Read by QxMD icon Read

Environmental Technology

Abdol Ghaffar Ebadi, Hikmat Hisoriev
Gasification is one of the most important thermochemical routes to produce both synthesis gas (syngas) and chars. The quality of produced syngas wieldy depends on the operating conditions (temperature, residence time, heating rate, and gasifying agent), hydrodynamic properties of gasifier (particle size, minimum fluidization velocity, and gasifier size), and type of feedstock (coal, biomass, oil, and municipal solid wastes). In the present study, simulation of syngas production via circulating fluidized bed (CFB) gasification of algal biomass (Cladophora glomerata L...
November 15, 2017: Environmental Technology
S Tugce Daglioglu, Burcin Karabey, Guven Ozdemir, Nuri Azbar
CO2, which is considered to be one of the major cause of climate change has reached to critical levels in the atmosphere due to tremendous consumption of fossil fuels all over the world.  In this study, anaerobic bioconversion of CO2 into bio-methane using a novel bioprocess configuration (HYBRID bioreactor) was studied under mesophilic conditions. Varying ratios of H2/CO2 gas mixture and volumetric feeding rates were investigated and no additional organic matter and trace element were needed throughout the study...
November 15, 2017: Environmental Technology
R E Costa, A A Battistelli, J K B Bernardelli, J P Bassin, T J Belli, F R Lapolli
A conventional (SB-CMBR) and a hybrid moving bed (SB-HMBR) sequencing batch membrane bioreactor treating municipal wastewater were compared during their start-up in terms of organic matter and nutrient removal, membrane fouling characteristics and microbial community. Both systems exhibited similar COD, ammonium, total nitrogen (TN) and phosphorus removal efficiency, amounting up to 96%, 99%, 70% and 85%, respectively. Most of the COD removal was coupled to phosphate release and denitrification in the anaerobic/anoxic phase of the operating cycle, whereas the low COD/N environment established in the aerated phase allowed full nitrification...
November 11, 2017: Environmental Technology
S D C Case, L S Jensen
The drive for a more circular economy has led to an increasing interest in recycling organic wastes as bio-based fertilizers, including those from urban settings, and food or biomedical industries. However, there is a lack of knowledge as to their fertilizer value and whether further processing could make these waste materials more valuable as bio-based fertilizers. This study screened 15 different organic waste materials including manures, digestates, sludges, composts, industry byproducts, and struvites. Nitrogen (N) and phosphorous (P) release was compared following addition to soil...
November 10, 2017: Environmental Technology
Xiaofeng Jiang, Shengpeng Zuo, Liangtao Ye, Wenxiu Hong
Nanomaterials and/or contaminants are becoming more common in the developing world, but their effects on interspecific interactions are rarely reported, particularly in aquatic ecosystems. Thus, the present study determined the effects of the novel pollutant nano-fumed silica (NFS) on algal control by a macrophyte via the allelochemical p-hydroxybenzoic acid in a microcosm test. The allelochemical p-hydroxybenzoic acid caused significant decreases in chlorophyll a, but increased the amount of superoxide anion radicals (O2(• -)) and the electric conductivity in Microcystis aeruginosa...
November 10, 2017: Environmental Technology
Thomas Krieg, Florian Mayer, Dieter Sell, Dirk Holtmann
Microbial fuel cells (MFCs) are often discussed as a part of a sustainable generation of electricity for the coming "energy revolution". In particular the applications of MFCs in wastewater treatment are often regarded as an attractive alternative method to reduce the costs of wastewater treatment and generate electricity. At the moment there is a lack of application of MFCs in real wastewater treatment plants (WWTPs). However, investigations in real plants are absolutely necessary to show the applicability of MFCs in WWTPs considering typical daily fluctuations and environmental effects like rain events affecting MFC performance remarkably...
November 5, 2017: Environmental Technology
Xin Tian, Warsama Ahmed, Robert Delatolla
Ammonia removal kinetics and solids production performance of the bio-cord technology are studied in this research. Three nitrifying reactors housing different bio-cord substratum were operated at five different ammonia loading rates. All of the bio-cord substrata demonstrated stable and high ammonia nitrogen removal efficiencies of 96.8 ± 0.9, 97.0 ± 0.6and 92.0 ± 0.4% at loading rates of 0.8, 1.6 and 1.8 g NH4(+)-N/m(2)·d, respectively. At these same loading rates, the bio-cord reactors housing the three substrata also showed low solids production rates of 0...
