The toxicity of ZnO and CuO nanoparticles on biological wastewater treatment and its detoxification: a review / 生物工程学报

The wide use of ZnO and CuO nanoparticles in research, medicine, industry, and other fields has raised concerns about their biosafety. It is therefore unavoidable to be discharged into the sewage treatment system. Due to the unique physical and chemical properties of ZnO NPs and CuO NPs, it may be toxic to the members of the microbial community and their growth and metabolism, which in turn affects the stable operation of sewage nitrogen removal. This study summarizes the toxicity mechanism of two typical metal oxide nanoparticles (ZnO NPs and CuO NPs) to nitrogen removal microorganisms in sewage treatment systems. Furthermore, the factors affecting the cytotoxicity of metal oxide nanoparticles (MONPs) are summarized. This review aims to provide a theoretical basis and support for the future mitigating and emergent treatment of the adverse effects of nanoparticles on sewage treatment systems.

Draft genome sequence of Chryseobacterium limigenitum SUR2T (LMG 28734T) isolated from dehydrated sludge

ABSTRACT The type strain SUR2 of the novel species Chryseobacterium limigenitum was isolated from a dehydrated sludge of the municipal sewage treatment plant in Dogoše near Maribor in Slovenia. The draft genome, with 60 contigs, 4,697,725 bp, 34.4% of G+C content, was obtained using the Illumina HiSeq 2500-1 platform. Joint Genome Institute Microbial Genome Annotation Pipeline (MGAP v.4) has identified 4322 protein-coding sequences including resistance genes against arsenic and other heavy metals. In addition, a subclass B3 metallo-β-lactamase, which confers resistance to penicillins, cephalosporins and carbapenems, was also present in the genome. The genome sequence provides important information regarding bioremediation potential and pathogenic properties of this newly identified species.

Diagnóstico participativo socioambiental e de riscos à saúde das comunidades do entorno do Complexo Petroquímico do Rio de Janeiro, Brasil / Participatory environmental diagnosis and of health risks from the surrounding communities the Petrochemical Complex of Rio de Janeiro, Brazil

Resumo O objetivo deste estudo foi diagnosticar os problemas socioambientais prioritários e os riscos à saúde das comunidades do entorno do Complexo Petroquímico do Rio de Janeiro. De abordagem participativa, a pesquisa-ação conduziu a aplicação de entrevistas, grupos focais, reuniões e oficina com atores sociais de Porto das Caixas e Sambaetiba, localizados em Itaboraí/RJ, no período de novembro de 2013 a dezembro de 2014. Uma análise estrutural dos problemas priorizados pelas comunidades (oferta de água, tratamento de esgoto e risco de doenças transmissíveis; risco de poluição do ar e doenças respiratórias; ausência de segurança pública e risco de violência) esquematizou a relação causa-efeito-intervenção, com base no Protocolo para Avaliação Comunitária de Excelência em Saúde Ambiental. O processo revelou ausência de representatividade dos atores sociais das localidades estudadas em espaços decisórios sobre a problemática ambiental. Urgem ações educativas com profissionais e moradores que visem a favorecer a constituição de movimentos coletivos, indispensáveis à garantia dos direitos de mitigação das situações de contaminação do ar e de acesso aos serviços de saneamento e de segurança pública e de condições de menor risco à saúde.

Abstract The aim of this study was to diagnose the priority socio environmental problems and the health risks from the surrounding communities the Petrochemical Complex of Rio de Janeiro. Characterized by a participatory approach, the action research has led to the application of interviews, focal groups, meetings and workshop with social actors of Porto das Caixas and Sambaetiba districts, located in Itaboraí city/RJ from November 2013 to December 2014. A structural analysis of the problems prioritized by the communities (water supply, sewage treatment and risk of transmissible diseases; risk of air pollution and respiratory diseases; absence of public security and risk of violence) sketched out the cause-effect-intervention relationship, on the basis of the Protocol for Assessing Community Excellence in Environmental Health. The process revealed the absence of representativity of the social actors of the studied localities in spaces of decision-making on the environmental issue. Educational actions with professionals and inhabitants that aim to promote the formation of collective movements urge, indispensable to guarantee the rights of mitigation of situations of contamination of air and access to sanitation services and public security and thus of conditions of lower risk to health.

