This study investigated the microbial colonization, bacterial community and potential risks in natural (montmorillonite (MMT)) and artificial substrates (activated carbon (AC), polypropylene (PP) and polystyrene (PS)) by microcosm incubations in surface water. Biofilm biomass and polysaccharide content indicate that the colonization potential of microbes on different substrates followed the order of AC > MMT > PP > PS. High-throughput sequencing results reveal that microbes selectively colonized various substrates and formed unique bacterial community. Compared to the artificial substrate, natural substrate enriched with high abundance but low diversity of microbial community. In addition, bacterial community on natural substrates exhibited stronger nitrogen cycling function than artificial substrates, whereas bacterial community on artificial substrates (especially microplastics) exhibited stronger carbon cycling functions, such as aromatic_compound_degradation and hydrocarbon_degradation. Also, Brevundimonas diminuta, Sphingomonas paucimobilis, Paracoccus sanguinis and other twenty-five species of pathogenic bacteria were identified in various substrates and their abundance was higher on MMT than on other substrates. However, many more species of pathogenic bacteria on microplastic are associated with human diseases, implying a higher environmental risk. These results indicated that microbial community composition and function on natural and artificial substrates exhibited substrate-driven differences, highlighting the lower concerns of artificial substrates than natural ones with associated biofilms in surface water.

Increasingly accumulated microplastics (MPs) in sludge could affect the sludge treatment process, while the contributions and mechanisms of MP particles and the released organic matters (MP-DOM) are not fully understood. To fill this gap, this study systematically investigates the effects and mechanisms of MPs on sludge anaerobic digestion. In the presence of MPs, the hydrolysis and acidogenesis of organic matters and methanogenesis all decreased due to the inhibition on the activity of anaerobic microorganisms and key enzymes. Mechanism analysis showed that MPs mainly acted as substrates to enrich anaerobic microorganisms and reduced the abundance and function of free microorganisms in sludge that metabolized organic matters. Moreover, a large amount of organic compounds including various plasticizers (dibutyl phthalate) and chain-scission products (benzoic acid) from physical abrasions of MPs with sludge particles, which made a 50.9-51.6 % contribution to the MP-inhibited sludge anaerobic digestion by the chemical toxicity and generated reactive oxygen species. Owing to the decreased digestion performance, the risk associated with ARGs and pathogenic bacteria increased distinctly. The findings highlight the concerns about MP-derived organic compounds compared to the substrate themselves and suggest the necessity for removing MPs in the sludge of wastewater treatment plants (WWTP).

Microplastics (MPs) exists widely in the environment, and the resulting pollution of MPs has become a global environmental problem. Plants can absorb MPs through their roots. However, studies on the mechanism of the effect of root exposure to different size MPs on vegetables are limited. Here, we use Polystyrene (PS) MPs with different particle sizes to investigate the internalization, physiological response and molecular mechanism of lettuce to MPs. MPs may accumulate in large amounts in lettuce roots and migrate to the aboveground part through the vascular bundle, while small particle size MPs (SMPs, 100 nm) have stronger translocation ability than large particle size MPs (LMPs, 500 nm). MPs can cause physiological and biochemical responses and transcriptome changes in lettuce. SMPs and LMPs resulted in reduced biomass (38.27 % and 48.22 % reduction in fresh weight); caused oxidative stress (59.33 % and 47.74 % upregulation of SOD activity in roots) and differential gene expression (605 and 907 DEGs). Signal transduction, membrane transport and alteration of synthetic and metabolic pathways may be the main causes of physiological toxicity of lettuce. Our study provides important information for understanding the behavior and fate of MPs in edible vegetables, especially the physiological toxicity of MPs to edible vegetables, in order to assess the potential threat of MPs to food safety and agricultural sustainable development.

