Typical Sewage Research Articles

Comparative analysis of bioaerosol emissions: Seasonal dynamics and exposure risks in hospital vs. municipal wastewater treatment systems

Hospital wastewater is known to contain various pathogenic microorganisms and harmful substances. During the hospital wastewater treatment process, the bioaerosols released may encapsulate these pathogens, leading to human infection. This study undertook an investigation to compare the dispersion characteristics and seasonal variations of bioaerosols from hospital and municipal sewage. The results indicated that the airborne bacterial concentration from hospital sewage (119 ± 118 CFU/m3) was higher than municipal sewage (46 ± 19 CFU/m3), with the highest concentration observed in summer. The dominant bacterial genera present in bioaerosols from both sewages were alike, with the proportions varied by sewage types and the structure mainly influenced by seasonal factors. Bacteroides, Escherichia-Shigella and Streptococcus were identified as the most prevalent pathogenic genera in spring, summer and winter bioaerosols, respectively, while Pseudomonas and Acinetobacter were abundant in autumn. Although the non-carcinogenic risk associated with bioaerosols was low (<1), the presence of pathogenic species and their potential synergistic interactions elevated the overall exposure risk. The diffusion modeling results demonstrated that bioaerosol emissions from the surface of hospital sewage can reach up to 10570 CFU/m3 in summer and can spread more than 300 m downwind. The potential pathogenicity of bioaerosols was also highest in summer, which may pose a health hazard to populations located downwind. Therefore, the management and control of bioaerosols from sewage should be strengthened, especially in summer.

Screening of Tuberculosis Infection through Acid-Fast Bacilli Tests among Waste Workers in Gresik, Indonesia

Highlights: 1. This study was the first in Gresik, Indonesia, to conduct mass screening of tuberculosis among waste workers, comprising various demographic profiles.2. Although the tuberculosis screening of the waste workers showed negative results, mass examination using an acid-fast bacilli smear remains crucial to detect latent infections and prevent transmissions. Abstract Tuberculosis is a major source of illness and mortality worldwide. Therefore, tuberculosis screening is important to increase the number of active case-finding in a community. Bacteriological examinations can be used to initiate community-based active case-finding. Waste workers face a high risk of contracting Mycobacterium tuberculosis due to their constant exposure to waste. This study aimed to conduct bacteriological examinations to identify tuberculosis infections among waste workers in Gresik, Indonesia, who were considered a high-risk group. An analytical observational study was carried out throughout September 2023 in the Ngipik subdistrict, Gresik, East Java, Indonesia. The primary study was conducted using a cross-sectional design using interviews, measurements, and sputum examinations for all samples. The screening involved a total of 72 waste workers who had daily contact with various types of sewage and waste, including medical waste. The data were analyzed descriptively because of the constant variable. Following the analysis, the data were presented using a table and a figure. According to the acid-fast bacilli examinations, all of the samples yielded negative results. Nevertheless, this study concludes that it is imperative to carry out mass tuberculosis screening in various settings, specifically among those with a high risk. Mass screening can uncover the potential of latent tuberculosis and, thus, reduce its transmission.

Airborne ARGs/MGEs from two sewage types during the COVID-21: Population, microbe interactions, cytotoxicity, formation mechanism, and dispersion

During the COVID-2021 epidemic, a large number of antibiotics were used for clinical treatment in hospitals or daily prevention. Sewage from hospital sewage treatment centers (HSTC) and wastewater treatment plants (WWTP) produced a lot of antibiotic-resistance genes/mobile genetic elements (ARGs/MGEs). In this study, the sewage and bioaerosol in the biochemical tank (BT) of an HSTC and a WWTP were sampled throughout the year. The results showed that the average absolute abundance of sewage in BT of WWTP (BTW-W) was higher than sewage in BT of HSTC (BTW-H). Sewage was an important source of microorganisms and ARGs/MGEs in the air of BT. Microorganisms and MGEs were the factors affecting the differences in ARGs/MGEs. Cytotoxicity experiment proved that the cytotoxicity changed from Grade III to Grade IV with the increase in drug-resistant Escherichia coli concentration. According to the formation mechanism formula, the average generation rate of ARGs/MGEs in BT of HSTC was lower than that in WWTP. The diffusion range of ARGs/MGEs of HSTC was larger than that of WWTP. According to the above results, this study found that when people were far away from BT, the health risk of HSTC caused by the diffusion of bioaerosol was higher than WWTP; When people were close to BT, the health risk of WWTP was higher than HSTC due to the aeration of BT. This study provided a basis for public protection of ARGs. In the future, the elimination of airborne ARGs and crowd protection can be further studied in detail.

