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Environmental Technology

Giovanni Cagnetta, Jun Huang, Igor Lomovskiy, Gang Yu
Zero valent iron is a valuable material for environmental remediation, because of its safeness, large availability, and inexpensiveness. Moreover, its reactivity can be improved by addition of (nano-) particles of other elements such as noble metals, which enhance electron transfer rate from iron to pollutants. However, common preparation methods for this kind of iron-based composites involve wet precipitation of noble metal salt precursors, so they are often expensive and not green, due to the employment of large volumes of solvent...
January 13, 2017: Environmental Technology
Han Yu, Min Zhao, Linus Zhang, Heng Dong, Hongbing Yu, Ze Chen
The novel double working-electrode electrochemical system with air diffusion cathode (ADC) and Ti/SnO2-Sb anode (TSSA) have shown higher efficiency and lower energy consumption for the degradation of organic pollutant from high salinity wastewater, compared to the traditional single anode system. To further investigate and improve this system, in this work, firstly the effect of vital factors of the double working-electrode electrochemical system including initial methyl orange (MO) concentration, NaCl concentration and initial pH value of organic solution were investigated, using MO as the targeted organic pollutant, carbon black ADC (CBAC) as cathode and stainless steel mesh electrode (SSME) as control...
January 13, 2017: Environmental Technology
José J Barrios Restrepo, Letícia Flohr, Silvia P Melegari, Cristina H da Costa, Cristiane F Fuzinatto, Armando B de Castilhos, William G Matias
Due to the diversified nature of municipal solid waste (MSW) and the different stages of its decomposition, the formed leachates result in a complex chemical mixture with toxic potential. These chemicals can cause environmental problems, such as the contamination of surface or groundwater, thus affecting the balance of aquatic ecosystems. The aim of our study was to evaluate the acute toxicity of leachates in Daphnia magna and Aliivibrio fischeri and to identify the main physicochemical variables that influence the toxicity of the landfill leachates produced in reactors within pilot simulations...
January 11, 2017: Environmental Technology
Patricia Pérez-Palacios, Elizabeth Agostini, Sabrina G Ibáñez, Melina A Talano, Ignacio D Rodríguez-Llorente, Miguel A Caviedes, Eloísa Pajuelo
The aim of this work was developing a biotechnological tool to hyperaccumulate high copper (Cu) concentrations from wastewaters. Transgenic tobacco hairy roots were obtained by expressing, either the wild type version of the gene copC from Pseudomonas fluorescens in the cytoplasm of plant cells (CuHR), or a modified version targeted to the vacuole (CuHR-V). Control hairy roots transformed with the empty vector (HR) were also generated. The roots were incubated in the presence of solutions containing Cu (from 1 to 50 mM)...
January 11, 2017: Environmental Technology
Nitin Kumar Singh, Akansha Bhatia, Absar Ahmad Kazmi
This study investigated the effect of various intermittent aeration (IA) cycles, characterized by the ratio of non-aeration to aeration time, on organics and nutrient removal, and microbial communities in an integrated fixed film activated sludge (IFAS) reactor treating municipal wastewater. Average effluent BOD, COD, TSS, TN and TP values were noted as 20, 50, 30, 12 and 1.5 mgL(-1), respectively in continuous aeration mode. A total of four operational conditions (run 1, continuous aeration; run 2, 150/30 min aeration on/off time; run 3, 120/60 min aeration on/off time; run 4, 90/60 min aeration on/off time) were investigated in IFAS reactor assessment...
January 11, 2017: Environmental Technology
Yeshui Zhang, Mohamad A Nahil, Chunfei Wu, Paul T Williams
A stainless steel mesh loaded with nickel catalyst was produced and used for the pyrolysis-catalysis of waste high density polyethylene with the aim of producing high value carbon products, including carbon nanotubes. The catalysis temperature and plastic to catalyst ratio were investigated to determine the influence on the formation of different types of carbon deposited on the nickel-stainless steel mesh catalyst. Increasing temperature from 700 to 900 °C resulted in an increase in the carbon deposited on the nickel loaded stainless steel mesh catalyst from 32...
January 11, 2017: Environmental Technology
Imanol Zabaleta, Paola Marchetti, Christian Riuji Lohri, Christian Zurbrügg
Hydrothermal Carbonization (HTC) is a thermochemical process that converts wet organic matter into a sterile, high-calorific solid material called hydrochar. This technology is considered an interesting option for low- and middle-income urban settings, often lacking adequate services and high fraction of wet organic waste. The aim of this study was to study the influence of the loading rate (total solid content) and the maximum temperature reached on the resulting energy ratio (ER) of the process and the fuel properties of the obtained hydrochar...
