Bioremediation of Acidic and Metalliferous Drainage (AMD) through organic carbon amendment by municipal sewage and green waste

Pit lakes (abandoned flooded mine pits) represent a potentially valuable water resource in hot arid regions. However, pit lake water is often characterised by low pH with high dissolved metal concentrations resulting from Acidic and Metalliferous Drainage (AMD). Addition of organic matter to pit lakes to enhance microbial sulphate reduction is a potential cost effective remediation strategy. However, cost and availability of suitable organic substrates are often limiting. Nevertheless, large quantities of sewage and green waste (organic garden waste) are often available at mine sites from nearby service towns. We treated AMD pit lake water (pH 2.4) from tropical, North Queensland, Australia, with primary-treated sewage sludge, green waste, and a mixture of sewage and green waste (1:1) in a controlled microcosm experiment (4.5 L). Treatments were assessed at two different rates of organic loading of 16:1 and 32:1 pit water:organic matter by mass. Combined green waste and sewage treatment was the optimal treatment with water pH increased to 5.5 in only 145 days with decreases of dissolved metal concentrations. Results indicated that green waste was a key component in the pH increase and concomitant heavy metal removal. Water quality remediation was primarily due to microbially-mediated sulphate reduction. The net result of this process was removal of sulphate and metal solutes to sediment mainly as monosulfides. During the treatment process NH(3) and H(2)S gases were produced, albeit at below concentrations of concern. Total coliforms were abundant in all green waste-treatments, however, faecal coliforms were absent from all treatments. This study demonstrates addition of low-grade organic materials has promise for bioremediation of acidic waters and warrants further experimental investigation into feasibility at higher scales of application such as pit lakes.     

Managing the impact of climate change on the hydrology of the Gallocanta Basin,NE-Spain

The Gallocanta Basin represents an environment highly sensitive to climate change. Over the past 60 years, the Laguna de Gallocanta, an ephemeral lake situated in the closed Gallocanta basin, experienced a sequence of wet and dry phases. The lake and its surrounding wetlands are one of only a few bird sanctuaries left in NE-Spain for grey cranes on their annual migration from Scandinavia to northern Africa. Understanding the impact of climate change on basin hydrology is therefore of utmost importance for the appropriate management of the bird sanctuary. Changes in lake level are only weakly linked to annual rainfall, with reaction times between hours and months after rainfall. Both the total amount of rainfall over the reaction period, as well as individual extreme events, affect lake level. In this study the characteristics and frequencies of daily, event, monthly and bi-monthly rainfall over the past 60 years were analysed. The results revealed a clear link between increased frequencies of high magnitude rainfall and phases of water filling in the Laguna de Gallocanta. In the middle of the 20th century, the absolute amount of rainfall appears to have been more important for lake level, while more recently the frequency of high magnitude rainfall has emerged as the dominant variable.     

云南高原湖泊流域土地利用与水质变化异质性分析

以云南省九大高原湖泊为例,通过面板数据方式分析对高原湖泊流域土地利用类型变化,通过库兹涅兹曲线相关内容对利用强度的分析以及与水质的动态变化情况,得到耕地、园地、湿地面积与湖泊含磷量存在一定负相关.林地、牧草地、建设用地面积与湖泊含磷量存在一定正相关.牧草地、耕地、园地、湿地面积与湖泊含氮量存在一定负相关,建设用地面积与湖泊含氮量存在一定正相关.园地和耕地面积与污染综合指数存在负相关,建设用地面积与污染综合指数存在负相关.分析指出,滇池、泸沽湖处于流域协调区间,阳宗海、抚仙湖、星云湖、程海处于流域冲突区间,洱海、异龙湖处于冲突区间向协调区间转型过程中.     

