介质阻挡放电等离子体老化微塑料及对Zn (II)吸附的影响

为了在实验中缩短微塑料的老化时间,更真实地模拟自然老化条件,采用介质阻挡放电（DBD）等离子体老化聚乙烯微塑料（PE-MP）和聚丙烯微塑料（PP-MP）,同时研究了老化前后PE-MP和PP-MP对Zn （II）的吸附过程和机理.随着放电时间延长和输入电压升高,微塑料表面出现微小裂纹或孔洞,形成含氧官能团.老化后PE-MP和PP-MP对Zn （II）的吸附容量分别提高了22.7%和14.8%.老化前后微塑料对Zn （II）的吸附均符合准二级动力学模型.颗粒内扩散模型表明,Zn （II）在微塑料上的吸附过程可分为快速吸附,慢速吸附和吸附平衡3个阶段.同时,老化前后微塑料对Zn （II）的吸附均符合Langmuir吸附等温线模型.热力学结果表明,微塑料对Zn （II）的吸附是自发的吸热过程.Ca²⁺、腐殖酸和低pH值不利于微塑料对Zn （II）的吸附.     

包埋硫铁生物填料的制备及自养反硝化性能

采用包埋固定化技术制备了包埋硫铁生物填料(ESI Filler),基于升流式自养反硝化反应器开展动态实验研究,通过改变水力停留时间(HRT)、pH值、溶解氧(DO)等运行条件,探究ESI Filler反应器的脱氮效果及微生物群落结构组成。结果表明,当进水硝酸盐氮(NO₃^--N)浓度为30mg/L,HRT为10h时,NO₃^--N去除率不断上升至99.80%。当HRT缩短为2.5h时,NO₃^--N去除率降至61.35%。ESI Filler反应器对pH值和DO的改变具有较高的稳定性,NO₃^--N平去除率可维持在82.5%以上。但对低温的耐受性较差,当温度从35℃降低至15℃时,NO₃^--N平均去除率由90.12%降低至68.80%。运行164d后,球体未出现破裂散落的现象,表现出较长的使用寿命。通过扫描电镜发现,填料表面疏松多孔,附着大量杆状细菌,已成为微生物的良好载体。高通量测序结果表明,包埋颗粒中优势菌属为典型的自养反硝化功能菌Thiobacillus,丰度为80.79%。     

A novel approach for VOC source apportionment combining characteristic factor and pattern recognition technology in a Chinese industrial area

Volatile organic compound (VOC) emission control and source apportionment in small-scale industrial areas have become key topics of air pollution control in China. This study proposed a novel characteristic factor and pattern recognition (CF-PR) model for VOC source apportionment based on the similarity of characteristic factors between sources and receptors. A simulation was carried out in a typical industrial area with the CF-PR model involving simulated receptor samples. Refined and accurate source profiles were constructed through in situ sampling and analysis, covering rubber, chemicals, coating, electronics, plastics, printing, incubation and medical treatment industries. Characteristic factors of n-undecane, styrene, o-xylene and propane were identified. The source apportionment simulation results indicated that the predicted contribution rate was basically consistent with the real contribution rate. Compared to traditional receptor models, this method achieves notable advantages in terms of refinement and timeliness at similar accuracy, which is more suitable for VOC source identification and apportionment in small-scale industrial areas.     

Potassium ferrate pretreatment promotes short chain fatty acids yield and antibiotics reduction in acidogenic fermentation of sewage sludge

During the acidogenic fermentation converting waste activated sludge (WAS) into short-chain fatty acids (SCFA), hydrolysis of complex organic polymers is a limiting step and the transformation of harmful substances (such as antibiotics) during acidogenic fermentation is unknown. In this study, potassium ferrate (K₂FeO₄) oxidation was used as a pretreatment strategy for WAS acidogenic fermentation to increase the hydrolysis of sludge and destruct the harmful antibiotics. Pretreatment with K₂FeO₄ can effectively increase the SCFA production during acidogenic fermentation and change the distribution of SCFA components. With the dosage of 0.2 g/g TS, the maximum SCFA yield was 4823 mg COD/L, which is 28.3 times that of the control group; acetic acid accounts for more than 90% of the total SCFA. The higher dosage (0.5 g/g TS) can further increase the proportion of acetic acid, but inhibit the overall performance of SCFA production. Apart from the promotion of hydrolysis and acidogenesis, K₂FeO₄ pretreatment can also simultaneously oxidizes and degrades part of the antibiotics in the sludge. When the dosage is 0.5 g/g TS, the degradation efficacy of antibiotics is the most significant, and the contents of ofloxacin, azithromycin, and tetracycline in the sludge are reduced by 69%, 42%, and 50%, respectively. In addition, K₂FeO₄ pretreatment can also promote the release of antibiotics from sludge flocs, which is conducive to the simultaneous degradation of antibiotics in the subsequent biological treatment process.     

