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Membrane filtration processes have been used to treat landfill leachate. On the other hand, closing the leachate treatment loop and finding a final destination for landfill leachate membrane concentrate (LLMC) – residual stream of membrane systems – is challenging for landfill operators. The re-introduction of LLMC into the landfill is typical; however, this approach is critical as concentrate pollutants may accumulate in the leachate treatment facility. From that, leachate concentrate management based on resource recovery rather than conventional treatment and disposal is recommended. This work comprehensively reviews the state-of-the-art of current research on LLMC management from leachate treatment plants towards a resource recovery approach. A general recovery train based on the main LLMC characteristics for implementing the best recovery scheme is presented in this context. LLMCs could be handled by producing clean water and add-value materials. This paper offers critical insights into LLMC management and highlights future research trends.

This work explores the techno-economic aspects of landfill leachate treatment by an integrated scheme composed of microfiltration (MF), nanofiltration (NF), and zeolite application for carbon and nitrogen removal. In bench-scale experiments, MF and NF were investigated, and zeolite batch tests were carried out to determine optimum conditions. A preliminary economic analysis is presented for a 200 m

A mudança global do clima é um dos principais desafios da atualidade. A partir de questionários quantitativos de pesquisa, o presente estudo analisa a percepção pública sobre as mudanças climáticas no Brasil. O artigo aborda os vários fatores de influência sobre a preocupação do público frente ao tema, a predisposição dos cidadãos em agir e os fatores limitantes da ação. Além disso, ele explora a predisposição individual de efetuar micro pagamentos regulares direcionados às ações de mitigação das mudanças do clima associados ao consumo de bens e serviços. No total, foram contabilizados 779 respondentes. A categoria gênero foi associada de forma significativa ao nível de preocupação climática, sendo maior entre as mulheres (62,8%) do que entre os homens (53,6%) (p-valor < 0,05). Mais de 60% dos respondentes apontaram a falta de informação e condições financeiras como fatores limitantes de ações visando à reversão das mudanças climáticas. Em contrapartida, 87% e 67% dos indivíduos indicaram o plantio de árvores e o boicote a empresas poluidoras como ações passíveis de adoção, respectivamente. No geral, 58% dos respondentes pagariam até R$ 1 regularmente (a cada compra) para contribuir com a resolução do problema, enquanto que 43% pagariam valor superior a R$1. Em conclusão, os resultados apresentados neste estudo fornecem informações para o planejamento de políticas públicas e estratégias alinhadas à agenda global de mitigação das mudanças climáticas.

Anaerobic digestion is a widely used and well-established technology for sewage treatment. Derived from this practice, the great advantage of enabling the biogas production, clean and sustainable energy, through sludge hydrolysis. However, one of the main limitations of this technology is the resistance to degradation of microbial cells present in this sludge. These cells often contain complex carbohydrates resistant to biodegradation, making the hydrolysis step slower compared to the other steps. In this sense, a series of technologies and methods are available for the pre-treatment of sludge, aiming to overcome these difficulties. Technical aspects and qualitative comparison of these techniques, discussed in this work, show that, in order to select the best pre-treatment technology, important variables such as availability of operational labor and sludge constitution should be taken into account. Some disadvantages associated with these technologies were also identified, such as high energy consumption and excessive degradation with biodegradable substrate loss. Thus, the authors conclude that the mixture of processes and the use of alternative energy sources are potential ways to make pretreatment techniques viable. However, the use of alternative energy for this purpose is still in initial stages, and it is necessary to go deeper into the subject in order to consolidate it in the near future.

