Publications by authors named "Jukka Rintala"

90 Publications

Incidence of parastomal and incisional hernia following emergency surgery for Hinchey III-IV diverticulitis: A systematic review.

Scand J Surg 2022 Apr-Jun;111(2):14574969221107276

Department of Surgery, Medical Research Center, University of Oulu, Oulu University Hospital, Oulu, Finland.

Purpose: The aim of this systematic review was to evaluate the risk of parastomal (PSH) and incisional hernias (IH) after emergency surgery for Hinchey III-IV diverticulitis, with comparison between the Hartmann procedure and other surgical techniques.

Methods: The Cochrane Library, Embase, PubMed (MEDLINE), Web of Science and Scopus databases were systematically searched. The primary endpoint was parastomal hernia incidence. The secondary endpoint was incisional hernia incidence.

Results: Five studies (four randomized controlled trials and one retrospective cohort) with a total of 699 patients were eligible for inclusion. The PSH rate was 15%-46% for Hartmann procedure, 0%-85% for primary anastomosis, 4% for resection, and 2% for laparoscopic lavage. The IH rates were 5%-38% for Hartmann procedure, 5%-27% for primary anastomosis, 9%-12% for primary resection, and 3%-11% for laparoscopic lavage.

Conclusions: Both the parastomal and incisional hernia incidences are poorly evaluated and reported, and varied greatly between the studies.
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http://dx.doi.org/10.1177/14574969221107276DOI Listing
June 2022

Monocarboxylate Transporters 1 and 4 and Prognosis in Small Bowel Neuroendocrine Tumors.

Cancers (Basel) 2022 May 22;14(10). Epub 2022 May 22.

Cancer and Translational Medicine Research Unit, Medical Research Center, Oulu University Hospital and University of Oulu, 90220 Oulu, Finland.

Monocarboxylate transporters (MCTs) are cell membrane proteins transporting lactate, pyruvate, and ketone bodies across the plasma membrane. The prognostic role of MCTs in neuroendocrine tumors is unknown. We aimed to analyze MCT1 and MCT4 expression in small bowel neuroendocrine tumors (SB-NETs). The cohort included 109 SB-NETs and 61 SB-NET lymph node metastases from two Finnish hospitals. Tumor samples were immunohistochemically stained with MCT1 and MCT4 monoclonal antibodies. The staining intensity, percentage of positive cells, and stromal staining were assessed. MCT1 and MCT4 scores (0, 1 or 2) were composed based on the staining intensity and the percentage of positive cells. Survival analyses were performed with the Kaplan-Meier method and Cox regression, adjusted for confounders. The primary outcome was disease-specific survival (DSS). A high MCT4 intensity in SB-NETs was associated with better DSS when compared to low intensity (85.7 vs. 56.6%, = 0.020). A high MCT4 percentage of positive cells resulted in better DSS when compared to a low percentage (77.4 vs. 49.1%, = 0.059). MCT4 scores 0, 1, and 2 showed DSS of 52.8 vs. 58.8 vs. 100% ( = 0.025), respectively. After adjusting for confounders, the mortality hazard was lowest in the patients with a high MCT4 score. MCT1 showed no association with survival. According to our study, a high MCT4 expression is associated with an improved prognosis in SB-NETs.
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http://dx.doi.org/10.3390/cancers14102552DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9139933PMC
May 2022

The effects of digestate pyrolysis liquid on the thermophilic anaerobic digestion of sewage sludge - Perspective for a centralized biogas plant using thermal hydrolysis pretreatment.

Waste Manag 2022 Jun 25;147:73-82. Epub 2022 May 25.

Faculty of Engineering and Natural Sciences, Tampere University, P.O.Box 541, 33104 Tampere University, Finland.

The use of pyrolysis process to valorize digestate from anaerobic digestion (AD) of municipal sewage sludge for biochar production was piloted in a central biogas plant. The pyrolysis also generates pyrolysis liquid with high organics and nutrient contents that currently has no value and requires treatment, which could potentially be done in AD. As the pyrolysis liquid may contain inhibitory compounds, we investigated the effects of adding the pyrolysis liquid on AD of sewage sludge and thermal hydrolysis pretreated sewage sludge (THSS) simulating the full-scale centralized biogas plant conditions. In batch assays, the pyrolysis liquid as such did not produce any methane, and the 1% and 5% (v/w) shares suppressed the methane production from THSS by 14-19%, while a smaller decrease in methane production was observed with sewage sludge. However, in the semi-continuous reactor experiments, pyrolysis liquid at a 1% (v/w) share was added in sewage sludge or THSS feed without affecting the methane yields or digestate characteristics. The laboratory results indicated that pyrolysis liquid can be treated in AD, while extrapolating the results to the centralized biogas plant indicated minor increase in the overall methane production and an increased potential for ammonium recovery.
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http://dx.doi.org/10.1016/j.wasman.2022.05.013DOI Listing
June 2022

Hydrothermal carbonization of pulp and paper industry wastewater treatment sludges - characterization and potential use of hydrochars and filtrates.

Bioresour Technol 2022 Jul 5;355:127258. Epub 2022 May 5.

Faculty of Engineering and Natural Sciences, Tampere University, P.O.Box 541, 33104 Tampere University, Finland.

The pulp and paper industry's mixed sludge represents waste streams with few other means of disposal than incineration. Hydrothermal carbonization (HTC) could be advantageous for the sludge refinement into value-added products, thus complementing the concept of pulp and paper mills as biorefineries. Laboratory HTC was performed on mixed sludge (at 32% and 15% total solids) at temperatures of 210-250 °C for 30 or 120 min, and the characteristics of the HTC products were evaluated for their potential for energy, carbon, and nutrient recovery. The energy content increased from 14.9 MJ/kg in the mixed sludge up to 20.5 MJ/kg in the hydrochars. The produced filtrates had 12-15-fold higher COD and 3-5-fold higher volumetric methane production than untreated sludge filtrates, even though the methane yield against g-COD was lower. The increased value of the hydrochars in terms of energy content and carbon sequestration potential promote HTC deployment in sludge treatment and upgrading.
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http://dx.doi.org/10.1016/j.biortech.2022.127258DOI Listing
July 2022

An online flow-imaging particle counter and conventional water quality sensors detect drinking water contamination in the presence of normal water quality fluctuations.

Water Res 2022 Feb 2;213:118149. Epub 2022 Feb 2.

Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 541, FI-33101, Tampere, Finland.

Contamination detection in drinking water is crucial for water utilities in terms of public health; however, current online water quality sensors can be unresponsive to various possible contaminants consisting of particulate and dissolved content or require a constant supply of reagents and sample preparation. We used a two-line test environment connected to a drinking water distribution system with flow-imaging particle counters and conventional sensors to assess their responses to the injection of contaminants into one line, including stormwater, treated wastewater, wastewater, well water, and Escherichia coli, while simultaneously measuring responses to normal water quality fluctuations in the other line. These water quality fluctuations were detected with all of the conventional sensors (except conductivity) and with 3 out of 5 of the size- and shape-derived particle classes of the flow-imaging particle counter. The flow-imaging particle counter was able to detect all of the studied contaminants, e.g. municipal wastewater at 0.001% (v/v), while the oxidation-reduction potential sensor outperformed other conventional sensors, detecting the same wastewater at 0.03% (v/v). The presence of particles less than 1 µm in size was shown to be a generic parameter for the detection of particulates present in the studied contaminants; however, they manifested a considerable response to fluctuations which led to lower relative response to contaminants in comparison to larger particles. The particle size and class distributions of contaminants were different from those of drinking water, and thus monitoring particles larger than 1 µm or specific particle classes of flow-imaging particle counter, which are substantially more abundant in contaminated water than in pure drinking water, can improve the detection of contamination events. Water utilities could optimize contamination detection by selecting water quality parameters with a minimal response to quality fluctuations and/or a high relative response to contaminants.
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http://dx.doi.org/10.1016/j.watres.2022.118149DOI Listing
February 2022

Microbial community assembly and dynamics in Granular, Fixed-Biofilm and planktonic microbiomes valorizing Long-Chain fatty acids at 20 °C.

Bioresour Technol 2022 Jan 7;343:126098. Epub 2021 Oct 7.

School of Chemical and Biological Sciences, and Ryan Institute, National University of Ireland Galway, University Road, Galway H91 TK33, Ireland; Water and Environment Group, School of Engineering, University of Glasgow, Glasgow G12 8LT, United Kingdom.

Distinct microbial assemblages evolve in anaerobic digestion (AD) reactors to drive sequential conversions of organics to methane. The spatio-temporal development of three such assemblages (granules, biofilms, planktonic) derived from the same inoculum was studied in replicated bioreactors treating long-chain fatty acids (LCFA)-rich wastewater at 20 °C at hydraulic retention times (HRTs) of 12-72 h. We found granular, biofilm and planktonic assemblages differentiated by diversity, structure, and assembly mechanisms; demonstrating a spatial compartmentalisation of the microbiomes from the initial community reservoir. Our analysis linked abundant Methanosaeta and Syntrophaceae-affiliated taxa (Syntrophus and uncultured) to their putative, active roles in syntrophic LCFA bioconversion. LCFA loading rates (stearate, palmitate), and HRT, were significant drivers shaping microbial community dynamics and assembly. This study of the archaea and syntrophic bacteria actively valorising LCFAs at short HRTs and 20 °C will help uncover the microbiology underpinning anaerobic bioconversions of fats, oil and grease.
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http://dx.doi.org/10.1016/j.biortech.2021.126098DOI Listing
January 2022

Thirty years of esophageal cancer surgery in Oulu University Hospital.

J Thorac Dis 2021 Aug;13(8):4638-4649

Surgery Research Unit, Cancer and Translational Medicine Research Unit, Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Oulu, Finland.

Background: Esophagectomy is the mainstay of surgical treatment of esophageal cancer, but involves high operative risk. The aim of this study was to review the evolution surgical treatment of esophageal cancer in Northern Finland, with introduction of minimally invasive techniques.

Methods: All elective esophagectomies performed in Oulu University Hospital between years 1987 and 2020 were included. Treatment strategies were compared to current guidelines including staging and use of neoadjuvant therapy, and benchmark values including postoperative morbidity, hospital stay, readmissions and 90-day mortality. Long-term survival was compared to previous national studies.

Results: Between years 1987 and 2020 a total of 341 underwent an esophagectomy. Transhiatal resection was performed to 167 (49.3%), Ivor Lewis to 129 (38.1%) and McKeown to 42 (12.4%) patients. MIE was performed to 49 (14.5%) patients. During the past four years 83.7% of locally advanced diseases received neoadjuvant treatment. Since 1987, gradual improvements have occurred especially in incidence of pleural effusion requiring additional drainage procedure (highest in 2011-2013 and in last four years 14.0%), recurrent nerve injuries (highest in 2008-2010 29.4% and lowest in 2017-2020 1.8%) and in 1-year survival rate (1987-1998 68.4% 2017-2020 82.1%). No major changes in comorbidity, complication rate, anastomosis leaks, hospital stay or postoperative mortality were seen.

Conclusions: Esophageal cancer surgery has gone through major changes over three decades. Current guideline-based treatment has resulted with progressive improvement in mid- and long-term survival. However, despite modern protocol, no major improvement has occurred for example in major complications, anastomosis leak rates or hospital stay.
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http://dx.doi.org/10.21037/jtd-21-520DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8411167PMC
August 2021

Hydrothermal carbonisation of mechanically dewatered digested sewage sludge-Energy and nutrient recovery in centralised biogas plant.

Water Res 2021 Aug 25;201:117284. Epub 2021 May 25.

Faculty of Engineering and Natural Sciences, Tampere University, P.O.Box 541, 33104 Tampere University, Finland.

