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Publisher: Springer-Verlag   (Total: 2292 journals)

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Transformation Groups     Hybrid Journal   (SJR: 1.926, h-index: 19)
Transgenic Research     Hybrid Journal   (Followers: 4, SJR: 0.877, h-index: 58)
Transition Metal Chemistry     Hybrid Journal   (Followers: 1, SJR: 0.337, h-index: 41)
Transition Studies Review     Hybrid Journal   (Followers: 1, SJR: 0.175, h-index: 6)
Translational Behavioral Medicine     Partially Free   (Followers: 1, SJR: 0.504, h-index: 7)
Translational Stroke Research     Hybrid Journal   (Followers: 3, SJR: 0.73, h-index: 12)
Transport in Porous Media     Hybrid Journal   (Followers: 1, SJR: 1.152, h-index: 46)
Transportation     Hybrid Journal   (Followers: 20, SJR: 1.645, h-index: 42)
Transportation Infrastructure Geotechnology     Hybrid Journal   (Followers: 6)
Trauma und Berufskrankheit     Hybrid Journal   (SJR: 0.108, h-index: 6)
Tree Genetics & Genomes     Hybrid Journal   (Followers: 2, SJR: 0.915, h-index: 29)
Trees     Hybrid Journal   (Followers: 5, SJR: 0.807, h-index: 52)
Trends in Organized Crime     Hybrid Journal   (Followers: 46, SJR: 0.642, h-index: 9)
Tribology Letters     Hybrid Journal   (Followers: 5, SJR: 1.428, h-index: 56)
Tropical Animal Health and Production     Hybrid Journal   (Followers: 4, SJR: 0.522, h-index: 26)
Tropical Plant Biology     Hybrid Journal   (Followers: 2, SJR: 0.511, h-index: 10)
Tropical Plant Pathology     Hybrid Journal   (Followers: 3, SJR: 0.29, h-index: 8)
Tumor Biology     Hybrid Journal   (Followers: 4, SJR: 0.977, h-index: 43)
Ukrainian Mathematical J.     Hybrid Journal   (SJR: 0.276, h-index: 11)
Universal Access in the Information Society     Hybrid Journal   (Followers: 36, SJR: 0.572, h-index: 19)
Updates in Surgery     Hybrid Journal   (Followers: 3, SJR: 0.489, h-index: 15)
Urban Ecosystems     Hybrid Journal   (Followers: 10, SJR: 0.837, h-index: 23)
Urban Forum     Hybrid Journal   (Followers: 6, SJR: 0.684, h-index: 16)
Uro-News     Hybrid Journal  
Urolithiasis     Hybrid Journal   (Followers: 3)
Urologic Radiology     Hybrid Journal   (Followers: 1)
User Modeling and User-Adapted Interaction     Hybrid Journal   (Followers: 5, SJR: 1.921, h-index: 45)
uwf UmweltWirtschaftsForum     Hybrid Journal  
Vegetation History and Archaeobotany     Hybrid Journal   (Followers: 3, SJR: 1.193, h-index: 36)
Verslaving     Hybrid Journal  
Vestnik St. Petersburg University: Mathematics     Hybrid Journal   (SJR: 0.278, h-index: 4)
Veterinary Research Communications     Hybrid Journal   (Followers: 2, SJR: 0.503, h-index: 34)
Vietnam J. of Mathematics     Hybrid Journal   (Followers: 1)
Virchows Archiv     Hybrid Journal   (Followers: 1, SJR: 1.237, h-index: 72)
Virologica Sinica     Hybrid Journal   (SJR: 0.353, h-index: 9)
Virtual Reality     Hybrid Journal   (Followers: 3, SJR: 0.397, h-index: 24)
Virus Genes     Hybrid Journal   (Followers: 2, SJR: 0.839, h-index: 42)
Visual Geosciences     Hybrid Journal  
Vocations and Learning     Hybrid Journal   (Followers: 5, SJR: 0.783, h-index: 7)
Voluntas: Intl. J. of Voluntary and Nonprofit Organizations     Hybrid Journal   (Followers: 8, SJR: 0.459, h-index: 23)
Waste and Biomass Valorization     Hybrid Journal   (Followers: 1, SJR: 0.768, h-index: 10)
Water History     Hybrid Journal   (Followers: 3, SJR: 0.221, h-index: 3)
Water Quality, Exposure and Health     Hybrid Journal   (Followers: 3)
Water Resources     Hybrid Journal   (Followers: 13, SJR: 0.274, h-index: 9)
Water Resources Management     Hybrid Journal   (Followers: 14, SJR: 1.349, h-index: 47)
