The dissolution of total suspended solids and treatment strategy of tailwater in a Litopenaeus vannamei recirculating aquaculture system

In recirculating aquaculture systems(RASs),the effective treatment of aquaculture tailwater is essential to maintain the health of the RAS.This study investigated the optimal time and method for tailwater treatment during three periods of the aquaculture of the Litopenaeus vannamei:nursery(0–26 d),middle(27–57 d),and later(57–104 d).The variation of several water parameters during the dissolution of total suspended solid(TSS)in tailwater,applied with the effects of ozone on the microorganism and water quality parameters were investigated.Results showed that the TSS concentrations in tailwater decreased with time,although not significantly(P>0.05),whereas total ammonia nitrogen(TAN),nitrite(NO-2-N),and nitrate(NO_(3)^(-)-N)increased significantly(P<0.05).Therefore,TSS should be removed from the tailwater as early as possible,being most optimal within 4 h.Ozone removed 38.24%–48.95%of TSS,17.78%–90.14%of TAN,and 87.50%–98.90%of NO-2-N after 4 h of treatment.However,it resulted in the significant accumulation of NO_(3)^(-)-N.Moreover,the total number of Vibrio and bacterial counts in aquaculture tailwater was reduced completely by ozone within 4 h.Thus,these results provided technical details and data support for the effective treatment of tailwater from shrimp RAS.

Practical Application of the Results for Optically Measured Total Suspended Solids Concentrations in the Drava River

The investigations described in this paper were performed in order to determine whether the concentrations of total suspended solids (TSS) in the Drava River, Slovenia, measured indirectly with optical sensors can be used to determine the amount and particle size of the suspended solids that can settle in stagnant water. The possibility of continuous monitoring of the TSS concentrations would allow a more reliable estimate of the amount of sediment in the accumulation lake of the planned, pumped-storage, hydroelectric power plant into which the water from the Drava River will be pumped. Therefore, during a period of one year, 90 water samples were taken directly at the optical sensors. The amount of sediments and their mineral and chemical compositions were investigated, and particle size analyses were made in 15 samples. Microbiological parameters, which included a determination of the amount of phytoplankton, zooplankton, bacteria, fungi and organic debris, were investigated in all the water samples, and the temperature and pH of the water were measured at the time when the samples were collected. The comparison of the parameters examined with the TSS concentrations showed that these concentrations can serve as a very good estimate of the amount of particles settled in the standing water, as well as of their size. These correlations are clearly expressed in the cases where the amounts of phytoplankton and organic debris in the water are low.

植被过滤带对城区道路径流的延滞效果及TSS、Zn削减效率影响

本项目研究目的是测量上海市城区道路植被带对径流延迟效果和对污染的净化效率,为城区道路路边绿化提供依据。对裸地、野生杂草狗尾草、人工草坪高羊茅、高羊茅/狗尾草植被过滤带测定表明,随着植物覆盖率增加,在夏季径流的优势流速（Up）从0.750m/min降低到0.411m/min,对径流出流时间（Tc）延滞约0.90～11.63 min,对径流终止时间（Ts）延滞约3.61～13.60min;对TSS的平均净化率从16.02%上升到90.53%,对Zn的平均净化率从9.70%上升到93.98%;冬季植物枯落时期,延滞效应、TSS和Zn净化率均有所下降。提高径流进水的污染物浓度条件（TSS=542mg/L,Zn=0.541mg/L）,有植被覆盖的过滤带的TSS净化率略有提高,而Zn的净化率都没有明显改善,裸地的TSS和Zn净化率均没有提高。进水的污染物浓度为TSS=827mg/L,Zn=0.803mg/L时,植被覆盖对TSS的净化率没有进一步提高,而Zn的净化率则增加,裸地仍没明显变化。

基于Sentinel-2卫星数据的城市湖泊湿地叶绿素A及总悬浮物浓度定量监测分析——以长沙市松雅湖为例

将湖南省长沙市松雅湖生态湿地湖泊作为研究区,以2016年12月9日和2020年11月8日两期Sentinel-2卫星MSI影像为基础数据源,基于二类水体区域性近岸海域水色算法(C2RCC),对监测区的叶绿素A浓度及总悬浮物浓度进行反演。监测结果表明,秋冬季节,松雅湖水生态修复区的叶绿素A浓度和总悬浮物浓度平均值与非修复区相比,呈现整体偏低的趋势。随着时间推移,松雅湖三个区域的整体叶绿素A浓度和悬浮物浓度均有明显降低。研究结果表明,此方法可为快速高效开展生态湿地湖泊水体的生态状况评价提供基础数据支撑。

