| 1. |
- Forgács, Gergely, 1983, et al.
(författare)
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Biological treatment of chicken feather waste for improved biogas production
- 2011
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Ingår i: Journal of Environmental Sciences. - : Elsevier BV. - 1001-0742 .- 1878-7320. ; 23:10, s. 1747-1753
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Tidskriftsartikel (refereegranskat)abstract
- A two-stage system was developed which combines the biological degradation of keratin-rich waste with the production of biogas. Chicken feather waste was treated biologically with a recombinant Bacillus megaterium strain showing keratinase activity prior to biogas production. Chopped, autoclaved chicken feathers (4%, W/V) were completely degraded, resulting in a yellowish fermentation broth with a level of 0.51 mg/mL soluble proteins after 8 days of cultivation of the recombinant strain. During the subsequent anaerobic batch digestion experiments, methane production of 0.35 Nm(3)/kg dry feathers (i.e., 0.4 Nm(3)/kg volatile solids of feathers), corresponding to 80% of the theoretical value on proteins, was achieved from the feather hydrolyzates, independently of the pre-hydrolysis time period of 1, 2 or 8 days. Cultivation with a native keratinase producing strain, Bacillus licheniformis resulted in only 0.25 mg/mL soluble proteins in the feather hydrolyzate, which then was digested achieving a maximum accumulated methane production of 0.31 Nm(3)/kg dry feathers. Feather hydrolyzates treated with the wild type B. megaterium produced 0.21 Nm(3) CH(4)/kg dry feathers as maximum yield.
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| 2. |
- Ibrahim, Victor, et al.
(författare)
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Determining Short Chain Fatty Acids in Sewage Sludge Hydrolysate: A Comparison of Three Analytical Methods and Investigation of Sample Storage Effects
- 2014
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Ingår i: Journal of Environmental Sciences(China). - 1001-0742. ; 26:4, s. 926-933
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Tidskriftsartikel (refereegranskat)abstract
- In anaerobic digestion (AD), the production of short-chain fatty acids (SCFAs) can be beneficial or harmful to the overall process, depending on the concentration of accumulated acids. Therefore, the accurate determination of the SCFA concentration in both fresh and stored sludge hydrolysates is important. To select a suitable method for monitoring SCFAs during the AD of sewage sludge, the accuracy of three available analytical methods, including 5 pH point acid titration (TITRA5), gas chromatography (GC), and spectrophotometry, were compared in the present study. The results revealed that TITRA5 and GC displayed better agreement in the achieved measurements and higher precision and accuracy than the spectrophotometric assay, as supported by the application of different statistical models. TITRA5 excelled in titrating unfiltered hydrolysate while simultaneously measuring the alkalinity, whereas the GC method provided detailed information on the contribution of different fatty acids to the total acidity. In contrast, the spectrophotometric assay suffered from many forms of interference, depending on the sample’s matrix. SCFA production followed the pattern of enzymatic reactions and fitted the Michaelis-Menten model. In addition to promoting TITRA5 as an accurate and robust analytical tool for routine SCFA analyses, this comparative study also demonstrated the possibility of storing hydrolysate samples at different temperatures and durations without altering the SCFA measurements.
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| 3. |
- Shi, P., et al.
(författare)
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Thermodynamic investigations on materials corrosion in some industrial and environmental processes
- 2011
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Ingår i: Journal of Environmental Sciences. - 1001-0742. ; 23:SUPPL., s. S1-S7
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Tidskriftsartikel (refereegranskat)abstract
- For better understanding of corrosion schemes and corrosion mechanisms of a wide range of steels/Fe-alloys, Ni-/NiFe-/Co-superalloys, Al-/Mg-/Ti-/Zr-/Sn-/Cu-/Zn-alloys, electronic-packing alloys, medical-instrument alloys and other materials, under various corrosive environments (such as aqueous solutions, non-aqueous solutions, molten salts, high-temperature gases, etc.) during production/application processes and experimental observations, the Thermo-Calc software/database/programming-interface package can be used. This article is aimed at presenting some application examples of thermodynamic calculations/simulations in some specific areas: aqueous corrosions of stainless steels and other alloys, and of high-performance corrosion-resistant materials (HPCRM); molten salt corrosions of stainless steels and high-temperature alloys; high-temperature gaseous corrosions of steels/alloys; formations of oxide-coated protective layers on steel/alloy surfaces; and emergence conditions during oxidation of steels/alloys.
