Assessment of Retention Ponds and Its Impacts on Health of Residents in Mogadishu, Somalia: Mixed Methods

The purpose of this study was to evaluate the effects of retention ponds on the environment and population health by analyzing water samples from various ponds in Mogadishu, to determine the prevalence of waterborne illnesses that occur during the rainy season in Mogadishu, and to find out what experts thought about the effects of retention ponds on the environment as well as population health in Mogadishu. Methods: Mixed designs were used in the study. The first design is an exploratory study where samples are taken from different retention ponds in Mogadishu. The second design involves gathering secondary data from the online FSNAU Dashboard regarding the incidence of rainfall and waterborne illnesses including malaria and cholera. Additionally, a cross-sectional survey of expert opinions using questionnaires was the third design. The 10 water samples were taken from retention ponds in Mogadishu as part of the sample size. Data on the fourth month was also gathered using the FNSAU dashboard, and seventy sample sizes were used for the expert self-administered questionnaire for the third design. Excel was used for data analysis in the initial design. While BMI SPSS versions 22 were used to analyze the data from the Self-administered Questionnaire, additional methods were utilized to compute descriptive statistics, such as mean and standard deviation, and to analyze demographic data in a frequency table. Findings: The results show that three samples had unsatisfactory scores (Grade D): Yaqshid (Warshadda Bastada) had a WQI of 80.85, Boondheer (Bondher Pond) had a WQI of 80.64, and Wartanabad (Xamar Jadiid Pond) had a WQI of 80.89. The remaining samples were all rated as fair (grade), which indicates that they ranged from 50 to 75. The months with the largest rainfall already occurred in December, November, and October, when the prevalence of diseases during the rainy season was highest for cholera cases. Although October and December saw a significant number of malaria cases, November did not. Retention ponds’ overall effects on residential environments were evaluated, and the results showed that the standard deviation was 0.802 and the cumulative average mean scores were 4.41 overall. This indicates that the respondents were in agreement that retention ponds in Mogadishu, Somalia, had an effect on residential areas. Recommendation: The study suggested that in order to identify retention pond contamination and create treatment units for its management, the Ministry of Health forms a district-level public health committee. All districts must have a sewer system installed by the local government, and retention ponds must be made easier in order to move waste outside of the city.

Evaluation of Human Impacts on Bartlett Pond Ecosystem, Laredo, Southern Texas, USA, through Empirical Modeling

The trace elements chemistry of Bartlett Pond, a small shallow wetland pond in Laredo, Southern Texas, was sampled to evaluate the dynamics of trace elements impacts on water quality and ecosystems ecology of the pond. Two types of fish (bass and tilapia) were also sampled to see the trace element accumulation in different parts of their body. The concentrations of trace elements in water samples were found in the following order: Fe ≫Sb > Pb > As ≫Co > Tl > Cr > Cd within Bartlett Pond. Overall, the water quality of the pond is unacceptable for drinking and any other purposes as trace element concentrations (e.g. As, Cd, Co, Cr, Pb, Fe, Sb and Tl) are exceedingly higher (several fold) than the WHO and US EPA guidelines. Predictive and correlation analysis shows that most trace elements exhibit a strong positive correlation among them indicating the same anthropogenic sources and biogeochemical processes regulate these trace elements within the pond. Distributions of the trace elements in water exhibit different shapes mostly as positively skewed distribution for As, Cd, Co, Cr, and Tl, symmetrical distribution for Fe and almost symmetrical distribution for Pb and Sb. Concentrations of As, Co and Tl accumulated much higher in different parts of the Bass than Tilapia fish. The concentrations of As, Tl, Co, and Sb appeared significantly higher in different parts of the body of both Bass and Tilapia than the maximum SRM certified values. Accumulation of these contaminants in fish tissues pose increased health risks to humans who consume these contaminated fish although fishing is prohibited. Anthropogenic activities in the region primarily degrade the whole pond ecosystem ecology of the Bartlett Pond and waters of this pond to be not recommended for any use. These findings may be useful for the scientific community and concerned authorities to improve understanding about these precious natural resources and conservation of the ecosystem ecology.