基于SWMM的不同降水量对城市降雨径流TSS的影响分析

受物理、化学、生物等多重因素的影响,城市降雨径流水质的模拟研究比较模糊。以TSS(总悬浮固体量)为例,利用SWMM的污染物模块及其土地利用模块、污染物累积模块和污染物冲刷模块进行城市雨水径流水质模拟;考虑了不同土地利用情况对污染物的累积及冲刷的影响,针对不同的降水量,利用EMC法(平均浓度法)以及指数方程法进行污染物的冲刷模拟,指数方程法的模拟精度大于EMC法的模拟精度,与监测值更接近。指数方程法的模拟结果表明:当降水量小于2.5mm时,其TSS冲刷量增长幅度较缓;而当降水量大于3.5mm时,其TSS冲刷量呈显著线性增加关系,从而表明,降水量较大的降水事件对于TSS的冲刷量影响更为显著。

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.

Tidal variation of total suspended solids over the Yangtze Bank based on the geostationary ocean color imager

Hourly mapping by a Geostationary Ocean Color Imager was used to reveal the spatial pattern and tidal variation of total suspended solids(TSS)over the Yangtze Bank in the Yellow and East China Seas during the winter.The TSS form a tongueshaped structure,which decreases further offshore in a stepwise manner.The stepwise change is separated by two fronts of TSS,which are located near the 20-m and 50-m isobaths.The tidal variation of TSS concentration during the study period is evident and can be divided into three stages:decay,maintenance,and growth.Compared with the relatively stationary TSS during the maintenance stage,drastic changes exist during the decay and growth stages.In terms of tide-induced mixing,the dynamic analysis shows that both the topography and the tidal currents play an important role in the spatio-temporal variation of TSS during the tidal period.In particular,spatial distribution is primarily determined by the topography,whereas the temporal variations in tidal scale are determined by the tidal currents.

果园种植面源污染电混凝去除的关键设计及PAM强化

针对果园种植面源污染电混凝去除尚不明确的问题,以果园种植面源常规污染物为研究对象,考察电混凝关键设计,分析pH和电导率的影响,并探讨聚丙烯酰胺(PAM)的强化条件。结果表明:电压为10 V(2.5 mA/cm^(2)),电极间距为1 cm时,电混凝处理性能达到最佳,其中总悬浮颗粒物(TSS)、硝氮(NO3--N)、氨氮(NH3-N)、总氮(TN)和总磷(TP)的去除率分别为70.6%、30.4%、78.4%、23.7%和92.1%;酸性(pH=5)和碱性(pH=9)条件均不利于这些污染物去除;电导率的增大有利于NH3-N去除,但不利于其它污染物去除;当PAM投加量为0.5 mg/L、沉淀时间为5 min时,其强化效果最明显,对TSS、NH3-N和TP去除均有强化,去除率增幅分别为39.1%、10.3%和7.5%,但对NO3--N和TN去除有一定的抑制。该研究结果可为电混凝预处理果园种植面源污染提供理论和数据参考。

黄连对生物絮凝系统氨氮处理效率的影响

为研究黄连对生物絮凝系统氨氮处理效率的影响,添加0 g/L、2 g/L、4 g/L和6 g/L的黄连,分别为对照组C和处理组T1、T2、T3,进行氨氮、亚硝酸盐转化试验,并测定各组生物絮团硝化酶、脱氢酶活性。结果显示:处理组总氨氮去除速率均高于对照组(0.38±0.07 mg/g·h),其中T2组最高(1.49±0.08 mg/g·h);亚硝酸盐氮去除速率T1组(1.38±0.10 mg/g·h)和T2组(2.05±0.14 mg/g·h)高于对照组(0.75±0.06 mg/g·h),T3组(0.17±0.05 mg/g·h)最低。试验后处理组总悬浮固体颗粒物均低于对照组(504.00±27.71 mg/L),T3组(363.33±40.41 mg/L)最低。研究表明,添加黄连能提高生物絮团氨氮转化速率,减少总悬浮固体颗粒物的积累。