This study aimed to assess the role of hydrothermal carbonisation (HTC) in digestate processing in centralised biogas plants receiving dewatered sludge from regional wastewater treatment plants and producing biomethane and fertilisers. Chemically conditioned and mechanically dewatered sludge was used as such (total solids (TS) 25%) or as diluted (15% TS) with reject water in 30 min or 120 min HTC treatments at 210 °C, 230 °C or 250 °C, and the produced slurry was filtered to produce hydrochars and filtrates. The different hydrochars contributed to 20-55% of the original mass, 72-88% of the TS, 74-87% of the energy content, 71-92% of the carbon, above 86% of phosphorous and 38-64% of the nitrogen present in the original digestates. The hydrochars' energy content (higher heating values were 11.3-12.2 MJ/kg-TS) were similar to that of the digestates, while the ash contents increased (from 43% up to 57%). HTC treatments produced filtrates in volumes of 42-76% of the dewatered digestate, having a soluble chemical oxygen demand (SCOD) of 28-44 g/L, of which volatile fatty acids (VFAs) contributed 10-34%, and methane potentials of 182-206 mL-CH/g-SCOD without any major indication of inhibition. All 32 pharmaceuticals detected in the digestates were below the detection limit in hydrochars and filtrates, save for ibuprofen and benzotriazole in filtrate, while heavy metals were concentrated in the hydrochars but below the national limits for fertiliser use, save for mercury. The integration of HTC to a centralised biogas plant was extrapolated to enhance the annual biogas production by 5% and ammonium recovery by 25%, and the hydrochar was estimated to produce 83 GJ upon combustion or to direct 350 t phosphorous to agriculture annually.
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http://dx.doi.org/10.1016/j.watres.2021.117284DOI Listing
August 2021

The Effect of Laparoscopic Technique on the Surgical Outcome of Colorectal Cancer in a Small-Volume Rural Finnish Lapland Central Hospital.

Gastrointest Tumors 2021 Jan 18;8(1):16-24. Epub 2020 Nov 18.

Cancer and Translational Medicine Research Unit, Medical Research Centre Oulu University of Oulu Oulu Finland, Oulu, Finland.

Introduction: Laparoscopic colorectal surgery has become widely used in treating colorectal cancer. Multicenter studies have shown that laparoscopy decreases postoperative complications and provides equivalent long-term oncological results compared to open surgery. Previous studies were conducted in high-volume institutions, with selected patients, which may influence the reported outcome of laparoscopy.

Methods: All patients with colorectal cancer that underwent surgery for a primary tumor between 2005 and 2015 in the Lapland Central Hospital were retrospectively collected. We retrieved data on the primary surgical outcome and complications within the first 30 days after surgery from patient records. We surveyed the national patient registry to determine long-term oncological results and patient survival.

Results: We identified 349 patients treated for colorectal cancer during 2005-2015. Of these, 219 patients (median age 71 years) underwent laparoscopy and 130 (median age 72 years) underwent open surgery. The 5-year disease-specific survival rates for stages I-III colon cancer were 83.3 and 87.7%, respectively. The 3-year disease-specific survival rates for stages I-III rectal cancer were 86.1 and 65.0%, respectively.

Conclusion: Our results showed that the introduction of laparoscopic colorectal surgery for treating cancer in a rural, small-volume hospital provided short- and long-term results comparable to findings from previous studies conducted in high-volume centers. Therefore, laparoscopy should be considered the treatment of choice for colorectal cancer in small, rural clinics.
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http://dx.doi.org/10.1159/000511104DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7942166PMC
January 2021

Effect of Oral Moxifloxacin vs Intravenous Ertapenem Plus Oral Levofloxacin for Treatment of Uncomplicated Acute Appendicitis: The APPAC II Randomized Clinical Trial.

JAMA 2021 01;325(4):353-362

Division of Digestive Surgery and Urology, Turku University Hospital, Turku, Finland.

Importance: Antibiotics are an effective and safe alternative to appendectomy for managing uncomplicated acute appendicitis, but the optimal antibiotic regimen is not known.

Objective: To compare oral antibiotics with combined intravenous followed by oral antibiotics in the management of computed tomography-confirmed uncomplicated acute appendicitis.

Design, Setting, And Participants: The Appendicitis Acuta (APPAC) II multicenter, open-label, noninferiority randomized clinical trial was conducted from April 2017 until November 2018 in 9 Finnish hospitals. A total of 599 patients aged 18 to 60 years with computed tomography-confirmed uncomplicated acute appendicitis were enrolled in the trial. The last date of follow-up was November 29, 2019.

Interventions: Patients randomized to receive oral monotherapy (n = 295) received oral moxifloxacin (400 mg/d) for 7 days. Patients randomized to receive intravenous antibiotics followed by oral antibiotics (n = 288) received intravenous ertapenem (1 g/d) for 2 days followed by oral levofloxacin (500 mg/d) and metronidazole (500 mg 3 times/d) for 5 days.

Main Outcomes And Measures: The primary end point was treatment success (≥65%) for both groups, defined as discharge from hospital without surgery and no recurrent appendicitis during 1-year follow-up, and to determine whether oral antibiotics alone were noninferior to intravenous and oral antibiotics, with a margin of 6% for difference.

Results: Among 599 patients who were randomized (mean [SD] age, 36 [12] years; 263 [44%] women), 581 (99.7%) were available for the 1-year follow-up. The treatment success rate at 1 year was 70.2% (1-sided 95% CI, 65.8% to ∞) for patients treated with oral antibiotics and 73.8% (1-sided 95% CI, 69.5% to ∞) for patients treated with intravenous followed by oral antibiotics. The difference was -3.6% ([1-sided 95% CI, -9.7% to ∞]; P = .26 for noninferiority), with the confidence limit exceeding the noninferiority margin.

Conclusion And Relevance: Among adults with uncomplicated acute appendicitis, treatment with 7 days of oral moxifloxacin compared with 2 days of intravenous ertapenem followed by 5 days of levofloxacin and metronidazole resulted in treatment success rates greater than 65% in both groups, but failed to demonstrate noninferiority for treatment success of oral antibiotics compared with intravenous followed by oral antibiotics.

Trial Registration: ClinicalTrials.gov Identifier: NCT03236961; EudraCT Identifier: 2015-003633-10.
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http://dx.doi.org/10.1001/jama.2020.23525DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7802006PMC
January 2021

Superior primary fascial closure rate and lower mortality after open abdomen using negative pressure wound therapy with continuous fascial traction.

J Trauma Acute Care Surg 2020 12;89(6):1136-1142

From the Department of Abdominal Surgery, Abdominal Center (S.R., P.M., A.L.), Helsinki University Hospital and University of Helsinki, Helsinki; Division of Digestive Surgery and Urology, Department of Surgery (P.S., T.S.), Turku University Hospital, University of Turku, Turku, Department of Surgery, Satakunta Central Hospital, Pori; Department of Abdominal Surgery (V.K.), Oulu University Hospital, Oulo; Department of Gastroenterology and Alimentary Tract Surgery (M.H., L-M.M.), Tampere University Hospital, Tampere; Department of Surgery (T.P.), Seinäjoki Central Hospital, Seinäjoki; Department of Surgery (J.H.), Satakunta Central Hospital, Pori; Department of Surgery (J.R.), Lapland Central Hospital, Rovaniemi; and Department of Surgery (T.R.), Kuopio University Hospital, Institute of Clinical Medicine, University of Eastern Finland, Eastern Finland, Finland.