Ecotoxicological assessment of landfill leachate has become a priority to determine its impacts on the ecosystem. Toxicity assays with microorganisms stand out due to their quick response, low cost and ease of testing. In this context, the present study evaluated the acute toxic effects of leachates from two landfills of different ages and modes of operation to bacterium A. fischeri and activated sludge microorganisms and the ammonia nitrogen and humic substances (HS) sensitivity to these organisms. Reductions greater than 30% in leachate toxicity were observed after ammonia removal for A. fischeri and activated sludge microorganisms. After 97% removal of HS, the greater reductions in toxicity (44.28 to 79.82%) were verified for microbial species studied, indicating that the organic compounds (measured as chemical oxygen demand, total organic carbon and humic substances) were the primary pollutants responsible for the toxicity of the leachates. Concerning the organisms studied, A. fischeri showed greater sensitivity to the leachates' pollutants compared to the activated sludge microorganisms. Nevertheless, a strong correlation was observed between A. fischeri and activated sludge microorganisms' toxicity responses, suggesting that respirometry assay can be used to determine leachate toxicity.

The 2019–2020 coronavirus pandemic imposed unprecedented challenges in Brazilian governance sectors, mostly in the waste management system. Herein, we analyse the main challenges of the recycling sector in Brazil to cope with this scenario. Understanding difficulties during the pandemic outbreak of COVID-19 can help improve waste recycling in the post-pandemic period in Brazil and other developing nations that face similar issues. The current pandemic exposed the deficiencies of this system, and some important lessons can be learned. Recommendations are drawn to advance the proper management of recyclables in the country. The Government must increase total investments in the recycling industry's infrastructure and support local recycling initiatives during a public health crisis and beyond. In sum, this paper strengthens the idea that waste segregation at the source and selective collection will not be sufficient without massive investments in the recycling sector’s infrastructure. The future challenge includes strengthening the economic markets for recycled materials. Graphic abstract

The leachate treatment by nanofiltration (NF) process has received much attention over the last two decades. Previous studies focused on the investigation of the technical feasibility of NF. However, there are a limited number of works that examined leachate treatment costs. On the other hand, in a landfill management system, the economic component is an imperative factor for the decisions of all operations. Thereby, this work aimed to investigate the technical feasibility and economic parameters involved in a full-scale NF plant for the treatment of leachate previously treated by the physicochemical process. The average quality of the pre-treated leachate was 2258 ± 230 mg L−1 chemical oxygen demand (COD) and 821 ± 86 mg L−1 humic substances (HS). NF was performed using a bench-scale filtration module with commercial polymeric membranes SR100 and NP030. At the end of each filtration, a cleaning protocol was applied to recover the initial membrane permeability. The concentration of recalcitrant compounds, expressed as HS, was reduced to 84 ± 8 mg L−1 in the permeate, and COD complies with the wastewater discharge standards imposed by local legislation. The capital costs for a full-scale NF was estimated at MUS$ 0.772, and specific total cost, treated leachate per volume unit, has been estimated at US$ 8.26 m−3.

Society faces eco-environmental challenges when it comes to managing industrial wastewaters. In particular, textile effluents are one of the main threats to living being due to toxic dyes. Technologies used to remove dye compounds include physicochemical and membrane filtration processes. However, since current technologies have several limitations, including high investment and energy demand, researchers have investigated cheaper and eco-friendly alternatives. Among them, anaerobic processes have been an effective method to decolourise dye-containing effluents. In that direction, the up-flow anaerobic sludge blanket (UASB) technology stands out in terms of high cost-effectiveness. The authors reviewed the published literature on UASB reactors in dye compounds removal. Mechanisms, merits, demerits, and technical aspects of UASB reactors are introduced. Challenges and opportunities are discussed. The major points are 1) mechanisms of dye removal in UASB reactors comprise mainly dye adsorption onto sludge granules and azo bond cleavage (biodegradation), 2) dye structure and concentration, external organic carbon source, redox mediators, and bioreactor operating conditions play a key role in the treatment performance, 3) UASB technology exhibits high decolourisation rates. Removal efficiencies of chemical oxygen demand and colour lie within the range of 60–85% and 75–96%, respectively. However, anaerobic treatments may not be able to mineralise by-products of anaerobic metabolisms. Consequently, post-treatment of the anaerobically treated effluent is required, and 4) the energy production during the decolourisation process in UASB reactors is estimated at 22 kWh per m3 of treated wastewater. Bio-energy recovery can promote wastewater valorisation and decrease the economic burdens of dye-containing effluents treatment. Future studies should focus on optimising influence parameters of full-scale UASB reactors and biogas recovery from dye-containing wastewater treatment.

