针对《固体废物处理与处置》课程知识点存在的面广形散,容易造成学生学习前后难以有效衔接,课程知识框架无法有效搭建的问题,我校以学生为中心重点做好课程章节教学体系的顶层设计,全面优化课堂教学内容,结合化工优势丰富教学内容,并强化教学过程管理突出学习过程考评等方式,努力做到以学生为中心,激发学生内生学习动力,持续改进课程教学效果,为化工类院校该课程持续改进教学效果,全面贯彻工程教育理念提供参考.

为完善杉木(Cunninghamia lanceolata)高效栽培技术,采用正交试验方法,研究施肥、造林密度和种植穴规格3个因素对杉木生长的影响,以期获得杉木高产的最佳组合.结果表明,造林密度和施肥条件是影响杉木早期生长的关键因素,种植穴规格影响不显著.不同区域的最优栽培技术组合略有不同,融安县和融水县试验点最优组合为A3B1C3,即造林密度1666株/hm2,种植穴规格40cm×40cm×40cm,施用基肥+追肥;全州县试验点最优组合为A1B2C2,即造林密度2500株/hm2,种植穴规格50cm×50cm×50cm,施用基肥;南丹县试验点最优组合为A1B3C3,即造林密度2500株/hm2,种植穴规格60cm×60cm×60cm,施用基肥+追肥.经综合分析,杉木造林密度宜选择1666～2500 株/hm2,立地条件较好的林地可适当稀植,种植穴宜选择40cm×40cm×40cm的规格,基肥+追肥的施肥条件可获得较高产量.

采用标准样地法对广西南丹县20年生秃杉人工林碳储量及其空间分布格局进行研究.结果表明,秃杉各器官碳含量为436.4～501.2 g/kg,其由大到小依次为干皮、树枝、树根、干材、树叶.灌木层、草本层和凋落物层碳含量分别为449.8、392.5和424.7 g/kg.土壤(0～80 cm)平均碳含量为19.0 g/kg,各土层碳含量随土层深度增加而减少.20年生秃杉人工林生态系统碳储量为255.81 t/hm2,其中乔木层为99.43 t/hm2,占整个生态系统碳储量的38.87％;灌草层为2.14 t/hm2,占0.84％;凋落物层为2.52 t/hm2,占0.98％;林地土壤(0～80 cm)为151.72 t/hm2,占59.31％.秃杉人工林各器官碳储量与其生物量成正比关系,干材的生物量最大,其碳储量也最高,占植被层碳储量的59.48％,树枝、树叶、干皮和树根的碳储量共占36.05％.20年生秃杉人工林乔木层年净生产力为12.52 t/(hm2·a),有机碳年净固定量为5.98 t/(hm2·a),年净CO2吸收量为21.93 t/(hm2·a).

在新时代大力提倡工程教育的环境中,针对目前普遍存在的《固体废物处理与处置》课程设计课程缺乏思政内容,学生知识储备不足及考评方式落后等问题,探索了对标工程认证教育要求,课程全程贯彻思政教育、优化课程设计教学内容,形成专业课程合力以及完善考评方式,重视学生设计过程表现考核等改革举措,着力加强工程教育背景下固体废物处理与处置课程设计环节的教学水平,可以为环境工程专业其他核心课程的教学模式改革提供借鉴.

《环境土壤学》课程是一门新兴的土壤学与环境科学交叉融合的综合性课程.由于其自身性质,开课的工科院校普遍存在着课程内容缺乏思政教学内容、课程结构和教学内容不够合理、实验和实践教学环节缺乏等问题,与目前大力推行的工程认证教育要求不符.针对以上问题,我校探讨了《环境土壤学》课程思政元素的必要性,着重围绕《环境土壤学》课程结构及实践教学内容进行了改革探索,以期为工程教育背景下相关课程的教学改革提供参考.