Background: Open abdomen (OA) is a useful option for treatment strategy in many acute abdominal catastrophes. A number of temporary abdominal closure (TAC) methods are used with limited number of comparative studies. The present study was done to examine risk factors for failed delayed primary fascial closure (DPFC) and risk factors for mortality in patients treated with OA.

Methods: This study was a multicenter retrospective analysis of the hospital records of all consecutive patients treated with OA during the years 2009 to 2016 at five tertiary referral hospitals and three secondary referral centers in Finland.

Results: Six hundred seventy-six patients treated with OA were included in the study. Vacuum-assisted closure with continuous mesh-mediated fascial traction (VACM) was the most popular TAC method used (N = 398, 59%) followed by VAC (N = 128, 19%), Bogota bag (N = 128, 19%), and self-designed methods (N = 22, 3%). In multivariate analysis, enteroatmospheric fistula and the number of needed TAC changes increased the risk for failed DPFC (odds ratio [OR], 8.9; 95% confidence interval [CI], 6.2-12.8; p < 0.001 and OR, 1.1; 95% CI, 1.0-1.3; p < 0.001, respectively). Instead, VACM and ruptured abdominal aortic aneurysm as cause for OA both decreased the risk for failed DPFC (OR, 0.1; 95% CI, 0.0-0.3; p < 0.001 and OR, 0.2; 95% CI, 0.1-0.7; p = 0.012). The overall mortality rate was 30%. In multivariate analysis for mortality, multiorgan dysfunction (OR, 2.4; 95% CI, 1.6-3.6; p < 0.001), and increasing age (OR, 4.5; 95% CI, 2.0-9.7; p < 0.001) predicted increased mortality. Institutional large annual patient volume (OR, 0.4; 95% CI, 0.3-0.6; p < 0.001) and ileus and postoperative peritonitis in comparison to severe acute pancreatitis associated with decreased mortality (OR, 0.2; 95% CI, 0.1-0.4; p < 0.001; OR, 0.5; 95% CI, 0.3-0.8; p = 0.009). Kaplan-Meier analysis showed increased survival in patients treated with VACM in comparison with other TAC methods (LogRank p = 0.019).

Conclusion: We report superior role for VACM methodology in terms of successful primary fascial closure and increased survival in patients with OA.

Level Of Evidence: Therapeutic/care management, level IV.
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http://dx.doi.org/10.1097/TA.0000000000002889DOI Listing
December 2020

Low concentration of zeolite to enhance microalgal growth and ammonium removal efficiency in a membrane photobioreactor.

Environ Technol 2021 Oct 26;42(24):3863-3876. Epub 2020 Apr 26.

Department of Civil and Environmental Engineering, University of South Florida, Tampa, FL, USA.

The aim of this work was to study the growth and nutrient removal efficiency of a mixed microalgal culture with and without the addition of low concentrations (0.5, 1, and 5 g L of total liquid volume in the reactor) of natural zeolite. A control test in which only zeolite was added into a similar membrane photobioreactor was also conducted. The addition of 0.5 g L zeolite to a continuously-fed membrane photobioreactor increased the microalgal biomass concentration from 0.50 to 0.90-1.17 g particulate organic carbon per L while the average ammonium removal efficiency increased from 14% to 30%. Upon microscopic inspection, microalgal cells were observed growing on the surface of zeolite particles, which indicates that zeolite can support attached microalgal growth. With higher zeolite doses (1 and 5 g L) inside the reactor, however, the breaking apart of added zeolite particles into finer particles dramatically increased solution turbidity, which likely was not beneficial for microalgal growth and ammonium removal due to reduced light penetration. This work shows that low doses of zeolite can be used as microcarriers to enhance microalgal biomass concentration and ammonium removal efficiency, while minimizing zeolite dose would likely reduce the turbidity effects.
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http://dx.doi.org/10.1080/09593330.2020.1752813DOI Listing
October 2021

Effect of tungsten and selenium on C gas bioconversion by an enriched anaerobic sludge and microbial community analysis.

Chemosphere 2020 Jul 14;250:126105. Epub 2020 Feb 14.

Chemical Engineering Laboratory (BIOENGIN Group), Faculty of Sciences and Center for Advanced Scientific Research (CICA), University of La Coruña (UDC), E-15008, La Coruña, Spain. Electronic address:

The effect of trace metals, namely tungsten and selenium, on the production of acids and alcohols through gas fermentation by a CO-enriched anaerobic sludge in a continuous gas-fed bioreactor was investigated. The CO-enriched sludge was first supplied with a tungsten-deficient medium (containing selenium) and in a next assay, a selenium-deficient medium (containing tungsten) was fed to the bioreactor, at a CO gas flow rate of 10 mL/min. In the absence of tungsten (tungstate), an initial pH of 6.2 followed by a pH decrease to 4.9 yielded 7.34 g/L acetic acid as the major acid during the high pH period. Subsequently, bioconversion of the acids at a lower pH of 4.9 yielded only 1.85 g/L ethanol and 1.2 g/L butanol in the absence of tungsten (tungstate). A similar follow up assay in the same bioreactor with two consecutive periods at different pH values (i.e., 6.2 and 4.9) with a selenium deficient medium yielded 6.6 g/L acetic acid at pH 6.2 and 4 g/L ethanol as well as 1.88 g/L butanol at pH 4.9. The results from the microbial community analysis showed that the only known CO fixing microorganism able to produce alcohols detected in the bioreactor was Clostridium autoethanogenum, both in the tungsten and the selenium deprived media, although that species has so far not been reported to be able to produce butanol. No other solventogenic acetogen was detected.
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http://dx.doi.org/10.1016/j.chemosphere.2020.126105DOI Listing
July 2020

Volatile fatty acid production from Kraft mill foul condensate in upflow anaerobic sludge blanket reactors.

Environ Technol 2021 Jun 13;42(16):2447-2460. Epub 2020 Jan 13.

UNESCO-IHE, Institute for Water Education, Delft, Netherlands.

