江苏省“十一五”环境质量状况及成因分析

结合江苏省“十一五”期间环境质量状况及变化情况,综合分析了环境空气、水环境、声环境质量及污染物排放状况.“十一五”期间,江苏省经济总量以13.5％的平均速度增长,社会、经济的快速发展给全省环境质量带来巨大的胁迫压力,资源能源消耗迅速攀升,“三废”产生总量持续增长;而由于加大了节能减排和环境治理投入力度,采取了一系列措施...     

碱/抗坏血酸活化分子氧氧化水中As（III）

研究了碱/抗坏血酸（H₂A）活化分子氧体系（碱/H₂A体系）氧化水中三价砷（As（III））的过程与机理.考察了pH、H₂A浓度、As（III）初始浓度、水中常见阴离子（Cl^-、NO₃^-、HCO₃^-）和有机质富里酸对As（III）氧化效率的影响,通过自由基抑制实验及电子自旋共振（ESR）鉴定了体系中的活性氧物质（ROS）,并采用液相色谱-质谱分析技术鉴定了H₂A的降解产物.结果表明,在pH=9~12范围内,pH值越高,As（III）氧化速率越快;pH=10条件下,随着H₂A浓度从0.05 mmol·L^-1增加到1 mmol·L^-1,反应1 h后,As（III）氧化率从24%增加至92%.机理研究结果表明,H₂O₂是碱/H₂A活化分子氧体系中氧化As（III）的主要ROS,它主要来自碱性条件下H₂A与分子氧的单电子或双电子反应,同时,体系中H₂A也发生了氧化性降解.碱/H₂A体系可用于含砷废水的预处理,并与离子交换吸附方法联合,实现高效除砷.     

蒙脱土原位生长MoS2复合材料光催化降解罗丹明B的机理研究

通过在Na⁺-MMT表面生长MoS₂来提高窄带隙半导体光生电子分离速率及稳定性.利用阳离子填充法及水热法成功制备了复合光催化剂Na⁺-MMT/MoS₂,并通过FT-IR、SEM、TEM、Raman、XRD、TG、XPS、UV-DRS和ESR等表征进一步证明了材料的成功负载及光、电化学性能. 同时,以有机染料罗丹明B为待降解染料来评价光催化剂的催化性能,发现其在80 min可有效降解罗丹明B,降解率达96%.经过5次循环使用后,Na⁺-MMT/MoS₂复合光催化剂仍具有较好的光催化性能.因此,利用MMT的表面电负性及稳定的片层结构负载MoS₂,可形成光生电子迁移通道进一步提高电荷迁移速率及光催化剂的稳定性.本研究可为黏土材料调控窄带隙半导体制备环境友好型光催化剂提供新思路.     

森林保险支付意愿及影响因素分析——基于异质性营林主体视角

基于期望效用函数理论分析了异质性营林主体的森林保险支付意愿及差异,并以传统小林农和新型林业经营主体为研究对象,以福建省382户传统小林农和88户新型林业经营主体的调研数据为基础,综合运用条件估值法、卡方检验及Cox比例风险模型,对异质性营林主体的森林保险支付意愿与差异及支付意愿影响因素进行对比与分析。研究表明：传统小林农和新型林业经营主体的森林保险意愿支付水平存在显著差异,在1000~2500元/亩保障水平下,传统小林农的意愿支付水平分别为1.911元/亩、2.941元/亩、3.532元/亩及3.979元/亩,新型林业经营主体为1.632元/亩、3.971元/亩、5.809元/亩及6.864元/亩;两类营林主体的支付意愿均随保额的提高而提高,但新型林业经营主体的提升幅度远高于小林农。异质性营林主体的森林保险支付意愿影响因素也存在明显差别,这与其在森林保险认知特征、林业生产经营特征、林业灾损特征、森林保险产品评价特征等方面存在显著差异有关。此外,林地面积对两类营林主体支付意愿均具有显著影响,规模化、集约化的林业生产经营可促进林业经营主体的森林保险愿意支付水平。     

基于产业投资视角的乡村旅游发展区域差异与形成机制

乡村旅游发展区域差异是乡村旅游投资空间不均衡的外在表现。新时代乡村振兴背景下乡村旅游投资不断增长,正加速影响乡村旅游发展空间格局与区域差异。在对比认识浙晋乡村旅游发展差异基础上,深入剖析了乡村旅游投资系统作用区域乡村旅游发展差异的深层机理。结果发现：（1）以乡村旅游精品线路为表征的浙晋乡村旅游发展水平和市场成熟度差异显著。（2）在乡村旅游投资“自然—产业—社会”环境中,产业基础环境对区域乡村旅游发展差异贡献最突出,是区域差异形成的核心要素,自然生态环境是基础,社会文化环境则发挥积极促进作用。（3）乡村旅游发展区域差异是不同乡村旅游投资环境引起区域乡村旅游投资收益预期和回报水平与乡村旅游发展路径及模式差异的结果。基于此,提出新时代乡村旅游投资IE-maps模式,以期促进区域乡村旅游协调发展和乡村振兴战略实施。     

Microwave-assisted continuous flow phytosynthesis of silver nanoparticle/reduced graphene oxide composites and related visible light catalytic performance