Microscopic analysis on eukaryotic algae and cyanobacteria in nine seasonal lakes and ponds in Vestfjella,Dronning Maud Land,Antarctica

Antarctic continental lakes and ponds are among the most impoverished aquatic environments on earth but many of them support flourishing populations of cyanobacteria,eukaryotic algae,protozoans,and some multicellular animals.In this study,we present results of a microscopic analysis of cyanobacteria and eukaryotic algae from nine diverse types of Antarctic continental water bodies during one austral summer.The results supplement and enlarge our previous studies on the limnological characteristics of the epiglacial and supraglacial lakes and ponds in Dronning Maud Land,an area that has received little attention from limnologists.The taxon with highest frequency among the samples(n=79)was Mesotaenium cf.berggrenii,a eukaryotic Zygnematophyceae,which occurred in 82%of the samples with a maximum cell density of 68 cells·mL^(-1).The taxa with second and third highest frequency were the prokaryotes Gloeocapsopsis(60%)and Leptolyngbya(41%),followed by Chlamydomonas(34%)and Cyanothece(29%).The number of taxa varied between 7-21 among the lakes and ponds,being highest in a supraglacial lake,and lowest in an epiglacial lake.The results did not reveal any obvious correlation between the abundance of any taxa and the water chemistry,but water bodies with inorganic sediments had higher cell densities and biomasses than those without sediment.This suggests the importance of sediment in supporting biological diversity in these ultraoligotrophic lakes and ponds.

Study on Migration Law of Runoff Pollutants in Bio-retention Tank

The migration law of runoff pollutants in bio-retention tank was studied through the experimental research, containing calculation formula of pollutants reduction coefficient. After that, the technology of reducing and controlling runoff pollution by bio-retention tank was demonstrated. The result showed that bio-retention tank can reduce runoff by 15%-85%, and the pollutant emissions can be cut by 35%-95%. At the same time, it had good ecological landscape effect. The study can provide a reference for the design method of road bio-retention tank in sponge city construction, and basic technical methods and parameters for the subsequent construction of comprehensive control platform for urban rainwater runoff and the layout optimization of comprehensive measures of water quality and quantity.

Impacts of Climate Change on Economic Performance of Tilapia Pond Operations in Minalin, Pampanga: A Case of Intensive Large-Scale Pond Culture

Pampanga is the top tilapia-producing province in Philippines. One of its municipalities, Minalin, is considered as one of its major centers of production. This study aims to determine the impacts of climate change hazards on the economic performance of tilapia-intensive pond culture in Minalin, Pampanga considering the threats to the industry, livelihoods, and food security. Results revealed that the economic performance of tilapia pond operations using semi-intensive large-scale culture was affected by climate change, as reflected in the reduction of yield among tilapia pond operators. This makes intensive tilapia pond farming in Minalin still a viable venture but will now require more than a year to pay for investment (variable and fixed) costs if under climate change risks. The study recommends strengthening capacity building related to climate-smart tilapia farming technologies for pond operators and to implement appropriate technologies to address climate change risks.