Elemental composition of vegetables cultivated over coal-mining waste

ABSTRACT We assessed elemental composition of the liver in mice subjected to one-time or chronic consumption of the juice of vegetables cultivated in a vegetable garden built over deposits of coal waste. Lactuca sativa L. (lettuce), Beta vulgaris L. (beet), Brassica oleracea L. var. italica (broccoli) and Brassica oleracea L. var. acephala (kale) were collected from the coal-mining area and from a certified organic farm (control). Elemental composition was analyzed by particle-induced X-ray emission (PIXE) method. Concentrations of Mg, S, and Ca of mice subjected to one-time consumption of broccoli and concentrations of these same elements plus Si of mice receiving kale were higher in the coal-mining area. Concentrations of P, K, and Cu were increase after chronic consumption of lettuce from the coal-mining area, whereas the levels of Si, P, K, Fe, and Zn were higher in the group consuming kale from the coal-mining area. Our data suggests that people consuming vegetables grown over coal wastes may ingest significant amounts of chemical elements that pose a risk to health, since these plants contain both essential and toxic metals in a wide range of concentrations, which can do more harm than good.

Microalgae population dynamics in photobioreactors with secondary sewage effluent as culture medium

Nitrogen and phosphorus present in sewage can be used for microalgae growth, possibiliting cost reduction in the production of microalgae at the same time that it decreases the eutrophication potential of the effluent. This research aimed at monitoring the native community of microalgae and coliform bacteria in a secondary effluent from anaerobic municipal sewage treatment. Two treatments (aerated and non-aerated) were performed to grow microalgae under semi-controlled conditions in semi-closed photobioreactors in a greenhouse. The results showed no significant pH and coliforms (total and Escherichia coli) variation between treatments. Nutrient concentrations were reduced supporting microalgae growth up to 107 cells.mL−1 independent of aeration. Exponential growth was obtained from the first day for the non-aerated, but a 5 day lag phase of growth was obtained for the aerated. Chlorella vulgaris was the dominant microalgae (99.9%) in both treatments. In the aerated, 5 algae classes were detected (Chlorophyceae, Cyanophyceae, Chrysophyceae, Bacillariophyceae and Euglenophyceae), with 12 taxa, whereas in the non-aerated, 2 classes were identified (Chlorophyceae and Cyanophyceae), with 5 taxa. We concluded that effluent is viable for microalgae growth, especially Chlorella vulgaris, at the same time that the eutrophication potential and coliforms are decreased, contributing for better quality of the final effluent.

[Evaluation of phosphorus removal from filtered effluent of activated sludge using the electrochemical process]

Phosphorus [in a concentration range of 0.005-0.05 mg/L-P] is enough for eutrophication of water bodies; therefore, phosphorus removal from effluents is necessary. The electrochemical process is one of the methods used for phosphorus removal. Thus, this study aimed to examine the effect of the electrochemical process on phosphorus removal from filtered effluent of activated sludge. This bench-scale experimental study was carried out on the samples of filtered effluent of activated sludge in a batch system. Phosphorus concentrations for 210 samples were measured through stannous-chloride method [The Standard Method, 4500 P-D.]. Data were analyzed using Green house Geisser, one-way ANOVA and the Tukey's post- hoc tests. The average phosphorus concentration before the electrochemical process in the filtered samples and the maximum efficiency of phosphorus removal were 1.93 +/- 0.86 mg/L-P and 98%, respectively. The residual phosphorus concentrations [electrical current >/= 0.3A, reaction time >/= 10min] in all samples were decreased to less than 1mg/L-P. Results showed that the electrochemical process can decrease the residual phosphorus to less than the standard limit [1mg/L-P] in Iran. The plot for the average residual phosphorus concentrations versus reaction time is a straight line [R[2]=0.837]. Phosphorus removal from the samples of filtered effluent of activated sludge is considered as a second-order reaction and the fitted model can be formulated as y= -0.001x[2] + 0.133x + 0.875 [R[2]=0.925]

Impactos das atividades humanas sobre a dinâmica do fósforo no meio ambiente e seus reflexos na saúde pública / The impact of human activities on the dynamics of phosphorus in the environment and its effect on public health

