Fluid bed gasification – Plasma converter process generating energy from solid waste: Experimental assessment of sulphur species

Often perceived as a Cinderella material, there is growing appreciation for solid waste as a renewable content thermal process feed. Nonetheless, research on solid waste gasification and sulphur mechanisms in particular is lacking. This paper presents results from two related experiments on a novel two stage gasification process, at demonstration scale, using a sulphur-enriched wood pellet feed.Notable SO₂ and relatively low COS levels (before gas cleaning) were interesting features of the trials, and not normally expected under reducing gasification conditions. Analysis suggests that localised oxygen rich regions within the fluid bed played a role in SO₂’s generation. The response of COS to sulphur in the feed was quite prompt, whereas SO₂ was more delayed. It is proposed that the bed material sequestered sulphur from the feed, later aiding SO₂ generation. The more reducing gas phase regions above the bed would have facilitated COS – hence its faster response. These results provide a useful insight, with further analysis on a suite of performed experiments underway, along with thermodynamic modelling.     

Lactic acid production with undefined mixed culture fermentation of potato peel waste

Potato peel waste (PPW) as zero value byproduct generated from food processing plant contains a large quantity of starch, non-starch polysaccharide, lignin, protein, and lipid. PPW as one promising carbon source can be managed and utilized to value added bioproducts through a simple fermentation process using undefined mixed cultures inoculated from wastewater treatment plant sludge. A series of non-pH controlled batch fermentations under different conditions such as pretreatment process, enzymatic hydrolysis, temperature, and solids loading were studied. Lactic acid (LA) was the major product, followed by acetic acid (AA) and ethanol under fermentation conditions without the presence of added hydrolytic enzymes. The maximum yields of LA, AA, and ethanol were respectively, 0.22 g g^?1, 0.06 g g^?1, and 0.05 g g^?1. The highest LA concentration of 14.7 g L^?1 was obtained from a bioreactor with initial solids loading of 60 g L^?1 at 35 °C.     

离子色谱法测定废气中的甲酸和乙酸

阐述了离子色谱法测定废气中甲酸、乙酸含量的方法和步聚。甲酸、乙酸检出限分别为0.02mg/L和0.05mg/L,方法平均回收率分别为92%和95%。本方法分析速度快,所需样品量少,且无需复杂的前处理。     

Prenatal diagnosis of medium-chain acyl-coenzyme A dehydrogenase deficiency

A fatal case of medium-chain acyl-coenzyme A dehydrogenase deficiency is described in a patient who presented with hypoglycaemia and a gross non-ketotic dicarboxylic aciduria. Cultured skin fibroblasts released ¹⁴CO₂ from [1–¹⁴C] octanoic acid at half the normal rate. Prenatal diagnosis was undertaken in a subsequent pregnancy in which cultured amniotic fluid cells revealed a marked reduction in octanoate oxidation indicative of an affected fetus. The pregnancy was terminated and the diagnosis was confirmed by enzyme analysis of skin fibroblasts taken from the fetus. The high residual octanoate oxidation by affected fibroblasts together with the absence of any characteristic abnormality of amniotic fluid organic acids are a potential limitation to the reliability of this type of prenatal diagnosis.     

西南酸雨地区土壤中铝溶出规律的探讨

本文介绍了实验室动态模拟结果,对西南地区酸性沉降引起的土壤铝淋溶过程予以探讨。通过计算机推算拟合,提出了预测土壤中铝淋溶容量计算法。运用正交实验法,研究了近似于天然的动态过程中影响铝淋溶的主要因素及各因素间的相关性。得到了当降雨pH<6.0时,酸性土或弱酸性土中铝溶量和时间呈指数关系,以及影响铝溶出因素主要是酸雨的pH值、土壤的缓冲能力和环境温度等结论。     

Persistence of herbicide fenoxaprop ethyl and its acid metabolite in soil and wheat crop under Indian tropical conditions

The persistence of fenoxaprop ethyl {Ethyl (RS)-2-[4-(6-chloro-1,3-benzoxazol-2-yloxy) phenoxy] propionate} herbicide and its active metabolite fenoxaprop acid was investigated in soil and wheat crop. Fenoxaprop acid was prepared by alkaline hydrolysis of fenoxaprop ethyl. A HPLC method was developed in which fenoxaprop ethyl herbicide and its acid metabolite showed sharp single peak at 6.44 and 2.61 min respectively. The sensitivity of the method for ester and acid was 2 and 1 ng respectively with limit of detection of 0.1 and 0.05 μg mL^?1. The recovery of fenoxaprop ethyl and fenoxaprop acid from soil, wheat straw and grain ranged between 73.8–80.2%. In a field experiment fenoxaprop ethyl (Puma super® 10 EC) when applied to wheat crop at the rate of 120 g and 240 g a.i. ha^-1 as post emergence spray, fenoxaprop ethyl converted to fenoxaprop acid. Residues of fenoxaprop ethyl and acid dissipated in soil with a half-life of 0.5 and 7.3 days, respectively. At harvest no detectable residues of fenoxaprop ethyl or acid were observed in soil, wheat grain and straw samples.     