Evidence on the causes of the rising levels of CODMn along the middle route of the South-to-North Diversion Project in China: The role of algal dissolved organic matter

As the biggest inter-basin water transfer scheme in the world,the South-to-North Water Diversion Project（SNWD） was designed to alleviate the water crisis in North China.The main channel of the middle route of the SNWD is of great concern in terms of the drinking water quality.In this study,we tested the hypothesis that the dissolved organic matter（DOM） derived from the planktonic algae causes the rising levels of COD_Mn along the middle route by monitoring data on water quality（2015-20...     

Phenol degradation in waters with high iodide level by layered double hydroxide-peroxodisulfate: Pathways and products

Recently, layered double hydroxide-peroxodisulfate (LDH-PDS) as an advanced oxidation system can effectively remove organics by the pathway of free radical. However, little has been known if there is a potential risk regarding the formation of high toxic iodine byproducts through another pathway when LDH-PDS is used in high iodide waters at coastal areas. Therefore, this study investigated phenol degradation pathways and transformation products to evaluate both removal mechanism and potential risk by LDH-PDS in high iodide waters. The results showed that in LDH-PDS system, with the degradation of PDS, phenol degraded till below detection limit in 1 hr in the presence of iodide, while PDS and phenol were hardly degraded in the absence of iodide, indicating iodide accelerated the transformation of PDS and the degradation of phenol. What is more, it reached the highest phenol removal efficiency under the condition of 100 mg/L LDH, 0.1 mmol/L PDS and 1.0 mmol/L iodide. In LDH-PDS system, iodide was rapidly oxidized by the highly active interlayer PDS, resulting in the formation of reactive iodine including hypoiodic acid, iodine and triiodide instead of free radicals, which contributed rapid degradation of phenol. However, unfortunately toxic iodophenols were detected. Specifically, 2-iodophenol and 4-iodophenol were formed firstly, afterwards 2,4-diiodophenol and 2,6-diiodophenol were produced, and finally iodophenols and diiodophenols gradually decreased and 2,4,6-Triiodophenol were produced. These results indicated that LDH-PDS should avoid to use in high iodide waters to prevent toxic iodine byproduct formation although iodide can accelerate phenol degradation.     

Ozone episodes during and after the 2018 Chinese National Day holidays in Guangzhou: Implications for the control of precursor VOCs

The impact of reducing industrial emissions of volatile organic compounds (VOCs) on ozone (O₃) pollution is of wide concern particularly in highly industrialized megacities. In this study, O₃, nitrogen oxides (NOx) and VOCs were measured at an urban site in the Pearl River Delta region during the 2018 Chinese National Day Holidays and two after-holiday periods (one with ozone pollution and another without). O₃ pollution occurred throughout the 7-day holidays even industrial emissions of VOCs were passively reduced due to temporary factory shutdowns, and the toluene to benzene ratios dropped from ∼10 during non-holidays to ∼5 during the holidays. Box model (AtChem2-MCM) simulations with the input of observation data revealed that O₃ formation was all VOC-limited, and alkenes had the highest relative incremental reactivity (RIR) during the holiday and non-holiday O₃ episodes while aromatics had the highest RIR during the non-pollution period. Box model also demonstrated that even aromatics decreased proportionally to levels with near-zero contributions of industrial aromatic solvents, O₃ concentrations would only decrease by less than 20% during the holiday and non-holiday O₃ episodes and ozone pollution in the periods could not be eliminated. The results imply that controlling emissions of industrial aromatic solvents might be not enough to eliminate O₃ pollution in the region, and more attention should be paid to anthropogenic reactive alkenes. Isoprene and formaldehyde were among the top 3 species by RIRs in all the three pollution and non-pollution periods, suggesting substantial contribution to O₃ formation from biogenic VOCs.     

