Treatment of potato processing wastewaters by activated carbon adsorption process

A laboratory study was conducted to determine the effects of degrees of pretreatment, types of activated carbons, dosages of activated carbons on the organic removal rates of potato processing wastewaters using the activated carbon adsorption process. Primary treated effluents, and secondary treated effluents using activated sludge and powdered activated carbon activated sludge processes were used as adsorbate in this study. Two types of activated carbon used consisted of granular activated carbon, Nuchar WV-L, and powdered activated carbon, Nuchar S-C, in dosages varied from 0.25 to 4 g per 50 ml of wastewater. Results indicated that activated sludge treatment removed 86–96% of COD from primary settled wastewaters. Activated sludge followed by activated carbon adsorption treatment removed 97% COD from primary settled wastewater with an effluent COD of 24 mg/1. Powdered activated carbon was more effective than granular activated carbon in removing COD from activated sludge treated effluents.     

Tertiary treatment of potato processing waste by biological activated carbon process

A biological activated carbon process was investigated for its feasibility as a tertiary treatment process for potato processing wastewaters. Bench-scale continuous complete-mix activated sludge reactors and biological activated carbon units were operated to evaluate the removal kinetics of organic materials and to determine the design parameters for a full-scale treatment unit. Raw wastewater contained 4300 mg/1, which was reduced to 130 to 340 mg/1 following the complete-mix activated sludge treatment and to 30 to 90 mg/1 after the biological activated carbon treatment.     

Biological and technical notes on spraying against potato blight

Summary The numerical ratio of the deposits of sporangia of the blight fungus on the upper and lower leaf surfaces was found to vary between 10 and 30 depending on the stage of the attack and the position of the leaves. The ratio of infections on the upper and lower leaf surfaces had lower values than would be expected from the sporangia deposits. At weak attack 7–8 and at heavy attack 3–4 as many infections occurred on the upper surfaces In field trials the protection of spraying only from above was found to be on the average equally good as combined sparying from above and from below. However, some potato varieties with an open type of growth (King Edward) were somewhat better protected by spraying from above, while combined spraying gave somewhat better results in varieties with a closed type of growth (Bintje). In laboratory trials with different droplet sizes on detached leaflets the smallest droplets of Bordeaux tested (M.M.D. 55μ) gave considerably better protection against infection than larger droplets. Articificial rain treatment of Bordeaux-sprayed leaves clearly improved an incomplete protection presumably through redistribution of fungicidal particles to unprotected leaf areas. Similar trials with Zineb gave more irregular results; in most cases rain deteriorated the protection.

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Zusammenfassung Das zahlenm?ssige Verh?ltnis der Depositionen von Sporangien desPhytophthorapilzes auf der Oberseite und Unterseite der Bl?tter erwies sich als schwankend zwischen 10 und 30, je nach Stadium des Befalls und Stellung der Bl?tter. Das Verh?ltnis der Infektionen auf der Oberseite und Unterseite der Bl?tter zeigte geringere Werte, als von den Sporangiendepositionen zu erwarten w?re. Bei schwachem Befall kamen 7–8 und bei starkem Befall nur 3–4 mehr Infektionen auf der Blattoberseite vor. Bei Feldversuchen ergab sich, dass der Schutz durch Spritzen „nur von oben” im allgemeinen ebenso gut war wie das kombinierte Spritzen „von oben und von unten”. Jedoch wurden einige Kartoffelsorte mit offenem Wuchs des Krautes (King Edward) etwas besser geschützt durch oberseitiges Spritzen, w?hrend das kombinierte Spritzen etwas bessere Ergebnisse zeigte bei Sorten mit geschlossenem Krautwuchs (Bintje). Bei Laboratoriumversuchen mit verschiedenen Tropfengr?ssen auf abgetrennten Bl?ttchen ergaben die kleinsten Tr?pfchen Bordeaux (Kupferkalkbrühe M.M.D. 55μ) einen bedeutend besseren Schutz gegen Infektion als die gr?sseren Tropfen. Künstlicher Regen auf den mit Bordeaux bespritzten Bl?ttchen verbesserte deutlich einen unvollst?ndigen Schutz, vermutlich durch die Neuverteilung der Partikelchen des Fungizids über die ungeschützten Blattstellen. Gleichartige Versuche mit Zineb ergaben mehr unregelm?ssige Resultate; in den meisten F?llen verschlechterte Regen den Schutz.