January 9, 2017: Environmental Technology
Filomena Costa, Teresa Tavares
The toxic effects of diethylketone in aqueous solution with different concentrations of Al(3+), Cd(2+), Ni(2+) and Mn(2+) were evaluated at lab scale. It was established that Streptococcus equisimilis is able to efficiently remove diethylketone with different concentrations with heavy metals. Pilot-scale experiments, aiming to treat large volumes of aqueous solutions containing high concentrations of diethylketone and Al(3+), Cd(2+), Ni(2+) and Mn(2+)) through the use of a Streptococcus equisimilis biofilm supported on vermiculite were conducted...
January 5, 2017: Environmental Technology
D S Perwitasari, L Edahwati, S Sutiyono, S Muryanto, J Jamari, A P Bayuseno
Precipitation strategy of struvite-family crystals is presented in this paper to recover phosphate and potassium from a synthetic wastewater in the presence of citric acid at the elevated temperature. The crystal-forming solutions were prepared from crystals of for MgCl2 and NH4H2PO4 with a molar ratio of 1:1:1 for Mg(+2) , NH4(+) and PO4(-3), and the citric acid (C6H8O7) was prepared (in the amounts of 1.00 and 20.00 ppm) from citric acid crystals. was added. The Rietveld analysis of XRPD pattern confirmed a mixed product of struvite, struvite-(K) and newberyite crystallized at 30 (O)C in the absence of citric acid...
January 4, 2017: Environmental Technology
Zheng Wang, Xiang Fei, Shengbing He, Jungchen Huang, Weili Zhou
This study was carried out to investigate the possibility of a thiosulfate-driven autotrophic denitrification for nitrate-N removal from micro-polluted surface water. The aim was to study the effects of S2O3(2-)/NO3(-) ratio (S/N molar ratio) and hydraulic retention time (HRT) on the autotrophic denitrification performance. Besides, utilization efficiencies of S2O3(2-)-S along the biofilter and the restart-up of the bioreactor were also investigated. Autotrophic denitrification using thiosulfate as an electron donor for treating micro-polluted surface water without the addition of external alkalinity proved to be feasible and the biofilter could be readied in two weeks...
January 4, 2017: Environmental Technology
Quanzhou Chen, Kanggen Zhou, Yan Chen, Aihe Wang, Fang Liu
In this paper, A poly ligand exchanger (PLE), Cu(II)-loaded chelating resin bearing the functional group of weak iminodiacetate acid was prepared to efficiently remove ammonia from solutions. Batch adsorption equilibrium experiments were conducted under a range of conditions to determine the optimum adsorption conditions. The effects of contact time, pH, resin dosage and temperature on the removal of ammonia by Cu(II)-loaded resin were determined. The maximum removal efficiency was reached at pH 9.5 at room temperature 25°C in 300min...
January 4, 2017: Environmental Technology
S Sguanci, T Lotti, C Caretti, S Caffaz, T Dockhorn, C Lubello
The suitability of the anammox process for the treatment of swine digester liquor was assessed through the evaluation of the short- and long-term inhibitory effect of three veterinary antibiotics commonly administered to Italian swine livestock. The toxicity of doxycycline, tiamulin and enrofloxacin was evaluated through batch tests designed to estimate specific anammox activity. Moreover, the short-term toxicity of combined concentrations of doxycycline and enrofloxacin was evaluated so as to verify whether a synergistic effect could be established...
January 4, 2017: Environmental Technology
A K Upadhyay, N K Singh, N S Bankoti, U N Rai
A simulated horizontal flow constructed wetland (CW) has been designed with gravel medium and aquatic plants Typha latifolia and Polygonum hydropiper to assess its performance efficiency for sewage treatment. Monitoring of fully developed CW revealed a high removal of nutrients and metals from sewage after treatment at varying retention times. The percent (%) removal of biological oxygen demand, total dissolved solids, total suspended solids, PO4-P and total nitrogen in CW planted with T. latifolia were 88...