The degradation of a nonylphenol isomer in water and soil of typical sewage irrigation area in China

AbstractNonylphenols (NPs), one of the known endocrine disrupting organic pollutants, had received full attention for their estrogenic potency and ubiquitous distribution in the environment. Due to its chemical properties and compositions of technical nonylphenols (tNPs), which was persistent and soil environments for a long time and affect the ecosystem vigorously, degradation behaviour of a nonylphenol isomer (NP38) and the para‐substituded nonylphenols (4‐NPs) in water and soil was compared in this study. The results showed that the 4‐NPs and NP38 could be degraded under the mercury lamp in ultrapure water, 90% of 4‐NPs and NP38 were photodegradated in 2 h, but the removal rate of the 4‐NPs was slightly faster than the NP38. The NP38 was almost completely decay under the UV in 120 min. The active species (NO3− and Fe3+) were benefit for the photogradation of NP38 and presented higher efficiency under the higher concentration. The biodegradable curves of the 4‐NPs and NP38 in the SS (The soil from sewage irrigation area) were similar, 84% of the NP38 was removed after 20 days later in SS, the 62.25% of the NP38 was remained after 60 days later in CS (the soil was from the groundwater irrigation area), but the removal rate of the NP38 was nearly two times to the 4‐NPs in the CS, and the structure of the nonylphenol isomers with α‐quaternary had influenced on its degradation in soils. The study was helpful for better understanding the migration and transformation behaviour of NPs and provided scientific basis for accurate assessment of environmental risk of NPs from the sewage irrigation area.

Carbon reduction measures-based life cycle assessment of the photovoltaic-supported sewage treatment system

This study developed a photovoltaic (PV)-supported wastewater treatment system (WWTS) and conducted a combined experimental and simulation-based life cycle assessment (LCA). The system's energy demand and greenhouse gas (GHG) emissions were predicted through data analysis from manufacturers and the Ecoinvent databases. The energy payback time (EPBT) and GHG payback time (GPBT) were assessed. Additionally, the life cycle cost (LCC) based economic analysis was performed. The result showed that the EPBT and GPBT of the PV-supported WWTS were 11.31 years and 8.3 years, respectively, while the EPBT and GPBT of the PV-supported wastewater treatment plant (WWTP) were 9.7 years and 7.1 years, respectively. Differences in treatment scale, equipment size, and electrical stability between the PV-supported WWTS and the PV-supported WWTP necessitate independent LCA assessments to ensure environmental consistency. Based on the LCA results, recommendations for further system optimization were proposed to reduce carbon emissions. Moreover, the analysis and comparison of the PV-supported WWTS under different scenarios revealed positive investment returns. These results provide the foundation for the system's expansion, which include different energy structures and various sewage types.

Efficient degradation of disodium adenosine triphosphate by Ca–Al-LDH-supported Fe-activated persulfate and in situ adsorption of the phosphate products