DSA电极处理垃圾渗滤液中污染物的研究

以垃圾渗滤液作为研究对象,使用自制的Ti-Ta_(2)O_(5)-SiO_(2)电极应用于电絮凝处理垃圾渗滤液中,探究其对总磷(TP)和悬浮物(SS)的去除效果。研究表明,在25 mA/cm^(2)和弱碱条件下,电絮凝处理垃圾渗滤液具有更高的处理效率;分别在稀释10倍原水和极板间距为4 cm时的各污染物去除率最高。当电流密度为25 mA/cm^(2),pH为9,极板间距为4 cm,原水稀释十倍后,经过电絮凝处理6 h后,总磷(TP)和悬浮物(SS)的去除率可分别达到99.6%和82.74%。该研究提供了一种电催化活性较高的新型钛基金属氧化物的电极,为电絮凝技术应用于垃圾渗滤液处理具有一定的指导意义。

Export of nutrients and suspended solids from major Arctic rivers and their response to permafrost degradation

The rapid warming of the Arctic has led to permafrost degradation,accelerating the transport of terrestrial materials by rivers.The quan-titative assessment of riverine nutrients and total suspended solids(TSS)flux is important to clarify the land-ocean connections in the Arctic.However,much is unknown about the estimates of these components from direct measurements in the Arctic rivers and the response of the components to permafrost degradation.Here,we report the results from the Arctic Great Rivers Observatory(Arctic-GRO)for the six major Arctic rivers(Yenisey,Lena,Ob',Mackenzie,Yukon,and Kolyma)to investigate the riverine exports of TSS,total dissolved nitrogen(TDN),nitrate(NO3-),bicarbonate(HCO3-),total dissolved phosphorus(TDP),and phosphate(PO43-).The results showed that from 2004 to 2017,the annual TSS,TDN,and NO3-exports to the Arctic Ocean were approximately 106,026 Gg,692 Gg,and 130 Gg,respectively,and the HCO3-,TDP,and PO43-exports were approximately 79,092 Gg,32 Gg,and 18 Gg,respectively.There were remarkable variations in component concentrations and fluxes between seasons.More than 80%of the TDN,TDP,PO43,and TSS exports mainly occurred in spring and summer,and a high HCO3-flux was recorded in summer,while a high NO3-flux in some rivers occurred in winter.The active layer thickness was significantly positively correlated with the annual TDN,NO3-,and HCO3-exports.In addition,the HCO3-flux of the six Arctic rivers increased by 247 Gg per year during 2004-2017.The positive relationship between the active layer thickness and river discharge indicates that permafrost degradation accelerated rivefine carbonate,nitrogen,and phosphorus exports.This study demonstrates that riverine exports play an important role both in the Arctic terrestrial and marine ecosystems,and permafrost degradation will likely increase the riverine material exports to the ocean.

厌氧氨氧化处理猪场沼液的废水预处理方法比较研究

【目的】探明不同的沉淀方法对悬浮固体(TSS)和化学需氧量(COD)的去除效果,明确适宜的猪场沼液预处理方法,破除TSS对厌氧氨氧化技术处理猪场沼液的障碍。【方法】比较曝气沉淀、污泥强化曝气沉淀和混凝絮凝沉淀等方法对猪场沼液的预处理效果。【结果】试验表明:曝气30 min、沉淀1 h为最适曝气沉淀条件,与空白组对比,COD去除率可提高9.24%;污泥强化曝气沉淀由于低水回收率不适用于猪场沼液的预处理;就化学沉淀而言,100 mg/L聚合硫酸铁(PFS)+8 mg/L聚丙烯酰胺(PAM)为最佳的浓度组合,可将TSS去除率提高52.08%。【结论】通过比较筛选获得了经济高效的猪场沼液预处理方法,即采用100 mg/L PFS+8 mg/L PAM的组合形式、沉淀1 h为最适合猪场沼液预处理方法。本研究可为厌氧氨氧化处理猪场沼液的工程应用提供技术支撑。

