Johannes van Leeuwen

Effect of competing solutes on arsenic(V) adsorption using iron and aluminum oxides.

The study focused on the effect of several typical competing solutes on removal of arsenic with Fe2O3 and Al2O3. The test results indicate that chloride, nitrate and sulfate did not have detectable effects, and that selenium(IV) (Se(IV)) and vanadium(V) (V(V)) showed slight effects on the adsorption of As(V) with Fe2O3. The results also showed that adsorption of As(V) on Al2O3 was not affected by chloride and nitrate anions, but slightly by Se(IV) and V(V) ions. Unlike the adsorption of As(V) with Fe2O3, that with Fe2O3 was affected by the presence of sulfate in water solutions. Both phosphate and silica have significant adverse effects on the adsorption of As(V) adsorption with Fe2O3 and Al2O3. Compared to the other tested anions, phosphate anion was found to be the most prominent solute affecting the As(V) adsorption with Fe2O3 and Al2O3. In general, Fe2O3 has a better performance than Al2O3 in removal of As(V) within a water environment where multi competing solutes are present.

Oxidation of As(III) by potassium permanganate

The oxidation of As(III) with potassium permanganate was studied under conditions including pH, initial As(III) concentration and dosage of Mn(VII). The results have shown that potassium permanganate was an effective agent for oxidation of As(III) in a wide pH range. The pH value of tested water was not a significant factor affecting the oxidation of As(III) by Mn(VII). Although theoretical redox analyses suggest that Mn(VII) should have better performance in oxidization of As(III) within lower pH ranges, the experimental results show that the oxidation efficiencies of As(III) under basic and acidic conditions were similar, which may be due to the adsorption of As(III) on the Mn(OH)2 and MnO2 resulting from the oxidation of As(III).

Ethanol production, purification, and analysis techniques: a review

World ethanol production rose to nearly 13.5 billion gallon in 2006. Ethanol has been part of alcoholic beverages for long time, but its application has expanded much beyond that during the 20th Century. Much of the recent interest is in the use of ethanol as fuel. In this paper, we have reviewed published literature on current ethanol production and separation methods, and chemical and sensory analysis techniques. Ethanol produced by fermentation, called bioethanol, accounts for approximately 95% of the ethanol production. It is recently widely used as an additive to gasoline. Corn in the Unites States and sugarcane in Brazil are widely used as raw materials to produce bioethanol. Cellulosic materials are expected to be the ultimate major source of ethanol and also represent a value-adding technology for agricultural coproducts. While bioethanol is considered as a sustainable energy source, it requires further purification for uses other than fuel. The most common purification technique utilized in the ethanol industry is rectification by further distillation. However, distillation has critical disadvantages including high cost and limited separation capacity. Several alternatives have been proposed to replace distillation such as non-heating fractional distillation by ultrasonic irradiation, oxidation of impurities by ozone, and adsorption of impurities by activated carbon or zeolite. Chemical and sensory analyses are used to determine the quality of alcohol and to optimize various steps in production. Near-infrared (NIR) spectrometry, high performance liquid chromatography (HPLC), gas chromatography (GC), and mass spectrometry (MS), have been developed for chemical analyses. Also, olfactometry is common for sensory analysis. This paper summarizes the state-of-the art of ethanol production, purification, and analytical techniques.

Simultaneous saccharification and fermentation and economic evaluation of ultrasonic and jet cooking pretreatment of corn slurry.

The potential of ultrasonics to replace hydrocooking in corn‐to‐ethanol plants was examined in this study. Batch and continuous experiments were conducted on corn slurry with sonication at a frequency of 20 kHz. Batch mode used a catenoidal horn operated at an amplitude of 144 μmpeak‐to‐peak (p–p) for 90 s. Continuous experiments used a donut horn operating at inner radius amplitude of 12 μmp–p. Jet‐cooked samples from the same ethanol plant were compared with ultrasonicated samples. The highest starch‐to‐ethanol conversion was obtained by the jet‐cooked samples with a yield of 74% of the theoretical yield. Batch and continuous sonication achieved 71.2% and 68% conversion, respectively, however, statistical analysis showed no significant difference between the jet cooking and ultrasonication. On the basis of the similar performance, an economic analysis was conducted comparing jet cooking and ultrasonic pretreatment. The analysis showed that the capital cost for the ultrasonics system was ∼ 10 times higher compared to the capital cost of a hydrocooker. However, due to the large energy requirements of hydrocookers, the analysis showed lower total overall costs for continuous ultrasonication than that for jet cooking, assuming the current energy prices. Because of the high utility cost calculated for jet cooking, it is concluded that ultrasonication poses as a more economical option than jet cooking. Overall, the study shows that ultrasonics is a technically and economically viable alternative to jet cooking in dry‐grind corn ethanol plant.