To efficiently treat organophosphorus pollutants and synchronously recover phosphorus resources, Fe-loaded layered double metal hydroxides (Fex/Ca–Al-LDHs) were successfully prepared via coprecipitation and impregnation. The effects of the Fex/Ca–Al-LDHs on the degradation of disodium adenosine triphosphate (5-ATP-Na2) in water and in situ separation of the oxidation product, PO43−, were analyzed. The amount of Fe impregnated into the Fex/Ca–Al-LDHs considerably influenced the capacity of the composite for the oxidative separation of 5-ATP-Na2. A 5-ATP-Na2 removal rate of 94.43% was achieved at pH 3 when the Fe content of the Fe0.4-LDHs, catalyst dosage, and potassium persulfate (PS) concentration were 0.4 mol L−1, 0.6 g L−1, and 0.8 mmol L−1, respectively. The removal rate of the Fex-LDHs/PS system was maintained at 71.81% after three oxidation adsorption−desorption cycles. The system was effective for the removal of other organophosphorus species and practical treatment of various sewage types. The activity of the catalyst is derived from the active Fe species (FeCl3, Fe(OH)2, and Fe2O3), which promoted the cyclic conversion of Fe(II) and Fe(III). An increase in the Fe(II) content promoted the activation of PS, enabling rapid pollutant degradation. The main pathway for 5-ATP-Na2 degradation involved oxidation by SO• 4− and •OH; the generated PO43− was primarily removed by adsorption on the Ca–Al-LDHs. The novel Fe-LDHs/PS catalytic adsorption system prepared in this study is an innovative platform for the efficient catalytic degradation of organophosphorus and simultaneous adsorption of the oxidation product, PO43−.

The Mass Spectrometry Identification, Antimicrobial Genes Detection, and Proteomics Analysis of Stutzerimonas stutzeri Strain Was Isolated from Industrial Wastewater

A large amount of organic matter, heavy metals, and even antibiotics are present in industrial wastewater, aquaculture waters, and various types of sewage, along with abundant microorganisms. To date, only a few studies involving the resistance and proteomics of Stutzerimonas stutzeri in high-salt wastewater are available. Herein, a comprehensive assessment of a newly isolated Stutzerimonas stutzeri strain, which is present in high-salt wastewater, was performed using mass spectrometry, genetic identification, and biochemical analysis to characterize the genetic and biochemical properties. Growth experiments revealed that the Stutzerimonas stutzeri strain had a moderate growth rate in nutrient broth, and the bacterial count was not high. Further analysis highlighted an apparent susceptibility of this strain to most antibiotics but some resistance to chloramphenicol and minocycline. A resistance gene assay results showed that the gene gyrB was associated with antibiotic resistance in this Stutzerimonas stutzeri strain. Proteomic analysis revealed for the first time the co-existence of two drug-resistance-related proteins (Multidrug/solvent RND membrane fusion protein and MexE) in Stutzerimonas stutzeri. Moreover, Stutzerimonas stutzeri isolated from high-salt wastewater was subjected to drug resistance gene detection, and the total protein of Stutzerimonas stutzeri was detected by protein mass spectrometry analysis. The subcellular classification shows that the 50 proteins with the highest abundance are divided into cell inner membrane, cell outer membrane, cytoplasm, cytoplasmic side, membrane, multi-pass membrane protein, and peripheral membrane protein, among which the proportion of cytoplasmic components is the highest. Overall, this study’s findings provide a new perspective for further research on the characteristics of Stutzerimonas stutzeri in high-salt wastewater.

Removal Efficiency and Fate of Chlorinated Paraffins (CPs) in a Municipal Sewage Treatment Plant near a Typical Petrochemical Park

Water resources play an important role in industrial, agricultural, and public activities. Chlorinated paraffins (CPs) in wastewater generated by these activities provide an important source of CP contamination. In this study, the occurrences of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) were simultaneously studied in a typical sewage treatment plant (STP) near China’s second-largest oil production base over a 1-year period. High levels of SCCPs and MCCPs (3809 ± 670 and 4803 ± 478 ng/L) were found in the influent due to receiving 75% of industrial wastewater. C14-CPs was the predominant congener group, accounting for 37% of the total CP concentrations. The dissolved removal efficiency of CPs was 83.5%. Mass balance results demonstrated that 3.2% of the initial CPs was found in the final effluent, and 66.3% of the initial CPs was found in the dehydrated sludge, while 30.4% of the initial CPs was lost due to the biodegradation and volatilization. This indicated that sorption onto sludge was the main fate of CPs in wastewater treatment. High mass fractions of CPs were found in the final effluent and dewatered sludge in the winter season due to the low biodegradation, biotransformation, and volatilization.