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| 4. |
- Yang, Weijin, et al.
(författare)
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Alterations of endogenous metabolites in urine of rats exposed to decabromodiphenyl ether using metabonomic approaches
- 2014
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Ingår i: Journal of Environmental Sciences(China). - : Elsevier. - 1001-0742 .- 1878-7320. ; 26:4, s. 900-908
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Tidskriftsartikel (refereegranskat)abstract
- There is large usage of polybrominated diphenyl ethers (PBDEs) especially for decabromodiphenyl ether (BDE-209, Deca-BDE) in controlling the risks of fire. The toxicological effects of PBDEs are worth being concerned about. Female SD rats were daily gavaged with BDE-209 ether at the dose of 100 mg/kg for 20 days. Histological observation was performed for the screening of the target organs for BDE-209 exposure. The distribution and metabolism of PBDEs in the exposed main organs were evidenced by HRGC-HRMS. Alterations of the endogenous metabolite concentrations in urine were investigated using metabonomic approaches based on (1)H NMR spectrum. Histopathological changes including serious edema in kidney, hepatocellular spotty necrosis and perivasculitis in liver indicated that BDE-209 caused potential influences on endogenous metabolism in the exposed liver and the kidney. BDE-209 was found to be highly accumulated in lipid, ovary, kidney and liver after 20 days' exposure. Occurrence of other lower brominated PBDEs in the rats demonstrated that reductive debromination process happened in vivo. Hydroxylated and methoxylated-BDEs, as metabolism products, were also detected in the rat tissues. A total of 12 different endogenous metabolites showed obvious alterations in urine from the exposed rats, indicating the disturbance of the corresponding internal biochemical processes induced by BDE-209 exposure. These findings in vivo suggested the potential health risk might be of concern due to the toxicological effects of BDE-209 as a ubiquitous compound in the environment.
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| 5. |
- Wang, Zengzhang, et al.
(författare)
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Management of process performance at low water temperatures in respect of filamentous organisms
- 2004
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Ingår i: Journal of Environmental Sciences(China). - 1001-0742 .- 1878-7320. ; 16:1, s. 113-116
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Tidskriftsartikel (refereegranskat)abstract
- The management of sludge-settling properties in Nordic conditions is of importance during the low temperature (spring) season because of the peak settler load. A survey was made in 10 Finnish waste water treatment plants(WWTP's) and the total extended filament length and DSVI in half of the plants exceeded the limits, which indicates sludge bulking(15 km/g SS and 150 ml/g respectively). The dominant organism was Microthrix parvicella, the abundance of which was 59.22% of total extended filament length on average. Chemicals were tested to control the filaments, and it was found that special attention has to be paid to maintaining the nitrification at low temperature. A dosage of(H2O2-based) oxidants controlled the growth of Microthrix parvicella effectively and rapidly, whereas with the use of aluminium hydroxidechloride a 2 to 5-week period was needed to decrease the filament length.
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| 6. |
- Eriksson, Ulrika, 1972-, et al.