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Resumé Il appert que la proportion numérique des dép?ts de sporanges du champignon du mildiou sur les surfaces supérieures et inférieures des feuilles varie entre 10 et 30, ceci en fonction des attaques plus ou moins sérieuses et de la position des feuilles. La proportion des infestations sur les surfaces supérieures et inférieures des feuilles a démontré des valeurs plus basses que les dép?ts de sporanges laissaient prévoir. Les surfaces supérieures des feuilles ont démontré, devant une attaque faible, 7 à 8 fois plus d'infestations, et, en présence d'une attaque sérieuse 3 à 4 fois plus d'infestations que les surfaces inférieures. Dans des essais entrepris en plein champ la protection par voie de pulvérisation des surfaces supérieures des feuilles était, en moyenne, aussi efficase que lorsque les feuilles furent pulvérisées des c?tés supérieur et inférieur. Toutefois, certaines variétés de pommes de terre d'une croissance étalée (King Edward par exemple) furent un peu mieux protégées par la pulvérisation de la surface supérieure des feuilles, alors qu'une pulvérisation combinée des c?tés supérieur et inférieur a donné des résultats légèrement meilleurs chez les variétés ayant un type de croissance fermée (Bintje). Dans des essais entrepris en laboratoire avec diverses grosseurs de gouttelettes sur des feuilles détachées de la plante, les gouttelettes les plus petites de bouillie bordelaise (M.M.D. 55μ) ont donné une protection nettement meilleure contre l'infestation que les gouttelettes plus grosses. Le traitement par pluie artificielle de feuilles pulvérisées par bouillie bordelaise a sensiblement amélioré la protection incomplète du fait probablement d'un redistribution des particules du fongicide appliqué sur les parties de la feuille restées non-protégées jusque-là. Desessaissimilaires avec Zineb ont donné des résultats plus irréguliers; dans la majorité des cas la pluie a corrompu l'efficacité de la protection.

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Lecture held at the 4th International Informal Potato Conference at Lund (Sw.), August 1957.     

Simulation and sensitivity study of potato flake food processing

We made a sensitivity study of the potato flake process using the ERRC Food Process Simulator computer program with cost as the primary objective function. The study showed that labor was the largest component of the processing cost followed by capital related expenses. Pilot plant operation demonstrated the feasibility of reducing labor requirements. Capital related expenses could be minimized by using four drum dryers to more closely match the through put of the rest of the process. In addition, the drum dryers should be run as close to 8% moisture as possible without exceeding 8% to optimize the yield of finished product. This study demonstrates the feasibility of using the ERRC Food Process Simulator to do a sensitivity study of potato processing.     

Predicting yield and processing quality of potato breeding selections

The linear relationship between “site mean” and potato cultivar performance was used to develop predictive models for total yield, yield of US No 1 grade, per cent US No 1 grade, specific gravity and fried chip color. The best fitting linear expression for each of the traits was determined by linear regression for specific cultivars. Common limits for “site means” could then be substituted into the expressions for predictive purposes. Application of this method to large and small data sets demonstrated its use for interpreting preliminary yield trial information for the identification of superior breeding selections.     

Eradication of potato virus X from potato by ribavirin treatment of cultured potato shoot tips

Ribavirin treatment of cultured potato shoot tips was tested as a means of eradicating potato virus X (PVX) from two potato cultivars. Shoot tips were cultured on liquid medium containing 0, 1, 10 or 100μg/ml ribavirin. Cultures were evaluated periodically for viability, and scored for vigor on a relative growth scale. Developed plantlets were assayed for PVX by transmission tests toGomphrena globosa. Ribavirin treatment was phytotoxic at all tested concentrations, and lethal to all cultivars treated at 100 μg/ml. Treatment also delayed plantlet development by up to 2 months at 1 and 10 μg/ml as compared with nontreated controls. PVX assays indicated that 80 and 83% of the plantlets were free of PVX following treatment with 10 μg/ml for cultivars Russet Burbank and Red McClure, respectively. Five and 6% of the plantlets developed from the 1 μg/ml treatment were PVX-free, whereas 0 and 2% of the controls were PVX-free for the same cultivars. Six to 8 months were required to develop plants from shoot-tip cultures treated with 10 μg/ml ribavirin.     

Shurchip: A new scab resistant processing potato variety

Shurchip is a slightly russeted, round to oblong chipping variety of medium maturity. It is resistaant to common scab (Streptomyces scabies) and tolerant to Fusarium (F. solani var. eumartii) and Verticillium (microsclerotial type) wilts. The vines are susceptible and the tubers are highly susceptible to late blight. In Nebraska, Shurchip is high yielding, moderately high in specific gravity, lower in reducing sugars and of good to excellent chipping quality when compared with the standard varieties Haig, Kennebec and Platte. The yield and specific gravity obtained with Shurchip in the 12 states in the North Central Regional Trials and in Texas and Alabama were equal to or greater than those obtained with the standard chipping varieties in the trials.     