Water, Air, & Soil Pollution     Hybrid Journal   (Followers: 19, SJR: 0.761, h-index: 70)
Water, Air, & Soil Pollution : Focus     Hybrid Journal   (Followers: 8)
Welding in the World     Hybrid Journal   (Followers: 4, SJR: 0.404, h-index: 17)
Wetlands     Hybrid Journal   (Followers: 15, SJR: 0.745, h-index: 55)
Wetlands Ecology and Management     Hybrid Journal   (Followers: 7, SJR: 0.685, h-index: 38)
Wiener klinische Wochenschrift     Hybrid Journal   (SJR: 0.332, h-index: 38)
Wiener klinische Wochenschrift Education     Hybrid Journal  
Wiener Klinisches Magazin     Hybrid Journal  
Wiener Medizinische Wochenschrift     Hybrid Journal   (SJR: 0.328, h-index: 23)
Wireless Networks     Hybrid Journal   (Followers: 8, SJR: 0.533, h-index: 65)
Wireless Personal Communications     Hybrid Journal   (Followers: 5, SJR: 0.322, h-index: 29)
Wirtschaftsdienst     Hybrid Journal   (Followers: 3, SJR: 0.206, h-index: 5)
WIRTSCHAFTSINFORMATIK     Hybrid Journal   (Followers: 3)
Wirtschaftsrechtliche Blätter     Hybrid Journal   (Followers: 2)
wissen kompakt     Hybrid Journal  
WMU J. of Maritime Affairs     Hybrid Journal   (Followers: 2)
Wohnrechtliche Blätter     Hybrid Journal  
Wood Science and Technology     Hybrid Journal   (Followers: 3, SJR: 0.808, h-index: 43)
World J. of Microbiology and Biotechnology     Hybrid Journal   (Followers: 3, SJR: 0.561, h-index: 49)
World J. of Pediatrics     Hybrid Journal   (Followers: 2, SJR: 0.478, h-index: 14)
World J. of Surgery     Hybrid Journal   (Followers: 14, SJR: 1.451, h-index: 106)
World J. of Urology     Hybrid Journal   (Followers: 3, SJR: 1.463, h-index: 59)
World Wide Web     Hybrid Journal   (Followers: 11, SJR: 1, h-index: 21)
Wuhan University J. of Natural Sciences     Hybrid Journal   (SJR: 0.149, h-index: 11)
ZDM     Hybrid Journal   (SJR: 0.496, h-index: 14)
Zeitschrift für angewandte Mathematik und Physik     Hybrid Journal   (Followers: 1, SJR: 1.136, h-index: 38)
Zeitschrift für Außen- und Sicherheitspolitik     Hybrid Journal   (Followers: 8)
Zeitschrift für Bildungsforschung     Hybrid Journal  
Zeitschrift für Didaktik der Naturwissenschaften     Hybrid Journal  
Zeitschrift für die gesamte Versicherungswissenschaft     Hybrid Journal   (SJR: 0.139, h-index: 2)
Zeitschrift fur Energiewirtschaft     Hybrid Journal   (Followers: 1)
Zeitschrift für Epileptologie     Hybrid Journal   (SJR: 0.122, h-index: 4)
Zeitschrift für Erziehungswissenschaft     Hybrid Journal   (Followers: 7, SJR: 0.303, h-index: 6)
Zeitschrift für Europäisches Unternehmens- und Verbraucherrecht     Hybrid Journal   (Followers: 1)
Zeitschrift fur Gerontologie und Geriatrie     Hybrid Journal   (Followers: 1, SJR: 0.318, h-index: 26)
Zeitschrift für Herz-,Thorax- und Gefäßchirurgie     Hybrid Journal   (Followers: 1, SJR: 0.114, h-index: 5)
Zeitschrift für Hochschulrecht, Hochschulmanagement und Hochschulpolitik: zfhr     Hybrid Journal   (Followers: 3)
Zeitschrift fur Management     Hybrid Journal   (Followers: 2)
Zeitschrift für öffentliches Recht     Hybrid Journal   (Followers: 16)
Zeitschrift für Politikberatung     Hybrid Journal   (Followers: 1)
Zeitschrift für Psychodrama und Soziometrie     Hybrid Journal  
Zeitschrift fur Rheumatologie     Hybrid Journal   (Followers: 2, SJR: 0.174, h-index: 31)
Zeitschrift für Vergleichende Politikwissenschaft     Hybrid Journal   (Followers: 6)
Zentralblatt für Arbeitsmedizin, Arbeitsschutz und Ergonomie. Mit Beiträgen aus Umweltmedizin und Sozialmedizin     Full-text available via subscription   (SJR: 0.111, h-index: 9)
Zoological Letters     Open Access  
Zoomorphology     Hybrid Journal   (Followers: 2, SJR: 0.581, h-index: 26)
Zorg en Financiering     Hybrid Journal  