Dynamic Behaviour of Pond Ash Mixed with Coir and Crumb Rubber

An experimental program was conducted to determine the dynamic properties of pond ash(PA)and pond ash mixed with admixtures like crumb rubber(CR)and coir fiber(CF)which are wastes of different industries.Additives CR and CF were mixed separately with pond ash in a percentage ranging from 0%–20%at an interval of 5%and 0%–2%at an interval of 0.5%by weight of pond ash,respectively.Dynamic properties(Shear modulus,Number of cycles to initiate liquefaction,Degradation index and Damping ratio)for pond ash mixes were determined using strain-controlled cyclic tri-axial apparatus.The shear strain was kept constant at 1.2%and the frequency varied from 0.4 to 1 Hz.Liquefaction resistance improves when crumb rubber is added to pond ash,however adding Coir fiber to pond ash has essentially no effect on the number of cycles required to initiate liquefaction.The dynamic shear modulus decreases when crumb rubber was mixed in pond ash whereas when coir fiber is added to pond ash,the dynamic shear modulus increases significantly.A mix of PA,CR,and CF was also tried to balance the number of cycles required to initiate liquefaction and shear modulus.The mixed sample in the proportion of PA(84%)+CR(15)+CF(1%)can be termed a balanced mix as the number of cycles to initiate liquefaction was more than all PA-CF mixes and also the shear modulus was more than all PA-CR mixes.Damping ratio increases with increasing frequency of loading(0.4 to 1 Hz).

Chemical weathering profile in the V–Ti–Fe mine tailings pond:a basalt-weathering analog

The(ultra-)mafic mine tailings pond revealed a weathering discrepancy in the tailings profile,which provided a valuable analog to assess the role of carbonate and silicate weathering of the basalt.In this study,drill-cores samples were selected from the Wanniangou V–Ti–Fe mine tailings pond(Sichuan province,China)to investigate the mineralogicand geochemical characteristics in the tailings profile.The results reveal(1)the tailings pond profile consist of upper and lower layers.The upper layer is composed of carbonate weathering(1.4%),which was formed in the initial stages of tailings exposure and represented a minimal weathering degree.(2)The lower layer was primarily observed at the aquifer zone of the tailings pond,and was consistent with 0.45%carbonate weathering and 48.4%silicate weathering.(3)The weathering discrepancy in the tailings profile could be due to the sulfide oxidation and aerobic/flowing aquifer,which facilitate the water-tailings reactions.The tailings profile provides an analog to studying basalt weathering,as it spans both carbonate and silicate weathering.This research reinforces the idea that silicate weathering is predominant in basaltic areas and plays a crucial role in regulating atmospheric CO_(2)(carbon dioxide)levels on Earth.

Carbon isotope ratios of n-alkanoic acids: new organic proxies for paleo-productivity in Antarctic ponds

Primary productivity in the Antarctic aquatic environment with simple ecosystems is sensitive to climate and environmental fluctuations.We investigatedδ13C values for n-alkanoic acids derived from phototrophic organisms in a lacustrine sediment core(IIL3)to indicate primary productivity in ponds on Inexpressible Island in the western Ross Sea,Antarctica.Short-chain n-alkanoic acids(C14–C18)were abundant in the IIL3 sediment profile.The carbon isotope ratios of short-chain n-alkanoic acids in the sediment samples and floating microbial mats were similar,indicating that the short-chain n-alkanoic acids in the IIL3 sediment profile predominantly originated from phototrophic organisms.Theδ13C values for the short-chain n-alkanoic acids varied widely through the sediment profile,and 13C-enrichment of n-alkanoic acids was most likely related to high productivity due to carbon-limited conditions caused by enhanced photosynthetic efficiency.Theδ13C values for the n-alkanoic acids changed over the past 3200 years in similar ways to organic proxies for aquatic productivity(n-alkanoic acid and sterol sedimentary fluxes).C16 n-alkanoic acid was enriched in 13C in periods of high aquatic productivity~750–1650 and 3000–3200 a BP but depleted in 13C in periods of relatively low productivity~150–600 and 2500–3000 a BP.The results indicated that carbon isotope ratios of lipids from phototrophic organisms could be used as new proxies to reconstruct paleo-productivity in Antarctic lakes and ponds and therefore improve our understanding of past climate changes.

