The safety and security of stored rainwater quality is the key to improve the efficiency of rainwater resources storage, and roof rainwater is the best scenario for rainwater storage and utilization. Through long-term monitoring of the evolution of water quality during the roof rainwater storage process, different storage materials (PE and glass) and different DO regulation modes (sealing and aeration) were constructed, and 16S rRNA microbial diversity sequencing and environmental factor correlation methods were used to characterize the changes in water quality under microbial metabolism during the rainwater storage process, as well as the potential risks of utilization and health. The results showed that the degradation of COD occurred mainly in the first 10 days of the storage process, and the nutrients were transformed mainly by microbial metabolism.
View Article and Find Full Text PDFThe tea plant is a kind of ammonium-preferring crop, but the mechanism whereby ammonium (NH ) regulate its growth is not well understood. The current study focused on the effects of NH on tea plants. Transcriptomic analysis was performed to investigate the early- and late-stage NH deprivation and resupply in tea plants shoots.
View Article and Find Full Text PDFTo explore the effects of dissolved oxygen (DO) on the treatment of low carbon/nitrogen municipal wastewater, this study examined the characteristics of the microbial community in a low carbon source environment. The treatment process was conducted with the aeration area having DO concentrations of 2-3, 1-2, and lower than 1 mg·L. The results demonstrated that reduced DO concentration in the aeration area increased the efficiency of the nitrogen removal process by 20.
View Article and Find Full Text PDFNitrogen removal in constructed wetlands (CWs) is highly affected by the supply of organic carbon. Thus, to enhance nitrogen removal in the horizontal subsurface flow of CWs, plant carbon sources were added during the downstream portion of the wetland. Moreover, the characteristics of static release and the denitrification potential of were evaluated using three different pretreatment methods (i.
View Article and Find Full Text PDFTwo parallel digestion systems of food waste (FW) and waste-activated sludge (WAS) were successfully initiated using a continuous stirred-tank reactor (CSTR), and the effect of different reduction extents of sludge retention time (SRT) on the co-digestion of FW and WAS was investigated. SRT Reduction extents longer than 8.3 d were not conducive to the stable operation of the co-digestion system when the organic load rate (OLR) was increased.
View Article and Find Full Text PDFHuan Jing Ke Xue
September 2018
In order to investigate the consumption mechanism of organic contaminants in different biological metabolism pathways within an urban sewage network, a pilot-scale system using two kinds of sediments (urban sewage sediment and artificial sediment) was constructed. The pilot system was operated to study the migration and transformation characteristics of COD, methane, nitrate, and sulfate between sediment and sewage. Results showed that the variation of COD in sewage was 170.
View Article and Find Full Text PDFIn order to investigate the effect of antibiotics on composting behavior, enzymatic activity, and microbial community succession during the aerobic composting of human feces using sawdust as the bulk carrier, tetracycline (TC) was added to the composting system at four different concentrations (0, 100, 250, and 500 mg·kg). Microbial community succession was examined by high-throughput 16S rRNA gene sequencing. The results showed that the influence of TC on the physical and chemical properties of compost was related to its concentration.
View Article and Find Full Text PDFThe aim of this study was to investigate the effectiveness of ozonation on the removal of organic matter with low coagulability from municipal secondary effluent. The results revealed that the removal efficiency of coagulation generally remained quite low. The residual organic matter belonged to low coagulability organic matter.
View Article and Find Full Text PDFHuan Jing Ke Xue
July 2018
Aerobic composting experiments were conducted under three different temperatures (55℃, 35℃, and non-temperature-controlled) with human feces and sawdust as the compost material and bulky matrix respectively. Attention was paid to the effects of temperature on the removal of four typical antibiotics (tetracycline, chlortetracycline, sulfadiazine, and ciprofloxacin) during human feces aerobic composting. Furthermore, three specific experiments were conducted to identify the possible antibiotic degradation mechanisms in aqueous solution and during composting with moist sterile sawdust but without feces and composting with feces and moist sterile sawdust.
View Article and Find Full Text PDFWe chose () and poliovirus as a typical pathogenic bacterium and virus, respectively. The effects of two typical disinfectants (chlorine and ultraviolet) on each of them were investigated based on microbial culture and quantitative PCR methods. The results showed that Poliovirus was appreciably more resistant to chlorine (required disinfection dose for 1-log microbial reduction:10.
View Article and Find Full Text PDFTargeting at the characteristics of low concentration but high risk of endocrine disrupting compounds in the aquatic environment, the current study investigated the distribution of estrogenicity and E2 level using recombinant yeast estrogen screen (YES) and enzyme linked immunosorbent assay (ELSIA) during domestic wastewater treatment processes. The results showed that the levels of estrogenicity and E2 in influents of wastewater treatment plants were 4.35-7.