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Journal Cover   Journal of Material Cycles and Waste Management
  [SJR: 0.392]   [H-I: 16]   [2 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1611-8227 - ISSN (Online) 1438-4957
   Published by Springer-Verlag Homepage  [2292 journals]
  • Pb-Laden CRT glass as classifying hazardous waste definition or exemption
           in landfill disposal in China
    • Abstract: Disposal of waste CRT glass is now an urgent environmental protection issue. We collected waste CRT glass from monochrome and color television sets, analyzed their chemical compositions using X-ray fluorescence, and studied the leaching characteristics of Pb in the glass using sulfuric and nitric acids and acetic acid buffer leaching toxicity tests. The results showed that the order of the Pb leaching levels was color panel glass < monochrome glass < color funnel glass. The average Pb concentrations leached in sulfuric and nitric acids from color funnel and panel glasses and from monochrome funnel and panel glasses did not exceed the regulatory limits for Pb according to the China Identification Standards for Hazardous Waste—Identification for Extraction Toxicity. Only the average concentration of Pb leached in acetic acid buffer from color funnel glass exceeded the regulatory levels for Pb while those from other glasses were lower than 1 mg/L. Monochrome panel and funnel glasses and color panel glass can be disposed off as common industrial solid waste or co-disposed off with municipal solid waste. Color funnel glass, however, should be managed and disposed off in strict conformity with the requirements for hazardous waste disposal.
      PubDate: 2015-07-02
       
  • Bioleaching of copper from metal concentrates of waste printed circuit
           boards by a newly isolated Acidithiobacillus ferrooxidans strain Z1
    • Abstract: The goal of this study is to determine the potential of Acidithiobacillus ferrooxidans strain Z1 in bioleaching of metal concentrates of waste printed circuit boards (PCBs). The influences of initial pH, initial Fe(II) concentration, metal concentrates dosage, inoculation quantity and particle size on the bioleaching process were investigated and optimum conditions were determined. The results showed that 92.57 % copper leaching efficiency was achieved within 78 h in a two-step process, and 85.24 % aluminum and 95.18 % zinc were leached out after 183 h under the optimum conditions of initial pH 2.25, initial Fe(II) 9 g/L, metal concentrates dosage 12 g/L, inoculation quantity 10 % and particle size 0.178–0.250 mm. It demonstrated that metals could be efficiently leached from metal concentrates by Acidithiobacillus ferrooxidans Z1 and the bioleaching period was reduced 81–78 h. Therefore, the strain Acidithiobacillus ferrooxidans Z1 could be suggested as a potential strain to bioleach metals from metal concentrates of waste PCBs.
      PubDate: 2015-07-02
       