[目的]研究秃杉人工林生长过程中生物量和生产力的积累过程及其变化规律,为秃杉人工林尤其是大径级用材林经营管理提供科学依据.[方法]以广西南丹县秃杉人工林为研究对象,采用样地调查与生物量实测方法,研究了不同年龄阶段(9、17、25、37年生)秃杉人工林生物量、生产力及其分配特征.[结果](1)乔木层生物量随林龄增加而增大,9、17、25、37年生的秃杉人工林生物量分别为76.77、157.06、200.82、304.88?t/hm2,其中经济生物量(干材)分别为35.84、90.10、126.16、212.71?t/hm2,树枝生物量分别为16.35、28.68、30.60、30.01?t/hm2,树根生物量分别为11.26、21.22、24.16、39.92 t/hm2,树叶生物量分别为9.95、10.32、11.72、9.88?t/hm2,干皮生物量分别为3.38、6.74、8.17、12.36?t/hm2.(2)林下植被生物量依次为1.54、3.38、5.15、5.80?t/hm2,其中灌木层生物量分别占59.09％、69.53％、73.26％、73.45％,草本层占40.91％、30.47％、26.74％、26.55％.凋落物层生物量依次为2.23、4.73、7.04、10.67?t/hm2,随林龄增加而显著增大.(3)各年龄阶段秃杉人工林乔木层净生产力依次为8.53、9.24、8.03、8.24?t/(hm2·a),其中干材净生产力组成比例(46.66％?～?69.78％)随林龄增加而增大,树叶和树枝的组成比例(3.28％?～?4.46％和9.83％?～?21.34％)则呈现相反的变化趋势.[结论](1)秃杉人工林乔木层生物量随林龄增加而逐渐积累,其中干材所占比例随林龄增加而增大,树叶、树枝和干皮生物量所占比例随林龄增加而下降,树根生物量所占比例波动较小.(2)与杉木和马尾松人工林相比,秃杉人工林具有速生期长和衰退晚的优点,生物生产力较高.研究结果为桂西北人工林可持续经营和发展提供了依据.

随着全球经济一体化的快速发展,具有国际视野、通晓国际规则、能够参与国际事务和国际竞争的国际化人才日益受到社会各界的青睐.结合我校环境工程专业工程教育认证的背景,分析了目前我国环境工程类专业国际化教学所面临的问题,从培养目标、教学理念、小班制度、教学方法、评价体系以及持续改进等方面探讨了环境工程微生物学的国际化教学模式,为构建适应工程教育认证新标准的专业课程建设提供指导.

In this study, a carbon shell was coated on Fe3O4 nanoparticles using a hydrothermal method followed by modification of carboxyl end groups on the Fe3O4@C to form Fe3O4@C-COOH for creating an immobilisation agent for remediating lead-contaminated soils. The surface of an Fe3O4@C nanoparticle was successfully covered with carboxyl end groups. The Fe3O4 core possessed the superparamagnetism property; the carbon shell protected the core from being oxidised or dissolved in acid solution, and provided good modifiability. Due to the strong interaction between lead and carboxyl end groups, this synthesised remediation agent exhibited high adsorption capacity. The Fe3O4@C-COOH nanoparticles principally promoted the transformation of lead (Pb) from a reducible to residual state, while having no obvious effect on the oxidation state of the lead. The amount of Fe3O4@C-COOH and the composition of soil organic matter had a higher influence on Pb distribution than soil pH, water content, or conductivity. Under optimal immobilisation conditions, the fractionation of the Pb acid-soluble, reducible, oxidative, and residual states in the contaminated soil changed significantly. The leaching and migration of Pb were significantly reduced, thus achieving remediation of lead-contaminated soils by immobilisation. Thus, remediation of lead-contaminated soils via Fe3O4@C-COOH immobilisation is a potentially practical and technologically feasible method.