November 3, 2017: Environmental Technology
João P Vareda, Luisa Durães
Recently developed tailored adsorbents for heavy metal uptake are studied in batch tests with Cu, Pb, Cd, Ni, Cr and Zn, in order to decontaminate polluted environments where these heavy metals are found in solution - water courses and groundwater. The adsorbents feature mercapto or amine-mercapto groups that are capable of complexating the cations. Through the use of equilibrium tests it is found that a remarkably high heavy metal uptake is obtained for all metals (ranging from 84 mg/g to 140 mg/g). These uptake values are quite impressive when compared to other adsorbents reported in the literature, which is also due to the double functionalization present in one of the adsorbents...
November 3, 2017: Environmental Technology
Tandjaoui Nassima, Abouseoud Mahmoud, Couvert Annabelle, Amrane Abdeltif, Tassist Amina
Peroxidase from Brassica rapa (BRP) was immobilized as cross-linked enzyme aggregates (CLEAs) and used to treat air containing phenol as a model molecule of volatile organic compounds (VOCs). Prior to enzymatic treatment, phenol was absorbed into aqueous or organic phase (silicone oil, Rhodorsil® 47V20) to reach concentrations ranging from 20 to 160mg/L. The process of enzymatic degradation was carried out by introducing a desired weighing of BRP-CLEAs into preparations and reaction was started by injecting H2O2 solution to medium...
November 3, 2017: Environmental Technology
Fatima Zahra Mennaa, Zouhayr Arbib, José Antonio Perales
The aim of this study was to investigate the growth, nutrient removal and harvesting of a natural microalgae bloom cultivated in urban wastewater in a bubble column photobioreactor. Batch and continuous mode experiments were carried out with and without pH control by means of CO2 dosage. Four coagulants (aluminium sulphate, ferric sulphate, ferric chloride and polyaluminium chloride (PAC)) and five flocculants (Chemifloc CM/25, FO 4498SH, cationic polymers Zetag (Z8165, Z7550 and Z8160)) were tested to determine the optimal dosage to reach 90% of biomass recovery...
November 3, 2017: Environmental Technology
Yayuan He, Wen Xiao, Guiyin Li, Fei Yang, Pian Wu, Tao Yang, Cuimei Chen, Ping Ding
A novel biological material with high adsorption capacity and good selectivity for Pb(2+) was synthesized. Response surface methodology (RSM) was utilized for the optimization of the variables during the systhesis. The synthesized biosorbent was characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The optimized preparation condition for lead ion imprinted magnetic biosorbent (Pb(Ⅱ)-IMB) was obtained (0.19 g chitosan (CTS), 0.43 g magnetic Fe3O4 and 2...
November 3, 2017: Environmental Technology
Agnieszka Tabernacka, Ewa Zborowska, Katarzyna Pogoda, Marcin Żołądek
One-step technological system containing activated sludge fed with synthetic domestic wastewater was applied to treat waste air polluted with tetrachloroethene. In the first stage of the experiment, air passed through bioscrubber, in the second and third stage - through the bioreactor containing activated sludge and bacteria immobilised in oak chips. These bacteria are active in tetrachloroethene biodegradation. Process efficiency in the final stage of experiment was high, the elimination capacity was 0.23 g•m(-3)•h(-1) with the tetrachloroethene mass loading rate of 0...
November 3, 2017: Environmental Technology
Zheqin Dai, Xiwu Lu, Zhaoqian Jing
The Alternate multiple tanks (AMT) system was originated by Southeast University to meet pressing requirements of new highly-compact sewage treatment with cost-effective balance and automated management. DO and ORP as economic monitoring indicators are closely linked to nutrients variations and controlling strategy. Thus this paper was to investigate the N and P periodic variations and removal mechanisms under different aeration strengths in scope of principal-type tank in AMT, and the relationship between nutrients and DO, ORP...