  • Spatial and temporal variability of odorous VOC in a food waste treatment
           plant using hydrothermal hydrolysis and aerobic fermentation technology
    • Abstract: Offensive odorant emissions from a food waste (FW) treatment plant that uses hydrothermal hydrolysis and aerobic fermentation technology were studied for 1 month through in situ monitoring and laboratory testing. Results showed that the emission flux (7000 μg kg−1FW h−1) of total volatile organic compounds and concentrations of most volatile organic compounds (VOCs) were highest at the discharge outlet of the hydrothermal hydrolysis reactor. Furthermore, VOC composition analysis showed that the concentrations of most hydrocarbons detected during the sorting/crushing process were higher than those in the aerobic fermentation process, but more oxygenated organic compounds and pinenes were released in the aerobic treatment process. The analysis of VOC temporal characteristics via t test indicated that even with various FW loads during the day and night, most VOC concentrations sampled in the storing room were not significantly different. However, great variances among most VOC concentrations were observed during the sorting/crushing process and at the hydrothermal hydrolysis reactor. The annoyance degrees of offensive gases were also determined via analysis of odor indices. The results suggested that sulfocompounds mainly dominated in terms of high odor activate values during the sorting/crushing process, and the fractional content of oxygenated organic compounds increased in the aerobic treatment processes.
      PubDate: 2015-07-02
       
  • Regeneration performance of spent granular activated carbon for tertiary
           treatment of dyeing wastewater by Fenton reagent and hydrogen peroxide
    • Abstract: The efficacy of Fenton reagent and hydrogen peroxide for the regeneration of saturated granular activated carbon with biological effluent of dyeing wastewater was compared based on adsorption–oxidation recycle experiments. The catalytic performance of granular activated carbon and the necessity of ferrous ions were discussed. It was demonstrated that Fenton reagent or H2O2 was effective in destroying toxic organics and removing organic pollutants from the surface of granular activated carbon. The regeneration efficiency of granular activated carbon was about 50 % with Fenton reagent or H2O2 evaluated by chemical oxygen demand removals in adsorption. However, the synergic catalysis of granular activated carbon and ferrous ions enhanced the mineralization of organic pollutants and resulted in a higher regeneration efficiency of granular activated carbon evaluated by total organic carbon removals in adsorption compared with H2O2 alone.
      PubDate: 2015-07-02
       
  • Biogas productivity of algal residues from bioethanol production
    • Abstract: The purpose of this study was to investigate biogas productivity of algal residues from bioethanol production. Pre-treatment based on enzyme was applied for saccharification to produce bioethanol from the alga, Hydrodictyon reticulatum. Pre-treatment with a combination of enzyme and acid was used for saccharification. The specific methane production yield from raw H. reticulatum, enzyme-saccharified and enzyme/acid-saccharified H. reticulatum residues was 147.6, 408.7, and 537.5 mL CH4/g VS (volatile solids), respectively. The methane yield of raw H. reticulatum from experiment was 22.4 % of the theoretical biochemical methane potential, whereas that of enzyme-saccharified and enzyme/acid-saccharified H. reticulatum residues increased up to 45.8 and 61.4 % of the theoretical value, respectively.
      PubDate: 2015-07-01
       
  • Municipal food waste management in Singapore: practices, challenges and
           recommendations
    • Abstract: Municipal food waste is a global challenge in solid waste management, especially in Singapore. It is scattered in location, non-ignorable in quantity, and non-uniform in quality. This report focuses on the state of the art and challenges of Singapore municipal food waste management for the first time. The previous studies only focus on general food waste from both industry and municipality. The physical properties of municipal food waste are incompatible to landfill and incineration by creating secondary environmental burdens and lowering treatment efficiency. A decentralized anaerobic co-digestion with other substrates, after comparing with other technologies, is recommended, since bio-energy is a recognized valuable final product in Singapore’s context. However, there are four major highlighted challenges of food waste recycling, including low final product demand, inefficient waste collection design, cheap disposal cost, and low social awareness. A “food waste management hierarchy” for Singapore is also proposed. The most to least preferred options are listed as: source reduction, industrial uses, renewable energy, and composting then incineration.
      PubDate: 2015-06-25
       