O fósforo é um nutriente com fontes finitas e não renováveis, cuja velocidade de exploração é atualmente muito superior às suas taxas de retorno ao seu ciclo natural, sendo que já existem previsões a respeito de um provável colapso nas suas fontes disponíveis e conhecidas, com impactos econômicos, sociais e ambientais graves e irreversíveis. Diante desse cenário, o presente trabalho busca apresentar informações sobre a dinâmica do fósforo no meio ambiente, avaliando os impactos causados pelas atividades humanas e verificando as ações que podem auxiliar na preservação do ciclo do nutriente. Visando contribuir para uma melhor visualização do assunto, foi analisada a evolução dos dados relativos à concentração populacional, número de industriais e extensão das áreas cultivadas em uma bacia hidrográfica, em relação às concentrações de fósforo nos compartimentos água e sedimento, ao longo de 22 anos. Para tanto, utilizou-se o rio Tietê como estudo de caso. Os resultados obtidos indicam que o controle das fontes domésticas, principalmente da quantidade de tripolifosfato de sódio (STPP) utilizada nos detergentes, é de grande importância para a melhoria da qualidade das águas, proteção ao meio ambiente e garantia da saúde pública.

Phosphorus is a nutrient with finite and non-renewable sources, the speed of exploitation of which is currently far higher than the rates of return to its natural cycle. It is already being predicted that available and known sources will soon be exhausted, with serious and irreversible economic, social and environmental impacts. In this context, this study sets out to present information about the dynamics of phosphorus in the environment, assessing the impacts caused by human activities and establishing what actions might contribute to preservation of the nutrient cycle. To contribute to enhanced understanding of the topic, the evolution of data on population density, the number of industries and the extension of cultivated areas in a river basin, was studied over 22 years in relation to concentrations of phosphorus in water and sediment. The Tietê River was used for the case study. The results revealed that the control of domestic effluent, especially the amount of sodium tripolyphosphate (STPP) used in detergents and soap products, is of major importance for improving water quality, ensuring environmental protection and safeguarding public health.

Geochemical behavior of heavy metals in differents environments in Rodrigo de Freitas lagoon - RJ/Brazil

The accelerated urbanisation without a planning, brought several environmental problems to Rio de Janeiro coastal zone, especially in areas such as Rodrigo de Freitas lagoon, which receives a great amount of untreated sewage every day. To assess the nature, potentially sources and extent of heavy metal pollution in the lagoon, sediments from the surrounding streets, from the entrance of the main canal that drains to the lagoon and from the bottom of the lagoon were collected and analysed by a modified selective extraction procedure in order to study the geochemical partitioning and bioavailability of Zn, Cu, Cr, Ni and Pb in these three compartments. The present study verified an increase in the Cu, Pb and Zn concentrations in the north of the Rodrigo de Freitas lagoon. Despite the different levels of oxidation between the sediments accumulated in the streets and in the bottom of the lagoon, the geochemical partitioning of the heavy metals did not show any pattern of variation for the metals, except for the element Cu. No concentrations were found in the soluble phase of samples collected in the surfacial sediments of the lagoon, suggesting no bioavailability of heavy metals.

A urbanização acelerada, sem planejamento, resultou em uma série de problemas à zona costeira do Rio de Janeiro, especialmente em áreas como a Lagoa Rodrigo de Freitas, a qual recebe uma grande descarga de esgoto não tratado todos os dias. No intuito de avaliar a natureza, as fontes potenciais e a extensão da poluição por metais pesados na lagoa, sedimentos das ruas do entorno, das entradas do principal canal de drenagem e de superfície de fundo foram coletados. As análises se deram através de um método modificado de extração sequencial, com o objetivo de estudar o fracionamento geoquímico e a biodisponibilidade de Zn, Cu, Cr, Ni e Pb, nestes três compartimentos. O presente estudo verificou um aumento nas concentrações de Cu, Pb, e Zn no setor norte da Lagoa Rodrigo de Freitas. Apesar dos diferentes níveis de oxidação entre os sedimentos acumulados nas avenidas e no sedimento de fundo da lagoa, o fracionamento geoquímico dos metais pesados não apresentou nenhum padrão de variação, com exceção do Cu. Não foram observadas concentrações na fase solúvel, das amostras coletadas nos sedimentos superficiais na lagoa, sugerindo a não biodisponibilidade dos metais pesados.