淡水养殖池塘水质评价及与底质相关性分析

在哈尔滨地区面积6 600 m^(2)、平均水深1.2 m、多年未清淤的泥沙底质典型淡水精养池溏中混养鲤(Cyprinus carpio)、鲇(Silurus asotus)、草鱼(Ctenopharyngodon idella)和鲢(Hypophthalmichthys molitrix),春季(4—5月)、夏季(6—8月)和秋季(9月)不同时间采集池塘水体和表层底泥样品,监测养殖周期内水质总氮(TN)、总磷(TP)、氨氮(NH_(4)^(+)-N)、亚硝酸盐氮(NO_(2)^(-)-N)、硝酸盐氮(NO_(3)^(-)-N)和总有机碳(TOC)含量及高锰酸盐指数(COD_(Mn))、p H的季节性变化,利用单项污染指数法、综合污染指数法评价水体污染程度,利用主成分分析法解析水质污染的主要驱动因子,并结合底质指标绘制网络关系图。结果表明:池塘水质整体处于严重污染水平,春季优于夏季和秋季。参与评价时池塘水质为Ⅳ类、Ⅴ类和劣Ⅴ类,水质超标数随着养殖时间延长而增加,TN在全养殖周期内均超出警戒水平;TN、TP、NH_(4)^(+)-N和COD_(Mn)是池塘水体的主要污染物。因子分析结果表明,池塘水质主要受鱼类的生长代谢、溶解氧和投饵的影响,污染物以N、P营养盐为主。水体TP、TN、NH_(4)^(+)-N和底泥NO_(2)^(-)-N呈极显著正相关关系(P<0.01),与底泥TOC呈显著正相关关系(P<0.05)。池塘水体和底泥中的有机物污染具有共现性,水体TOC和底泥TOC呈极显著正相关关系(P<0.01)。

中国淡水池塘养殖发展的时空格局与前景展望

淡水池塘养殖是我国重要的渔业生产方式,解析其时空发展格局对于研判和把握未来的发展趋势十分必要。本研究以历年来中国渔业统计年鉴数据为基础,对近40年以来(1980-2020年,以5年为间隔;另有2021、2022年)全国31个省级行政单元淡水池塘养殖产量、面积、单产、占渔业总产量的比例进行了统计分析。结果表明:(1)养殖产量总体呈持续增加趋势,但增长率波动式放缓,1980-2020年增长率从181.9%下降至12.0%,2020-2022年均值为2348.3万吨,平均增长率为2.9%;(2)养殖面积亦呈持续增加趋势,但增长率波动式放缓,从53.1%下降至4.8%,2020-2022年均值261.8万hm^(2),平均增长率为0%;(3)单产总体呈波动式增长,但增长率从82.8%逐步下降至13.7%,2020-2022年均值604.7 kg/667 m^(2),平均增长率为2.4%;(4)各省淡水池塘养殖产量占渔业总产量比重的均值呈先上升后逐渐持平的趋势,1995-2022年波动持平变幅在44.6%~49.0%。受水土资源和环境保护刚性约束,当前淡水池塘养殖发展亟需从数量规模型向质量效益型转变,生态-经济合作型渔业综合体将是未来高质量发展的重要途径。

洪湖周边三种典型养殖类型池塘浮游植物群落特征及其与环境因子的关系

不同养殖水体浮游植物群落结构和丰度的变化,可反映水质和水产品状态,认识其变化特征和驱动力,对养殖管理和尾水处理有重要的指导意义。本研究于2019-2020年在洪湖养殖区域选择了三种典型养殖类型池塘(克氏原螯虾、中华绒螯蟹、大宗淡水鱼,以下分别简称为龙虾塘、河蟹塘和鱼塘),解析了各类型池塘浮游植物的物种组成、细胞密度、生物量和多样性的季节变化趋势。结果显示:(1)共检测到浮游植物132种,隶属于7门96属。浮游植物细胞密度和生物量总体趋势为鱼塘>河蟹塘>龙虾塘,年平均细胞密度分别为1.06×10^(8)、6.04×10^(7)和2.35×10^(7)cell/L,年平均生物量(叶绿素a表示)分别为94.82、65.95和31.15μg/L。(2)三种养殖模式池塘中浮游植物群落结构具有显著性差异,并具有明显的季节演替。春夏两季中龙虾塘与河蟹塘的浮游植物群落结构组成更为相似,而秋冬两季中河蟹塘与鱼塘更为相似。龙虾塘和河蟹塘浮游植物多样性指数和均匀度指数均在收获季节(龙虾为夏季,河蟹为秋季)最低。(3)冗余分析结果表明温度(Temp)、溶氧(DO)、pH和溶解性总磷(DTP)是影响养殖池塘中浮游植物群落组成的主要环境因子。多元线性回归模型显示,不同季节中解释浮游植物生物量变化的主要因素不同,春季和秋季为总氮(TN)和养殖动物类型,冬季为TP、DTP、NH_(4)^(+)-N。鉴于各养殖类型在排水季节的浮游植物优势类群变动,建议加强养殖尾水监控,以预判尾水种源迁移对邻近水域的潜在影响。