  • Speciation of the radioactive nuclides in incinerator fly ash of municipal
           solid waste using sequential extractions
    • Abstract: The radioactive nuclides in the incinerator fly ashes from municipal solid waste sampled in June 2006 were analyzed with γ-ray spectrometry. The incinerator ashes were collected in northern Kyushu, Japan. Potassium-40, 137Cs, 210Pb, 226Ra, 228Ra and 228Th were identified and quantified in the γ-ray spectra of fly ash. Gamma-ray spectrometry was combined with a modified sequential extraction procedure based on the Tessier method used for the analysis of radioactive nuclides in fly ash. The crystalline phases and the elemental composition of fly ash were determined by using powder X-ray diffractometry and X-ray fluorescence spectrometry. After sequential extraction, most of 40K and 137Cs and part of 210Pb mainly existed as water-soluble salts, while 226Ra, 228Ra and 228Th were enriched in the residual material of fly ash, especially depending on basicity (Ca/Si ratio) of MSW. Although, 210Pb and stable Pb are isotopes of each other, the distribution of 210Pb is different from that of stable Pb. The differences in the chemical states of 210Pb and stable Pb might result from their distinct origins; 210Pb originates from the decay of 222Rn and is associated with aerosols, whereas stable Pb is mainly derived from relatively inert chemical forms.
      PubDate: 2015-06-24
       
  • Mitigation of non-methane organic compounds through landfill soil cover
           and its environmental implications
    • Abstract: Field measurement campaigns were conducted at a Chinese municipal solid waste landfill to investigate variation of non-methane organic compounds (NMOCs) when migrating through an intermediate soil cover. Flux change ratio (FCR) was introduced to indicate quantitative variation of NMOCs between two depths through the soil cover. FCR of NMOCs showed a positive correlation with methane oxidation fraction (99 % confidence level), indicating the synergistic effects of methane oxidation and NMOCs mitigation in soil cover. Emission reduction indicator (ERI), ozone-forming potential reduction indicator (ORI), and toxicity reduction indicator (TRI) of halogenated hydrocarbons were calculated to evaluate the environmental effects of intermediate soil cover for NMOCs control and reached up to 7.85 mg m−2 day−1, 20.8 mg m−2day−1 and 7.27 µg m−2 day−1, respectively. Enhancement of methane oxidation in landfill covers could be an effective way to reduce NMOCs emission and decrease its environmental effects, which would give guidance on landfill management.
      PubDate: 2015-06-20
       
  • Preparation of sludge-derived KOH-activated carbon for crude glycerol
           purification
    • Abstract: Activated carbon (AC) was prepared from wastewater treatment sludge by KOH activation and then used for the adsorptive purification of crude glycerol (CG). The effect of different KOH: char (w/w) ratios (1–6), KOH soaking times (5–25 h), and activation temperatures (500–900 °C) on the surface properties of the obtained sludge-derived ACs and their adsorption capacity for impurities in H3PO4 pretreated CG was explored. The preparation conditions affected the textural properties and surface chemistry of the sludge-derived AC and its efficiency in the adsorptive purification of CG. Oxygen-containing surface functional groups, particularly carbonyl groups, as well as the textural properties, played a more important role in the adsorptive purification of CG. Among the sludge-derived ACs, the one impregnated at a KOH: char (w/w) ratio of 5.0 for 25 h and then activated at 800 °C exhibited the most suitable surface properties for the purification of pretreated CG, attaining a 93.0 % (w/w) glycerol level at an AC dose of 67 g/L for 2 h with agitation at 250 rpm. The AC adsorption of impurities from the pretreated CG followed the Langmuir isotherm. However, the reusability of the used AC by hexane or diethyl ether extraction was not suitable.
      PubDate: 2015-06-10
       
  • Community-based solid waste bank program for municipal solid waste
           management improvement in Indonesia: a case study of Padang city
    • Abstract: Indonesia has a regulation UU No. 18/2008 which changes the paradigm from waste dumping to recycling. The purpose of this study is to understand the achievement and obstacles of community-based waste recycling through the solid waste bank (SW bank) program and its potency to improve the local MSW management in Indonesia. SW bank program is a unique organization developed among Indonesian communities to facilitate citizen participation in solid waste recycling. The banking system is adopted, and the community deposits the wastes instead of money. Case study was done for Padang city. The existing condition in 2013 suggests that the amount of solid waste recycled by SW bank activity was only 0.05 % of the total MSW generation. This condition results in 35 % waste without proper treatment. To improve the existing condition, development scenario is planned for 15 years. This development scenario may result in the increase of recycling amount of SW bank activity to 6 % of the total MSW generation in 2028. SWOT analysis suggests that some strategies such as creating a local regulation may be adopted to utilize the potency of SW bank for local MSW management improvement.
      PubDate: 2015-05-27
       