Ozonation-Based Decolorization of Food Dyes for Recovery of Fruit Leather Wastes

Commercial manufacture of fruit leathers (FL) usually results in a portion of the product that is out of specification. The disposition of this material poses special challenges in the food industry. Because the material remains edible and contains valuable ingredients (fruit pulp, sugars, acidulates, etc.), an ideal solution would be to recover this material for product rework. A key practical obstacle to such recovery is that compositing of differently colored wastes results in an unsalable gray product. Therefore, a safe and scalable method for decolorization of FL prior to product rework is needed. This research introduces a novel approach utilizing ozonation for color removal. To explore the use of ozonation as a decolorization step, we first applied it to simple solutions of the commonly used food colorants 2-naphthalenesulfonic acid (Red 40), tartrazine (Yellow 5), and erioglaucine (Blue 1). Decolorization was measured by UV/vis spectrometry at visible wavelengths and with a Hunter colorimeter. Volatile and semivolatile byproducts from ozone-based colorant decomposition were identified and quantified with solid phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). Removal of Yellow 5, Red 40 and Blue 1 of about 65%, 80%, and 90%, respectively, was accomplished with 70 g of ozone applied per 1 kg of redissolved and resuspended FL. Carbonyl compounds were identified as major byproducts from ozone-induced decomposition of the food colorants. A conservative risk assessment based on quantification results and published toxicity information of potentially toxic byproducts, determined that ozone-based decolorization of FL before recycling is acceptable from a safety standpoint. A preliminary cost estimate based on recycling of 1000 tons of FL annually suggests a potential of

Improved quantification of livestock associated odorous volatile organic compounds in a standard flow-through system using solid-phase microextraction and gas chromatography–mass spectrometry

275,000 annual profit from this practice at one production facility alone.

Ultrasonic Pretreatment of Corn Slurry in Batch and Continuous Systems

Aerial emissions of odorous volatile organic compounds (VOCs) are an important nuisance factor from livestock production systems. Reliable air sampling and analysis methods are needed to develop and test odor mitigation technologies. Quantification of VOCs responsible for livestock odor remains an analytical challenge due to physicochemical properties of VOCs and the requirement for low detection thresholds. A new air sampling and analysis method was developed for testing of odor/VOCs mitigation in simulated livestock emissions system. A flow-through standard gas generating system simulating odorous VOCs in livestock barn emissions was built on laboratory scale and tested to continuously generate ten odorous VOCs commonly defining livestock odor. Standard VOCs included sulfur VOCs (S-VOCs), volatile fatty acids (VFAs), and p-cresol. Solid-phase microextraction (SPME) was optimized for sampling of diluted odorous gas mixtures in the moving air followed by gas chromatography-mass spectrometry (GC-MS) analysis. CAR/PDMS 85μm fiber was shown to have the best sensitivity for the target odorous VOCs. A practical 5-min sampling time was selected to ensure optimal extraction of VFAs and p-cresol, as well as minimum displacement of S-VOCs. Method detection limits ranged from 0.39 to 2.64ppbv for S-VOCs, 0.23 to 0.77ppbv for VFAs, and 0.31ppbv for p-cresol. The method developed was applied to quantify VOCs and odorous VOC mitigation with UV light treatment. The measured concentrations ranged from 20.1 to 815ppbv for S-VOCs, 10.3 to 315ppbv for VFAs, and 4.73 to 417ppbv for p-cresol. Relative standard deviations between replicates ranged from 0.67% to 12.9%, 0.50% to 11.4%, 0.83% to 5.14% for S-VOCs, VFAs, and p-cresol, respectively. This research shows that a simple manual SPME sampler could be used successfully for quantification of important classes of odorous VOCs at concentrations relevant for real aerial emissions from livestock operations.

Purification and Quality Enhancement of Fuel Ethanol to Produce Industrial Alcohols with Ozonation and Activated Carbon

The effects of ultrasonication of corn slurry, on particle size distribution and enzymatic hydrolysis was studied for the dry-grind mill ethanol industry. Two independent ultrasonic experiments were conducted at a frequency of 20 kHz; in batch and continuous systems. The ground corn slurry (33% m/v) was pumped at flow rates 10-28 L/min in continuous flow experiments, and sonicated at constant amplitude (20µmpeak-to-peak(p-p)). Ultrasonic batch experiments were conducted at varying amplitudes of 192-320µmp-p. After ultrasonication, StargenTM001 enzyme was added to the samples and a short 3h hydrolysis followed. The treated samples were found to yield 2-3 times more reducing sugar compared to the control (untreated) samples. In terms of energy density, the batch ultrasonic system was found to deliver 25-times more energy than the continuous flow systems. Although the experiments conducted in continuous system released less reducing sugar than the batch system, the continuous system was more energy efficient. The particle size of the sonicated corn slurry (both batch and continuous) was reduced relative to the controls (without treatment). The reduction of particle size was directly proportional to the energy input during sonication. The study suggests that both batch and continuous flow ultrasonic systems enhances enzymatic hydrolysis yield, reduces particle size of corn slurry and could be a potential effective pretreatment for corn slurry.

Ultrasonic Enhanced Liquefaction and Saccharification of Corn for Bio-Fuel Production

The total ethanol production capacity in the US just passed 6 billion gals/year. The production process of ethanol from corn includes corn milling, cooking, enzymatic starch conversion, fermentation and distillation. Food-grade alcohol production requires more care and undergoes costly additional purification to remove volatile organic impurities. These impurities could be of health concern and/or impart unpleasant tastes and odors to beverage alcohol. Multiple distillation steps are usually employed. The additional purification of ethanol to obtain food-grade alcohol adds at least

Simultaneous Saccharification and Fermentation of Ultrasonically Treated Corn Slurry

0.30 per gallon in processing costs. In this research, we tested a novel approach to purify fuel grade ethanol to pharmaceutical and beverage grade. The cost of the proposed treatment process is expected to be less than