A field experiment was conducted to assess the atmospheric deposition effects on lead (Pb) contamination in wheat by two contrasting treatments: wheat exposed or not to atmospheric deposition. Plants were housed in a shed during wheat greening for the non-exposed treatment. The Pb contents of wheat during different growth stages, of soil and of atmospheric deposits were analysed and combined with Pb stable isotope data to quantify the contribution of atmospheric deposition and soil to Pb in wheat tissue. The Pb content in atmospheric deposits was significantly higher than those in soil and wheat tissue, and the Pb content in wheat tissue exposed to atmospheric deposition was significantly higher than the Pb content in non-exposed tissue (p < 0.05). The 206Pb/207Pb of soil was significantly higher than the 206Pb/207Pb of atmospheric deposits (p < 0.05), and soil and atmospheric deposition were the two sources of Pb in wheat tissue. Atmospheric deposition was the main source of wheat tissue Pb in the exposed treatment, and most of the wheat tissue Pb, except for that in the stem, also came from atmospheric deposition in the maturing stage. The proportion of Pb from atmospheric deposition in roots, stems and leaves evidently decreased after the shed was erected, and the contribution of Pb from atmospheric deposition to wheat tissue was significantly higher in the exposed treatment than in the non-exposed treatment (p < 0.05). This contrast test directly confirmed that atmospheric deposition was the main source of Pb in the wheat tissues. Therefore, taking measures to reduce the absorption of Pb by wheat from atmospheric deposition can effectively ensure food safety.

An indoor microcosm experiment showed that decomposition rate of poplar leaf litter was significantly and negatively related to ZnO nanoparticle concentration under natural sunlight.

The influence of matured compost inoculation during sewage sludge with sawdust composting was assessed. Mature compost reduced the heating rate, thermophilic phase, peak temperature, and volatile solid degradation rate, with no significant effect on pH and germination index. Matured compost addition also increased the cellulase, peroxidase, arylsulfatase, and urease contents during the mesophilic phase, and increased the urease content but decreased the cellulase, peroxidase, protease, and arylsulfatase contents during the cooling phase, with no significant effect on enzyme activities at the thermophilic phase. Matured compost increased the diversity of bacteria during the mesophilic and thermophilic phases, but reduced the fungal diversity throughout composting. Matured compost significantly improved uniformity of the bacterial community and affected the structure of the bacterial and fungal communities, while changing the correlation between some functional microorganisms and enzyme activities. These results provide guidance for optimizing the composting process when matured compost as bulking agent.

[目的]探究马尾松人工林的养分积累及其分配特征,为马尾松人工林丰产经营管理提供依据.[方法]以广西南丹县26年生马尾松人工林为研究对象,采用野外调查和室内化学分析的方法,探讨马尾松人工林5种养分元素含量、积累量、年净积累量及其分布特征.[结果]除Ca元素外,马尾松人工林不同器官养分元素含量均以树叶最高,其次是树枝、干皮和树根,干材最低;各器官养分元素含量大致以N最高,其次是K或Ca,P最低;马尾松人工林养分积累量为1390.35 kg·hm-2,其中乔木层养分积累量(1204.60 kg·hm-2)占86.64％、灌木层(93.78 kg·hm-2)占6.75％、凋落物层(91.97 kg·hm-2)占6.61％;马尾松人工林乔木层养分年净积累量为46.32 kg·hm-2·a-1,每生产1 t干物质需要5种养分元素6.40 kg.[结论]桂西北马尾松人工林养分积累量较大,具有较高的养分利用效率.

In order to trace the source of Pb pollution in wheat, the contribution ratio of soil and atmospheric fallout source was quantified based on stable isotope ratios. Results showed that the average Pb content of soil was significantly lower than that of fallout, and Pb in the fallout had a higher weak acid fraction than soil. Pb in wheat had a distinct distribution in its tissues and the content of Pb in wheat roots was significantly higher than it in shoots. The 206Pb/207Pb ratio of soil was significantly higher than that in atmospheric fallout (p < 0.05). According to a binary mixing model, the 206Pb/207Pb ratio in wheat roots, leaves, and grains reflect 67%, 65%, and 90% of Pb content contributions from fallout, respectively. This results suggest that fallout Pb was absorbed by wheat leaves and transferred to other organs, and it is important to develop effective strategies to control fallout Pb risks.