  • The development of low cost adsorbents from clay and waste materials: a
           review
    • Abstract: Increased energy consumption due to industrial growth has increased the levels of carbon dioxide (CO2) emission being released into the atmosphere. CO2 emission is a type of greenhouse gas which is a major cause of global warming. Since the issue of CO2 emissions has drawn much attention in recent years, the development of CO2 capture technology has become a necessity. Although CO2 adsorbents are still at the early development stage, it has been suggested that CO2 adsorbents are the most effective technology in controlling CO2 emissions. Solid adsorbents have great potential as an alternative method to conventional adsorbents in adsorbing CO2. In this paper, low cost adsorbents including activated carbon, zeolites, mesoporous silica and clays are discussed in terms of adsorbent preparation methods and CO2 adsorption capacity. The low cost adsorbents are mainly derived from waste materials such as fly ash, steel slag, red mud, bagasses wastes and wood wastes. Besides that, natural resources such as clays have also been applied as low cost CO2 adsorbents. Surface modifications have also been applied to the low cost adsorbents, including metal ion exchange and amine impregnation to enhance CO2 adsorption capacity. In the last section, the current status of CO2 adsorbents is summarized and future trends are discussed briefly to predict the potential materials which can be applied as CO2 adsorbents.
      PubDate: 2015-05-19
       
  • Mechanochemical degradation of hexachlorobenzene using Mg/Al 2 O 3 as
           additive
    • Abstract: In the present work, we investigate the destruction efficiency of hexachlorobenzene (HCB) by milling with various reagents in a planetary ball mill under different milling conditions. Under the same conditions of mill rotary rate and charge ratio, the mixture of magnesium powder and aluminum oxide (Mg/Al2O3) was found best in promoting the destruction of HCB, which can be completed destroyed after 90 min grinding at a charge ratio of 20:1 (reagent/HCB, m/m), a ball mass/reagent mass ration of 30:1 and a mill rotation speed of 550 rpm. The ground samples were characterized and analyzed by X-ray fluorescence, gas chromatography (GC), X-ray diffraction and ion chromatography. The intermediate products, such as pentachlorobenzene, tetrachlorobenzene, trichlorobenzene isomers, dichlorobenzene and monochlorobenzene were detected by GC. Then the main dechlorination path way for HCB was proposed. With a series of verification experiments, the final degradation products of HCB were amorphous carbon and inorganic chlorine. Based on this study, Mg/Al2O3 has the potential to complete the innocuous treatment of chlorinated compounds.
      PubDate: 2015-05-19
       
  • Evaluation of waste slags produced by zinc industry in bituminous hot
           mixtures
    • Abstract: Owing to the large amount of waste slags produced by zinc industry, it has become necessary to recycle it in some areas. Road construction has significant potential for the use of waste materials because more material is always needed. In this study, the engineering behaviour of asphalt concrete was investigated using mineral aggregates with waste slag, which is a by-product of the zinc–lead production industry. The asphalt concrete tested in this study was fabricated using 25, 50, 75 and 100 % mixing ratios instead of the conventional fine mineral aggregate (11, 22, 33 and 44 % rate of total aggregate mixture) to determine the possibility of using slags in the binder course of bituminous hot mixtures. The asphalt concretes, made of waste slags and conventional asphalt concrete, were evaluated in terms of their fundamental engineering properties such as Marshall stability, flow, Marshall quotient (MQ), bulk specific gravity, air voids and voids filled with bitumen in the total mix characteristics. The results indicate that the addition of waste slag as mineral aggregate improves the engineering characteristic performance and that it can be used in bituminous hot mixtures. In addition, principal component analyses were applied to examine the significance of each Marshall parameter, and a regression model was developed to estimate the MQ value using effective parameters.
      PubDate: 2015-05-17
       