基于遥感数据估算近地面PM2.5浓度的研究进展

卫星反演的气溶胶光学厚度(AOD)具有广泛的空间覆盖度和相对较高的时空分辨率. 基于AOD与PM_2.5的相关关系来估算PM_2.5浓度已成为监测近地面PM_2.5的有效途径,其估算结果较可靠,能够为治理PM_2.5污染提供数据基础和科学依据. 从反演AOD数据集和PM_2.5浓度估算模型2个方面进行梳理归纳,从卫星轨道运行类型角度分析各类传感器的产品特征,并对缺失AOD的插补方法进行分类评价;对PM_2.5浓度的估算模型进行比较分析,指出不同模型的优缺点和适应性. 结果表明:①各类卫星传感器均具有特定功能及优缺点,其中地球同步轨道(GEO)卫星的快速发展,使其在估算PM_2.5浓度的应用上越来越广泛. ②插补后的AOD比AOD初始产品具有更连续的时空分布和更高的准确性,基于模型的多变量估算不仅可以实现数据的全面覆盖,还可以获得更好的估算精度. ③组合模型成为估算PM_2.5浓度的重要方法,机器学习模型的加入能够有效提高PM_2.5浓度的估算精度. 研究显示,利用AOD估算近地面PM_2.5浓度不仅弥补了地面PM_2.5监测的空间不连续性,更有助于解析PM_2.5浓度的时空分布特征及污染来源.      

辽宁营口滨海湿地春季迁徙期水鸟现状评价

2016－2020年连续对营口滨海湿地春季迁徙期水鸟种类和数量进行了调查监测。5年的长期调查监测共记录到水鸟4目8科39种,其中鸻鹬类、鸥类及雁鸭类（共占记录物种总数的92.31%）是构成营口滨海湿地春季迁徙期水鸟的主要类群。年际间水鸟种类和数量总体呈增加趋势,翘鼻麻鸭（Tadorna tadorna）、斑尾塍鹬（Limosa lapponica）、黑尾塍鹬（Limosa limosa）、大杓鹬（Numenius madagascariensis）、环颈鸻（Charadrius alexandrinus）、黑腹滨鹬（Calidris alpina）6种优势种处于动态变化之中。记录到的39种水鸟都被列入国内外有关保护条例,且分布达到全球种群评估数量1%的濒危大杓鹬、易危黑嘴鸥（Saundersilarus saundersi）、翘鼻麻鸭、环颈鸻、黑尾塍鹬、斑尾塍鹬、黑腹滨鹬7种水鸟,表明营口滨海湿地及水鸟具有国际重要保护价值。为更好地保护营口滨海湿地水鸟及其栖息地,建议尽早在目前未受保护的营口滨海湿地新建国家公园、自然保护区或自然公园,或纳入生态保护红线;并将营口滨海湿地申报列入《国际重要湿地名录》。     

基于简化基因组测序的三门湾海域无脊椎动物的遗传多样性分析

本研究通过简化基因组测序（2b-RAD）技术,对浙江省三门湾海域定居性优势无脊椎动物（哈氏仿对虾、口虾蛄、脊尾白虾、三疣梭子蟹、曼氏无针乌贼、棒锥螺和牡蛎）进行遗传结构和遗传多样性分析,以评估三门湾海域水生无脊椎动物资源现状,并为渔业可持续发展提供物种遗传资源监测依据。7个物种共获得12336～108139个SNP位点,变异位点比例为0.168%～1.571%。遗传分析结果显示,7个物种的平均核苷酸多样性（Pi）为0.147～0.306,平均观测杂合度（Ho）为0.142～0.289,多态信息含量（Polymorphism Information Content,PIC）为0.124～0.234,个体间平均遗传距离为0.118～0.246。本研究表明,三门湾水域7种代表性无脊椎动物中,生物群体变异位点比例较低,遗传多样性水平较低,且相同种群个体间的遗传分化较小, 结合本次对三门湾海域渔业资源调查分析,这可能与人工增殖放流等因素有关。