内陆地区南美白对虾淡化养殖池塘浮游植物群落结构特征及其生态影响因子

在新疆昌吉市森淼渔业专业合作社6 667 m^(2)、水深约1.6 m池塘中,放入经12 d淡化至盐度0.8左右的南美白对虾(Litopenaeus vannamei)苗种,放养密度约为45 ind./m^(3)。放苗当天即采用标准方法开始第一次采样,每周采样1次,共采集12次,调查新疆昌吉地区南美白对虾淡化养殖池塘中浮游植物群落组成变化,借助多变量分析方法揭示浮游植物群落的结构特征、时空变动及其主要生态影响因子。结果显示:本次调查共鉴定浮游植物103种(属),其中绿藻门种类数最多为39种(属),其次为硅藻门29种(属)和蓝藻门23种(属),其他各门种类数不多于4种(属);优势种8种(属)。调查期间浮游植物总平均密度为(2.05±2.93)×10~8ind./L,变幅为4.58×102~9.66×10~8ind./L,总平均生物量为(30.49±33.81)mg/L,变幅为0.80~101.47 mg/L。冗余分析(RDA)表明,铵态氮和活性磷与具星小环藻(Cyclotella stelligera)的相关性较低,而蛋白核小球藻(Chlorella pyrenoidosa)、月牙藻(Selenastrum bibraianum)和衣藻(Chlamydomonas spp.)更易在较高的铵态氮环境中建立优势地位;活性磷含量的增加可能是促进蓝藻大量繁殖的重要因素;植食性浮游动物牧食会对浮游植物群落变动产生一定影响,这种变动更倾向于从小型可食性到较大个体或不可食性种类转变。南美白对虾淡化养殖池塘浮游植物群落结构受生态因子的影响存在显著时空变化,掌握其变动规律对进一步开展池塘水质调控技术提供科学依据。

水稻浮床对养殖池塘水质净化效果研究

为研究水稻对养殖池塘水质净化效果及对鱼类产量的影响,设计2个处理,分别为水稻浮床组(试验组)和常规养殖组(对照组)。试验期间,定期检测2个试验池塘水质理化指标,试验结束后统计养殖鱼类产量、成活率及水稻产量。结果表明:试验组平均水温略低于对照组,透明度(SD)高于对照组;试验初期,试验组溶解氧(DO)含量高于对照组,中后期DO含量低于对照组。水稻浮床对养殖池塘水体总磷(TP)、总氮(TN)、氨氮(NH_(4)^(+)-N)、亚硝酸盐氮(NO_(2)^(-)-N)、化学耗氧量(COD_(Mn))的平均去除率分别为30.6%、29.6%、27.9%、21.0%和15.6%。试验组不同养殖鱼类成活率均高于对照组,养殖鱼类产量22557.15 kg/hm^(2),浮床水稻产量5234.57 kg/hm^(2)。