Light irradiation is considered as most important process for the aging of microplastics (MPs); however, which factors drive the process is still unknown. This study investigated the role of typical environmental factors including ultraviolet (UV), oxygen, temperature and physical abrasion in the photoaging of polystyrene (PS) in freshwater. Results showed that UV irradiation and abrasion were dominant factors for affecting photoaging of PS based on dynamic analysis in the property of MP itself and leachate. Especially, when both factors worked together on MPs, they caused more destructive effect. Mechanical exploration revealed that photoaging of MPs was mainly controlled by reactive oxygen species (ROS,1O2) generated from the reaction of dissolved oxygen/water molecules with polymer radicals initiated by UV energy. As an attacker on MPs, ROS formation was significantly linked with UV intensity, highlighting the important role of UV. The fragmentation was correlated to abrasion intensity, where a higher abrasion generated stronger physical force to tear MPs into fragments. The low roles of oxygen and temperature were presumably related to multiple effects of ROS formation and UV absorption. The findings firstly clarify the drivers in the photoaging of MPs, and contribute our effort to assess their fate and pollution risk in the environment.

Nanoplastics (NPs) have become an emerging pollutant that has attracted much attention. As plants are the major food sources, it will be of great use to investigate NPs in plants. The crack-entry mode is considered to be the main mode for NPs to enter plants roots. The migration of NPs is feasible, which includes the process of internalization into xylem vessels through the apoplast pathway and migration to the aerial part. The development of chromatography, mass spectrometry, and labeling techniques has made it possible to quantify NPs, although this is difficult to apply in practical settings. How to analyze and quantify NPs in complex environmental media is still an urgent problem to be solved. This article provides a comprehensive overview of NPs detection, uptake, migration, current analytical techniques and ecological risks in plants, bringing together scattered information and analyzing current deficiencies, providing recommendations for future research.

In this study, a combination of property analysis and high-throughput sequencing was used to investigate the microbial colonization ability and their community structures and functions in polypropylene microplastics (PPMPs), polystyrene microplastics (PSMPs) and montmorillonite (MMT), respectively as the representatives of artificial and natural substrates in aerobic sludge treatment. After 45 d of incubation, the surface properties of substrates were altered with the increased oxygen functional groups and surface roughness, indicating microbial settlement. Moreover, MPs had different microbial structures from that of MMT, and PSMPs exhibited higher microbial diversity and abundance than PPMPs and MMT. Also, these substrates changed the inherent ecological niche in sludge. Especially, the abundance of some pathogens (e.g., Pseudomonas, Klebsiella and Flavobacterium) was increased in MPs, and the disease risk of Kyoto Encyclopedia of Genes and Genomes metabolic pathway (e.g., Infectious diseases: Bacterial, Infectious diseases: Parasitic and Immune diseases) was higher. Also, the presence of MPs inhibited the decomposition of organic matter including soluble chemical oxygen demand and protein compared to natural substrates. The findings revealed the crucial vector role of MPs for microbes and the effect on aerobic sludge treatment, highlighting the necessity of MP removal in sludge.

Although anaerobic bioengineering treatment of chicken manure has the advantages of low energy consumption, less pollution, and recyclable biomass energy, antibiotics are usually added in the process of modern intensive farming. And antibiotics still exist in feces and pose a threat to human health. Therefore, this study aimed to deeply understand the role of TC in the anaerobic digestion of chicken manure and to analyze the effect of tetracycline antibiotics on the anaerobic digestion of chicken manure based on data mining. In this study, chicken manure was used as raw material for anaerobic fermentation, and the effects of tetracycline (TC) on anaerobic and anaerobic fermentation of chicken manure were compared through batch and sequence experiments. Also, this study analyzes the fermentative transformation to elucidate the effect of TC on anaerobic manure conversion in chicken manure, which further studies the effect of TC on the anaerobic fermentation of chicken manure. The experimental results in this study show that when the TC concentration is 50–150 mg/L, the content of tryptophan and tyrosine proteins in the treatment group is also higher than that in the control group. It shows that at low concentrations (10, 25 mg/L), TC mainly promotes the degradation of LEPS by promoting the dissolution of intracellular substances in the sludge. With the increase of TC concentration (50–300 mg/L), TC mainly promotes the breakdown of the sludge cell membrane by promoting the rupture of the sludge cell membrane, thereby promoting the degradation of LEPS.