Presence of fluoroquinolones and sulfonamides in urban sewage sludge and their degradation as a result of composting

The concentrations of some widely used pharmaceuticals, namely fluoroquinolones [ciprofloxacin C[17]H[18]FN[3]O[3], norfloxacin C[16]H[18]FN[3]O[3] and ofloxacin C[18]H[20]FN[3]O[4]] and sulfonamides [sulfadimethoxine C[12]H[14]N[4]O[4]S and sulfamethoxazole C[10]H[11]N[3]O[3]S] were determined in urban sewage sludge utilized for making compost. The levels of degradation of these pharmaceuticals resulting from sludge treatment were assessed. The concentrations of the studied pharmaceuticals sufficiently varied both in sewage sludge and in compost and due to this phenomenon the possible danger resulting from the presence of pharmaceuticals in sewage sludge, used for composting, can not be ignored. The concentrations of the studied pharmaceuticals were lower in compost, if compared to the relevant concentrations in sewage sludge. The highest pharmaceutical concentration in sewage sludge - 426 micro g/kg - was detected in the case of ciprofloxacin. The highest concentrations present in compost were 22 micro g/kg of norfloxacin and 20 micro g/kg of ciprofloxacin. Results show that before using the sewage sludge for making compost or before using the compost a fertilizer for food plants, they should be carefully tested against the content of commonly used pharmaceuticals

Effect of sewage water on seed germination and vigour index of different varieties of groundnut (Arachis hypogaea L.).

The study has been focused on the investigation on ground nut (Arachis hypogea) fields influenced by sewage water. Sewage water sampled in and around Mysore city and analyzed forphysicochemical parameters. Different concentrations such as 1, 5, 10, 25, 50, 70 and 100% of sewage water on seed germination and vigour index of Arachis hypogea verities such as DH - 2 - 30, ICJS - 11, JL - 24, K - 134, TMV - 2 and VRI - 2 were studied. From the recorded observation it is concluded that the sewage water diluted to 25% concentration for irrigation of groundnut enhances germination percentage and vigour index in K- 134 variety which is more susceptible than other tested varieties.

Biomanagement of sago-sludge using an earthworm, Lampito mauritii.

In the present study vermicomposting was carried out at three different concentrations of sago-sludge namely 50, 75 and 100% with an indigenous earthworm, Lampito mauritii for a period of 50 days. The fecundity of earthworm Lampito mauritii was found to be high in 50%. At the end of 50 days composting period. There were about 12 cocoons, 5 juveniles and 2 nonclitellates appeared at 50% sago-sludge concentration. The microbial analysis showed that after 40 days of composting their population stabilized and further increase in composting period did not increase their population size. Chemical analysis of Lampito mauritii worked substrates showed there is a step wise increase of nitrogen and phosphorus. The fold increase of phosphorus and nitrogen were found to be high for sago-sludge undergoing vermicomposting than the control. From the initial value of 1.8, 1.4 and 0.5 mg kg(-1) total nitrogen increased in a stepwise manner and reached a value of 5.8, 3.9 and 2.3 mg kg(-1), respectively for vermicomposting at 50, 75 and 100%. During composting the organic carbon decreased from its initial value of 56, 74 and 107 mg kg(-1) to 15, 25 and 58 mg kg(-1) for vermicomposting and 34, 45 and 72 mg kg(-1) for 50, 70 and 100% control, respectively. The results indicate that 50% and 75% concentration of sludge mixed with bedding material was ideal for the vermicomposting.

Evaluation of specific biological heat potential of oily wastewater in an autothermal thermophilic aerobic treatment system.

This study focuses on the specific biological heat potential (h(b)) of oil and grease wastewaterin an autothermal thermophilic aerobic treatment (ATAT) system. A novel experimental device was applied to evaluate h(b) by using heat balance model under steady state. In the study the treatment system was daily fed with realistic and artificial wastewater at 11250 and 17420 mg COD l(-1), respectively. The wastewater was rich in oil and grease at 1220 and 600 mg l(-1), respectively. The sludge retention time (SRT) was controlled at 5 days. The results showed that the average values of h(b) were 3.7 and 3.1 kcal g(-1) COD removed and the true growth yield (Y0) were 0.10 and 0.13 mg MLSS mg(-1) COD for realistic and artificial wastewater respectively. These two systems could maintain reactoroperating temperatures at 43 degrees C and 48 degrees C, respectively. The COD removal efficiency was as high as 90 to 97%. The oil and grease reduction was 68 to 72%. The high organic matter removal capacity and low sludge yield of ATAT process have been demonstrated.

Biomanagement of sago-sludge using an earthworm, Eudrilus eugeniae.