  • Valorization of fish by-products: rheological, textural and
           microstructural properties of mackerel skin gelatins
    • Abstract: The fish processing industry generates significant amounts of waste which is usually discarded. The present study investigated the recovery of gelatins from Atlantic mackerel (Scomber scombrus) skins after pre-treatment with different environmentally friendly organic acids (acetic, citric, lactic, tartaric or malic acid). The chemical composition, the rheological and the textural properties as well as the microstructural characteristics of the extracted gelatins were analysed and compared to commercial bovine hide gelatin. Although the organic acid used in the pre-treatment step did not affect the extraction yield and the chemical composition of the prepared gelatins, differences were observed in terms of rheology and texture. The highest gel strength (P < 0.05) was observed with gelatins extracted after pre-treatment with acetic, citric and malic acids (71–80 g). From an industrial point of view, gelatin can be extracted using any of these organic acids with similar yield. However, in order to obtain better rheological and textural properties the use of acetic, citric or malic acid in the pre-treatment step is recommended.
      PubDate: 2015-05-15
       
  • Investigations on enhanced in situ bioxidation of methane from landfill
           gas (LFG) in a lab-scale model
    • Abstract: The performance of an exogenous bacterium, Methylobacterium extorquens, in inducing bioxidation of methane from landfill gas (LFG) was assessed in a laboratory scale bioreactor. The study show that enhanced oxidation of methane is attained when the bacteria are introduced into the landfill soil. The maximum percentage reduction of methane fraction from LFG when the bioreactor was inoculated with the methanotrophic bacteria was 94.24 % in aerobic treatment process and 99.97 % in anaerobic process. In the experiments with only the indigenous microorganisms present in the landfill soil, the maximum percentage reduction of methane for the same flow rate of LFG was 59.67 % in aerobic treatment and 45 % in anaerobic treatment. The methane oxidation efficiency of this exogenous methanotrophic bacterium can be considered to be the optimum in anaerobic condition and at a flow rate of 0.6 L/m2/min when the removal percentage is 99.95 %. The results substantiate the use of exogenous microorganisms as potential remediation agents of methane in LFG.
      PubDate: 2015-05-13
       
  • Effect of pretreatment techniques on food waste solubilization and biogas
           production during thermophilic batch anaerobic digestion
    • Abstract: The purpose of this study was to optimize the alkaline, ultrasonication, and thermal pretreatment in order to enhance the solubilization of food waste (FW) for the production of volatile fatty acids, hydrogen, and methane in thermophilic batch anaerobic digestion. Initially, the effect of pretreatment techniques in the acidogenic phase was studied, and the optimal combinations of different conditions were determined. It was found that each pretreatment technique affected food waste solubilization differently. Alkaline pretreatment increased hydrogen yield in the acidogenic sludge by four times over control. COD solubilization was increased by 47 % when FW pre-heated at 130 °C for 60 min. Ultrasonication at 20 kHz and 45 min reduced processing time to 38 h from the 60–80 h needed in normal operation. Response surface methodology (RSM) was used to optimize a combination of alkaline, ultrasonication, and thermal pretreatment. Optimized conditions were applied to methanogenic single-stage thermophilic AD process, and their impact on biogas production was monitored. Results showed that FW heated at 130 °C for 50 min geminates biogas production compared to control experiment. In conclusion, a short thermal pretreatment regime could significant affect biogas production in single-stage thermophilic AD.
      PubDate: 2015-05-08
       
  • Waste rechargeable electric lamps: characterisation and recovery of lead
           from their lead-acid batteries
    • Abstract: Electrical electronics constitute a significant quantity of municipal solid wastes which are discarded after use in open dumpsites especially in the developing countries. The aim of this study was to characterise the material and chemical components, evaluate current management practices and investigate recovery of lead from battery electrodes (BEs) of waste rechargeable electric lamps (RLs). Twenty-six waste RLs of different models were sampled in Nigeria and characterised. Their BEs were analysed for Pb, Cr, Mn, Cu, Zn, Ni and Fe after acid digestion. Questionnaires were distributed to unselected respondents to assess usage and disposal of the lamps. Reaction of citric acid solutions with Pb in the presence of H2O2 was used for the recovery of Pb. 69 % of the respondents disposed their waste RLs in open dumpsites. The mean ± SD concentrations of Pb, Cr, Mn, Cu, Zn, Ni and Fe in the BEs were 600 ± 0.2 g/kg, 65.4 ± 40 mg/kg, 5.05 ± 4.0 mg/kg, 6.81 ± 5.0 mg/kg, 5.98 ± 3.0 mg/kg, 50.0 ± 30 mg/kg and 40.2 ± 35 mg/kg, respectively. The results show that the batteries are lead-acid batteries which require management. At the optimal conditions of S/L = 0.14, temperature = 20 °C and leaching time = 5 h, about 95 % Pb was recovered in form of lead citrate from the battery. High recovery of Pb is possible with simple and environment-friendly reactions.
      PubDate: 2015-05-05
       