In this study, the process stability and the protective role of extracellular polymeric substances (EPS) were evaluated during the anaerobic digestion (AD) of chicken manure (CM) suffering chlortetracycline (CTC) concentrations from 0 mg/L to 100 mg/L in a continuous stirred tank reactor (CSTR) operated for 270 days. Results showed that during the phases with low levels of CTC (0, 1.25, and 2.5 mg/L), the volume biogas production rate increased from 0.77 +/- 0.01 L/(L.d) to 1.15 +/- 0.02 L/(L.d) with an obvious decrease in the concentration of VFAs from 2.57 +/- 0.07 g/L to 1.17 +/- 0.08 g/L. The reactor remained stable with continued operation as the CTC in the CM spiked to 5 mg/L and 10 mg/L, respectively. During the phases with high levels of CTC (25, 50, and 100 mg/L), despite a reduction in biogas production of 18%, 43% and 56%, respectively, compared to the steady stage, the reactor finally could maintain the inhibition-steady stage. This stage was characterized by steady biogas production along with accumulating VFAs and ammonia nitrogen, which increased the inhibition thresholds of CTC on the AD of CM. An appreciable increase in EPS was identified. Spectral analysis results showed the fluorescence of protein-like in EPS was quenched with increasing dosages of CTC. The quenching constant (K-q) induced by CTC for tyrosine was found to be 3.969 x 10(12) (R-2 = 0.942), implying that the increased CTC prompt anaerobic microbes excrete more EPS to protect themselves from the CTC toxins by the formation of the complex tyrosine-CTC. This protection led to a decrease in the biodegraded CTC from 61.6 to 40.9%, and an increase in the adsorbed CTC on EPS in sludge from 35 to 56.1%. The results indicated that the absorbed CTC on EPS may pose a risk to the soil ecosystem due to the agriculture utilization of the biogas residue.

A simultaneous partial nitritation, anammox, denitrification, and COD oxidation (SNADCO) process was used to evaluate the nitrogen and biodegradable organic matter removal of swine manure digestate based on a nitrite limitation and ammonium surplus strategy. As influent ammonium concentration increased from 500 mg/L to 2100 mg/L, the 5 day biochemical oxygen demand (BOD5) maintained at a high removal efficiency of 95.4%. However, nitrogen removal efficiency (NRE) decreased from 90.9% to 68.2% due to the inhibition of AnAOB caused by an ammonium concentration of 2100 mg/L. The contribution of AnAOB to nitrogen removal was 75.6-86.5%, while that of denitrifying bacteria was 4.6-7.0%. In the case of COD removal, the contributions were from ordinary heterotrophic organisms and denitrifying bacteria, at 27.1-64.9% and 11.2-22.1%, respectively. The results of specific bacteria activity tests and microbial analysis showed that a highly efficient synergism between functional microorganisms is essential for the stability of the SNADCO process.

This paper presents a study of V and N co-doping TiO2 embedding multi-walled carbon nanotubes (MWCNTs) supported on γ-Al2O3 pellet (V/N-TiO2-MWCNTs/γ-Al2O3) composite photocatalyst induced by pulsed discharge plasma to enhance the removal of acid orange II (AO7) from aqueous solution. The photocatalytic activity of the V/N-TiO2-MWCNTs/γ-Al2O3 composite to AO7 removal induced by the pulsed discharge plasma was evaluated. The results indicate that the V/N-TiO2-MWCNTs/γ-Al2O3 composite possesses enhanced photocatalytic activity that facilitates the removal of AO7 compared with the TiO2-MWCNTs/γ-Al2O3 and TiO2/γ-Al2O3 composites. Almost 100% of AO7 is removed after 10 min under optimal conditions. The V0.10/N0.05-TiO2-MWCNTs/γ-Al2O3 photocatalyst exhibits the best removal effect for AO7. Analysis of the removal mechanism indicates that the enhancement of the removal of AO7 resulting from V and N co-doping causes TiO2 lattice distortion and introduces a new impurity energy level, which not only reduces the band gap of TiO2 but also inhibits the recombination of the ecb-/hvb+ pairs.

