不同环境因素对厌氧甲烷氧化型自养反硝化系统脱氮性能的影响及其微生物群落分析

采用序批实验研究了不同环境因素(甲烷供应、初始硝氮浓度和pH值)对厌氧甲烷氧化型反硝化系统脱氮性能的影响,并采用高通量测序对不同pH下反应器内微生物群落结构进行了分析.结果 表明:当甲烷供给充足时,系统反硝化效果明显;随着初始硝氮浓度的升高,系统平均脱氮率呈现先升高后下降的趋势,表明适当增大硝氮质量浓度(＜30 mg·...     

浦阳江流域(浦江县段)面源污染模型估算及河流生态缓冲带重点区域识别

以浦阳江流域(浦江县段)为研究区,从流域面源污染空间特征入手,提出浦阳江流域岸边带建设的重点区域。采用DPeRS面源污染负荷估算模型,具体分析了2018年浦阳江流域面源污染负荷空间分布特征,并采用面向对象方法提取了岸线和河流生态缓冲带土地覆盖类型,以汇水区为单元,结合面源污染估算结果识别了浦阳江流域河流生态缓冲带重点区。结果表明：浦阳江流域中部和中北部地区面源污染排放负荷较高,面源污染入河负荷高值区主要集中于中下游地区;该流域31个汇水区中,TN和NH₄⁺-N重点汇水区有17个,主要分布在流域的中部和东北部;TP和COD重点汇水区有12个,集中分布于流域中部;浦阳江流域河流生态缓冲带范围内,植被类型和非植被类型面积占比分别为65.49%和34.51%,其中耕地面积占比29.36%,建筑用地占比11.89%;综合浦阳江流域面源污染重点汇水区和河流生态缓冲带现状遥感提取结果,筛选出的重点区包括下游地区的7号汇水区和中游地区的18~25号汇水区所在的河流生态缓冲带。今后,可针对其重点区域设计生态防护工程,也应结合源头减量、过程拦截、末端消纳与资源循环利用的防控策略,综合削减面源污染物入河量。     

Anammox-HAP颗粒污泥型膨胀床反应器的氮磷同步去除能力及污泥特性

为实现集成、高效的氮磷处理,提高厌氧氨氧化工艺的运行稳定性及功能集成性,搭建了一种新型的anammox-HAP颗粒污泥型膨胀床反应器。设置了3个不同温度条件下的反应器,通过控制进入反应器中的钙、磷元素,以及调控反应器pH,探究了膨胀床反应器对氮、磷的同步去除能力,并对污泥特性进行了分析。结果表明：anammox-HAP颗粒污泥型膨胀床反应器在35、25、15℃条件下均可稳定运行,并能分别实现(44.90±0.32)、(17.12±0.97)、(8.79±0.14 ) g·(L·d)⁻¹的氮去除速率,且总氮去除率稳定维持在85%以上;磷元素以HAP核的形式聚集在anammox颗粒内部,可在随剩余污泥排出的同时进行回收;anammox-HAP反应器中颗粒污泥的沉降性能明显高于一般厌氧或anammox工艺中的颗粒污泥,并与颗粒中的磷含量正相关。本研究阐释了anammox-HAP颗粒污泥型膨胀床反应器的特点,可为废水中氮磷的处理提供参考。     

How does population structure affect pollutant discharge in China? Evidence from an improved STIRPAT model

Environmental Science and Pollution Research - China is the most populous country in the world, and the pollution caused by the excessive population should not be underestimated. In recent years,...     

Research progress and hot spots of hydrothermal liquefaction for bio-oil production based on bibliometric analysis

Environmental Science and Pollution Research - Hydrothermal liquefaction (HTL) of biomass used HTL reaction under high temperature and pressure to produce bio-oil. This technology is considered as...     

Microbial degradation of phthalic acid esters under anaerobic digestion of sludge

The microbial degradation by anaerobic sludge of three phthalates, priority pollutants, listed by both China National Environmental Monitoring Center and the U.S.EPA, namely, dimethyl (DMP), di-n-butyl (DBP) and di-n-octyl (DOP) phthalates was investigated. The experimental results indicated that the biodegradation rate and the biodegradability of three phthalates under anaerobic conditions appeared to be related to the length of the alkyl-side chains. More than 90% of DMP and DBP with the short alkyl-side chain phthalates can be degraded, whereas the DOP degradation appeared to be relatively slow under the same experimental conditions. The quantity of methane produced was measured and the results showed that both the ester groups and the phthalate ring were mineralized at a significant rate. The kinetics study demonstrated that the biodegradation of three phthalates conformed to the first-order model with respect to their concentrations.     

MicroRNA: a novel implication for damage and protection against ionizing radiation

Environmental Science and Pollution Research - Ionizing radiation (IR) is a form of high energy. It poses a serious threat to organisms, but radiotherapy is a key therapeutic strategy for various...     

Migration and transformation of heavy metals in hyperaccumulators during the thermal treatment: a review

Environmental Science and Pollution Research - The pollution of heavy metals (HMs) in the soil has become one of the important factors affecting the national environment and human health....     

Applicability of hybrid bionic optimization models with kernel-based extreme learning machine algorithm for predicting daily reference evapotranspiration: a case study in arid and semiarid regions,China

Environmental Science and Pollution Research - The accurate prediction of daily reference crop evapotranspiration (ETO) enables effective management decision-making for agricultural water...     

生物质利用方式对富营养水体中碳氮磷含量及其比例的影响

生物质常被添加至富营养水体中以调节碳氮比(C/N),促进脱氮,但不清楚生物质的粒径和投加方式对富营养水体中营养物质浓度和比例的影响。通过机械粉碎制得20~40、40~80、80~160目稻壳颗粒,并选取直接投加和无纺布包裹投加2种投加形式,以不添加稻壳或无纺布包裹砖块作为对照组。以超纯水为水样研究不同粒径和投加方式下稻壳的3 d碳氮磷释放特性;以成都市府河下游河段水样为研究对象,考察了不同粒径和投加方式下稻壳的21 d静态脱氮特性。结果表明,在超纯水中,稻壳释放出COD_Mn(5.5~16.5 mg·L⁻¹)、TP(0.18~0.45 mg·L⁻¹)、TN(0.39~0.95 mg·L⁻¹)、COD_Mn/TN(8.5~19.7)、COD_Mn/TP(27.9~37.5),前四者均呈现出80~160目>40~80目>20~40目的规律,仅COD_Mn和COD_Mn/TN呈现直接投加>无纺布包裹投加的规律。在静态脱氮实验中,21 d后,添加了稻壳的水样COD_Mn含量由28.1 mg上升至71.7~143.0 mg,TP含量由1.2 mg下降至0.2~0.5 mg,COD_Mn/TN由0.9上升至8.5~16.5,COD_Mn/TP由24.2上升至170以上,这4个参数的变化情况与稻壳的碳氮磷释放规律相同;TN含量由30.04 mg下降至7.64~8.68 mg,低于对照组(13.2~13.9 mg),但粒径和投加方式仅对实验初期水中氮的存在形态有影响。粒径决定稻壳的比表面积,投加方式决定稻壳的间隙,并影响微生物的附着效果,进而影响稻壳的碳氮磷释放效果。在实际应用时可根据情况,采用不同的生物质粒径和投加方式,以调节水中营养物质浓度和比例。