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Effect of Season, Substrate Composition, and Plant Growth on Landfill Leachate Treatment in a Constructed Wetland
Published in Gerald A. Moshiri, Constructed Wetlands for Water Quality Improvement, 2020
J. M. Surface, J. H. Peverly, T. S. Steenhuis, W. E. Sanford
All bi-weekly leachate samples were analyzed for nutrients, metals, and organic carbon by Cornell University’s Soil, Crops, and Atmospheric Sciences Nutrients Analysis Laboratory. NO3−, NH4+, and total soluble phosphate were analyzed colorimetrically according to USEPA guidelines.7 The Fe(III)/Fe(II) ratio was measured through a modification of Stucki’s technique,8 which allows determination of total Fe and Fe(II) in solution as an Fe-ortho-phenanthroline complex with photoreduction of Fe(III) to Fe(II). Organic carbon was measured with a carbon analyzer, where carbon compounds in the water are oxidized to CO2 and then reduced to methane for detection.5 BOD was determined by standard methods.5 All other elements in water were determined by inductively coupled plasma (ICP) spectrophotometry.5
Fuels From Recycled Carbon
Published in Veera Gnaneswar Gude, Green chemistry for Sustainable Biofuel Production, 2018
Michele Aresta, Angela Dibenedetto
As said, the anaerobic digestion converts organic carbon into “biogas,” i.e., a mixture of methane and CO2, from which the energy rich methane can be separated. The process takes place in a closed and controlled bioreactor and its cost is determined by capital investment (CAPEX) and operative costs (OPEX). In general, bioreactors are quite simple with not high CAPEX and OPEX, and can have various geometries (vertical, inclined, horizontal). The overall conversion efficiency is quite variable (30-55%) and depends on the amount of low biodegradable solid fraction (see below) present in the raw biomass (cellulose, lignin, hemicel- lulose are not easily biodegraded). The process has long retention times (20-30 days) [74]. Biogas technology is being continuously improved by optimizing the process parameters and reactor geometry [75] and with process integration. The methane separation technology is mature and continuously improved for its efficiency [76]. The produced gas can be locally used for thermal or electric energy production or else emitted into methanoducts.
Anaerobic processes
Published in Nick F. Gray, Water Science and Technology: An Introduction, 2017
Anaerobic processes are used to treat strong organic wastewaters (biological oxygen demand >500 BOD mg L−1), and for further treatment of primary and secondary sludges from conventional wastewater treatment. Liquid wastewaters rich in biodegradable organic matter are generated primarily by the agricultural and food-processing industries. Such wastewaters are difficult to treat aerobically mainly due to the problems and costs of satisfying the high oxygen demand and maintaining aerobic conditions. The majority of the organic carbon removed from solution during conventional wastewater treatment is converted into waste sludge (Section 10.2). This can be further stabilized either aerobically or, more conventionally, using anaerobic digestion. Anaerobic treatment, although slow, offers a number of attractive advantages in the treatment of strong organic wastes. These include a high degree of purification, ability to treat high organic loads, production of a small quantity of excess sludge that is normally very stable and the production of an inert combustible gas (methane) as an end product (Sterritt and Lester, 1988). Unlike aerobic systems, complete stabilization of organic matter is not possible anaerobically, and so subsequent aerobic treatment of anaerobic effluents is normally necessary. The final effluent produced by anaerobic treatment contains solubilized organic matter, which is amenable to aerobic treatment indicating the potential of using combined anaerobic and aerobic units in series. The advantages and disadvantages of anaerobic treatment are outlined in Table 14.1.
Combined process of chemically enhanced sedimentation and rapid filtration for urban wastewater treatment for potable reuse
Published in Environmental Technology, 2022
Cleber Pinto da Silva, Sandro Xavier de Campos
Due to the higher organic load of the effluents treated in UASB reactors, the concentrations of disinfection by-products (i.e. trichloromethane, dichloromethane, bromodichloromethane, among others) by chlorination are generally high. In general, the formation of disinfection by-products was correlated with the increase in the values of total organic carbon (TOC). In addition, recent studies indicate that the same trend was found in relation to BOD and COD values [29]. In this sense, the high removal of DOC, COD and BOD using RF in this study, may have contributed significantly to the non-formation of disinfection by-products in the chlorine disinfection process. This was because the grinding and sand filters helped to reduce the load of dissolved organic matter and the final filter to increase its efficiency.
Model-based analysis of sulfur-based denitrification in a moving bed biofilm reactor
Published in Environmental Technology, 2022
S. O. Decru, J. E. Baeten, Y.-X. Cui, D. Wu, G.-H. Chen, E. I. P. Volcke
Anaerobic wastewater treatment is a well-proven technology, during which organic carbon is converted in the form of biogas, a renewable energy source. Direct anaerobic treatment of municipal wastewater is widely applied in warmer climates, in countries such as Brazil and India [1] but also holds potential for colder climates [2]. The absence of aeration and the lower sludge production reduce the operating costs by 50% compared to conventional aerobic carbon removal [1]. However, anaerobic treatment does not remove nitrogen, which remains in the anaerobic effluent primarily as noxious ammonium (). The growing interest in anaerobic treatment technologies for energy recovery during municipal wastewater treatment thus require a parallel focus on the development of efficient downstream technologies to remove nitrogen, as well as residual carbon [3].
Hydrodeoxygenation of bio-oil and model compounds for production of chemical materials at atmospheric pressure over nickel-based zeolite catalysts
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Zhiyu Li, Weiming Yi, Zhihe Li, Xueyuan Bai, Peng Fu, Chunyan Tian, Yuchun Zhang
The depletion of fossil reserves day by day, increased energy demand and global warming have prompted people to find a new energy which is very clean and has green technology due to stringent emission protocols. (Manigandan et al. 2019; Manigandan et al. 2020a). Among the various new energy sources, biomass is the only renewable organic carbon resource with unique advantages in producing various value-added chemicals and fuels (Shi et al. 2017; Li et al. 2015a). Fast pyrolysis bio-oil is considered the most promising alternative energy source (Niu et al. 2019). Bio-oil contains a series of chemicals, such as phenols, acids, sugars, aldehydes and alcohols. These bio-based fuels and chemicals (such as biodiesel, hydrogen, etc.) are alternatives for petroleum-based fuels and chemicals (Lee et al. 2016; Manigandan et al. 2020a). However, the high oxygen content of 35–50 wt% lead to deteriorated properties, such as corrosiveness, poor heating values, high viscosities, low thermal and chemical stabilities, and immiscibility with conventional fossil fuels (Li et al. 2019; Lu et al. 2017).