supplementary_material_Clean for Cost estimation of landfill leachate treatment by reverse osmosis in a Brazilian landfill by Ronei de Almeida, Daniele Maia Bila, Bianca Ramalho Quintaes and Juacyara Carbonelli Campos in Waste Management & Research

Landfill leachate consists mostly of a high content of refractory organic matter, ammonia and toxic compounds. All these compounds, regardless of their nature, have a potential pollution effect on local ground and surface waters. In this context, the purpose of the present study was to evaluate a treatment process (coagulation-flocculation with lime coupled with nanofiltration) applied to landfill leachate from Seropédica, Rio de Janeiro (Brazil). Jar tests were conducted to determine the optimum dosage of lime (ranged from 0 to 10 g L

Due to its toxic effects in aquatic organisms and in humans, Bisphenol A (BPA) has been replaced by Bisphenol S (BPS) as additive in the production of epoxy glues, baby bottles, cardboard, thermal paper, among others. In this study, the removal of chronic toxicity of BPS from aqueous solution was evaluated by adsorption on powdered activated carbon (PAC) using commercial carbons from two distinct matrices (vegetal and mineral). The characterization of adsorbents was performed by infrared spectroscopy, surface area BET (Brunauer, Eminett e Teller), Scanning Electron Microscopy (SEM) and zeta potential. The adsorption kinetics and isotherms were evaluated. The chronic toxicity was measured through assays with the organism Ceriodaphnia dubia for 7 days. The kinetics for both absorbents were fitted to pseudo-second-order models in experimental initial conditions of 2 mg L−1 and 30 mg L−1, pH 6.5 and temperature of 25 °C, with removal efficiency of 94 % at equilibrium in 60 min for mineral PAC and of 88 % in 120 min for vegetal PAC. Furthermore, the isotherm model proposed by Freundlich presented the best settings for both PAC. Activated carbon adsorption may be an efficient method for the reduction of chronic toxicity, reaching no observed effect concentration (NOEC) in the organisms at 1.56 μg BPS L−1.

This study aimed to evaluate the use of coagulation/flocculation and Fenton processes for the removal of the recalcitrant component, in particular humic substances, from two different leachates generated in the Gericino and Gramacho landfills in Rio de Janeiro State (Brazil). A coagulation/flocculation process, using FeCl3·6H2O as the coagulant, was applied to the two leachate samples. In the case of the leachate from Gericino landfill, the treatment removed 93% of color, 71% of TOC, 69% of COD, 76% of HS, 73% of humic acids (HA) and 82% of fulvic acids (FA). In addition, there was a 75% reduction in the absorbance at 254 nm, using 3,000 mg L−1 of coagulant. In the case of the leachate from Gramacho landfill, the treatment removed 91% of color, 69% of TOC, 68% of COD, 77% of HS, 75% of HA and 80% of FA. In addition, there was a 70% reduction in the absorbance at 254 nm using the same concentration of coagulant (3,000 mg L−1). The Fenton processes, using FeSO4·7H2O and H2O2 in a ratio of 1:5, were ...