The utilization of foul condensate (FC) collected from a Kraft pulp mill for the anaerobic production of volatile fatty acids (VFA) was tested in upflow anaerobic sludge blanket (UASB) reactors operated at 22, 37 and 55°C at a hydraulic retention time (HRT) of ∼75 h. The FC consisted mainly of 11370, 500 and 592 mg/L methanol, ethanol and acetone, respectively. 42-46% of the organic carbon (methanol, ethanol and acetone) was utilized in the UASB reactors operated at an organic loading of ∼8.6 gCOD/L.d and 52-70% of the utilized organic carbon was converted into VFA. Along with acetate, also propionate, isobutyrate, butyrate, isovalerate and valerate were produced from the FC. Prior to acetogenesis of FC, enrichment of the acetogenic biomass was carried out in the UASB reactors for 113 d by applying operational parameters that inhibit methanogenesis and induce acetogenesis. Activity tests after 158 d of reactor operation showed that the biomass from the 55°C UASB reactor exhibited the highest activity after the FC feed compared to the biomass from the reactors at 22 and 37°C. Activity tests at 37°C to compare FC utilization for CH versus VFA production showed that an organic carbon utilization >98% for CH production occurred in batch bottles, whereas the VFA production batch bottles showed 51% organic carbon utilization. Furthermore, higher concentrations of C-C VFA were produced when FC was the substrate compared to synthetic methanol rich wastewater.
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http://dx.doi.org/10.1080/09593330.2019.1703823DOI Listing
June 2021

Large-scale spatial synchrony in red squirrel populations driven by a bottom-up effect.

Oecologia 2020 Feb 11;192(2):425-437. Epub 2020 Jan 11.

Section of Ecology, Department of Biology, University of Turku, Turku, Finland.

Spatial synchrony between populations emerges from endogenous and exogenous processes, such as intra- and interspecific interactions and abiotic factors. Understanding factors contributing to synchronous population dynamics help to better understand what determines abundance of a species. This study focuses on spatial and temporal dynamics in the Eurasian red squirrel (Sciurus vulgaris) using snow-track data from Finland from 29 years. We disentangled the effects of bottom-up and top-down forces as well as environmental factors on population dynamics with a spatiotemporally explicit Bayesian hierarchical approach. We found red squirrel abundance to be positively associated with both the abundance of Norway spruce (Picea abies) cones and the predators, the pine marten (Martes martes) and the northern goshawk (Accipiter gentilis), probably due to shared habitat preferences. The results suggest that red squirrel populations are synchronized over remarkably large distances, on a scale of hundreds of kilometres, and that this synchrony is mainly driven by similarly spatially autocorrelated spruce cone crop. Our research demonstrates how a bottom-up effect can drive spatial synchrony in consumer populations on a very large scale of hundreds of kilometres, and also how an explicit spatiotemporal approach can improve model performance for fluctuating populations.
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http://dx.doi.org/10.1007/s00442-019-04589-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7002333PMC
February 2020

Anaerobic treatment of LCFA-containing synthetic dairy wastewater at 20 °C: Process performance and microbial community dynamics.

Sci Total Environ 2019 Nov 10;691:960-968. Epub 2019 Jul 10.

Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland. Electronic address:

Facilitating anaerobic degradation of long-chain fatty acids (LCFA) is key for tapping the high methane production potential of the fats, oil and grease (FOG) content of dairy wastewaters. In this study, the feasibility of using high-rate granular sludge reactors for the treatment of mixed LCFA-containing synthetic dairy wastewater (SDW) was assessed at 20 °C. The effects of the LCFA concentration (33-45% of COD) and organic loading rates (2-3 gCOD/L·d) were determined using three parallel expanded granular sludge bed reactors. For the first time, long term anaerobic treatment of LCFA-containing feed at 20 °C was shown to be feasible and was linked to the microbial community dynamics in high-rate reactors. During a two-month operation, a soluble COD removal of 84-91% and COD to methane conversion of 44-51% was obtained. However, granular sludge flotation and washout occurred after two months in all reactors without volatile fatty acids (VFA) accumulation, emphasizing the need for sludge retention for long-term granular sludge reactor operation with LCFA-containing feed at low ambient temperatures. The temporal shifts in microbial community structure were studied in the high-rate treatment of SDW, and the process disturbances (elevated LCFA loading, LCFA accumulation, and batch operation) were found to decrease the microbial community diversity. The relative abundance of Methanosaeta increased with higher LCFA accumulation in the settled and flotation layer granules in the three reactors, therefore, acetoclastic methanogenesis was found to be crucial for the high-rate treatment of SDW at 20 °C. This study provides an initial understanding of the continuous anaerobic treatment of LCFA-containing industrial wastewaters at low ambient temperatures.
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http://dx.doi.org/10.1016/j.scitotenv.2019.07.136DOI Listing
November 2019

Acetotrophic Activity Facilitates Methanogenesis from LCFA at Low Temperatures: Screening from Mesophilic Inocula.

Archaea 2019 2;2019:1751783. Epub 2019 May 2.

Faculty of Engineering and Natural Sciences, Tampere University, Tampere, Finland.

The inoculum source plays a crucial role in the anaerobic treatment of wastewaters. Lipids are present in various wastewaters and have a high methanogenic potential, but their hydrolysis results in the production of long chain fatty acids (LCFAs) that are inhibitory to anaerobic microorganisms. Screening of inoculum for the anaerobic treatment of LCFA-containing wastewaters has been performed at mesophilic and thermophilic conditions. However, an evaluation of inocula for producing methane from LCFA-containing wastewater has not yet been conducted at low temperatures and needs to be undertaken. In this study, three inocula (one granular sludge and two municipal digester sludges) were assessed for methane production from LCFA-containing synthetic dairy wastewater (SDW) at low temperatures (10 and 20°C). A methane yield (based on mL-CH/g-COD) of 86-65% with acetate and 45-20% with SDW was achieved within 10 days using unacclimated granular sludge, whereas the municipal digester sludges produced methane only at 20°C but not at 10°C even after 200 days of incubation. The acetotrophic activity in the inoculum was found to be crucial for methane production from LCFA at low temperatures, highlighting the role of (acetoclastic archaea) at low temperatures. The presence of bacterial taxa from the family ( and uncultured taxa) in the inoculum was found to be important for methane production from SDW at 10°C. This study suggests the evaluation of acetotrophic activity and the initial microbial community characteristics by high-throughput amplicon sequencing for selecting the inoculum for producing methane at low temperatures (up to 10°C) from lipid-containing wastewaters.
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http://dx.doi.org/10.1155/2019/1751783DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6525847PMC
April 2020

Scaling up the treatment of the fine fraction from landfill mining: Mass balance and cost structure.