Anaerobic digestion (AD) of high solid swine manure has been facing the problem of inhibition and accumulation of ammonia. In order to improve the waste treatment efficiency as well as to obtain a higher methane yield, adding carbon-rich raw materials seems to be a good choice to optimize the carbon to nitrogen ratio (C/N) of the substrate in AD system. Recently, biochar has become an important exogenous additive to relieve the ammonia inhibition of AD due to its excellent mesoporous structure and adsorption performance. Therefore, in order to investigate the influence of three factors including total solid concentration (TS), amount of added biochar and C/N on biogas production rate, a regression equation was obtained using quadratic orthogonal rotation method by a five-level, three-factor experiment. The results of variance analysis showed that the p value of the model was smaller than 0.0001, which was quite significant. The out of fitness of the model was 0.3507 > 0.1, so the fitting effect is good. The optimum theoretical methane yield of 269 mL/g VS was obtained under the parameter combination values of 6.18% (TS), 8.73% (amount of added biochar) and 21.69 (C/N), respectively. The order of the importance of selected parameters from highest to lowest was TS > C/N > biochar addition.

高等院校培养人才的质量包括专业素质和思想政治素质,而思想政治教育为建设中国特色社会主义提供思想保障."环境监测实验"是一门实践性很强的课程,重在培养环境专业学生的综合能力.本文通过剖析"环境监测实验"本科教学过程中"思政育人"的必要性、重要性、及存在的不足,提出了"环境监测实验"教学过程中"思政育人"的策略,以满足新时代中国特色社会主义建设对环境专业人才的要求.

Shaping the microbial community involved in anaerobic digestion (AD) systems to achieve highly efficient methane production is a major challenge. In order to improve the methane recovery from dairy manure, soil, which has the potential of enhancing methane production from biomass, was used in an AD system as an additive. The results showed that the AD process performance and methane production efficiency were significantly improved by soil; an improvement in daily methane production, reduced time to steady state, enhancement of the methane content, and reduction in carbon dioxide content were obtained. The maximum methane production was obtained at a feedstock: soil ratio of 2.5:1 with yellow soil addition, which was 147.7 L/kg volatile solids (VS) and 25.4% higher than that of the control. High-throughput sequencing of the 16S ribosomal RNA gene and synthetic solution with cations equivalent to those of yellow and black soil revealed that soil addition mainly stimulated the growth of bacterial genera Ochrobactrum and Clostridium and archaeal genera Methanosaeta and Methanosarcina. The method of ion extraction was used to extract ions from the soil, and the ions were verified to be a main contributor to methane production improvement. By mimicking the cation components of soil, a synthetic solution was prepared and used in the AD system. The results showed that the cations contained in the ion liquid played a key role in improving methane production. The contribution of VS in the soil to the AD system was studied and found to have no significant effect on the improvement in methane production. It was found that the cations in soil played a key role in enhancing AD efficiency. Therefore, the simplified, low cost, and efficient approach used in this study had good practicability and could be used for treating other various biowastes with high energy recovery, which has the potential of promoting the development of AD technology. (C) 2019 Elsevier Ltd. All rights reserved.

通过国内外专利大数据分析,对杂环类缓蚀剂的专利技术进行归纳总结,对咪唑啉缓蚀剂的技术演化进行了系统梳理,进而指出了咪唑啉类缓蚀剂的发展方向,以期对油田用有机缓蚀剂的产业发展提供有价值的参考.