物理沉淀法处理刺参海水养殖尾水及其水质变化研究

目的研究刺参海水养殖尾水经过物理沉淀后的水质变化规律.方法以刺参海水养殖尾水为实验材料,采用静置物理沉淀的处理方法,分别于不同沉淀时间(1、4、8d)取样,对表层尾水中悬浮物、化学需氧量、无机氮、活性磷酸盐、总氮、总磷等指标进行实验室检测分析.结果尾水中悬浮物含量在沉淀1d后即显著降低(P<0.01),沉淀4、8 d后呈现持续降低的趋势;化学需氧量、无机氮、活性磷酸盐、总氮、总磷含量在沉淀1 d后显著降低(P<0.01),随着沉淀时间的延长,上述污染因子含量逐渐升高,均呈上升趋势.结论尾水经短期物理沉淀可有效降低表层悬浮物、化学需氧量、无机氮、活性磷酸盐、总氮、总磷含量.

太湖梅梁湾沿岸带水体生物学与光学特性

基于 1998～ 1999年周年 4季原位水下光场观测资料及中国科学院太湖湖泊生态系统研究站 1992～ 2 0 0 1年悬浮物、叶绿素 a、透明度长期历史观测资料分析了太湖梅梁湾沿岸带第 2号站点水体的生物学与光学特性 ,探讨了水下光合有效辐射(PAR)总量的日变化、垂直分布 ;光衰减系数的季节变化及光谱分布 ;影响光衰减系数的主要水色因子。结果表明 ,无论是 PAR还是光谱衰减系数其值都很高 ,其中 PAR衰减系数在 1.4 0～ 5 .30 / m间变化 ,均值为 2 .4 3± 0 .5 5 / m,秋季最大、夏季最小 ,真光层深度在 0 .87～ 3.2 9m间变化 ,均值为 1.98± 0 .4 1m;水下光谱在蓝光波段衰减最强烈 ,其次是红光、绿光 ,随着深度增加光谱成分出现绿移和红移现象 ,绿红光占得比例越来越大 ;光谱衰减系数随着波长的增加大致呈下降趋势 ,但在 6 70 nm附近有个峰值 ;基于线性相关分析发现在混浊的沿岸带水体中影响光衰减主要因子为水体中的悬浮物和有色可溶性有机物 ,叶绿素 a对 PAR衰减系数的贡献率只占到 1.5 9%～ 14 .2 1%。

杭州西湖水体光学状况及影响因子分析

2004年10月8日在杭州西湖6个不同湖区共布设10个采样点进行水下光场的测定,并采集水样分析悬浮物、叶绿素a、有色可溶性有机物(CDOM)浓度.结果表明,3类主要光衰减物质总悬浮物、叶绿素a和DOC的浓度分别为3.68～42.76 mg/L、4.64～85.95 μg/L、5.19～9.22 mg/L;CDOM在440 nm波长处吸收系数为0.30～1.46 m-1;PAR衰减系数在1.13～6.04 m-1间变化,均值为4.00±1.69 m-1;对应的真光层深度为0.76～4.08 m,均值为1.54±1.11 m;仅南湖和茅家埠两个湖区真光层深度大于水深,其他湖区由于水深远大于真光层深度,在现有的光照条件和水位下要恢复沉水植物困难较大.对PAR衰减系数、真光层深度、透明度等表观光学参数与主要水色因子进行相关分析发现,水体中浮游藻类和有机颗粒物对西湖水体光学性质影响最大.

温度与污泥浓度对剩余污泥水解及脱水性能的影响

污泥碱性水解产生短链脂肪酸,可应用到污水脱氮除磷中,但会使其脱水性能恶化.为考察温度和污泥浓度对剩余污泥水解及脱水性能的影响,试验研究了20 d内剩余污泥在pH=10、温度25和35℃、不同总悬浮固体(total suspended solids,TSS)下厌氧水解和脱水性能的变化,对溶解性化学需氧量(soluble chemical oxygen demand,SCOD)和毛细管吸收时间(capillary suction time,CST)进行了分析.试验表明:25℃时污泥脱水性随ρ(TSS)升高先恶化后变化不大,各发酵时间SCOD均升高后变缓;35℃时污泥脱水性随ρ(TSS)升高先恶化后略提高,SCOD变化与25℃时一致.SCOD变化情况与CST显著正相关;较高温度SCOD溶出更多,脱水性能稍有恶化;TSS对污泥脱水性能的影响较温度更显著.