Due to rapid growth of industrialization and human activities, such as mining and smelting, lead (Pb) has become a major environmental contaminant. As Pb can pose risks to human health, preventing Pb pollution in wheat is important for food safety, requiring accurate verification of pollution sources. Pb concentrations and isotope ratio levels in soil, in the atmosphere, and wheat tissue (root, stem, leaf, grain) in an area of high-Pb deposition (in the vicinity of a Pb smelter in Jiyuan city) and an area of low deposition (the northwest suburb of Zhengzhou city) were examined. The Pb isotope ratio and the binary mixed model were used to quantify the contribution of soil and atmospheric deposition to Pb content in wheat tissues. Results show that Pb content in soil, atmospheric deposition, and wheat in the high deposition area were significantly higher than those in the low deposition area. Pb content in soil, atmospheric deposition, wheat roots, stems, leaves, and grains in the high-deposition area were 355.32 ± 14.78, 5477.90 ± 187.85, 158.72 ± 9.56, 21.36 ± 1.72, 26.49 ± 1.96, and 0.94 ± 0.02 mg kg−1, respectively. Pb content in the low-deposition area were 6.10 ± 0.75, 78.50 ± 4.35, 2.47 ± 0.23, 1.03 ± 0.07, 2.11 ± 0.13, and 0.08 ± 0.01 mg kg−1, respectively. The Pb isotope ratio recorded obvious differences between soil and atmospheric deposition in the two areas. Combined with the significant correlation between Pb isotopes in various tissues of wheat and environmental media, and analysis of the isotopic composition characteristics of wheat and environmental media, in the high-deposition area, the contribution rate of atmospheric deposition in wheat roots, stems, leaves, and grains was 14%, 66%, 84%, and 77%, respectively. And the soil contribution rate was 86%, 34%, 16%, 23%, respectively. In the low-deposition area, the contribution rate of atmospheric deposition in wheat roots, stems, leaves, and grains was 49%, 73%, 93%, and 83%, respectively. And the soil contribution rates were 51%, 27%, 7%, and 17%, respectively. In the low-Pb deposition area, the contribution rate of atmospheric deposition in wheat was higher than that in the high-deposition area. Atmospheric deposition was the main source of Pb in grains, leaves, and stems of wheat in different depositional areas. Pb in wheat roots mainly derives from soil, and the Pb contribution rate of soil to wheat roots in the high-deposition area was significantly higher than that in the low-deposition area.

系统总结了有机固体废物好氧堆肥化处理过程的调控手段、堆肥各个阶段的微生物群落演替、堆肥过程中酶活性的变化以及臭气的产生情况.堆肥过程中温度变化对微生物的生长繁殖产生显著影响,微生物群落先由嗜温菌演替至嗜热菌,再由嗜热菌演替至嗜温菌,有机物被逐步降解.各种有机物降解需不同酶参与,主要有芳基硫酸酯酶、脲酶、蛋白酶、葡萄糖激酶、纤维素酶、β-葡萄糖苷酶、过氧化物酶等;微生物发酵过程蛋白质的降解产生NH3,厌氧条件下硫酸盐还原菌与产甲烷菌的生命活动产生H2S,氨基酸脱羧作用、厌氧降解及局部厌氧发酵产生挥发性有机物(VOCs),这些臭味物质均会对环境造成二次污染.可以尝试调控微生物酶系统来提高堆肥效率,并阻断发酵过程中臭气物质的产生.

