion processes is typically measured by introducing a substrate or pollutant into a digester and then monitoring the effluents for the pollutant or substrate, a costly and slow process. A new method for rapid measurement of the rates and efficiencies of anaerobic degradation of pollutants and lignocellulose substrates from various pretreatments is described. The method uses micro-reactors (10-30mL) containing a mixed culture of anaerobic bacteria obtained from a working anaerobic digester. The rate of degradation of pollutants and metabolic heat rate are measured in parallel sets of micro-reactors. Measurement of metabolic rate and pollutant degradation simultaneously is an effective means of rapidly examining pollutant degradation on a micro-scale. Calorimetric measurements alone allow rapid, relative evaluation of various substrate pretreatment methods.