January 4, 2017: Environmental Technology
Hee-Kyung An, Chang-Gu Lee, Seong-Jik Park
In this study, we fabricated a nanofibrous composite (NFC) membrane as a substrate to produce forward osmosis (FO) membranes, and we also assessed the use of liquid fertilizer as a draw solution for the FO process in order to produce agricultural irrigation water. Commercial cellulose triacetate (CTA) and thin-film composite (TFC) FO membranes were included in this study. Under FO tests, the NFC, CTA, and TFC membranes achieved initial osmotic water flux values of 35.31, 6.85, and 3.31 L/m(2)·h and final osmotic water flux values of 12...
January 4, 2017: Environmental Technology
Ru Zhang, Li Wang, Zhuo Kang, Qiang Li, Huixian Pan
Modified sol-gel method was adopted to prepare TiO2, Zr-TiO2 and N/Zr-TiO2 composite catalyst. The as-synthesized photocatalysts were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Brunner- Emmet- Teller measurement and UV-Vis diffuse reflectance spectroscopy. And the photocatalytic performance toward CO2 reduction was evaluated under ultraviolet light. The catalyst particles were demonstrated in the nanometer level size. When N and Zr are co-doped, on the one hand, Ti(4+) can be replaced by Zr4 +, which leads to lattice distortion and inhibits electron-hole recombination...
January 4, 2017: Environmental Technology
Jeffrey Cobbledick, Victor Zhang, Sasha Rollings-Scattergood, David R Latulippe
There is considerable interest in recuperative thickening (RT), the recycling of partially digested solids in an anaerobic digester outlet stream back into the incoming feed, as a 'high-performance' process to increase biogas production, increase system capacity, and improve biosolids stabilization. While polymer flocculation is commonly used in full-scale RT operations, no studies have investigated the effect of flocculation conditions on RT process performance. Our goal was to investigate the effect of polymer type and dosage conditions on dewatering performance and biogas production in a lab-scale RT system...
January 4, 2017: Environmental Technology
Bruna Coelho Lopes, Ananda Lima Sanson, Sérgio Francisco de Aquino, Cláudio Leite de Souza, Carlos Augusto de Lemos Chernicharo, Robson José de Cássia Franco Afonso
This work has assessed the seasonal changes and the dynamics in the concentration of six pharmaceutical compounds during photolysis as a tertiary treatment of sewage previously treated by an anaerobic/aerobic system comprised by a UASB (Upflow Anaerobic Sludge Blanket) reactor and a trickling filter (TF). The target compounds were 4 antibiotics (ciprofloxacin, clindamycin, sulfamethoxazole, trimetoprime), 1 beta blocker (atenolol) and 1 anti-inflammatory (diclofenac). Six hydraulic retention times (HRT) were evaluated (5, 10, 20, 40, 80 and 160 minutes) with the intent of varying the UVC radiation doses applied to the effluent from biological treatment containing the target contaminants...
January 3, 2017: Environmental Technology
Akanksha Mehrotra, T R Sreekrishnan
Simultaneous sludge digestion and metal leaching (SSDML) have been reported at mesophilic temperature. It is generally perceived that while sludge stabilization is effected by heterotrophs at neutral pH, metal bioleaching is done by acidophilic autotrophs. However, little information is available on the microbial communities involved in the process. This study carried out SSDML in a single stage reactor using sludge indigenous microorganisms and looked at the bacterial communities responsible for the process...
January 3, 2017: Environmental Technology
Huseyin Koca, Derya Oz Aksoy, Reyhan Ucar, Sabiha Koca
In this study, solid wastes taken from Seyitomer coal-fired power plant bottom ashes were subjected to experimental research to obtain a carbon-rich fraction. The possible recycling opportunities of remaining inorganic fraction in the cement and concrete industry was also investigated. Flotation technique was used to separate unburned carbon from inorganic bottom ashes. Collector type, collector, dispersant and frother amounts, and pulp density are the most important variables in the flotation technique. A number of flotation collectors were tested in the experiments including new era flotation reactives...
January 3, 2017: Environmental Technology
Ling Zhang, Yong Wang, SuWan Jin, QunZan Lu, Jiang Ji
The adsorption of sulfadiazine from water by expanded graphite (EG), a low cost and environmental-friendly adsorbent, was investigated. Several adsorption parameters (including the initial sulfadiazine concentration, contact time, pH of solution, ionic strength and temperature) were studied. Results of equilibrium experiments indicated that adsorption of sulfadiazine onto EG were better described by the Langmuir and Tempkin models than by the Freundlich model. The maximum adsorption capacity is calculated to be 16...
January 3, 2017: Environmental Technology
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