(författare)
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Contribution of precursor compounds to the release of per- and polyfluoroalkyl substances (PFASs) from waste water treatment plants (WWTPs)
- 2017
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Ingår i: Journal of Environmental Sciences(China). - : SCIENCE PRESS. - 1001-0742 .- 1878-7320. ; 61, s. 80-90
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Tidskriftsartikel (refereegranskat)abstract
- Per- and polyfluoroalkyl substances (PFASs) are ubiquitous in sludge and water from waste water treatment plants, as a result of their incorporation in everyday products and industrial processes. In this study, we measured several classes of persistent PFASs, precursors, transformation intermediates, and newly identified PFASs in influent and effluent sewage water and sludge from three municipal waste water treatment plants in Sweden, sampled in 2015. For sludge, samples from 2012 and 2014 were analyzed as well. Levels of precursors in sludge exceeded those of perfluoroalkyl acids and sulfonic acids (PFCAs and PFSAs), in 2015 the sum of polyfluoroalkyl phosphoric acid esters (PAPs) were 15-20 ng/g dry weight, the sum of fluorotelomer sulfonic acids (FTSAs) was 0.8-1.3 ng/g, and the sum of perfluorooctane sulfonamides and ethanols ranged from non-detected to 3.2 ng/g. Persistent PFSAs and PFCAs were detected at 1.9-3.9 ng/g and 2.4-7.3 ng/g dry weight, respectively. The influence of precursor compounds was further demonstrated by an observed substantial increase for a majority of the persistent PFCAs and PFSAs in water after waste water treatment. Perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS) had a net mass increase in all WWTPs, with mean values of 83%, 28%, 37% and 58%, respectively. The load of precursors and intermediates in influent water and sludge combined with net mass increase support the hypothesis that degradation of precursor compounds is a significant contributor to PFAS contamination in the environment. (C) 2017 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.
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| 7. |
- Gao, Guangbin, et al.
(författare)
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Understanding filamentous cyanobacteria and their adaptive niches in Lake Honghu, a shallow eutrophic lake
- 2025
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Ingår i: Journal of Environmental Sciences (China). - 1001-0742. ; 152, s. 219-234
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Tidskriftsartikel (refereegranskat)abstract
- Freshwater lakes globally are witnessing an escalation in the frequency and intensity of cyanobacterial harmful blooms. However, underlying factors influencing the succession or coexistence of cyanobacteria, especially filamentous ones, remain poorly understood. Lake Honghu, a Ramsar Wetland of International Importance with degrading aquatic ecological quality, served as a case study to elucidate the intricate relationship between environmental changes and cyanobacterial dynamics. Our analysis revealed a significant increase in the dominance of filamentous cyanobacteria, marked by high spatiotemporal variability in community structure. This dominance of filamentous diazotrophic cyanobacteria is attributed to a decrease in the ratio of dissolved inorganic nitrogen to total phosphorus and their capacity to utilize organic phosphorus in phosphorus-deficient conditions. Species-specific density variations were linked to diverse environmental factors, with total nitrogen or total phosphorus concentration remaining as a crucial factor influencing dominant cyanobacterial density fluctuations. The dominance of low-temperature-tolerant Aphanizomenon and Pseudanabaena was evident in spring and winter, whereas Dolichospermum and Cylindrospermopsis, which prefer higher temperatures, thrived in summer and autumn. Additionally, non-algal turbidity and heterogeneity can potentially alter the competitive outcome among filamentous cyanobacteria or foster coexistence under conditions of elevated temperatures and nutrient limitation. This study predicts that filamentous cyanobacteria may spread and persist in lakes spanning a wide trophic range. Current findings enhance our comprehension of the dynamic responses exhibited by filamentous bloom-forming cyanobacteria in the face of environmental changes within shallow eutrophic lakes and provide valuable insights for lake managers involved in the remediation of degraded shallow lakes.
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| 8. |
- González-Arias, Judith, et al.