鱼、虾、蟹养殖池塘清塘排水水质及污染强度

为准确估计混养鱼、青虾、河蟹养殖池塘清塘时污染物的排放强度,实验选取三种类型池塘(混养鱼塘、青虾塘、河蟹塘)各5口。混养鱼塘清塘时一边捕捞一边用潜水泵排水;青虾塘在捕捞完成后即用潜水泵排水;河蟹塘在捕捞完成后1个月左右采用自流装置从表层开始排水并滞留30 cm水于塘内。采集三类池塘清塘前塘内水样及清塘过程中排水口水样,分析总氮、总磷、化学耗氧量和悬浮物等污染物浓度。分别以塘内水质和排水口水质的监测值估算了污染物的表观排放强度和实际排放强度。结果表明,随着塘内水位下降,混养鱼塘和青虾塘排水口的污染物浓度显著提高(P<0.05)。混养鱼塘的实际污染强度显著高于其表观污染强度(P<0.05)。然而河蟹池塘污染物的实际排放强度却显著低于表观排放强度(P<0.05)。结果提示以塘内水质来估算池塘养殖污染物排放强度有明显误差;通过改进排水技术可以削减养殖污染排放量。

美人蕉生态护坡对径流污染净化作用的初步研究

2010-04-10月,研究了合肥市南淝河美人蕉生态护坡对河道的水质改善作用。试验用水取自南淝河,TSS、TN、NH4+-N、TP和COD的平均浓度分别是94.1,5.42,2.98,0.202和55.5 mg/L,河水经流生态护坡后,相应的平均去除率分别为:76.4%,45.6%,57.5%,40.1%和29.0%。另外,考察了植物对土壤微生物(细菌、真菌、放线菌)数量的影响,美人蕉护坡微生物的数量显著多于无植物坡岸(p<0.01),微生物总数分别为:3.17×107和0.830×107cfu/g。由此,植物护坡兼具净化和生态景观效应。

湖北省纽荷尔脐橙果实品质状况的研究

以纽荷尔脐橙为试材,分析了湖北省13个产地果实的常规品质和果皮色差值,结果显示,不同产地纽荷尔脐橙果实品质差异明显。系统聚类结果表明,秭归县、巴东县和兴山县的常规品质聚为第一类,长阳县、郧县、公安县、枝江市和宜都市聚为第二类,而丹江口市、阳新县、通城县、天门市和京山县聚为第三类;就果皮色差值来看,长阳县、郧县、兴山县和宜都市聚为第一类,巴东县、京山县、枝江市、丹江口市、阳新县、公安县、秭归县聚为第二类,天门市和通城县聚为第三类。综合分析常规品质和果皮色差值可以看出,三峡库区的兴山县、秭归县、巴东县纽荷尔脐橙综合品质最好,邻近三峡库区的长阳县、宜都市、枝江市,丹江库区的郧县和卷桥库区的公安县次之,丹江口市、阳新县、京山县,尤其是天门市和通城县的品质表现不如上述各个产地。因此湖北省纽荷尔脐橙应重点集中在三峡库区这一优势区域内优先发展,同时向其邻近的适宜地区辐射,而在其它产地宜选择小气候适宜地区适当发展。

三峡小江回水区真光层深度及其影响因素分析

为探讨三峡水库运行初期小江回水区水体的光学特性，2007年5月～2008年5月对回水区5个断面水下光合有效辐射（PAR）与常规水质指标进行监测，分析了真光层深度的时空特征及其影响因素。研究区域真光层深度空间差异不明显，但季节变化显著，冬季最高，夏季最低。回归分析表明光合有效辐射（PAR）衰减系数与透明度、总悬浮物浓度有显著的相关性（R^2=0．8619，R^2=0．764），与叶绿素a相关性不明显（R^2=0．0113）。进一步研究分析表明真光层深度、总悬浮物浓度、叶绿素a主要受小江河口流量、小江回水区水位的影响，复杂的水动力条件与独特的水文条件是影响三峡水库小江回水区真光层深度变化的主要因素。