典型汞尾矿汞的释放特征——以万山岩屋坪尾矿库为例

为研究汞尾矿中汞的释放特征,以我国典型汞矿区——万山岩屋坪尾矿库为研究对象,采用静态浸泡和动态淋溶方法,结合试验前后尾矿的矿物组成、汞赋存形态占比及释放动力学,共同探究汞在尾矿中的释放特征。研究结果显示:在静态浸泡中,pH值为4.5,固液比(g∶mL)为1∶10条件下汞释放质量浓度最大,静态浸泡后尾矿物相组成减少,碳酸盐结合态汞和离子交换态汞占比降低。在动态淋溶中,降雨pH值为4.5,降雨强度为2.616 mL/min条件下释放的汞质量浓度最大,动态淋溶后各物相组成减少,残渣态汞、碳酸盐结合态汞和离子交换态汞占比降低。释放动力学拟合结果表明,汞的释放过程符合二级动力学模型。研究为汞矿区尾矿中汞的释放及矿区的潜在污染防治等环境问题提供了理论支撑及科学依据。

淡水池塘养殖尾水处理技术研究综述

为实现水产养殖业节能减排、低碳高效和可持续发展,必须解决传统池塘养殖尾水处理问题。根据典型池塘养殖尾水污染物特性,全面总结国内外淡水池塘养殖尾水的处理方法和技术特点;对比了“三池两坝”“集装箱+生态塘”“生态湿地”等典型池塘养殖尾水处理模式;分析了竖流沉淀、旋流分离、滤筛、气浮等物理净化技术以及臭氧-微纳米浮选、絮凝、微生物制剂、活性污泥、新型生物膜反应器过滤、水生植物等化学及生物净化技术;指出了该领域的热点研究方向和关键技术问题,包括发展“节能、减排、生态、高效”集约化池塘养殖模式、研发养殖尾水专用处理装备、提高净化效率和减少占地面积等,可为池塘养殖尾水处理技术及相关装备研发提供一定的理论参考。

排渗失效下尾矿库溃坝三维模型试验研究

针对尾矿库渗透破坏模式,为克服二维试验槽边壁效应对模型渗流走向及溃决位置的影响,本文以某尾矿库为原型,基于自主设计的三维尾矿库溃坝模型试验平台,进行了排渗设施失效诱发的尾矿库溃坝模型试验研究,揭示了该尾矿库的溃决模式及溃决机理。结果表明:(1)排渗失效导致的溃坝呈现局部流土破坏-坝体累计变形-深层滑动面发展贯通-整体突发失稳的渐进伴突发型溃决演化模式;(2)坝体孔隙水压力骤变是坝体发生滑动破坏的关键响应指标,预示着坝体将在短时间内由滑动体前后缘局部散浸软化、流土、塌陷转变为大范围溃决,可作为坝体溃决事故的前兆信息;(3)排渗失效导致的尾矿库溃坝过程具有渐进性和突发性的特点,发生散浸与流土破坏的过程时间较长,发生深层滑动和溃决的时间短暂,该特征可为尾矿库渗透破坏隐患治理及坝体溃决应急响应提供参考。研究结果对尾矿库溃坝的灾害预防具有重要的现实意义。

不同时间尺度下气象-水文要素变化对察尔汗盐湖盐田蒸发作用的影响

目前对察尔汗盐湖蒸发量的研究主要集中在气象-水文因素与卤水蒸发量定量关系,缺乏在不同时间尺度下盐湖蒸发量的驱动因素动态变化研究。利用2020年11月5日—2023年5月1日察尔汗盐湖盐田的空气温度、露点温度、风速、相对湿度、总辐射日累计以及盐田的蒸发量、水温、水位等监测数据,结合获取的察尔汗盐湖补给河流格尔木河流量等水文资料,采用相关性分析、多元回归模型等方法探讨了不同时间尺度下盐田蒸发作用与气象-水文因素之间的关系。研究表明,不同盐田的水温、水位、淡水蒸发量变化保持一致,卤水蒸发量变化与盐田密度有关。随着时间尺度的增大,蒸发量与气象要素之间的相关性增强。察尔汗盐田蒸发量在逐小时与逐月尺度主要受到环境温度的影响,日尺度下主要受到太阳辐射的影响。在极端天气作用下河流水文与盐湖微气象因子呈同步变化,对蒸发量的影响具有滞后性。这一研究结果可为盐田生产工艺优化提供理论指导。