(författare)
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Hydrochar and synthetic natural gas co-production for a full circular economy implementation via hydrothermal carbonization and methanation: An economic approach
- 2024
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Ingår i: Journal of Environmental Sciences. - 1001-0742 .- 1878-7320. ; 140, s. 69-78
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Tidskriftsartikel (refereegranskat)abstract
- Herein we study the economic performance of hydrochar and synthetic natural gas co-production from olive tree pruning. The process entails a combination of hydrothermal carbonization and methanation. In a previous work, we evidenced that standalone hydrochar production via HTC results unprofitable. Hence, we propose a step forward on the process design by implementing a methanation, adding value to the gas effluent in an attempt to boost the overall process techno-economic aspects. Three different plant capacities were analyzed (312.5, 625 and 1250 kg/hr). The baseline scenarios showed that, under the current circumstances, our circular economy strategy in unprofitable. An analysis of the revenues shows that hydrochar selling price have a high impact on NPV and subsidies for renewable coal production could help to boost the profitability of the process. On the contrary, the analysis for natural gas prices reveals that prices 8 times higher than the current ones in Spain must be achieved to reach profitability. This seems unlikely even under the presence of a strong subsidy scheme. The costs analysis suggests that a remarkable electricity cost reduction or electricity consumption of the HTC stage could be a potential strategy to reach profitability scenarios. Furthermore, significant reduction of green hydrogen production costs is deemed instrumental to improve the economic performance of the process. These results show the formidable techno-economic challenge that our society faces in the path towards circular economy societies.
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| 9. |
- Gu, S., et al.
(författare)
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Anthropogenic land use substantially increases riverine CO2 emissions
- 2022
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Ingår i: Journal of Environmental Sciences (China). - : Elsevier BV. - 1001-0742. ; 118, s. 158-170
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Tidskriftsartikel (refereegranskat)abstract
- Carbon dioxide (CO2) emissions from inland waters to the atmosphere are a pivotal component of the global carbon budget. Anthropogenic land use can influence riverine CO2 emissions, but empirical data exploring cause-effect relationships remain limited. Here, we investigated CO2 partial pressures (pCO2) and degassing in a monsoonal river (Yue River) within the Han River draining to the Yangtze in China. Almost 90% of river samples were supersaturated in CO2 with a mean ± standard deviation of 1474 ± 1614 µatm, leading to emissions of 557 - 971 mmol/m2/day from river water to the atmosphere. Annual CO2 emissions were 1.6 - 2.8 times greater than the longitudinal exports of riverine dissolved inorganic and organic carbon. pCO2 was positively correlated to anthropogenic land use (urban and farmland), and negatively correlated to forest cover. pCO2 also had significant and positive relationships with total dissolved nitrogen and total dissolved phosphorus. Stepwise multiple regression models were developed to predict pCO2. Farmland and urban land released nutrients and organic matter to the river system, driving riverine pCO2 enrichment due to enhanced respiration in these heterotrophic rivers. Overall, we show the crucial role of land use driving riverine pCO2, which should be considered in future large-scale estimates of CO2 emissions from streams. Land use change can thus modify the carbon balance of urban-river systems by enhancing river emissions, and reforestation helps carbon neutral in rivers. © 2022
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| 10. |
- Gu, Zhenhong, et al.
(författare)
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Analysis of the most widely used building environmental assessment methods
- 2006
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Ingår i: Journal of Environmental Sciences(China). - : Informa UK Limited. - 1001-0742 .- 1878-7320. ; 3:3, s. 175-192
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Tidskriftsartikel (refereegranskat)abstract
- Building Environmental Assessment (BEA) is a term used for several methods for environmental assessment of the building environment. Generally, Life Cycle Assessment (LCA) is an important foundation and part of the BEA method, but current BEA methods form more comprehensive tools than LCA. Indicators and weight assignments are the two most important factors characterizing BEA. From the comparison of the three most widely used BEA methods, EcoHomes (BREEAM for residential buildings), LEED-NC and GBTool, it can be seen that BEA methods are shifting from ecological, indicator-based scientific systems to more integrated systems covering ecological, social and economic categories. Being relatively new methods, current BEA systems are far from perfect and are under continuous development. The further development of BEA methods will focus more on non-ecological indicators and how to promote implementation. Most BEA methods are developed based on regional regulations and LCA methods, but they do not attempt to replace these regulations. On the contrary, they try to extend implementation by incentive programmes. There are several ways to enhance BEA in the future: expand the studied scope from design levels to whole life-cycle levels of constructions, enhance international cooperation, accelerate legislation and standardize and develop user-oriented assessment systems.
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