Waste Manag 2019 Mar 20;87:464-471. Epub 2019 Feb 20.

Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 527, FI-33014 Tampere University, Finland.

The treatment of the fine fraction (FF) obtained from landfill mining is necessary in order to reduce the amount of organic matter and biological activity in FF, thus increasing its potential to be utilized after landfill mining. This paper suggests the scaled up anaerobic and aerobic treatment of FF, with or without continuous irrigation, and presents the mass balance and cost structure of such treatment based on two hypothetical landfills. The physical treatment structure for the treatment of FF should prevent emissions, and in this paper, it includes suitable bottom and top liners as well as the collection and treatment of the gaseous and leachate emissions formed during the treatment. Methane produced in anaerobic treatments could either be utilized for energy recovery or be flared. The cost of the anaerobic and aerobic treatment of FF, including investments and operation costs, are 20-65 €/t FF, depending on size of the landfill. The costs of anaerobic treatment and passive aeration are similar, and active aeration is slightly more expensive, but the cost of the continuous irrigation is the most significant, as it multiplies the leachate treatment costs. The overall cost of treatment could be lowered by reducing the treatment time and utilizing existing landfill structures. The results of this paper can be used in planning and estimating the cost of the biological treatment of FF when evaluating landfill mining projects, as the fate of FF may have a major impact on the economics of landfill mining projects.
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http://dx.doi.org/10.1016/j.wasman.2019.02.032DOI Listing
March 2019

Microalgae grow on source separated human urine in Nordic climate: Outdoor pilot-scale cultivation.

J Environ Manage 2019 May 18;237:119-127. Epub 2019 Feb 18.

Faculty of Engineering and Natural Sciences, Tampere University, Finland.

Human urine contributes approximately 80% of nitrogen and 50% of phosphorous in urban wastewaters while having a volume of only 1-1.5 L/d per capita compared to 150-200 L/d per capita of wastewater generated. There is interest to study source separation of urine and search methods to recover the nutrients form the urine. In this study, the objective was to use the nutrients in source separated urine for outdoor cultivation of microalgae in Nordic climate. A freshwater green microalga Scenedesmus acuminatus was grown in different dilutions (1:20 and 1:15) of source separated human urine, in a semi-continuously operated outdoor raceway pond with a liquid volume of 2000 L, at hydraulic retention time of 15 d. The microalgae could remove 52% nitrogen and 38% phosphorus even at culture temperatures as low as 5 °C, while obtaining a biomass density of 0.34 g VSS/L. Harvested microalgal biomass could be used to produce methane with a yield of 285 L CH/kg volatile solids.
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http://dx.doi.org/10.1016/j.jenvman.2019.02.074DOI Listing
May 2019

Evaluation of methods for enhancing methane oxidation via increased soil air capacity and nutrient content in simulated landfill soil cover.

Waste Manag 2018 Dec 16;82:82-92. Epub 2018 Oct 16.

Laboratory of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere, Finland. Electronic address:

Landfill soil covers and methanotrophs therein have potential to act as final sinks of the greenhouse gas methane (CH) generated in landfills, but soil characteristics in landfills might not support methanotrophic activity due to poor soil material selection or mineralisation over time. Hence, our aim was to determine the performance of mineral landfill soil under simulated CH flux and screen methods for elevating the CH elimination capacity (EC) of soil. The methods tested during the column experiment were inorganic fertilisation (nitrate, phosphate, sulphate, copper), decompaction and amelioration of the soil with compost. The addition of compost proved to be the most effective method for increasing the CH EC of soil, increasing from 55 to 189 g m d relative to the untreated control soil. This increase could be attributed to increased air capacity, concentration of soil nutrients and number of cultivable methanotrophs. Also, soil water-holding capacity was identified as a more crucial factor for methanotrophic activity than total porosity. Inorganic fertilisation and decompaction induced only a temporary increase in CH EC, likely resulting from the temporary supply of fertiliser to the nutrient-deprived soil. In conclusion, we suggest that compost amelioration (22 w-%) could be useful for restoring CH EC of old landfill covers as an aftercare action to control environmental impacts of closed landfills.
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http://dx.doi.org/10.1016/j.wasman.2018.10.015DOI Listing
December 2018

Semi-continuous mono-digestion of OFMSW and Co-digestion of OFMSW with beech sawdust: Assessment of the maximum operational total solid content.

J Environ Manage 2019 Feb 5;231:1293-1302. Epub 2018 Oct 5.

Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, via Di Biasio 43, 03043 Cassino, FR, Italy.

In this study, mono-digestion of the organic fraction of municipal solid waste (OFMSW) and co-digestion of OFMSW with beech sawdust, simulating green waste, were used to investigate the maximum operational total solid (TS) content in semi-continuous high-solids anaerobic digestion (HS-AD). To alleviate substrate overloading in HS-AD, the effluent mass was relatively reduced compared to the influent mass, extending the mass retention time. To this aim, the reactor mass was daily evaluated, permitting to assess the reactor content removal by biogas production. During mono-digestion of OFMSW, the NH inhibition and the rapid TS removal prevented to maintain HS-AD conditions (i.e. TS ≥ 10%), without exacerbating the risk of reactor acidification. In contrast, the inclusion of sawdust in OFMSW permitted to operate HS-AD up to 30% TS, before acidification occurred. Therefore, including a lignocellulosic substrate in OFMSW can prevent acidification and stabilize HS-AD at very high TS contents (i.e. 20-30%).
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http://dx.doi.org/10.1016/j.jenvman.2018.10.002DOI Listing
February 2019

Remediation of sedimented fiber originating from pulp and paper industry: Laboratory scale anaerobic reactor studies and ideas of scaling up.

Water Res 2018 10 26;143:209-217. Epub 2018 Jun 26.

Laboratory of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FIN-3310, Tampere, Finland.

Anaerobic treatment of sedimented fibers collected from bottom of a bay that had been receiving pulp and paper mill wastewater for about 70 years were studied for the first time in semi-continuously fed continuously stirred tank reactors (CSTR). Anaerobic treatment of the fiber sediment was shown to be feasible, without dilution and with nitrogen and buffer supplement, at organic loading rates (OLR) up to 2.5 kg VS/md and hydraulic retention times (HRT) of 60 d resulting in methane yields of 201 ± 18 L CH/kg VS. Co-digestion of sedimented fiber with sewage sludge at an OLR of 1.5 kg VS/md and HRT of 20 d resulted in a methane production of 246 ± 10 L CH/kg VS. The techno-economic feasibility of mono and co-digestion process together with several case dependent factors such as maximum operable OLR, digestate utilization needs to be evaluated before making further conclusions for larger scale remediation applications.
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http://dx.doi.org/10.1016/j.watres.2018.06.054DOI Listing
October 2018

Anaerobic digestion of 30-100-year-old boreal lake sedimented fibre from the pulp industry: Extrapolating methane production potential to a practical scale.

