再生水补充地下水水质指标及控制技术

再生水补充地下水是扩大污水回用最有益的一种方式,具有广阔发展前景.本文分析与总结了国内外再生水补充地下水研究与应用实例、水质标准,结合我国再生水的水质特点及水文地质状况,从保护地下水资源和人体健康的角度,探讨了我国利用再生水补充地下水应控制的水质指标及控制技术.按地表回灌和井灌方式分别提出了水质基本控制项目COD、BOD、氨氮、粪大肠菌群数等22项,选择控制项目Hg、三氯甲烷等重金属和微污染有机物52项及其建议指标值,并提出了再生水处理控制技术.     

河岸带地下水理化指标变化及与洪水的响应关系研究

河岸带地下水和河水存在复杂的交互作用,地下水和地表水存在明显的补排关系,洪水事件是影响河岸带地下水水质波动的重要水文过程.以黄河湿地国家级自然保护区孟津湿地为对象,通过河岸带地下理化指标(特别是小浪底水库调水调沙期间)野外定位观测,深入分析了河岸带地下水水质与洪水的响应关系.结果表明,受河流与荷塘蓄水的影响,地下水温度...     

华北平原农田硝态氮淋溶率和淋溶负荷估计

由于化肥过度施用且强度逐渐增加,华北平原氮淋溶问题日趋严重且造成了地下水污染风险.利用1991年以来公开发表的文献中290 组农田NO₃^--N 淋溶试验样本(淋溶率和10个影响因素),基于Bayesian递归回归树模型初步建立了华北平原农田NO₃^--N淋溶迁移过程统计模型.以2008年为例,基于华北平原县域合成氮肥、复合肥施用量和1 km×1 km的影响因素和土地利用(耕地)数据,最终得到1 km×1 km的华北平原农田NO₃^--N淋溶率和淋溶负荷及其不确定性水平.初步结果表明:①模型校准和验证R²分别达到0.832和0.829,模拟结果相对可靠;②华北平原耕地NO₃^--N的淋溶率具有显著的空间分异,其中位值为15.4%(R₅₀为12.6%~18.2%),其主要影响因素为土壤TN量、施N量、灌溉比例与降雨量的比值等;相应地,2008年淋溶负荷和淋溶量分别为995.1 Gg·a^-1(833.4~1156.7 Gg·a^-1);③NO₃^--N淋溶率较高的区域集中在太行山脉以东、黄河附近以及苏北的县(区、市),淋溶负荷贡献最大为河南(~37.7%)、江苏(~24.8%)和河北(~21.6%).     

Screening level modeling of long-term impact of petroleum hydrocarbon contamination on fresh groundwater lenses in the Arabian Gulf region

The Gulf War in 1991 created an environmental catastrophe, one of the major consequences of which was setting several oil wells on fire in the Arabian Gulf area. The total oil spilled as a result of the damaged wells was about 3.5 × 10⁶ m³. Out of these, 3.3 × 10⁶ m³ of oil was recovered and exported. The rest was left behind as it was not economical to collect. The oil left behind was subject to severe weathering over the past ten years. Soil and subsurface contamination pose a serious risk to the quality of the already scarce fresh groundwater resources in the area which was subject to oil spill in the study region. This paper presents the computer modeling activities carried out towards simulating the transport of the hydrocarbon contamination of the fresh groundwater resources at a study area in the Arabian Gulf region, and predicting the contamination levels at the fresh groundwater lenses in the area in the future, should current contamination levels persist in the soil and groundwater. The modeling activities relied on both semi-analytical and numerical flow and transport models.     

新疆喀什三角洲地下水SO2-4化学特征及来源

"水质型"缺水问题是新疆喀什地区水资源紧缺的主要原因之一.位于喀什地区西部的喀什三角洲面积13 329 km~2,73. 2%面积的潜水和53. 2%面积的承压水SO_4~(2-)浓度超过地下水质量Ⅲ类标准,同时伴随有高TDS、高硬度等特征.运用δD、δ~(18)O-H_2O和δ~(34)S-SO_4~(2-)同位素等手段分析地下水SO_4~(2-)化学特征及来源.结果表明:①区内剥蚀山区钙质粉砂岩、钙质细砂岩和石膏等盐类矿物的溶解控制了流域水化学组成,形成了水化学类型以SO_4型为主的地表水和地下水.地下水化学类型演变方向为HCO_3·SO_4→SO_4→SO_4·Cl,山麓斜坡冲洪积砾质平原为溶滤-径流带,河流冲积平原为径流-累积带,上游至下游地下水化学成分趋向盐化;②区内地下水初始补给源主要为大气降水,且受一定蒸发作用影响.不同水文地质单元地下水δD和δ~(18)O分布特征明显,上游至下游,同位素值由低到富集,受蒸发作用由弱到强;冲积平原承压水同位素分布较离散,受到上覆潜水混合作用影响;③南部、北部山麓斜坡冲洪积砾质平原潜水SO_4~(2-)来源分别为海陆交互相和陆相蒸发岩的溶滤;河流冲积平原潜水SO_4~(2-)除了陆相蒸发岩溶滤来源外,还存在化肥淋滤的污染;承压水受蒸发岩溶滤外,还受到潜水的混合作用和细菌还原硫酸盐作用影响.     