Control of the Colorado potato beetle by treatment of potato seed pieces

Dusting or soaking freshly cut potato seed pieces in systemic insecticides controlled the first generation larvae of the Colorado potato beetle at Yakima, Washington in 1970. The most promising materials were tested again in a larger experiment in 1971. Fifty days after treatment, Bay 37344 (4-(methylthio)-3,5,xylyl methylcarbamate), Dasanit^® (O,O-diethyl-O-[p-(methylsulfinyl) phenyl] phosphorothioate), Shell SD 17250 (N-(methylcarbamoyl)oxy]thioacetimidic acid ester with 3-mercaptopropionitrile) and Plant Protection PP062 (dimethylamino)-4,5,6-dimethyl pyrimidinyl dimethylcarbamate) all gave significantly better control of the larvae than methomyl, azinphosmethyl and menazon.     

Alpha-amylase inhibitor changes during processing of sweet potato and taro tubers

Alpha-amylase inhibitor changes during processing ofsweet potatoes (Ipomoea batatas) and taro (Colocasia esculenta)indicated that varietal differences profoundly influence the thermalinactivation profile. The -amylase inhibitors of taro were almosttotally inactivated during oven drying of the chips at 90 ^°C and100 ^°C for 24h, while 0.8–10% activity was retained in sweetpotato chips under the same conditions. Relatively better thermal stabilitywas exhibited by the sweet potato amylase inhibitors at lower temperatures(70 and 80 ^deg;C) as well. Cooking by boiling the tuber pieces inwater resulted in retention of 29–59% amylase inhibitor in sweet potatoand 11–16% in taro. Microwave baking was a better method forinactivation of amylase inhibitors in these tubers. Flour prepared from thetubers retained only trivial amounts of the inhibitor.     

Biological control of fusarium dry rot of potato tubers under commercial storage conditions

Lack of effective chemicals impedes control of Fusarium dry rot of stored potato tubers destined for processed and table stock use. Biological control of dry rot incited byGibberella pulicaris (anamorph=Fusarium sambucinum) has been demonstrated in laboratory studies but not in commercial storage environments. Several Gram-negative bacterial strains that were efficacious and amenable to production in liquid culture in laboratory studies were selected for pilot studies in Idaho and for bin trials at commercial storage houses in Idaho and North Dakota. In the first year of pilot studies,Pseudomonas fluorescens S22:T:04 (≈1 x 10⁸ cfu/ml) decreased dry rot caused byG. pulicaris by 19% when coinoculated with the pathogen compared to controls and to the fungicide thiabendazole (TBZ) applied at label rates. In second year pilot studies,P. fluorescens P22:Y:05 andEnterobacter cloacae S11:T:07 (≈4 x 10⁸ cfu/ml) reduced the severity of disease incited byG. pulicaris (25% and 17% average disease decrease, respectively) when antagonists were applied after pathogen inoculum. Treatment effects on dry rot that developed from inoculation withNectria haematococca (anamorph=Fusariumsolani var.coeruleum) were variable and influenced by interactions between antagonists, a wetting agent, and TBZ. In commercial storage bin trials,E. cloacae S11:T:07 reduced naturally occurring levels of dry rot by an average of 21% compared to 14% for TBZ, demonstrating that this antagonist was effective when produced using a liquid culture medium and methodology that approximates commercial practices for producing biomass.     

Critical petiole nitrate concentration of two processing potato cultivars in Eastern Canada

Plant-based diagnostic methods of nitrogen (N) nutrition such as petiole nitrate (NO₃-N) concentration can be used to improve the efficiency of N utilization, and hence decrease the risks of N losses to the environment. Our first objective was to determine the effect of N fertilization and supplemental irrigation on the petiole NO₃-N concentration during tuber growth of two potato cultivars, Russet Burbank and Shepody, widely grown for processing in Eastern Canada. Our second objective was to establish the critical petiole NO₃-N concentration using the relationship between petiole NO₃-N concentration and the N nutrition index (NNI), an index based on the N concentration of shoots and tubers. This on-farm study was conducted at two sites in each of three years, 1995 to 1997. The N fertilization rates ranged from 0 to 250 kg N ha^?1 with three rates in 1995, six rates in 1996, and four rates in 1997. The NO₃-N concentration of petioles from the most recently mature leaves was measured on three sampling dates in 1995 and four sampling dates in 1996 and 1997. The petiole NO₃-N concentration generally decreased with time. At all sites and on all sampling dates, the petiole NO₃-N concentration increased with increasing N fertilization and was significantly greater for Shepody than for Russet Burbank. Irrigation had no consistent effect on petiole NO₃-N concentration. Petiole NO₃-N concentration was related to NNI (0.29<R²<0.62). Critical petiole NO₃-N concentrations required to reach a NNI of 1.0, indicating a situation where N is not limiting growth, were greater for Shepody than for Russet Burbank, and they decreased with time. Critical petiole NO₃-N concentrations (Y) expressed as a function of the number of days after planting (X) are Y = 4.80 - 0.055X for Russet Burbank and Y = 5.03 - 0.054X for Shepody.