To assess the potential of big biochar as composting amendment, the study was performed on aerobic composting of sewage sludge amended with litchi wood biochar (10% of fresh mixture weight, 20-40 mm) in a 400 L bioreactor system. Physicochemical properties and microbial activities were monitored during the first fermentation process of aerobic compost. Application of big biochar reduced peak temperature and shortened thermophilic phase, but increased the activities of aryl-sulfatase, beta-glucosidase, and dehydrogenase, which led to higher removal efficiency of total carbon, nitrogen, and sulphur. Big biochar inhibited degradation of organic matters in composting. Therefore, a comprehensive assessment including physicochemical and microbial properties can help to better understand the effect of big biochar on sewage sludge composting.

[目的]探究桂西北马尾松人工林的碳汇功能,为合理评估其生态效益提供依据.[方法]以广西南丹县26年生马尾松人工林为研究对象,采用野外调查和实验室分析方法,研究马尾松人工林生态系统碳含量、碳储量及其空间分布格局.[结果]马尾松平均碳含量为489.3 g·kg-1,不同器官碳含量依次为:树叶>干材>干皮>树根>树枝;林下灌木层、草本层和凋落物层碳含量分别为453.0、425.6和433.8 g·kg-1;林地土壤有机碳含量变化范围为6.20～32.15 g·kg-1,随土壤层深度增加而降低.马尾松人工林生态系统碳储存量为232.13 t·hm-2,其中乔木层、灌木层、草本层、凋落物层和土壤层分别为92.67、1.36、1.12、2.49和134.49 t·hm-2,依次占整个生态系统碳贮量的39.92％、0.59％、0.48％、1.07％和57.94％.马尾松人工林乔木层年净生产力为10.83 t·hm-2·a-1,年净固碳量为5.41 t·hm-2·a-1,年净吸收CO2量为19.83 t·hm-2·a-1.[结论]桂西北马尾松人工林具有较高的碳汇功能,为该区域碳汇林业的经营提供了依据.

To explore the contributions of functional bacterial community in composting, we performed medium-scale composting of sewage sludge and sawdust mixtures amended with rice straw biochar at different dosages (5, 10, and 20% of fresh mixture weight) in 400 L bioreactor systems. The dynamics of enzyme activity and bacterial community composition were monitored during the composting. The addition of biochar above 10% inhibited the activity of protease but promoted the activities of cellulase and peroxidase, which also increased the fluctuation of bacterial diversity during the composting. The relationship between the activity of most enzymes and bacterial community was strengthened by the addition of biochar (10% and 20%), which further enhanced the contributions of the functional bacterial communities to composting. Therefore, the study provides evidence for the promoting effects of biochar on the functions of bacterial community.

Titanium dioxide (TiO2) nanoparticles have been applied in diverse commercial products, which could lead to toxic effects on aquatic microbes and would inhibit some important ecosystem processes. The study aimed to investigate the chronic impacts of TiO2 nanoparticles with different concentrations (5, 50, and 500 mg L-1) on Populus nigra L leaf decomposition in the freshwater ecosystem. After 50 d of decomposing, a significant decrease in decomposition rates was observed with higher concentrations of TiO2 nanoparticles. During the period of litter decomposition, exposure of TiO2 nanoparticles led to decreases in extracellular enzyme activities, which was caused by the reduction of microbial especially fungal biomass. In addition, the diversity and composition of the fungal community associated with litter decomposition were strongly affected by the concentrations of TiO2 nanoparticles. The diversity and composition of the fungal community associated with litter decomposition was strongly affected. The abundance of Tricladium charrocladium decreased with the increasing concentrations of TiO2 nanoparticles, indicating the little contribution of the species to the litter decomposition. In conclusion, this study provided the evidence for the chronic exposure effects of TiO2 nanoparticles on the litter decomposition and further the functions of freshwater ecosystems.

随着人类面临的环境问题越来越多,国家建设对环境专业应用型人才的需求量日益增加.本文旨在探索新时期背景下环境微生物学的教学新方法,以《蓝藻细胞的特殊结构》的教学设计为例,将环境问题与课程重难点融会贯通,提高学生分析解决实际问题的能力,实现应用型人才的培养目标.