大型通江湖泊有色可溶性有机物对不同水文情景的响应

鄱阳湖和洞庭湖作为我国面积最大的两个通江湖泊,其湖体水质变化对长江干流水质以及湖区周围居民用水安全至关重要.通过三维荧光-平行因子分析得到4个荧光组分,研究两个湖泊的有色可溶性有机物(CDOM)光谱组成在丰、平和枯这3种水文情景下的变化规律,试图揭示鄱阳湖和洞庭湖CDOM来源及组成对不同丰枯情景的响应机制.结果表明:不同水文情景对鄱阳湖CDOM水质参数影响更为显著,CDOM吸收系数a(254)和溶解性有机碳(DOC)浓度表现为丰水期平水期枯水期(t-test,P0.01),CDOM光谱吸收斜率S_(275-295)表现为枯水期平水期丰水期(t-test,P0.01),洞庭湖a(254)在不同水文情景下差异不显著,比紫外吸收系数SUVA_(254)最大值出现在平水期.平行因子分析法解析三维荧光光谱得到4个荧光组分,枯水期两湖CDOM类蛋白组分贡献率较大,平水期类蛋白组分及类腐殖酸组分贡献率大致相当,丰水期两个湖泊类腐殖酸贡献率占主要部分.在空间分布上,枯水期鄱阳湖4个组分的荧光强度在上游南部湖区偏小,北部偏大,丰水期反之,东洞庭湖4个组分的荧光强度在空间差异上表现为枯水期大于丰水期.鄱阳湖DOC浓度对水位的响应更明显(r~2=0.99,P0.01),东洞庭湖类色氨酸组分C2与水位呈显著性负相关关系(r~2=0.99,P0.05).鉴于此,应根据鄱阳湖、洞庭湖CDOM在不同水文情景下的响应特征,有针对性地对湖区水质进行管理.     

宁武亚高山湖泊细菌群落的时空格局及驱动机制

受人类活动和气候变化的影响,亚高山湖泊生态系统日趋退化,导致微生物群落生物多样性和结构改变.本研究以宁武亚高山湖泊公海(GH)水体细菌群落为研究对象,通过Q-PCR和DGGE技术分析了不同季节和不同深度的水体中细菌群落多样性分布格局,探究细菌群落的时空动态及其多样性维持机制.结果表明,温度(T)、酸碱度(p H)、溶解氧(DO)、电导率(EC)、盐度(SAL)和铵态氮(NH4+)在每个月的不同采样深度间均有显著差异.细菌群落丰度具有明显的时空动态,其中8月的丰度最高,11月最低;在水体中层(2、4和6 m)的丰度较高,表层和底层(0 m和8 m)相对较低.细菌群落α多样性指数在各月份和不同深度间均有显著性差异,从4～12月整体上呈现先减少后增加的趋势.相似性分析(PERMANOVA)结果表明,不同深度之间细菌群落的空间分布格局明显不同(P 0. 001).冗余分析(RDA)和方差分解(VPA)结果表明在不同深度下,细菌群落多样性格局是环境选择和扩散限制共同作用的结果,但是环境选择的相对作用更强,其中水体无机氮(NO3-、NO2-和NH4+)浓度是主要的影响因子.总之,宁武亚高山湖泊公海中细菌群落多样性有明显的时空分布格局,环境选择作为主要因素驱动了细菌群落的多样性格局.     

国有自然资源资产管理体制改革的建议与思考

自然资源产权管理和专业监管的分立可充分发挥市场作用,进一步促进简政放权,实现对山水林田湖草的综合管理,克服监管盲点,提升综合保护绩效,促进绿水青山转化为金山银山。设立专门机构开展自然资源资产管理,《生态文明体制改革总体方案》等规定了改革依据;自然资源统一确权登记试点取得积极进展,奠定了工作基础;与自然资源资产负债表、绿色GDP核算、生态文明建设目标评价考核等结合起来,促进改革的系统化和连贯化;建议在国家和省、市成立三级国有自然资源资产管理机构,在部分区域和流域派驻机构。为保障改革的实施,需界定国有自然资源资产的范围及所有权、监管权的角色和权限;改革生态补偿、排污权有偿使用、资源有偿利用等制度;明晰流域与属地的权力(利)关系;明确自然资源资产管理职责和生态环保党政同责的关系;重构环境保护税、资源税和自然资源资产使用费的关系;规定自然资源资产管理的原则、体制、制度和责任;建立自然资源资产清单、权利清单和管理信息平台;厘清各方权利边界和监管边界,建立评价考核和奖惩机制。     