Health Risk Assessment of Heavy Metals in Soil and Wheat Grain in the Typical Sewage Irrigated Area of Shandong Province

Sewage irrigation is a common alternative to make up for the shortage of agricultural irrigation in intensive agricultural areas. Abundant organic matter and nutrients in sewage can improve soil fertility and crop yield, but hazardous materials, such as heavy metals, will damage the soil environmental quality and threaten human health. To better understand the characteristics of heavy metal enrichment and potential health risk in a sewage irrigated soil-wheat system, a total of sixty-three pairs of topsoil and wheat grain samples were collected from the sewage irrigated area of Longkou City in Shandong Province. The contents of Cr, Cu, Ni, Pb, Zn, As, Cd, and Hg were determined to analyze heavy metal contamination and calculate bio-accumulation factor (BAF), estimated daily absorption (EDA), as well as hazard quotient (HQ). The results showed that the average contents of the eight heavy metals were 61.647, 30.439, 29.769, 36.538, 63.716, 8.058, 0.328, and 0.028 mg·kg-1, respectively, which all exceeded the background values of corresponding heavy metals in the eastern Shandong Province. Especially, the average content of Cd was higher than the current standard value of soil environmental quality of agricultural land soil pollution risk control, indicating the apparent soil contamination. However, the correlations between the heavy metal contents in soil and wheat grains were not significant, suggesting that it is difficult to conclude the enrichment degree of heavy metals in wheat grains merely by the heavy metal contents in soil. The results of BAF showed that the high enrichment capacity of wheat grain was primarily obtained with Zn, Hg, Cd, and Cu. According to the national food safety limit standard, the over-limit ratios of Ni (100%) and Pb (96.8%) in wheat grains were the most serious. As a result, under the current consumption of local wheat flour, the EDAs of Ni and Pb were high, accounting for 28.278% and 1.955% of the acceptable daily intakes (ADI) for adults and 131.980% and 9.124% of the ADIs for children. The results of the health risk assessment exhibited that As and Pb were the main sources causing health risks, accounting for approximately 80% of the total risk. Although the sums of the HQ of the eight heavy metals for adults and children were below 10, the total HQ of children was 1.245 times higher than that of adults. The food safety of children should receive more attention. When considering spatial characteristics, the health risk in the southern study area was higher than that in the northern part of the study area. The prevention and control of heavy metal contamination in the southern area should be strengthened in the future.

Life cycle assessment of greenhouse gas emissions of typical sewage sludge incineration treatment route based on two case studies in China

The rapidly increasing amount of municipal sewage sludge generated in China necessitates a thorough examination and evaluation of available treatment options. In recent years, thermal-drying and incineration technology has gained popularity, however, it may lead to significant greenhouse gas (GHG) emissions. Nevertheless, the differences in boundary conditions and technological characteristic across various cases may affect emission levels significantly. Therefore, this study utilizes a life cycle assessment to estimate the GHG emissions associated with two typical sludge incineration routes in China: direct thermal-drying combined with coal co-incineration incinerator in Case 1 and indirect thermal-drying and self-sustain combustion in Case 2. The entire treatment processes, containing different functional units, were comprehensively investigated. The results demonstrate that Case 1 and Case 2 produce 1133.33 and 350.89 kg CO2-eq/tDS (sludge dry solid) of GHG emissions, respectively. In Case 1, coal co-incineration produces 828.63 kg CO2-eq/tDS of GHG emissions, accounting for 73.1% of the total GHG emissions. Moreover, the exhaust gas treatment is a significant GHG emission source, accounting for 9.2% and 16.9% of the total GHG emissions in Case 1 and Case 2, respectively. Additionally, the sludge thickening and dewatering unit in Case 2 produces 213.75 kg CO2-eq/tDS of GHG emissions, accounting for 60.9% of the total GHG emissions. Analysis of energy flow and heat balance characteristics indicate that the indirect heat transfer method used in thermal-drying leads to significant heat loss, which limits heat recovery potential and hinders GHG emission reduction. This study proposed a scenario case based on Case 2, addressing the issues with the improvement of heat transfer process and reduction of electricity consumption, potentially reducing GHG emissions by 8.8%. Additionally, applying an exhaust gas heat recovery system could further offset up to 22.8% of the total GHG emission.