November 3, 2017: Environmental Technology
Carlo Solisio, Saleh Al Arni, Attilio Converti
This study focused on kinetics and equilibrium isotherms of mercury biosorption from water using dry biomass of Chlorella vulgaris as biosorbent at pH 5.0. Biosorption tests were performed at 2.0 g/L biomass dosage varying initial Hg concentration from 11.0 to 90.6 mg/L. The Lagergren equation was found to best describe the process, with R(2) of 0.984 and specific rate constant of 0.029±0.004 min(-1). Although equilibrium data were well fitted by the Dubinin and Radushkevich isotherm (R(2) = 0.870; qDR = 16...
November 3, 2017: Environmental Technology
J G Rangel-Peraza, K Mendivil-García, C I G Cedillo-Herrera, J J Rochín-Medina, A E Rodríguez-Mata, Y A Bustos-Terrones
This study describes the optimization of wastewater treatment process through the use of a free water surface flow constructed wetland with floating macrophytes at laboratory level (20 L). A factorial design 2(3) was used in order to find the best operation conditions of the wastewater treatment process. The performance of macrophytes Eichhornia crassipes and Typha domingensis were investigated by operating the wetland system at hydraulic retention times of 2 and 4 days. The results showed an optimum operational condition that removed 92...
November 3, 2017: Environmental Technology
Liyu Chen, Robert Delatolla, Patrick M D'Aoust, Ru Wang, Frances Pick, Alexandre Poulain, Colin D Rennie
Improper design and maintenance of stormwater ponds (SWPs) may lead to hypoxic conditions, poor water quality and the production of hydrogen sulfide (H2S). The objective of this study is to develop a comprehensive understanding of hypoxic conditions of SWPs, with a focus on the potential for H2S production and emission. This study was conducted at two retention SWPs in Ottawa, Canada; a problematic pond with the propensity for H2S emission and a reference pond that did not demonstrate H2S emission. The investigation illustrated a significant impact of low dissolved oxygen (DO) concentrations, hypoxic conditions, on the concentration of total sulphides in the water column...
November 1, 2017: Environmental Technology
Fernando César Andreoli, Lyda Patricia Sabogal-Paz
Removing protozoa from a water supply using coagulation, flocculation, dissolved air flotation and filtration on a bench scale was evaluated. Flocculation in calcium carbonate with and without immunomagnetic separation was chosen to detect Giardia spp. cysts and Cryptosporidium spp. oocysts in the studied samples. Analytical quality of assays of the detection protocol of target organisms was performed and the results were compared to the criteria established in Method 1623.1 from the US Environmental Protection Agency...
November 1, 2017: Environmental Technology
Raissa Antonelli, Karla Santos de Araújo, Ricardo Francisco Pires, Ana Luiza de Toledo Fornazari, Ana Claudia Granato, Geoffroy Roger Pointer Malpass
The present paper presents the study of (1) the optimization of electrochemical-free chlorine production using an experimental design approach, and (2) the application of the optimum conditions obtained for the application in photo-assisted electrochemical degradation of simulated textile effluent. In the experimental design the influence of inter-electrode gap, pH, NaCl concentration and current was considered. It was observed that the four variables studied are significant for the process, with NaCl concentration and current being the most significant variables for free chlorine production...
October 28, 2017: Environmental Technology
Ozgul Calicioglu, Goksel N Demirer
This study comparatively evaluated the effect of co-substrates on anaerobic digestion (AD) and biochemical methane potential of wastewater-derived microalgal biomass, with an emphasis on carbon-to-nitrogen (C:N) and substrate-to-inoculum (S:I) ratios. A semi-continuous photobioreactor was inoculated with Chlorella vulgaris and the nutrient recovery potential was investigated. Then, the derived microalgal slurry was subjected to AD in the absence and presence of co-substrates, namely, model kitchen waste (MKW) and waste activated sludge (WAS)...
October 27, 2017: Environmental Technology
Yang He, Jie Chi
Abstracts The results of phytoremediation of sediments contaminated with polycyclic aromatic hydrocarbons (PAHs) by two submerged aquatic plants (Vallisneria spiralis and Hydrilla verticillata) at pilot-scale were reported for the first time in this study. During a 108-day period, the plants grew well, and more PAHs were dissipated in planted sediments than in unplanted sediments. At the end, dissipation ratios of phenanthrene and pyrene were 85.9% and 79.1% in sediments planted with V. spiralis, 76.3% and 64...
October 27, 2017: Environmental Technology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"