盐城地区地下水溶质来源及其成因分析

位于淮河下游典型冲海积平原区的盐城,地下水具有开发利用程度高,浅层水显著咸化的特点.在浅层地下水空间采样的基础上,通过各要素空间分布、Pipper、水化学侵蚀模式和富集因子法,研究离子的主要来源及其成因,探讨人类活动的作用.结果表明:①浅层地下水中溶解性总固体(TDS)范围为211～3790 mg·L-1,其中,微咸水...     

凉水河流域地下水水化学特征和时空变化规律

北京凉水河流域的同位素和水化学特征分析表明:1)地下水水质在100m以浅相对较差,但到2017年为止,水质保持稳定.2)浅层地下水与平原区河水同位素相对富集,且落在同一条蒸发线上;但整体上河水与浅层地下水水化学类型不同,据此推断山前冲洪积扇河水入渗是区域地下水补给的重要来源,下游地下水主要受到侧向径流影响.3)同位素平...     

Salt Flushing,Salt Storage,and Controls on Selenium and Uranium: A 31‐Year Mass‐Balance Analysis of an Irrigated,Semiarid Valley

Salinity, selenium, and uranium pose water‐quality challenges for the Arkansas River in southeastern Colorado and other rivers that support irrigation in semiarid regions. This study used 31 years of continuous discharge and specific conductance (SC) monitoring data to assess interannual patterns in water quality using mass balance on a 120‐km reach of river. Discrete sampling data were used to link the SC records to salinity, selenium, and uranium. Several important patterns emerged. Consumptive use reduced discharge by a median value of 33% and drove corresponding increases in salinity and uranium concentrations. Increased water availability for irrigation from rainfall and upstream snowpack in 1995–1999 flushed additional salinity and uranium into the river in 1996–2000; average annual total dissolved solids (salinity) concentrations increased 25%, and loads increased 131%. Smaller flushing events have occurred, sometimes lagging an increase in water availability by about one year. The pattern indicates flushing of salts temporarily stored, evaporatively concentrated, or of geologic origin. Mobilization of selenium from the reach was minor compared to salinity and uranium, and net selenium removal from the river was suggested in some years. Several processes related to irrigation could be removing selenium. The results provide context for efforts to improve water quality in the Arkansas River and rivers in other semiarid regions.     

Is Standardized Precipitation Index (SPI) a Useful Indicator to Forecast Groundwater Droughts? — Insights from a Karst Aquifer

The study sought to understand the relationships between meteorological and groundwater droughts on water levels and spring discharges in Edwards Aquifer, Texas. Standardized Precipitation Index (SPI)‐styled Standardized Groundwater Index (SGI) was used to quantify groundwater droughts. SGI time series signal was delayed and damped, while SPI was volatile. SGI values correlated well with SPI values that were observed five to eight months ago. Dynamic regression models with lagged SPI terms and autoregressive integrated moving average errors indicated a statistically significant yet weak relationship between Lag‐1 SPI and SGI. The utility of SPI for groundwater drought forecasting was minimal in this aquifer. Nonseasonal and seasonal autoregressive terms played an important role in forecasting SGI and highlighted the need for long‐term, high‐resolution monitoring to properly characterize groundwater droughts. Spring flows exhibited stronger and quicker responses to meteorological droughts than changes in storage. In aquifers with spring discharges, groundwater monitoring programs must make efforts to inventory and monitor them. Groundwater drought contingency measures can be initiated using SPI but this indicator is perhaps inappropriate to remove groundwater drought restrictions.     

北京市垃圾填埋场地下水中砷、汞含量分析

生活垃圾的处置一直以填埋为主,垃圾填埋承载着巨大的环境压力,尤其是垃圾填埋产生的渗滤液会对地下水造成砷、汞污染。为了解北京市生活垃圾填埋场地下水砷、汞污染水平,在北京市5座生活垃圾填埋场布设采样点,采集36个地下水样品,采用氢化物发生-原子荧光法,分析了地下水砷、汞含量特征。结果表明,36个地下水样品砷浓度范围0.41~4.82μg/L,汞浓度范围0.024~0.121μg/L,北京市典型垃圾填埋场地下水样品不存在砷、汞污染问题。