The effect of synthetic silver nanoparticles on the antibiotic resistome and the removal efficiency of antibiotic resistance genes in a hybrid filter system treating municipal wastewater

Engineered nanoparticles, including silver nanoparticles (AgNPs), are released into the environment mainly through wastewater treatment systems. Knowledge of the impact of AgNPs on the abundance and removal efficiency of antibiotic resistance genes (ARGs) in wastewater treatment facilities, including constructed wetlands (CWs), is essential in the context of public health. This study evaluated the effect of increased (100-fold) collargol (protein-coated AgNPs) and ionic Ag+ in municipal wastewater on the structure, abundance, and removal efficiency of the antibiotic resistome, integron-integrase genes, and pathogens in a hybrid CW using quantitative PCR and metagenomic approaches. The abundance of ARGs in wastewater and the removal efficiency of ARGs in the hybrid system were significantly affected by higher Ag concentrations, especially with collargol treatment, resulting in an elevated ARG discharge of system effluent into the environment. The accumulated Ag in the filters had a more profound effect on the absolute and relative abundance of ARGs in the treated water than the Ag content in the water. This study recorded significantly enhanced relative abundance values for tetracycline (tetA, tetC, tetQ), sulfonamide (sul1, sul2), and aminoglycoside (aadA) resistance genes, which are frequently found on mobile genetic elements in collargol- and, to a lesser extent, AgNO3-treated subsystems. Elevated plasmid and integron-integrase gene levels, especially intI1, in response to collargol presence indicated the substantial role of AgNPs in promoting horizontal gene transfer in the treatment system. The pathogenic segment of the prokaryotic community was similar to a typical sewage community, and strong correlations between pathogen and ARG proportions were recorded in vertical subsurface flow filters. Furthermore, the proportion of Salmonella enterica was positively related to the Ag content in these filter effluents. The effect of AgNPs on the nature and characteristics of prominent resistance genes carried by mobile genetic elements in CWs requires further investigation.

Performance evaluation of a typical sewage system remediation project in Yangtze River protection

The Yangtze River protection is an important environmental protection strategy for China, and the quality and efficiency of the sewage system is also one of the environmental protection actions that China is working hard to implement in recent years. As the first batch of pilot cities for the protection of the Yangtze River, Wuhu City has significantly improved its sewage system through a series of comprehensive sewage system improvement engineering measures. This paper briefly described the general situation and measures of the sewage system renovation project in the CD area of Wuhu City, and based on the systematic thinking of “source-network-plant-river”, the performance of improving the quality and efficiency of the sewage system was evaluated. With the implementation of the sewage system remediation project, the water quality at the source and discharge outlet as well as the water quantity of sewage collected had been greatly improved. The sewage collection volume had been increased from 10,000 m3/d to 42,000 m3/d and the COD concentration of the influent has increased significantly. The introduction and analysis of this project may provide some reference for other similar sewage system remediation projects in China and other countries and regions.

Heavy Metal Pollution and Health Risk Assessment of Vegetable-Soil Systems of Facilities Irrigated with Wastewater in Northern China.

Soil pollution by heavy metals is a major concern in China and has received much attention in recent years. Aiming to investigate the status of heavy metal pollution and the safety of vegetables in the soil of wastewater-irrigated facilities, this study investigated the distribution and migration characteristics of heavy metals in vegetable–soil systems of facilities in a typical sewage irrigation area of the Xi River, Shenyang City, northern China. Health risks due to the fact of exposure to heavy metals in the vegetable soil of facilities and ingrown vegetables through different exposure pathways were evaluated. Spatial interpolation and a potential ecological risk assessment were applied to evaluate the soil quality. Bioaccumulation factors (BCFs) were used to analyze the absorption and transportation capacity of Cd, Cu, Pb, and Zn by different parts of different vegetables. The results showed that the average concentration of Cd exceeded the standard values by 1.82 times and accumulated by 11 times, suggesting that Cd poses the most severe pollution among the four metals in the soil of facilities in the Xi River sewage irrigation area. In the city, a significant accumulation of Cd in the soil was identified with different spatial distributions. Cd also contributed the most in terms of the estimated potential ecological risk index, while the impacts of the other three metals were relatively small. The concentrations of heavy metals were mostly lower than the limit set by the corresponding Chinese standards. Various BCFs were observed for the four metals in the order Cd > Zn > Cu > Pb. Vegetables also demonstrated different BCFs in the order of leaf vegetables > Rhizome vegetable > Solanaceae vegetable. The magnitude of the noncarcinogenic risk for all four heavy metals was less than one for all three exposure routes and did not cause significant noncarcinogenic health effects in humans. However, the carcinogenic risk of Cd from some vegetables via dietary intake was considered higher. Protection measures should be taken to implement better pollution control and land use planning.