  • Electro-dissolution of metal scrap anodes for nickel ion removal from
           metal finishing effluent
    • Abstract: This contribution reports a novel and cost efficient strategy for nickel ion removal from metal finishing effluents by electro-dissolution of scrap aluminium and iron sacrificial anodes. Electro-coagulation of effluent was carried out at 30 mA/cm2 current density for 60 min. The nickel ion concentration of electroplating effluent was analysed by Atomic Absorption Spectroscopy. SEM images of iron and aluminium scrap anodes were critically analysed. Parameters such as heavy metal removal, anode dissolution rate with respect to heavy metal removal, reaction kinetics and cost estimation have been elaborately studied. Electro-coagulation at 30 mA/cm2 for 60 min using iron and aluminium scrap anodes resulted in 95.9 and 94.1 % nickel ion reduction, respectively, with 0.0094 and 0.0053 g/ppm dissolution rates. The energy consumption for scrap aluminium and iron anodes was 0.0547 kWh/L. Loose internal bonding and spongy surface morphology of used metal scrap render high porosity and active surface area, enhancing reaction rate. Low cost and ready availability of waste scrap makes the process of electro-coagulation economically viable. Thus, the findings from this contribution point decisively at the superiority of waste metal scrap-based anodes for economic and environmentally sustainable heavy metal ion removal from metal finishing effluent.
      PubDate: 2015-04-25
       
  • Evaluation of metals in the residue of paper sludge after recovery of pulp
           components using an ionic liquid
    • Abstract: The quantity of sludge produced by the paper industry in Japan in 2011 was estimated to be 27.91 million tons wet weight. This amount is the third largest among all industrial wastes. To explore ways of reusing recovered paper pulp and safely disposing of the residue, we investigated the distribution of metals in the process of recovery of pulp from two types of paper sludge using an ionic liquid. 32 and 46 % of pulp from paper sludge A and B was recovered using ionic liquid, respectively; the resultant weight reduction of the solid mass was comparable to that of incineration. There were virtually no heavy metals but aluminum in the recovered pulp, which makes its reuse viable at present. The characteristics of the metals in the residues differed according to the treatment used and properties of the paper sludge. Copper accounted for ~10 % in the ionic liquid used for recovery of pulp from the paper sludges. This suggests that [bmIm]Cl has the potential to dissolve a specific amount of copper compared to other metals.
      PubDate: 2015-04-23
       
  • Life cycle assessment and valuation of the packaging waste recycling
           system in Belgium
    • Abstract: This study analyses the packaging waste management system in Belgium. Waste management operations involve a significant number of processes associated with energy consumption and emission of pollutants in air and water. To assess the impact on the environment of the several waste management operations, a life cycle assessment was developed. The operations of selective and refuse collection, sorting, recycling and incineration of packaging waste were considered. A comparison between two scenarios was developed. The first scenario comprised the packaging waste management system in operation in 2010. This system comprises the waste management operations envisaging the recycling of the packaging materials. The second scenario was developed based on the hypothesis that there was no recycling system and all packaging waste would be collected in the refuse collection system. An environmental valuation was performed to convert the environmental results into a common unit (EUR). To accomplish this valuation, three methods were used: Ecocost, Ecovalue and Stepwise. These methods were developed in Europe and follow different methodologies. The environmental results were compared using the three methods and they were consistent with the conclusion that the recycling scenario (i.e. the actual situation in 2010) is more environmentally sound.
      PubDate: 2015-04-22
       
 
 
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