View Article and Find Full Text PDFIn order to accurately evaluate the comprehensive ecotoxicity of domestic wastewater and the toxicity reduction efficiency of different treatment processes, standardized assays focusing on , SOS/umu test and yeast estrogen screen were applied. Simultaneously, male zebrafish was used to address the mode of action of endocrine disrupting effects of wastewater and reclaim water on aquatic life. Results of this study indicated that the influent was severely polluted:highly acute toxicity, genotoxicity and estrogenicity were observed.
View Article and Find Full Text PDFBecause of the limited dissolved organic matter removal efficiency in conventional pre-ozonation-coagulation process, the hybrid ozonation-coagulation (HOC) process was developed for wastewater reclamation in this study. In this process, coagulation and ozonation could synchronize within a single unit. Compared with the pre-ozonation-coagulation process and traditional coagulation process at the same coagulants dosage, the HOC process exhibited higher treatment efficiency, especially better organic matter removal performance at each pH value, which were 37.
View Article and Find Full Text PDFPolyphenols are one of the most important secondary metabolites, and affect the decomposition of litter and soil organic matter. This study aims to monitor the mass loss rate of tea leaf litter and nutrient release pattern, and investigate the role of tea polyphenols played in this process. High-performance liquid chromatography (HPLC) and classical litter bag method were used to simulate the decomposition process of tea leaf litter and track the changes occurring in major polyphenols over eight months.
View Article and Find Full Text PDFJ Environ Sci Health A Tox Hazard Subst Environ Eng
November 2015
Antibiotic resistance of fecal coliforms in an urban river poses great threats to both human health and the environment. To investigate the occurrence and distribution of antibiotic resistant bacteria in an urban river, water samples were collected from the Chanhe River in Xi'an, China. After membrane filtration of water samples, the tetracycline resistance rate of fecal coliforms and their resistance genes were detected by plating and polymerase chain reaction (PCR), respectively.
View Article and Find Full Text PDFHuan Jing Ke Xue
November 2014
In order to explore heavy metals pollution situation,changes in characteristics, the correlation between each heavy mental and pollution source analysis of Xi'an various regions in different season in one year. This study collected several samples of Xi'an rainfall typical urban trunk roads throughout the year in 2013 and used inductively coupled plasma mass spectrometry (ICP-MS) to determine the level of Fe, Mn, Pb, Zn, Al, Cd of the samples, then, analyzed the seasonal change of heavy mental. Studies have shown that: the heavy metal of Xi'an road runoff pollutes seriously, the concentration of Fe over three times of the national standard and maintain the higher levels throughout the year, meanwhile the concentration with the intensity of human activities increases.
View Article and Find Full Text PDFHuan Jing Ke Xue
September 2014
The biodegradability and speciation of organics were studied through long-term analysis of A2/O treatment. The majority of the organic matters were particle organics which accounted for 61% of the total organics. The proportions of rapidly degradable, slowly degradable and refractory organics were 15.
View Article and Find Full Text PDFThe volumetric oxygen transfer coefficient (k(L)a) was tested with mature aerobic granules in the same aeration measurement device and under the same aeration conditions. The k(L)a (min(-1)) was 0.586 1 +/- 0.
View Article and Find Full Text PDFBased on morphological analysis and PDA online monitoring, a method was established for the evaluation of floc strength. In order to calculate the binding force of flocs formed under a given flocculation condition, a jar test was conducted. The morphological characteristics of flocs were studied by image analysis and the particle image velocimetry technology.
View Article and Find Full Text PDFJ Zhejiang Univ Sci B
December 2012
This study aimed to analyze the volatile chemical profile of Longjing tea, and further develop a prediction model for aroma quality of Longjing tea based on potent odorants. A total of 21 Longjing samples were analyzed by headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Pearson's linear correlation analysis and partial least square (PLS) regression were applied to investigate the relationship between sensory aroma scores and the volatile compounds.
View Article and Find Full Text PDFWater Sci Technol
January 2013
Densification may be an alternative method for controlling sludge bulking; however, little information is available on the method. Various methods including different oxygen concentrations, surface velocities of aeration, calcium concentrations and extended starvation period were employed for triggering densification of filamentous sludge in this study. It was found that high surface velocity of aeration could effectively improve the settleability of filamentous sludge in the short term, which resulted in filamentous granulation, but could not avoid filamentous bulking even after granulation.
View Article and Find Full Text PDFHuan Jing Ke Xue
June 2012
Qualitative rather than quantitative method was available in the study of aerobic granular sludge. This work therefore investigated two systems, one was the conventional heterotrophic system without anaerobic mix period, the other was the phosphorous removal system with anaerobic period, and it was found that the latter was more stable from the point view of diameter, density and morphology. It was further found that the stability of granule was associated with the metabolic characteristics, i.
View Article and Find Full Text PDFUncontrolled variation of diameter and density of aerobic granules frequently resulted in instability and thus brought about operation failure. An innovative reactor was therefore developed for the control of diameter and density of aerobic granules. There were two ways to select the sludge, one was the short settling time select the big and dense granules in the reactor, and the other was the hydro cyclone that washed out the big and compact granules preventing big and compact fourthly growth in the reactor.
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