Hydrodynamic cavitation as an efficient water treatment method for various sewage:- A review.

With the development of industry and the rapid growth of population, the current water treatment technologies face many challenges. Hydrodynamic cavitation as a green and efficient means of water treatment has attracted much attention. During the hydrodynamic cavitation, enormous energy could be released into the surrounding liquid which causes thermal effects (local hotspots with 4600 K), mechanical effects (pressures of 1500 bar) and chemical effects (hydroxyl radicals). These conditions can degrade bacteria and organic substance in sewage. Moreover, the combination of hydrodynamic cavitation and other water treatment methods can produce a coupling effect. In this review, we summarize the methods of hydrodynamic cavitation and the performance of water treatment for different types of sewage. The application of hydrodynamic cavitation reactors with different structures in water treatment are also evaluated and discussed. The design and optimization of high-performance hydrodynamic cavitation reactor are the most crucial issues for the application of hydrodynamic cavitation in water treatment. Finally, recommendations are provided for the future progress of hydrodynamic cavitation for water treatment.

Changes in antibiotic resistance genotypes and phenotypes after two typical sewage disposal processes

Antibiotic resistome is a growing concern around the world. Wastewater treatment plants (WWTPs) have been identified as hotspots for antibiotic resistance gene (ARG) research. However, the distribution of antibiotic resistance genotypes and phenotypes in biofilm wastewater treatment system is poorly understood. In this study, the abundance and fate of antibiotic resistance genotypes and phenotypes in two typical wastewater treatment processes [biological aerated filter (BAF), anaerobic-oxic (A/O)] were quantitatively studied. The average removal rate of total ARGs was greater than 90%. In the biological treatment unit, the abundance of ARGs increased in the A/O unit and decreased in the biofilm unit. In addition, the resistance of tetracycline resistant bacteria changed after sewage disposal, which was closely related to the evolution of bacterial community. In total, the removal rate of resistance bacteria in A/O system was lower than that in BAF system. Genotypes were the basis of determining the phenotypes of microbial resistance. But it is necessary to pay close attention to antibiotic resistance phenotype due to its high variability. More specifically, antibiotic resistance mitigation in WWTPs should focus more on removing bacterial hosts to reduce the release of ARGs into the environment.

Preliminary Study Into the Decolorization of Selected Dyes By the Ozone Application

Abstract Synthetic dyes widely used in many kinds of industry affect the colour of wastewater when released to environment due to insufficient treatment in typical sewage treatment plants. Only a small dose of those dyes may significantly affect colour of water and, according to the chemical composition, may pose risks to wildlife and humans. In the research described in this study, decolorization of three various dyes was investigated. Since colour removal of Congo Red such as Methylene blue using ozone have been reported by several authors, and the literature on Naphthol Green B is rather limited, in the present study we compare the decolorization rate of CR, MB and NGB. The colour removal occurred quickly and more than 90% of colour reduction was achieved within 3-6 minutes throughout all tested pH of the solution.

How are typical urban sewage treatment technologies going in China: from the perspective of life cycle environmental and economic coupled assessment.

Sewage treatment is an important public service, but it consumes a lot of energy and chemicals in the process of removing wastewater pollutants, which may cause the risk of pollution transfer. To find the corresponding hot issues, this paper took the lead in integrating life cycle assessment (LCA) with life cycle costing (LCC) to evaluate four most typical sewage treatment technologies with more than 85% share in China. It is found that anaerobic/anoxic/oxic (AAO) was the optimal treatment scheme with relatively small potential environmental impact and economic load. The normalized results show that the trends of the four technologies on eleven environmental impact categories were basically the same. Marine aquatic ecotoxicity potential accounted for more than 70% of the overall environmental impact. Contribution analysis indicates that electricity and flocculant consumption were the main processes responsible for the environmental and economic burden. Overall, electricity consumption was the biggest hot spot. Sensitivity analysis verifies that a 10% reduction in electricity could bring high benefits to both the economy and the environment. These findings are expected to provide effective feedback on the operation and improvement of sewage treatment. Graphical abstract.