海水多品种养殖池塘沉积物-水界面氮磷通量

为探明生源要素氮、磷在沉积物与水体间的迁移过程,比较3种不同养殖模式下、不同时间养殖池塘沉积物-水界面的氮、磷通量变化,2014年6—10月,在3种综合养殖池塘:海蜇+凡纳滨对虾+菲律宾蛤仔、海蜇+凡纳滨对虾+缢蛏和海蜇+凡纳滨对虾的整个养殖周期内,采集检测3口池塘沉积物-水界面样品中的亚硝态氮、硝态氮、氨氮和活性磷酸盐含量,分析沉积物-水界面的亚硝态氮+硝态氮、氨氮和活性磷酸盐的通量变化。试验结果显示,6—10月,3种综合养殖池塘沉积物上覆水中亚硝态氮和硝态氮均以向沉积物中扩散为主,仅10月海蜇+凡纳滨对虾池塘沉积物中亚硝态氮和硝态氮向上覆水释放。海蜇+凡纳滨对虾+菲律宾蛤仔、海蜇+凡纳滨对虾+缢蛏池塘沉积物上覆水中氨氮向沉积物扩散,6月海蜇+凡纳滨对虾+缢蛏池塘沉积物中氨氮向上覆水扩散;与海蜇+凡纳滨对虾+菲律宾蛤仔和海蜇+凡纳滨对虾+缢蛏池塘相比,海蜇+凡纳滨对虾池塘氨氮通量变化幅度较大,6—7月上覆水中氨氮向沉积物扩散,且扩散速率逐渐降低,9—10月沉积物中氨氮向上覆水释放,释放速率逐渐上升。6、7、10月海蜇+凡纳滨对虾+菲律宾蛤仔池塘沉积物中活性磷酸盐向上覆水释放,8—9月上覆水中活性磷酸盐向沉积物扩散;6—10月,海蜇+凡纳滨对虾+缢蛏池塘沉积物中活性磷酸盐向上覆水释放;海蜇+凡纳滨对虾池塘上覆水中活性磷酸盐向沉积物扩散,10月沉积物中活性磷酸盐向上覆水释放。试验结果表明,配养底栖贝类,可以通过改变综合养殖池塘沉积物-水界面的氮、磷通量,改善池塘的底质和水质环境。

不同面积蒸发池水温特征及Penman模型改进

分析蒸发池水温特征可深入认识蒸发池能量平衡特性,研究Penman模型计算误差来源并改进,对农业计划、水源评估和水文预报具有重要意义。基于太谷均衡实验站3个不同面积蒸发池的水温、蒸发量及气象数据,分析各蒸发池的垂向水温分布和蒸发量的变化特征,基于Penman模型探究适合3个蒸发池的模型参数。结果表明:1 m^(2)和5 m^(2)蒸发池4—8月水温随水深增加而显著降低,20 m^(2)蒸发池各月水温分布均比较均匀,且水温更高;1 m^(2)和5 m^(2)蒸发池各月蒸发量相近,与净辐射变化趋势一致,20 m^(2)蒸发池蒸发峰值滞后于净辐射峰值3个月;Penman模型中加入反映除净辐射外能量的综合影响参数可提高模型计算精度,夏季尤为明显,1、5、20 m^(2)蒸发池夏季的参数值分别为3.5、3.3和2.1。

农村纳污坑塘水体治理技术

研究出一套针对农村纳污坑塘水体治理的相关技术,即预处理+缺氧生化+复合型人工湿地。将纳污坑塘隔离出3个区,农村污水依次经过预处理区、缺氧生化区和水生植物稳定区,通过过滤、混凝、微生物降解、湿地基质吸附和植物吸收等作用,实现纳污坑塘水体的高效净化,改善农村的生态环境。