Water Res 2018 04 18;133:218-226. Epub 2018 Jan 18.

Laboratory of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FIN-3310, Tampere, Finland.

Since the 1980s, the pulp and paper industry in Finland has resulted in the accumulation of fibres in lake sediments. One such site in Lake Näsijärvi contains approximately 1.5 million m sedimented fibres. In this study, the methane production potential of the sedimented fibres (on average 13% total solids (TS)) was determined in batch assays. Furthermore, the methane production from solid (on average 20% TS) and liquid fractions of sedimented fibres after solid-liquid separation was studied. The sedimented fibres resulted in fast methane production and high methane yields of 250 ± 80 L CH/kg volatile solids (VS). The main part (ca. 90%) of the methane potential was obtained from the solid fraction of the sedimented fibres. In addition, the VS removal from the total and solid sedimented fibres was high, 61-65% and 63-78%, respectively. The liquid fraction also contained a large amount of organics (on average 8.8 g COD/L), treatment of which also has to be considered. The estimations of the methane production potentials in the case area showed potential up to 40 million m of methane from sedimented fibres.
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http://dx.doi.org/10.1016/j.watres.2018.01.041DOI Listing
April 2018

Effect of macro- and micro-nutrients addition during anaerobic mono-digestion of grass silage in leach-bed reactors.

Environ Technol 2019 Jan 26;40(4):418-429. Epub 2017 Oct 26.

d Department of Chemistry and Bioengineering , Tampere University of Technology , Tampere , Finland.

The effect of macro- (NHCl) (set I) and micro-nutrients (Fe, Ni, Co and Mo) (set II) addition on chemical oxygen demand (COD) solubilisation during anaerobic mono-digestion of grass silage was investigated in two sets of leach bed reactor experiments at 35°C. Results showed that addition of NHCl and micro-nutrients improved COD solubilisation by 18% (0.56 g SCOD g volatile solids) and 7% (0.45 g SCOD g VS), respectively than control. About 20-50% of the added micro-nutrients were bioavailable in the produced leachates, while the rest (50-80%) were adsorbed onto the grass silage. Results of biological methane potential assays showed that, specific methane yields of grass silage were improved by 17% (0.36 ± 0.02 m CH kg VS) when NHCl was supplemented while Fe, Ni, Co and Mo addition improved methane yields by 15% (0.33 ± 0.005 m CH kg VS) when compared to control.
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http://dx.doi.org/10.1080/09593330.2017.1393462DOI Listing
January 2019

Cultivation of Scenedesmus acuminatus in different liquid digestates from anaerobic digestion of pulp and paper industry biosludge.

Bioresour Technol 2017 Dec 4;245(Pt A):706-713. Epub 2017 Sep 4.

Laboratory of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere, Finland.

Different undiluted liquid digestates from mesophilic and thermophilic anaerobic digesters of pulp and paper industry biosludge with and without thermal pretreatment were characterized and utilized for cultivating Scenedesmus acuminatus. Higher S. acuminatus biomass yields were obtained in thermophilic digestates (without and with pretreatment prior to anaerobic digestion (AD): 10.2±2.2 and 10.8±1.2gL, respectively) than in pretreated mesophilic digestates (7.8±0.3gL), likely due to differences in concentration of sulfate, iron, and/or other minor nutrients. S. acuminatus removed over 97.4% of ammonium and 99.9% of phosphate and sulfate from the digestates. Color (74-80%) and soluble COD (29-39%) of the digestates were partially removed. Different AD processes resulted in different methane yields (18-126L CH kgVS), digestate compositions, and microalgal yields. These findings emphasize the importance of optimizing each processing step in wood-based biorefineries and provide information for pulp and paper industry development for enhancing value generation.
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http://dx.doi.org/10.1016/j.biortech.2017.08.218DOI Listing
December 2017

Environmental variability and population dynamics: do European and North American ducks play by the same rules?

Ecol Evol 2016 10 9;6(19):7004-7014. Epub 2016 Sep 9.

Department of Forest Sciences University of Helsinki Helsinki Finland.

Density dependence, population regulation, and variability in population size are fundamental population processes, the manifestation and interrelationships of which are affected by environmental variability. However, there are surprisingly few empirical studies that distinguish the effect of environmental variability from the effects of population processes. We took advantage of a unique system, in which populations of the same duck species or close ecological counterparts live in highly variable (north American prairies) and in stable (north European lakes) environments, to distinguish the relative contributions of environmental variability (measured as between-year fluctuations in wetland numbers) and intraspecific interactions (density dependence) in driving population dynamics. We tested whether populations living in stable environments (in northern Europe) were more strongly governed by density dependence than populations living in variable environments (in North America). We also addressed whether relative population dynamical responses to environmental variability versus density corresponded to differences in life history strategies between dabbling (relatively "fast species" and governed by environmental variability) and diving (relatively "slow species" and governed by density) ducks. As expected, the variance component of population fluctuations caused by changes in breeding environments was greater in North America than in Europe. Contrary to expectations, however, populations in more stable environments were not less variable nor clearly more strongly density dependent than populations in highly variable environments. Also, contrary to expectations, populations of diving ducks were neither more stable nor stronger density dependent than populations of dabbling ducks, and the effect of environmental variability on population dynamics was greater in diving than in dabbling ducks. In general, irrespective of continent and species life history, environmental variability contributed more to variation in species abundances than did density. Our findings underscore the need for more studies on populations of the same species in different environments to verify the generality of current explanations about population dynamics and its association with species life history.
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http://dx.doi.org/10.1002/ece3.2413DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5513220PMC
October 2016

Outcome of stent grafting for esophageal perforations: single-center experience.

Surg Endosc 2017 09 11;31(9):3696-3702. Epub 2017 Jan 11.

Department of Surgery, Oulu University Hospital, PL 21, 90029, Oulu, Finland.