Sago, the tapioca starch is manufactured by over 800 small-scale units located in the Salem district, Tamil Nadu, India. During the processing of sago it generates huge quantities of biodegradable solid waste, as crushed tubers. In present study an attempt was made to convert these biodegradable solid sago tubers into value added compost using an exotic earthworm, Eudrilus eugeniae. The experiments were carried out in a plastic tray at various concentrations of sago-sludge (50% 75% and 100%) for a period of 90 days. During the vermicomposting, data were collected on life form (cocoon, non clitellates, clitellates) of earthworm and it was found to be high in 50% followed by 75% and 100% concentrations. Chemical analysis of worked substrates showed a step wise increase of nitrogen and phosphorus. The fold increase of phosphorus and nitrogen were found to be high for sago-sludge undergoing vermicomposting than the control. During the composting period the organic carbon decreased from its initial value of 58, 76 and 107 mg/kg to 21, 24 and 65 mg/kg for 50, 70 and 100%, respectively The microbial analysis showed that after 75 days of composting, their population stabilized and further increase in composting period did not increase their population size. The results indicate that 50% and 75% concentration of sludge mixed with bedding material was ideal for the vermicomposting.

Metals and organic components of sewage and sludges.

Sewage and sludge samples were collected from rural areas of Vellore district. The metals like Cu, Zn, Cd, Pb, Fe, Ca and Mg were determined by Inductively coupled plasma atomic emission spectrophotometry (ICP-AES). For this determination HCl - HNO3 and 4N HNO3 extracts were used. The total organic carbon (TOC), chemical oxygen demand (COD) and organic matter (OM) have also been determined to evaluate the presence of organic and metallic contents in sewage and sludge environment.

Role of water hyacinth in the health of a tropical urban lake.

The paper assesses health of the tropical urban Robertson Lake, Jabalpur which receives domestic sewage from neighboring human inhabitation and is infested with water hyacinth. Peak density of this macrophyte was 12.5 t dw ha(-1). The water-column was anaerobic (0.6 to 1.9 mg O2 L(-1)), neutral in pH, and enriched with inorganic carbon (23.5 to 37.1 mg L(-1)), NH4-N (0.48 to 2.96 mg L(-1)), and organic nitrogen and phosphorus. Density of heterotrophic bacteria was high (6.8 to 15x10(5) cfu ml(-1)) along with that of total coliforms and fecal bacteria. Species diversity of phytoplankton and submerged macrophytes was very low. Growing stands of water hyacinth could store up to 613 g C m(-2), 23.5 g N m(-2) and 5.5 g P m(-2) and released them during decomposition. The release of nutrients was 3-4 times faster than the uptake. Water hyacinth stabilized water quality and provided substantial support to bacterial density, which in turn contributed significantly to its growth and nutrient dynamics. Turnover of water hyacinth was only 70-80%, adding approximately 175 t humus in the lake. The results denote poor health of the lake, characterized by low species diversity, fast shallowing, dominance of detritus food--webs, and the water unsuitable for human consumption.

Influence of the organophosphorus insecticide phosphamidon on lentic water.

The inland freshwater resources are being increasingly subjected to heavy stress as a result of indiscriminate dumping of industrial wastes, domestic sewage and agricultural run-off causing deterioration of the water quality and adverse impact on aquatic biota. Pesticides drained to the aquatic environment are primarily of agricultural origin. Phosphamidon (widely used organophosphate pesticide in paddy field) significantly reduced dissolved oxygen (DO) at 1.8 mg/l exposure and reduced alkalinity at 0.9 and 1.8 mg/l. Hardness also reduced gradually but not significantly. Free carbondioxide was increased significantly at 1.8 mg/l of the insecticide compared to control. The insecticide had no influence on pH and temperature. There was maximum reduction of phytoplankton and zooplankton population at 1.8 mg/l of phosphamidon. Though gradual reduction of plankton community was also noticed at different lower concentrations of pesticides but in case of phytoplankton an abrupt reduction (about 50% of the control) was observed. The normal behaviour and feeding rate of air breathing teleost, Channa punctatus was also hampered. Therefore, phosphamidon even at low concentrations may create disorders in the aquatic ecosystem.

Factors that can interfere with virus concentration from wastewater when using zeta plus 60S filter membranes

Zeta plus filter membranes (ZP60S) have been shown to be efficient for rotavirus concentration from wastewater and for the reduction of cytotoxicity for cell cultures. Recently a variability in both properties was observed. In view of the low costs and the high virus recovery rates obtained in the past, we re-evaluated the application of ZP60S filter membranes for virus concentration from environmental samples. Some factors that could interfere with the concentration strategy using ZP60S were also considered and assessed including the type of water to be filtered and the possible release of toxic substances from the membrane matrix during filtration.