Poultry manure is the main source of agricultural and rural non-point source pollution, and its effective disposal through anaerobic digestion (AD) is of great significance; meanwhile, the high nitrogen content of chicken manure makes it a typical feedstock for anaerobic digestion. The performance of chicken-manure-based AD at gradient organic loading rates (OLRs) in a continuous stirred tank reactor (CSTR) was investigated herein. The whole AD process was divided into five stages according to different OLRs, and it lasted for 150 days. The results showed that the biogas yield increased with increasing OLR, which was based on the volatile solids (VS), before reaching up to 11.5 g VS/(L·d), while the methane content was kept relatively stable and maintained at approximately 60%. However, when the VS was further increased to 11.5 g VS/(L·d), the total ammonia nitrogen (TAN), pH, and alkalinity (CaCO3) rose to 2560 mg·L−1, 8.2, and 15,000 mg·L−1, respectively, while the volumetric biogas production rate (VBPR), methane content, and VS removal efficiency decreased to 0.30 L·(L·d)−1, 45%, and 40%, respectively. Therefore, the AD performance immediately deteriorated and ammonia inhibition occurred. Further analysis demonstrated that the microbial biomass yield and concentrations dropped dramatically in this period. These results indicated that the AD stayed steady when the OLR was lower than 11.5 g VS/(L·d); this also provides valuable information for improving the efficiency and stability of AD of a nitrogen-rich substrate.

针对抗生素污染对鸡粪厌氧消化影响不明的问题,该文利用批次试验探究了不同质量浓度金霉素(chlortetracycline,CTC)(4～200 mg/L)对鸡粪中温厌氧消化过程、产气效率及抗生素降解的影响.结果表明,低浓度的CTC(质量浓度≤20 mg/L)促进了鸡粪中温厌氧消化作用,其对累积水解、酸化、乙酸化及甲烷化的最大促进率较对照(质量浓度0 mg/L)分别提高了12.69％,11.55％,11.31％和9.82％,厌氧消化有效降解了鸡粪中的CTC,降解率为59.87％～71.95％,这是因为厌氧污泥胞外聚合物(extracellular polymeric substances,EPS)由结合态(松散结合态(loosely bound EPS,LB-EPS)和紧密结合态(tightly bound EPS,TB-EPS))转化为黏液态(slime EPS,S-EPS)促进了水解作用,另外,CTC降解提供的碳源进一步促进了甲烷的生成.高浓度CTC(质量浓度≥60 mg/L)抑制了鸡粪中温厌氧消化作用,且抑制率随CTC质量浓度的增大而升高,对累积水解、酸化、乙酸化及甲烷化的最大抑制率分别为16.48％,18.54％,18.96％和19.94％,CTC的降解率为43.4％～51.44％;在此条件下污泥EPS较对照提高了13.81％～39.23％,其中EPS蛋白浓度由943.01 mg/L增加为1083.69～1338.20 mg/L.中温条件下CTC对鸡粪厌氧消化抑制阈值为22.16 mg/L.消化结束后,沼液和沼渣中的CTC分别占总量的0.46％～3.13％和96.87％～99.54％,表明CTC绝大部分残留在沼渣中,存在较大环境风险,所以应对沼渣进一步无害化处理后才可还田使用.

Magnetic Fe3O4 assembled on nanoscale zero-valent iron (nZVI) supported on an activated carbon fiber (ACF) to form nanoscale magnetic composites (nZVI-Fe3O4/ACF) for removing Cr(VI) and Cu(II) from aqueous solution through a permeable reactive column was synthesized via an in situ reduction method. The nZVI-Fe3O4/ACF composites and the interaction between nZVI-Fe3O4/ACF and both Cr and Cu ions were characterized by field emission scanning electron microscopy (FESEM) with EDX, TEM, XRD, and XPS. Batch experiments were used to analyze the effects of main factors on Cr(VI) removal and investigate the simultaneous removal of Cr(VI) and Cu(II) through a permeable reactive column. The results indicated that the ACF and Fe3O4 can inhibit the agglomeration and enhance the dispersibility of nZVI, and Fe3O4 and nZVI displayed good synergetic effects. The removal efficiency of Cr(VI) improved with the increase amount of Fe3O4 in the nZVI-Fe3O4/ACF composites. With low initial concentration of Cr(VI) and acidic conditions, ~ 90% of 20.0 mg·L−1 Cr(VI) in the solution was removed after 60 min. The removal of Cr(VI) was also affected by coexisting ions. The removal efficiency of 10.0 mg·L−1 Cu(II) was ~ 100% after 45 min of reaction, and the presence of Cu(II) can accelerate the reduction of Cr(VI). The simultaneous removal mechanisms of Cr(VI) and Cu(II) by the nZVI-Fe3O4/ACF composites also were proposed.