基于产业调整的太湖流域生态环境优化探讨

以流域为单元进行水资源综合管理,是实现资源、环境与经济社会协调发展的重要途径. 产业调整能控制污染源的数量和种类,是区域环境治理的关键环节和有效手段. 从湖泊流域产业的特有结构分析出发,以太湖为例,分析了当前太湖流域环境问题、产生的原因及其存在的产业不合理性,探讨了点源污染、线源污染和面源污染的成因及其对污染总量的贡献、治理方案并加以对比分析;探讨了湖泊流域产业调整和优化对区域生态环境的改善及污染控制治理中的作用,基于污染总量恒定或稳步下降、经济发展速度不变的情况下,对流域产业升级和优化调整提出了具体的产业结构和政策,这对指导湖区流域可持续发展具有一定的理论意义和实践价值.      

Heavy-metal contents in suspended solids of Meiliang Bay, Taihu Lake and its environmental significances

Surface water was taken from river mouth to the central area of Meiliang Bay, Taihu Lake, a large shallow eutrophic lake in China. Suspended solids were condensed by centrifugation 25L surface water samples from each selected site. Suspended solids and surface sediments were further freeze-dried and microwave digested before determining the metals by ICP-AES. Among the metals analyzed in suspended solids and sediments, contents of Cr, Cu, Mn, Ni, and Zn in suspended solids were significantly higher than those in sediments while contents of AI, Ba, Be, Ca, Co, Fe, K, Mg, Pb, and V in suspended solids were 10%-30% higher than those in sediments. Sr and Ti contents in suspended solids and sediments were very similar. Na content in suspended solids was lower than that in sediments. Heavy metals were significantly accumulated in suspended solids. From the river mouth to the center of Meiliang Bay, contents of Cr, Cu, Pb, and Zn in suspended solids showed a gradual decreasing trend indicating the river(Zhihugang River) still discharged large quantity of heavy metals to Meiliang Bay. The study suggests that the geochemical behaviors and ecological effects of heavy metals in suspended solids may serve as a good indicator for the pollution of lake.     

湖泊资源特征及与其功能的关系分析

在地质、地貌、气象、水文、化学和生物等各种内外营力长期相互作用下形成的湖泊资源,是自然资源的一种类型,在国民经济可持续发展中发挥着重要的经济、环境和社会效益。同时,湖泊自身系统结构是通过赋存其中的各种资源而显现的,并存在着内在的有机联系,也就由此而衍生出湖泊具有多种功能。因此,湖泊的资源是其功能的载体,资源具有直观性,而功能则具有抽象性,往往容易被忽略,这也是人们认识湖泊是经历资源型到功能型逐步发展过程的原因所在。人类是自然之骄子,具有择水而居的习性,对自然的认识是从对自然资源的依赖性和对自然现象充满神秘感开始的。湖泊是国土资源的重要组成部分,并具有强大的生态服务功能和鲜明的特点,在塑就人类文明史方面发挥了重要作用。文章对我国湖泊资源的特征和湖泊资源利用过程中存在的问题,以及湖泊由不同资源类型组成的生态结构所维系的功能进行了初步探讨。     

Modelling Phosphorus Retention in Lakes and Reservoirs

Steady-state models for the prediction of P retention coefficient (R) in lakes were evaluated using data from 93 natural lakes and 119 reservoirs situated in the temperate zone. Most of the already existing models predicted R relatively successfully in lakes while it was seriously under-estimated in reservoirs. A statistical analysis indicated the main causes of differences in R between lakes and reservoirs: (a) distinct relationships between P sedimentation coefficient, depth, and water residence time; (b) existence of significant inflow–outflow P concentration gradients in reservoirs. Two new models of different complexity were developed for estimating R in reservoirs: , where τ is water residence time (year), was derived from the Vollenweider/Larsen and Mercier model by adding a calibrated parameter accounting for spatial P non-homogeneity in the water body, and is applicable for reservoirs but not lakes, and , where [P_in] is volume-weighted P concentration in all inputs to the water body (μg l⁻¹), was obtained by re-calibrating the OECD general equation, and is generally applicable for both lakes and reservoirs. These optimised models yield unbiased estimates over a large range of reservoir types.