Search results for "PULP"

Chlorinated phenolic compounds in coniferous needles. Effects of metal and paper industry and incineration

1997

Abstract Pine needles were analyzed for their contents of chlorinated phenolic compounds. Altogether about 30 samples from surroundings of a metal scrap plant, a pulp and paper mill, a hazardous waste incinerator and reference samples outside of the immediate influence of these were analyzed by GC/ECD and GC/MS. Most phenolic compounds in the needles were found to be bound to the plant material and were not extractable as such by organic solvents. The concentrations of some bound chlorinated phenolic compounds were on level of 1–300 ng/g in dried needle. For many compounds the concentrations were remarkably higher in the three years old needles compared to the concentrations in the one and …

PCDDs, PCDFs, PCDTs, PCBs and some other organochlorine compounds in pine needles exposed to pulp and paper mill emissions and effects of waste combu…

1997

Concentrations of semivolatile chlorinated organic compounds α-HCH, lindane, HCB, DDT, DDE, DDD, chlordanes and PCBs, and low-volatility compounds PCDDs, PCDFs and PCDTs in pine needles in a recipient area of the emissions from a pulp and paper mill where also waste combustion was done were measured. Mostly, the concentrations were found to be near the background levels. Elevated concentrations of HCB, some PCB congeners and some HxCDF isomers in samples from two sampling points were observed. Some other possible point sources of these compounds are situated in the vicinity of the pulp and paper mill.. Also the community of Pietarsaari is one possible source of the slightly elevated concent…

Organic material dissolved during oxygen-alkali pulping of hot-water-extracted spruce sawdust

2016

Untreated and hot-water-extracted (HWE) Norway spruce (Picea abies) sawdust was cooked using the sulfur-free oxygen-alkali (OA) method under the following conditions: temperature, 170 °C; liquor-to-wood ratio, 5:1 L/kg; and NaOH charge, 19% on the oven-dry sawdust. In comparison with earlier studies conducted with birch sawdust, the spruce cooking yield data, together with the amount of the pulp rejects (78% to 86% for reference pulps from the initial feedstock and 73% to 83% for pulps from the HWE feedstock), revealed that the pretreatment stage prior to spruce OA pulping caused different effects on pulping performance. The analyses of the three main compound groups (i.e., lignin, volatile…

Characterization of Hardwood Soda-AQ Lignins Precipitated from Black Liquor through Selective Acidification

2016

In the development of integrated biorefinery process alternatives to produce value-added by-products, various black liquors from sulfur-free pulping processes offer potential feedstocks for recovering their main chemical constituents, lignin and aliphatic carboxylic acids. In this study, lignin fractions were obtained from silver birch (Betula pendula) soda-anthraquinone black liquor by carbonation (pH to about 8.5) or by acidification (pH to about 2) with H2SO4 after carbonation or directly. These fractions were characterized by Fourier transform infrared (FTIR), ultraviolet (UV), energy dispersive X-ray fluorescence (ED XRF), and 13C nuclear magnetic resonance (13C NMR) spectroscopy. In a…

Co-digestion of sewage sludge and sterilized solid slaughterhouse waste: Methane production efficiency and process limitations

2012

The rendering product of Category 2 and 3 Animal By-Products is known as sterilized mass (SM) and it is mainly composed of fat and proteins, making it interesting substrate for anaerobic digestion. Batch and semi-continuous laboratory experiments were carried out to investigate the effect of SM addition in co-digestion with sewage sludge on methane production and possible process limitations. Results showed that SM addition in the feed mixture up to 5% (w/w), corresponding to 68.1% of the organic loading, increased methane production 5.7 times, without any indication of process inhibition. Further increase of SM addition at 7.5% (w/w) caused methane production decrease and volatile solids r…

Influence of mw pretreatment on main gasification/combustion characteristics of different types of biomass

2020

ANALYSIS OF THE MOBILITY OF HEAVY METALS IN SLUDGE FOR THE SEWAGE TREATMENT PLANT IN DALESZYCE

2020

Sewage sludge is a by-product of wastewater treatment processes. However, it has high fertilising and soil-forming properties, but it cannot always be used for this purpose. The two main criteria limiting their natural use are heavy metals and parasite eggs. Sewage sludge taken from the Daleszyce wastewater treatment plant has been analysed for heavy metals. For this purpose a space analysis was performed to divide the total metal content into four mobility fractions. The mobility issue determines the ability of an element, or one of its forms, to move in the environment. The studies were performed using a four-stage BCR procedure. The results were analyzed and compared to the limits applic…

An oxygen monitoring and control system inside a malaxation machine to improve extra virgin olive oil quality

2013

In recent years, oxygen content regulation during malaxation has been noted as a process parameter. The aim of this study was to identify the optimal time during the malaxation process of the olives of the Sicilian cultivar Nocellara del Belice when the presence of oxygen in the machine headspace activates the enzyme complex in favour of the volatile compounds, without compromising the phenolic composition. During the malaxation process, the atmosphere inside the malaxation machine was modified by blowing pure oxygen from cylinders at specific stages of the process (i.e., 5, 15, 25, and 35 min after the start of malaxation), using a system that allows the automatic and continuous maintenanc…

Sulfur-free pulping of hot-water-extracted spruce sawdust

2016

Softwood (Picea abies) sawdust was hot-water-extracted with two multi-phase processes (160-180°C, 100-280 min, and liquor-to-wood ratio 5 l/kg) corresponding to P-factors of ~780 (yield 80.0%) and ~4580 (yield 72.4%). The pre-treated materials were then pulped with the soda-AQ cooking (170°C, NaOH charge 20%, AQ charge 0.1%, 30-150 min, and liquor-to-wood ratio 5 l/kg), resulting in a yield range of 36.1-61.4% (for reference cooks without pre-extraction 47.9-60.0%). It was observed that the pre-extraction under moderate conditions enhanced the dissolution especially of large-molar-mass lignin during cooking, and the total amount of the dissolved lignin was also higher than that removed from…

Anaerobic digestion of grass silage in batch leach bed processes for methane production.

2007

Abstract Anaerobic digestion of grass silage in batch leach bed reactors, with and without a second stage upflow anaerobic sludge blanket (UASB) reactor, was evaluated. Sixty six percent of the methane potential in grass was obtained within the 55 days solids retention time in the leach bed–UASB process without pH adjustment, whereas in the one-stage leach bed process 20% of the methane potential in grass was extracted. In two-stage operation, adjustment of the pH of influent to the leach bed reactor to 6 with HCl led to inhibition of both hydrolysis/acidogenesis and methanogenesis. In the leach bed–UASB process 39% of the carbohydrates and 58% of the acid soluble lignin were solubilised wi…