"双一流"学科建设是为实现我国高等教育强国作出的重大战略决策.在"双一流"学科建设背景下,本文针对我国各高校非优势学科面临的挑战与机遇,如何在较短时间内改变自身学科发展的劣势,提出更新观念、以培育师资队伍为基础、以强化特色为突破点、主动联合、开放自我、牢抓人才培养的初心,走符合自身实际的学科建设道路.

针对高固体鸡粪厌氧消化运行困难问题,利用完全混合式厌氧反应器(CSTR),通过逐级提高进料总固体浓度(TS)的方法,研究不同进料TS((5.20士0.56)％、(7.24士0.36)％、(9.30±0.26)％和(6.22士0.26)％)的鸡粪连续中温厌氧消化效果.实验结果表明,进料TS由(5.20±0.56)％提高为(9.30士0.26)％,挥发性固体(VS)产气率由(0.64±0.05)L·g-1下降为0.07 L·g-1,有机物去除率明显减少,挥发性脂肪酸(VFAs)由(0.53±0.02)g·L-1累积至(1.62士0.02) g·L-1,总氨氮浓度(TAN)和游离氨浓度(FA)分别由(1.06±0.11)g·L-1和(0.07±0.02) g·L-1累积至3.40 g·L-1和0.68 g·L-1,消化过程受到氨抑制.采用Boltzmann模型对不同氨氮浓度下VS产甲烷率和VS去除率进行模拟,拟合结果表明,TAN升高所引发的FA持续累积导致高固体鸡粪厌氧消化氨抑制逐步形成,与VS产甲烷率相比,VS去除率对氨氮的抑制响应具有滞后性.降低进料TS至(6.22±0.26)％,氨抑制得到有效缓解,但反应器处于“抑制稳定状态”.因此,为保证反应器长期高效平稳运行,建议鸡粪连续中温厌氧消化的进料浓度不超过7.24％.研究为高固体鸡粪厌氧消化的工程化应用提供参考.

In order to assess the sulfate-induced inhibition of anaerobic digestion of antibiotic manufacturing bio-waste. The effect of COD/SO ratio on biogas production potential and substrate utilization characteristics during the acidogenic phase of anaerobic digestion of penicillin bacterial residues were investigated through batch experiments. The results obtained indicated that biogas production was gradually enhanced after 10 days of anaerobic digestion. However, the maximum cumulative methane production probably exceeded about 208 mL·g(on TS basis) since COD/SO≥3. Because adaptive acclimation, more than 71% COD removal, which may have been converted to methane, was achieved. Consequently, at COD/SO≤1.5, methane production was suppressed by 49% and 100% when the organics and SO removal rates were less than 17% and 5%, respectively. This indicated that methanogens and sulfate-reducing bacteria were inhibited at high sulfate loading rates. In addition, the COD balance analysis revealed that less than 9.1% of the COD was converted to methane. However, 5.0%-9.0% of the COD was used for sulfate reduction. This means that methanogens are more susceptible than sulfate-reducing bacteria to sulfide-induced inhibition. The S balance showed that the reduced sulfate was mainly present as sulfide in the digester. A small fraction of it was present as hydrogen sulfide in the biogas. The analysis of substrate utilization characteristics during the acidogenic phase revealed that methanation of soluble protein was initiated after methanation of soluble carbohydrate.