Background: Recent studies showed that stent grafting is a promising technique for treatment of esophageal perforation. However, the evidence of its benefits is still scarce.

Methods: Forty-three consecutive patients underwent stent grafting for esophageal perforation at the Oulu University Hospital, Finland. The main endpoints of this study were early and mid-term mortality. Secondary outcome endpoints were the need of esophagectomy and additional surgical procedures on the esophagus and extraesophageal structures.

Results: Patients' mean age was 64.6 ± 13.4 years. The mean delay to primary treatment was 23 ± 27 h. The most frequent cause of perforation was Boerhaave's syndrome (46.5%). The thoraco-abdominal segment of the esophagus was affected in 58.1% of cases. Minor primary procedures were performed in 25 patients (58.1%) and repeat surgical procedures in 23 patients (53.5%). Forty-nine repeat stent graftings were performed in 22 patients (50%). Two patients (4.7%) underwent esophagectomy, one for unrelenting preprocedural stricture of the esophagus and another for persistent leakage of a perforated esophageal carcinoma. The mean length of stay in the intensive care unit was 6.0 ± 7.5 days and the in-hospital stay was 24.3 ± 19.6 days. In-hospital mortality was 4.6%. Three-year survival was 67.2%.

Conclusions: Stent grafting seems to be an effective less invasive technique for the treatment of esophageal perforation. Repeat stent grafting and procedures on the pleural spaces are often needed to control the site of perforation and for debridement of surrounding infected structures. Stent grafting allows the preservation of the esophagus in most of patients. The mid-term survival of these patients is suboptimal and requires further investigation.
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http://dx.doi.org/10.1007/s00464-016-5408-6DOI Listing
September 2017

Anaerobic batch conversion of pine wood torrefaction condensate.

Bioresour Technol 2017 Feb 22;225:299-307. Epub 2016 Nov 22.

Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere, Finland.

Organic compound rich torrefaction condensate, owing to their high water content and acidic nature, have yet to be exploited for practical application. In this study, microbial conversion of torrefaction condensate from pine wood through anaerobic batch digestion (AD) to produce methane was evaluated. Torrefaction condensate exhibited high methane potentials in the range of 430-492mL/g volatile solids (VS) and 430-460mL/gVS under mesophilic and thermophilic conditions, respectively. Owing to the changes in the composition, the methane yields differed with the torrefaction condensates produced at different temperatures (225, 275 and 300°C), with a maximum of 492±18mL/gVS with the condensate produced at 300°C under mesophilic condition. The cyclic batch AD experiments showed that 0.1VS:VS is optimum, whereas the higher substrate loading (0.2-0.5) resulted in a reversible inhibition of the methane production. The results suggest that torrefaction condensate could be practically valorized through AD.
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http://dx.doi.org/10.1016/j.biortech.2016.11.073DOI Listing
February 2017

Screening biological methods for laboratory scale stabilization of fine fraction from landfill mining.

Waste Manag 2017 Feb 16;60:739-747. Epub 2016 Nov 16.

Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FI-33101 Tampere, Finland.

Increasing interest for the landfill mining and the amount of fine fraction (FF) in landfills (40-70% (w/w) of landfill content) mean that sustainable treatment and utilization methods for FF are needed. For this study FF (<20mm) was mined from a municipal solid waste (MSW) landfill operated from 1967 to 1989. FF, which resembles soil, was stabilized in laboratory scale reactors in two phases: first, anaerobically for 101days and second, for 72days using four different methods: anaerobic with the addition of moisture (water) or inoculum (sewage sludge) and aerobic with continuous water washing, with, or without, bulking material. The aim was to evaluate the effect on the stability of mined FF, which has been rarely reported, and to study the quality and quantity of gas and leachate produced during the stabilization experiment. The study showed that aerobic treatment reduced respiration activity (final values 0.9-1.1mgO/gTS) and residual methane potential (1.1LCH/kgTS) better than anaerobic methods (1.8-2.3mg O/g TS and 1.3-2.4L CH/kg TS, respectively). Bulking material mixed in FF in one aerobic reactor had no effect on the stability of FF. The benefit of anaerobic treatment was the production of methane, which could be utilized as energy. Even though the inoculum addition increased methane production from FF about 30%, but the methane production was still relatively low (in total 1.5-1.7L CH/kg TS). Continuous water washing was essential to remove leachable organic matter and soluble nutrients from FF, while increasing the volume of leachate collected. In the aerobic treatment, nitrogen was oxidized into nitrite and nitrate and then washed out in the leachate. Both anaerobic and aerobic methods could be used for FF stabilization. The use of FF, in landscaping for example, is possible because its nutrient content (4gN/kg TS and 1g P/kg TS) can increase the nutrient content of soil, but this may have limitations due to the possible presence of heavy metal and other contaminants.
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http://dx.doi.org/10.1016/j.wasman.2016.11.015DOI Listing
February 2017

Activin inhibition limits early innate immune response in rat kidney allografts-a pilot study.

Transpl Int 2017 Jan 23;30(1):96-107. Epub 2016 Nov 23.

Department of Bacteriology and Immunology and Department of Physiology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.

Activins are members of the transforming growth factor-beta (TGF-β) superfamily of cytokines. They play critical roles in the onset of acute and chronic inflammatory responses. The aim of this study was to investigate how activin inhibition affects acute kidney injury and inflammation after transplantation. The study was carried out in kidney transplantation and renal ischemia-reperfusion models in the rat. Soluble activin type 2 receptor (sActRIIB-Fc) was used to inhibit activin signaling. Transplantation groups were as follows: (i) cyclosporine A (CsA) (ii) CsA + sActRIIB-Fc, (iii) CsA+ inactive protein control Fc-G1. IRI groups were as follows: (i) no treatment, (ii) sActRIIB-Fc. Serum activin B concentration was significantly elevated after transplantation and IRI, whereas activin A was produced locally in renal allografts. Activin inhibition efficiently limited neutrophil, macrophage, and dendritic cell infiltration to the allografts measured 72 h after transplantation. In addition, sActRIIB-Fc treatment modulated serum cytokine response after transplantation and reduced the early accumulation of fibroblasts in the graft interstitium. In conclusion activin inhibition reduces the innate immune response early after renal transplantation in the rat. It also limits the accumulation of fibroblasts in the graft suggesting that activins may be involved in the fibrogenic signaling already early after kidney transplantation.
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http://dx.doi.org/10.1111/tri.12876DOI Listing
January 2017
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