长江宜昌水文站流量、含沙量和悬移质粒度关系

以长江宜昌水文观测站实测资料为基础，基于长江上游河道特点，用回归分析的方法研究了宜昌站流量、含沙量与悬移质泥沙粒度的复杂关系。通过对流量、含沙量多年年内变化的正相关特性的分析，建立了流量与含沙量之间相应的回归模型；通过对流量与悬移质粒度复杂关系的研究，揭示了二者明显的双值关系以及水流挟沙力的控制性影响。对水文数据年际变化的研究表明由于短时间尺度内长江上游流量没有阶段性变化，流量与含沙量之间相关性不是很好，丰水年不一定是丰沙年；悬移质粒度与流量变化基本上不存在周期性变化。     

PATTERNS OF SUSPENDED SEDIMENT TRANSPORT IN A COASTAL ALASKA STREAM1

Suspended sediment data from a 154 ha watershed on northeast Chichagof Island, Alaska, were collected over three fall storm seasons from 1980 to 1982. Sediment rating curves for nine pooled storms explained less than 34 percent of the variation in total suspended solids (TSS). Significantly higher concentrations of suspended sediment occurred during the rising limb of storm hydrographs than for similar flows on the falling limb, accounting for hysteresis loops in TSS versus streamflow plots for individual storms. These hysteresis loops were wider during early season storms, indicating that easily transportable fine sediment may have been flushed from the upper portion of channel banks and from behind large organic debris during early season peak flows. Regression relationships (TSS versus Q) developed for the highest stormflows (> 1 m³/s) had steeper slopes than the lower stormflows (< 1 m³/s). Turbidity correlated well (r=0.94) with TSS for all storm-flow data combined. Organic matter constituted an average of 35 percent (by weight) of TSS for all water quality samples.     

SIMULATION OF WATER POLLUTION GENERATION AND ABATEMENT ON SUBURBAN WATERSHEDS1

ABSTRACT: Computer simulation and model calibration of three “suburban” watersheds near Salt Lake City, Utah, indicate that coliform bacteria and suspended solids are produced mainly by the presence of people, domestic animals, vehicles, disposal systems, and other constructed faclities. The importances of each of these activities is investigated and pollution abatement procedures are outlined for purposes of improved watershed management.     

interactions amongst policies designed to resolve individual air issues

Six air issues are currently on science and policy agendas in Canadaand elsewhere. These are climate change, stratospheric ozone depletion(increased UV-B radiation), acidic deposition, SMOG (increasedground-level ozone), suspended particulate matter, and hazardous airpollutants. Atmospheric scientists and decision makers have largelyaddressed these issues individually resulting in single-issue policies. However, it is now recognized that these issues are inter-related, andthey may interact to cause negative as well as some beneficial effects,not only on the state of the atmosphere but also on societal andecological systems. This paper illustrates through several examples theatmospheric dysfunction caused by the linkages among the six airissues. It also points to potentially conflicting policies arising from thesingle-issue approach, and it emphasizes the need for better integrationof air issues. The linkages are summarized qualitatively in Table I.     

基于“哨兵3号”卫星OLCI影像和C2RCC算法的南黄海叶绿素a及总悬浮物反演效果分析

利用遥感数据处理软件SNAP中基于神经网络技术的C2RCC算法,对2019年5月9日南黄海“哨兵3号”卫星OLCI影像数据进行了叶绿素a及总悬浮物浓度反演,将其与5月间江苏省海洋环境监测预报中心的海水表层叶绿素a和悬浮物实测数据进行了比较分析。结果表明,叶绿素a的遥感反演尚未能达到业务化应用,总悬浮物遥感反演结果的空间分布与实测值的一致性相对较好。但在星地同日或相差一天监测的南通海域,遥感反演叶绿素a浓度的空间分布趋势以及总悬浮物遥感反演结果与海面实测结果的一致性较好,可达到一定的业务化应用效果。     

长江中下游悬浮物稀土元素地球化学特征及其对三峡工程的响应

通过分析枯水季(2008年1月)长江中下游干流和支流(湖泊)悬浮物的稀土元素(REE)组成,探讨三峡水库的泥沙拦截对该区域沉积物组成和干、支流输沙关系的影响。结果表明:长江干流宜昌至城陵矶段的REE变异系数显著大于城陵矶以下站位,且部分站位出现显著的Ce或Eu异常,该段沉积物的物质组成存在显著差异;洞庭湖沉积物继承了长江干流的REE组成特征;鄱阳湖和汉江等支流(湖泊),与干流的REE组成存在一定的差异,通过端元混合模型估算得,观测期间鄱阳湖和汉江对长江干流沉积物的贡献分别约为58%和23%。由此可见,三峡水库的运行,导致了长江中下游枯季的物质来源和组成发生改变:中游河床出现了显著的侵蚀,汉江和鄱阳湖等支流(湖泊)对干流的物质输送相对增加。     