Resumo Substâncias Húmicas (SH) são definidas como polímeros amorfos, de massa molar elevada, estruturas complexas e heterogêneas, que alteram com frequência as suas conformações em função das interações que ocorrem entre os grupos funcionais presentes na sua estrutura. A presença dessas substâncias principalmente nos lixiviados de aterros de resíduos sólidos e, em maior quantidade, em lixiviados de aterros antigos, dificulta o tratamento dos lixiviados, devido ao alto grau de recalcitrância de tal matéria orgânica. Nesse estudo, dois métodos de quantificação de SH foram testados em dois lixiviados gerados em aterros do Estado do Rio de Janeiro, oriundos do Aterro Controlado de Gericinó (ACG) e o Aterro Metropolitano de Gramacho (AMG), assim como o seu fracionamento nas frações Ácidos Húmicos (AH) e Ácidos Fúlvicos (AF). Os resultados de SH foram, respectivamente, 616 e 608 mg L-1 para o lixiviado proveniente do ACG e 1182 e 1191 mg L-1 para o lixiviado proveniente do AMG. O lixiviado oriundo do ACG apresentou 33% (201 mg L-1) de AH e 67% (411 mg L-1) de AF e o de AMG apresentou 37% (437 mg L-1) de AH e 63% (741 mg L-1) de AF. Abstract Humic substances (HS) are defined as amorphous polymers, with high molecular weight and complex and heterogeneous structures that frequently change their configurations depending on the interactions between the functional groups present in their structures. The presence of these substances, particularly in landfill leachates and in greater quantities in leachates from old landfills, hinders the treatment of leachate due to the high degree of recalcitrance of organic matter. In this study, two quantification methods were tested for two leachates generated in solid waste landfills located in Rio de Janeiro State: the Gericinó Controlled Landfill Gericinó (GCL) and the Gramacho Metropolitan Landfill (GML). The study also analyzed the fractionation of humic substances in fractions of Humic acids (HA) and fulvic acids (FA). The results of the quantification of HS were, respectively, 616 and 608 mg L-1 for the leachate from GCL and 1182 and 1191 mg L-1 for leachate from GML. The leachate from GCL presented 33% (201 mg L-1) of HA and 67% (411 mg L-1) of FA and the leachate from GML presented 37% (437 mg L-1) of HA and 63% (741 mg L-1) of FA.

O presente trabalho teve por objetivo básico determinar a ocorrência de correlação entre a vazão de água nos colmos de cana-de-açúcar e o grau de suscetibilidade das cultivares ao raquitismo da soqueira, pelo método de vazão de água, à pressão constante, através de colmos inoculados com a bactéria do raquitismo da soqueira (RS) e sadios (tratados termicamente). Com base na observação de que a doença é de natureza vascular, mediram-se os diâmetros do lume dos vasos de quatro cultivares de reação conhecida ao RS, para verificar se a anatomia vascular é ou não um fator de resistência, ao raquitismo da soqueira. Através de contagem de bactérias em colmos tratados termicamente e inoculados com caldo bruto (RS), procurou-se verificar se existe uma relação direta entre o grau de suscetibilidade e o número de bactérias. O número de bactérias com colmos inoculados foi sempre maior do que nos, do tratamento térmico, supostamente sadios. Por ser este método de recente introdução, foi estudado o efeito do armazenamento e umidade do solo sobre o mesmo. Os resultados da medida de vazão evidenciaram que cultivares resistente apresentam baixa vazão de água entre colmos tratados termicamente e inoculados, ao passo que cultivares suscetíveis revelaram o contrário. A anatomia vascular não é suficiente, por si só, para explicar as diferentes reações das cultivares ao RS. O armazenamento ocasiona acentuada queda de vazão, principalmente 24 horas após a colheita. O conteúdo de água no solo, também, interfere no método. Concluiu-se que essa técnica pode constituir-se, num futuro próximo, no método mais eficiente, seguro e rápido de separar cultivares resistentes de suscetíveis. This work has the objective of determining the correlation between the water flow on sugarcane cuttings and the susceptible degree to the ratoon stunting disease (RSD) of some cultivars by the method of water flow in a constant pressure with healthy and diseased cuttings. The diameters of the xylem of four cultivars with known reactions to RSD were measured to verify whether the vascular anatomy is a factor of resistance to this disease. The bacteria in cuttings submitted to the long hot water treatment and inoculated with sugarcane juice (RSD) were counted to verify if there is a direct relation between the degree of susceptibility and number of bacteria. The number of bacteria on inoculated cuttings was always higher than on those treated with hot water (healthy). Because it is a new method of RSD evaluation, it was studied the storage and soil moisture effect over the method. A low water flow was observed in inoculated cuttings of resistant cultivars and the high water flow was presented in susceptible ones. The vascular anatomy alone is not sufficient to explain the different reactions of cultivars to RSD. Storage causes a great water flow decrease, mainly 24 hours after harvesting. The moisture content of the soil interfere in this method. It was concluded that this technic can be in future the more efficient method, secure and rapid for screening resistant from susceptible cultivars.