The creation of an environmentally friendly synthesis method for silver nanomaterials (AgNPs) is an urgent concern for sustainable nanotechnology development. In the present study, a novel straightforward and green method for the preparation of silver nanoparticle/reduced graphene oxide (AgNP/rGO) composites was successfully developed through the combination of phytosynthesis, continuous flow synthesis and microwave-assistance. Oriental persimmon (Diospyros kaki Thunb.) extracts were used as both plant reducing and capping agents for fast online synthesis of AgNP/rGO composites. The experimental parameters were optimized and the morphologies of the prepared materials were investigated. The characterization results reveal that spherical AgNPs were quickly synthesized and uniformly dispersed on rGO sheets using the proposed online system. Fourier transform infrared spectroscopy analysis confirmed that phenols, flavonoids, and other substances in the plant extracts played a decisive role in the synthesis of AgNP/rGO composites. Using sodium borohydride (NaBH₄) degradation of p-nitrophenol (4-NP) as a model, the catalytic activity of the prepared AgNP/rGO materials was evaluated. The complete degradation of 4-NP was achieved within 12 min through the use of AgNP/rGO materials, and the composite had a much better catalytic activity than the bare AgNPs and rGO had. Compared with the conventional chemical method, our online method is facile, fast, cost-efficient, and environmentally friendly.     

MoS2 quantum dots based MoS2/HKUST-1 composites for the highly efficient catalytic oxidation of elementary mercury

Due to the ever-tightening regulation on mercury emission in recent decades, there is an urgent need to develop novel materials for the removal of elemental mercury at coal-fired power plants. In this study, a series of MoS₂ quantum dots (QDs)-based MoS₂/HKUST-1 composite materials were prepared. It is found that MoS₂ QDs were encapsulated by HKUST-1 and enhanced the crystallinity and specific surface area of HKUST-1. The MoS₂/HKUST-1 showed excellent performance in catalytic oxidation of Hg⁰ as compared with pristine HKUST-1. It is found that surface layer of lattice oxygens is active and participates in Hg⁰ oxidation, while the consumption of surface oxygens then leads to the formation of oxygen vacancies on the surface. These vacancies are effective in the adsorption and dissociation of O₂, which subsequently participates in the oxidation of Hg⁰. Moreover, the study on the influence of commonly seen gas components, such as SO₂, NO, NH₃ and H₂O, etc., on Hg⁰ oxidation demonstrated that synergistic effects exist among these gas species. It is found that the presence of NO promotes the oxidation of Hg⁰ using oxygen as the oxidant.     

Enhancing anoxic denitrification of low C/N ratio wastewater with novel ZVI composite carriers

External organic carbon sources are needed to provide electron donors for the denitrification of wastewater with a low COD/NO₃^--N（C/N） ratio, increasing the treatment cost. The economic strategy is to enhance the bioactivity and/or biodiversity of denitrifiers to efficiently utilize organic substances in wastewater. In this study, novel zero-valent iron（ZVI） composite carriers were prepared and implemented in a suspended carrier biofilm reactor to enhance the bioactivity an...     

冬季巢湖SPOM来源、空间变化及营养盐效应

为研究枯水期巢湖水体悬浮颗粒物（SPM）营养元素组成及其潜在环境效应,分析了2020年1月巢湖18个采样点表层水体SPM含量、颗粒有机质（SPOM）含量及氮磷组成,并利用颗粒有机碳、氮同位素组成及C/N研究了冬季巢湖SPOM的来源及其空间变化. 结果表明,悬浮颗粒物总磷(PP)浓度为0.032~0.065 mg/L,平均值为0.049 mg/L;悬浮颗粒物无机磷(PIP)浓度为0.018~0.046 mg/L,平均值为0.032 mg/L,是PP的主要组分,二者浓度均呈西湖区>东湖区>中湖区的空间分布特征. 悬浮颗粒物总氮(PN)浓度为0.254~0.424 mg/L,平均值为0.342 mg/L,其中悬浮颗粒物有机氮(PON)占比较高,表明颗粒态氮以湖泊内源性有机来源为主. 巢湖表层水体SPOM的δ13C范围在?28.72‰~?26.68‰之间,δ15N为3.34‰~9.97‰,C/N为2.51±0.95,指示冬季枯水期水体SPOM主要来自内源水生生物碎屑,而陆源径流输入对湖泊颗粒物影响较小. 研究显示:冬季巢湖悬浮颗粒有机质主要来自湖泊内源,具有潜在的营养盐效应,污染控制需要相应的策略.      

渤、黄海在低氧形成期与消亡期生源要素的分布差异及响应特征

近年来,渤、黄海海域呈现溶解氧浓度降低并导致季节性低氧的特征,对海洋生态环境形成潜在危害。在此背景下,本文基于2011年6月（低氧形成期）和2011年11－12月初（低氧消亡期）在渤、黄海的观测数据,通过分析水体表观耗氧量（AOU）、pH、溶解无机碳（DIC）及营养盐之间的相关关系,探讨了生源要素在低氧形成期与消亡期的变化特征及主要控制机制。结果表明,生物的光合作用与有机物的降解过程是调控低氧事件前后渤海生源要素变化的主要因素之一,而黄海底层水体有机物的降解过程是调控水体溶解氧浓度及营养盐浓度变化的主要原因之一。