Enhancing the total organic carbon measurement efficiency for water samples containing suspended solids using alkaline and ultrasonic pretreatment methods

In this study,we investigated the effect of sample pretreatments(ultrasonication and alkaline extraction) on total organic carbon(TOC) measurements for water samples containing suspended solids(SS) of four different origins(algae,soil,sewage sludge,and leaf litter) to more clearly assess the impact of particulate organic carbon(POC) in water.The effects each of ultrasonication(power,pulse,etc.) and alkaline extraction condition(concentration,time,etc.) on the TOC recovery and precision were investigated,and the results were compared with those of a new sample pre treatment method combining both methods.Alkaline treatment(0.01 mol/L NaOH) showed higher precision than ultrasonication(100/5 on/off pulse),and notably,the differences among the measured TOC values in samples of different origins were also further reduced in the alkaline treatment.This suggests that the ultrasonic pretreatment results can be mainly attributed to the increase in POC recovery through particle size reduction,whereas the alkaline treatment results are achieved through the enhancement of POC solubilization.It is also particularly noteworthy that a higher TOC recovery of 87.6%±7.4% with a higher precision of 8.4%could be obtained using the combined method,compared to each treatment(ultrasonic:TOC recovery 34.7%,relative standard deviation 63.1%;alkaline:49.6% and 23.0%,respectively).Thus,simultaneous pretreatment with ultrasonication and alkaline extraction is expected to increase the oxidation rate of organic matter and the homogeneity of the samples,minimizing the loss of POC measurement values,and thereby improving the reliability of the TOC measurements of water samples containing SS.     

稠油废水回用处理工艺中悬浮物测定方法

对污水中悬浮物分析方法进行了实验研究。采用微孔膜过滤重量法、紫外可见分光光度法和激光粒度分析仪三种测试方法,对稠油污水各处理单元的出水悬浮物进行了对比分析。实验结果表明:微膜过滤重量法的影响因素为膜的溶解损失、烘干温度、烘干时间和冷却时间;紫外可见分光光度法的影响因素为搅拌强度、搅拌时间和温度。在测定沉降、浮选工艺出水中悬浮物含量时,采用重量法更准确、更有效。     

Volatilization and Biodegradation of VOCs in Membrane Bioreactors (MBR)

Volatilization and biodegradation are major competitive volatile organic compound (VOC) removal mechanisms in biological wastewater treatment process, which depend on compound specific properties and system design/operational parameters. In this study, a mathematical model was used to determine major removal pathways at various organic loading rates (OLR), solids residence time (SRT) and dissolved oxygen (DO) concentrations in a biological process for vinyl acetate. Model results showed that biological treatment process should be designed with long SRT, high OLR and low DO concentrations to maximize biodegradation and minimize volatilization of VOCs. Unless a VOC is toxic to microorganisms under the given conditions, low VOC emission rates are an inherent advantage of MBRs, which operate at higher OLR and longer SRT compared to conventional activated sludge process. A lab scale membrane bioreactor (MBR) was operated at varying OLR to investigate the relative volatilization and biodegradation rates for acetaldehyde, butyraldehyde and vinyl acetate. Synthetic wastewater containing three VOCs was introduced to the MBR. The DO concentration and SRT was maintained at 2.0 mg L^{− 1} and 100 days, respectively. The overall VOC removal rate was more than 99.7% for three VOCs at all the OLR. For vinyl acetate, the biodegradation rate increased from 93.87 to 99.40% and the volatilization removal rate decreased from 6.09 to 0.59% as OLR was increased from 1.1 to 2.0 kg COD m^{− 3} d^{− 1}. It was confirmed that a MBR can be a promising solution to reduce VOC emissions from wastewater.     

人工湿地对污染物去除的研究现状及发展前景

人工湿地是近年兴起的高效、经济、环保型的污水处理方式。在前人研究的基础上本文对人工湿地去除非点源污染物中的总氮、总磷、总悬浮物的研究现状及设计湿地的植物和填料对去除污染物影响方面进行了概述，并对其今后研究发展的趋势作了探讨。