Author
Marcelo Zaiat
Bio: Marcelo Zaiat is an academic researcher from University of São Paulo. The author has contributed to research in topics: Chemical oxygen demand & Anaerobic digestion. The author has an hindex of 45, co-authored 319 publications receiving 7562 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, the authors present the actual context of anaerobic digestion within the sugarcane ethanol production in Brazil, presenting the main obstacles for its full application and the directions to promote it as well.
Abstract: The replacement of fossil fuels by biofuels has been extremely important worldwide to stimulate the growth of economies based on the sustainability through the use of renewable resources. Anaerobic digestion for biogas production is recognized as a clean technology that allies the suitability of wastes with energy generation, fulfilling the requirements for a sustainable alternative to provide the optimization of the biofuels production. This alternative is especially interesting for the sugarcane ethanol production in Brazil, in which the generation of vinasse, the main liquid waste, is very expressive. Nevertheless, the use of vinasse for anaerobic digestion has been finding some challenges to its establishment in the Brazilian sugarcane biorefineries. This paper reviews the actual context of anaerobic digestion within the sugarcane ethanol production in Brazil, presenting the main obstacles for its full application and the directions to promote it as well. Alternatives for biogas use are also presented and compared, highlighting the environmental and energy advantages of applying anaerobic digestion in the sugarcane biorefineries. This scenario is envisaged as a suitable way to achieve the future biorefineries model, based on the use and recovery of renewable resources with economic, social, and environmental benefits.
320 citations
TL;DR: In this article, the authors evaluated vinasse anaerobic digestion in a sugarcane biorefinery in terms of energy, environmental, and economic considerations, and found that the energy potential of a single biorefa-finery is comparable to the electricity supply demand of a city of approximately 130,000 inhabitants or to the surplus energy from bagasse burning that is exported by some sugar cane mills in Brazil.
240 citations
TL;DR: In this article, a broader view on the possible applications of anaerobic treatment systems not only for organic matter removal but also for resources recovery aiming at the improvement of the sustainability of domestic sewage treatment (DST).
Abstract: Anaerobic digesters have been responsible for the removal of large fraction of organic matter (mineralization of waste sludge) in conventional aerobic sewage treatment plants since the early years of domestic sewage treatment (DST). Attention on the anaerobic technology for improving the sustainability of sewage treatment has been paid mainly after the energy crisis in the 1970s. The successful use of anaerobic reactors (especially up-flow anaerobic sludge blanket (UASB) reactors) for the treatment of raw domestic sewage in tropical and sub-tropical regions (where ambient temperatures are not restrictive for anaerobic digestion) opened the opportunity to substitute the aerobic processes for the anaerobic technology in removal of the influent organic matter. Despite the success, effluents from anaerobic reactors treating domestic sewage require post-treatment in order to achieve the emission standards prevailing in most countries. Initially, the composition of this effluent rich in reduced compounds has required the adoption of post-treatment (mainly aerobic) systems able to remove the undesirable constituents. Currently, however, a wealth of information obtained on biological and physical-chemical processes related to the recovery or removal of nitrogen, phosphorus and sulfur compounds creates the opportunity for new treatment systems. The design of DST plant with the anaerobic reactor as core unit coupled to the pre- and post-treatment systems in order to promote the recovery of resources and the polishing of effluent quality can improve the sustainability of treatment systems. This paper presents a broader view on the possible applications of anaerobic treatment systems not only for organic matter removal but also for resources recovery aiming at the improvement of the sustainability of DST.
195 citations
TL;DR: In this article, the influence of different seed sludge sources and pretreatment methods on bio-hydrogen production in up-flow anaerobic fixed-bed reactors fed with sucrose was investigated.
178 citations
TL;DR: In this article, an upflow anaerobic packed bed reactor configuration to produce hydrogen using cheese whey as the substrate was tested, and the microbiological composition was linked to the reactor operation.
164 citations
Cited by
More filters
TL;DR: In this paper, the authors provide a state-of-the-art review on the development in heterogeneous catalysts including single metal, mixed metal, and nonmetal carbon catalysts for organic contaminants removal, with particular focus on peroxymonosulfate (PMS) activation.
Abstract: Sulfate radical-based advanced oxidation processes (SR-AOPs) employing heterogeneous catalysts to generate sulfate radical (SO4 −) from peroxymonosulfate (PMS) and persulfate (PS) have been extensively employed for organic contaminant removal in water. This article aims to provide a state–of–the–art review on the recent development in heterogeneous catalysts including single metal, mixed metal, and nonmetal carbon catalysts for organic contaminants removal, with particular focus on PMS activation. The hybrid heterogeneous catalyst/PMS systems integrated with other advanced oxidation technologies is also discussed. Several strategies for the identification of principal reactive radicals in SO4 −–oxidation systems are evaluated, namely (i) use of chemical probe or spin trapping agent coupled with analytical tools, and (ii) competitive kinetic approach using selective radical scavengers. The main challenges and mitigation strategies pertinent to the SR-AOPs are identified, which include (i) possible formation of oxyanions and disinfection byproducts, and (ii) dealing with sulfate produced and residual PMS. Potential future applications and research direction of SR-AOPs are proposed. These include (i) novel reactor design for heterogeneous catalytic system based on batch or continuous flow (e.g. completely mixed or plug flow) reactor configuration with catalyst recovery, and (ii) catalytic ceramic membrane incorporating SR-AOPs.
1,802 citations
TL;DR: Newer membrane processes coupled with complete anaerobic treatment of wastewater offer the potential for wastewater treatment to become a net generator of energy, rather than the large energy consumer that it is today.
Abstract: In seeking greater sustainability in water resources management, wastewater is now being considered more as a resource than as a waste-a resource for water, for plant nutrients, and for energy. Energy, the primary focus of this article, can be obtained from wastewater's organic as well as from its thermal content. Also, using wastewater's nitrogen and P nutrients for plant fertilization, rather than wasting them, helps offset the high energy cost of producing synthetic fertilizers. Microbial fuel cells offer potential for direct biological conversion of wastewater's organic materials into electricity, although significant improvements are needed for this process to be competitive with anaerobic biological conversion of wastewater organics into biogas, a renewable fuel used in electricity generation. Newer membrane processes coupled with complete anaerobic treatment of wastewater offer the potential for wastewater treatment to become a net generator of energy, rather than the large energy consumer that it is today.
1,457 citations
TL;DR: Current optimisation techniques associated with anaerobic digestion are reviewed and possible areas where improvements could be made are suggested, including the basic design considerations of a single or multi-stage reactor configuration, the type, power and duration of the mixing regime and the retention of active microbial biomass within the reactor.
1,383 citations
TL;DR: Results suggest some changes to the pilot plant configuration are necessary to reduce power consumption although maximizing biodigester performance, and a modification of the typical continuous stirred tank reactor is a promising process being relatively stable and owing to its capability to manage considerable amounts of residuals at low operational cost.
Abstract: Intensive poultry production generates over 100,000 t of litter annually in West Virginia and 9×106 t nationwide. Current available technological alternatives based on thermophilic anaerobic digestion for residuals treatment are diverse. A modification of the typical continuous stirred tank reactor is a promising process being relatively stable and owing to its capability to manage considerable amounts of residuals at low operational cost. A 40-m3 pilot plant digester was used for performance evaluation considering energy input and methane production. Results suggest some changes to the pilot plant configuration are necessary to reduce power consumption although maximizing biodigester performance.
1,287 citations
TL;DR: In this article, the authors presented the hydrogen-based energy system as four corners (stages) of a square shaped integrated whole to demonstrate the interconnection and interdependency of these main stages.
1,090 citations