Short-term impact of olive mill wastewater (OMWW) applications on the physico-chemical and microbiological soil properties of an olive grove in Argentina

The purpose of this work was to investigate the effects of spreading olive oil mill wastewater (OMWW) on soil biochemical parameters and olive production in an organically managed olive orchard. The experiment was carried out with three different doses of OMWW (80, 160 and 500 m³ ha^?1) and a control (untreated soil). Three samplings were done at 10, 30 and 90 days after the administration of the byproduct. OMWW application differentially modified the biochemical properties of the soil analyzed. Organic matter, organic carbon, total nitrogen and extractable phosphorus soil contents increased proportionally with each increasing dose. The values of these parameters decreased gradually with time. Total microbial activity was altered and the OMWW 500 m³ ha^?1 treatment proved to be the most active when compared with the other applied doses. OMWW agricultural application also modified the structure of soil microbial communities, particularly affecting Gram positive and negative bacteria, while fungal biomass did not show consistent changes. Although there was a salinity increase in the treated soil, especially at the highest dose, the productive parameters analyzed (fruit and oil tree^?1) were not affected. In light of the obtained results, we consider that low dose of OMWW could be considered an alternative farming practice for semiarid regions.     

Extraction procedure optimization for perfluorooctane sulfonate and perfluorooctanoic acid in food packaging determination by LC-MS/MS

This research aimed to optimize the extraction method parameters for sample pretreatment and determine the levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) contamination in food packaging made of paper. Techniques used were pressurized liquid extraction (PLE) followed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Influence parameters of PLE were carefully evaluated for extracted concentration of samples in low level (ng g^?1). The study found that the optimal conditions for PLE were 30 min static extraction time with a flush volume of 100% cell volume and one extraction cycle at 80°C and 1,000 psi. The extraction technique validated the absolute recovery from PFOS and PFOA fortified control samples at three different levels (5, 50, and 200 ng g^?1), with seven repeats at each fortification level. The average recoveries were 79% or higher, with relative standard deviation (RSD) less than 11%. Optimization of the PLE method was established based on recovery data, accuracy, precision, and repeatability of the method. Using optimal PLE technique, PFOS and PFOA were extracted from 34 food-packaging samples collected in Thailand. PFOS and PFOA were detected in all kinds of collected samples, with average concentrations of 4.89 and 2.87 ng g^?1, respectively. The concentrations of PFOS and PFOA were highest in fast-food container samples: 36.99 and 9.99 ng g^?1, respectively.     

Tolerance of S. cerevisiae and Z. mobilis to inhibitors produced during dilute acid hydrolysis of soybean meal

The objective of this research was to determine the minimum inhibitory concentration of 5-hydroxymethyl furfural, furfural, and acetic acid on Saccharomyces cerevisiae (NRRL Y-2233) and Zymomonas mobilis subspecies mobilis (NRRL B-4286) in both detoxified hydrolyzed soybean meal and synthetic YM broth spiked with the three compounds. Soybean meal was hydrolyzed with dilute sulfuric acid (0.0, 0.5, 1.25, and 2.0% wt v^?1) at three temperatures (105, 120, and 135°C) and three durations (15, 30, and 45 min) followed by detoxification with activated carbon. Of all the combinations, only the treatments obtained at 135°C, 2.0% H₂SO₄, and 45 min and the one at 135°C, 1.25% H₂SO₄, and 45 min showed inhibition in the growth of the tested microorganisms. Spiked YM broths showed inhibition for the highest levels of inhibitors, either applied individually or in combination.     

The effect of adaptation of Lactobacillus amylovorus to increasing concentrations of sweet potato starch on the production of lactic acid for its potential use in the treatment of cannery waste

Abstract

Lactobacillus amylovorus, an amylolytic species, was cultured in increasing concentrations of sweet potato starch to test the effect of this progressive acclimation on lactic acid production. This research is part of a project on the use of the waste stream from a sweet potato cannery to produce lactic acid. The media used for this acclimation was a modified version of the de Man, Rogosa and Sharpe medium, in which glucose was partially or totally substituted with sweet potato starch. The process was done in five steps, starting with 100% glucose in the first step and ending with 100% sweet potato starch in the last one. At each step, the effectiveness of the acclimation was tested by running fermentations with and without pH control for 62?h. The effect of the overall adaptation process was tested by comparing the growth and activity of the acclimated vs non-acclimated bacteria using sweet potato starch as the only source of carbohydrates. Growth and activity assessments indicated that L. amylovorus was able to ferment sweet potato starch into lactic acid. In most cases, pH control resulted in better substrate utilisation and larger amounts of lactic acid. In the comparison study, however, the adaptation process had a major influence on lactic acid production than the effect of pH. For 20?g L^–1 sweet potato starch media, adapted L. amylovorus under no pH control yielded 11.20?g L^–1 versus the non-adapted bacteria, which yielded 7.10?g L^–1. Under controlled pH conditions, 14.80 and 4.20?g L^–1 lactic acid were produced by adapted and non-adapted bacteria respectively.