Efficient degradation of polyacrylate containing wastewater by combined anaerobic–aerobic fluidized bed bioreactors

Polyacrylate containing wastewater (PCW) is the typical sewage discharged by the textile industry. It has extremely poor biodegradability, and chemical methods were used conventionally as the only way for treating PCW. This study is demonstrating a novel biological method. In batch experiment monod kinetics was applied to the experimental data, which indicated that anaerobic treatment used for PCW is feasible. The pilot-scale experiment combined a Spiral Symmetry Stream Anaerobic Bioreactor (SSSAB) and an air-lift external circulation vortex enhancement nitrogen removal fluidized bed bioreactor (AFB). The COD and NH4+-N removal reached up to 95.2% and 96.6%, respectively, which were higher than the value obtained by other chemical methods. High-throughput sequencing analysis indicated that the relative abundance of Proteobacteria, Firmicutes and Bacteroidetes increased, which contribute to the degradation of PCW. Therefore, PCW can be degraded efficiently by using a SSSAB-AFB technique and thus provides an alternative to the chemical methods.

Agravos sensíveis à atenção primária e os aspectos socio-sanitários de criança menores de dois anos

Objetivo: Verificar associação entre os aspectos sócio-sanitários e os processos de adoecimentos por condições sensíveis à atenção primária (diarreia e pneumonia) em crianças menores de dois anos residentes de um município do Sertão Central do Ceará. Método: Estudo transversal realizado com 94 mães de crianças menores de dois anos nos meses de agosto a outubro de 2016. Realizaram-se entrevistas estruturadas e análise inferencial por meio dos testes de Qui-quadrado e Linear by linear. Resultados: A diarreia mostrou-se associada com: água utilizada para beber (p=0,001), água utilizada para preparação dos alimentos (p=0,020) e contato com o chão/terra (p=0,011). Já a pneumonia associou-se com: tipo de moradia (p=0,007), forma como é feita a limpeza da casa (p=0,003), água utilizada para beber (p=0,027), tipo de esgoto (p&lt;0,001), tipo de descarte do lixo (p=0,027), contato da criança no chão/terra (p=0,030), limpeza do chão antes das brincadeiras (p&lt;0,001) e lavagem das frutas e verduras (p=0,006). Conclusão: Constatou-se que as condições sanitárias podem influenciar o desenvolvimento de condições sensíveis à atenção primária. Assim, os profissionais devem intervir nestas condições para melhor promoção da saúde da criança.

Pollution status and ecological risk of heavy metals in the soils of five land-use types in a typical sewage irrigation area, eastern China.

Sewage irrigation has been widespread in the water shortage area of eastern China and inevitably tends to result in heavy metal accumulation in soils. A total of 148 surface soil samples from five land-use types were collected in Longkou, a typical sewage irrigation area of China, and As, Cd, Cu, Pb, and Zn concentrations were determined. The Nemerow index method and improved fuzzy comprehensive evaluation method were used to examine the pollution status of heavy metals. The potential ecological risk was evaluated by the Hakanson model by adjusting the assessment threshold, and its spatial distribution was interpolated using geostatistical techniques. As, Cd, Cu, Pb, and Zn accumulated in different amounts in the five land-use types. Urban industrial land and mining land were moderately polluted, irrigated land was slightly polluted, orchards were minimally polluted, and bare land was at a safe level of pollution. Cd exhibited high percentages of strong and severe levels of potential ecological risks. For Cd, irrigated land, orchard, and bare land mainly presented moderate risks, whereas urban industrial land and mining land mainly presented high risks. The comprehensive ecological risk of the five heavy metals was at a severe level for all tested land-use classes except for bare land.