Performance of Nanofiltration (NF) and Low Pressure Reverse Osmosis (LPRO) Membranes in the Removal of Fluorine and Salinity from Brackish Drinking Water

Certain areas in Senegal have a serious problem of high fluoride and salinity in underground water because of soil properties. This water currently used for drink has a bad taste on consumption and caused diseases like dental fluorosis and skeletal fluorosis. A membrane filtration plant constructed by Pall Corporation was improved through nanofiltration (NF) and Low Pressure Reverse Osmosis (LPRO). Both NF and LPRO membranes were shown applicable for salinity and fluoride ions removal from brackish and high fluorinated drinking water in a remote community. The NF membrane has given a fluorine retention rate varying between 63.3% and 71% while the LPRO membrane allow to reach 97 to 98.9% for fluorine rejection. Highest salinity rejection rates expressed through conductivity measurements are around 46% and 97% for respectively NF and LPRO.

Research Progress of Brackish Water Desalination by Reverse Osmosis

Brackish water (BW) desalination is a primary path to relieve the shortage of water. As one of the BW desalination methods, reverse osmosis (RO) technology has advantage for both technology and process procedure. The expounding of this research studied or reviewed recent years, reverse osmosis membrane, energy recovery, new energy and application technology in BW desalination of RO at home and abroad. Wind power and solar energy can be combined with energy recovery device for RO. The research also explains that BW desalination by RO is practical and feasible in some areas in China.

The brackish-water bivalve Waagenoperna from the Lower Jurassic Badaowan Formation of the Junggar Basin and its palaeoenvironmental and palaeogeographic significance

The brackish-water bivalve Waagenoperna Tokuyama, 1959 is reported from the Lower Jurassic Badaowan Formation at four localities, along the southern margin and western margin of the Junggar Basin. Taphonomic features recorded in the field indicate that it occurs in autochthonous or parautochthonous assemblages. The autecology of Waagenoperna therefore yields information on the palaeoenvironment of the area. The restriction of Waagenoperna to marine and brackish-water settings suggests that the sea water once reached these areas during the Sinemurian. This paper discusses the palaeogeographic implications and suggests an ingression of the sea water from the west to the western and southern part of the Junggar Basin. Additionally, the two Waagenoperna species collected from the Haojiagou section in the Junggar Basin are taxonomically documented.

Molecular Characterization of Aerobic Heterohophic Bacteria Isolated from Petroleum Hydrocarbon Polluted Brackish Waters of Bodo Creeks, Rivers State Nigeria

Surface water sources in the oil producing Niger Delta region of Nigeria are highly susceptible to pollution by petroleum hydrocarbons and so it is important to understand the microbial diversity of such ecosystems. Water and sediment samples were collected between April-August, 2013 from Bodo creeks and taken to Environmental Microbiology laboratory of University of Portharcourt for analysis. A total of thirty aerobic heterotrophic bacterial strains isolated ranged from 3.0 - 7.0 × 104 cfu for surface water and 1.6 - 5.6 × 104 cfu for sediment samples of Bodo creek using serial dilution and spread plate technique. Pure cultures of bacteria were obtained on the basis of their morphological characteristics and subjected to biochemical tests and further classified on the basis of 16S rRNA gene sequence analysis. The DNA was isolated from size fractionated samples and the diversity of bacteria in each fraction was studied using PCR amplification of partial 16S rRNA. The sequences were submitted to NCBIGen bank for identification and assigning of accession numbers. The isolated aerobic heterotrophic bacteria belong to the families of Enterobacteriaceae, Bacilliceae, Alcaligenaceae, Pseudomonadaceae, Flavobactericeae and Planococcaceae.

An Air Operated Domestic Brackish Water Reverse Osmosis Plant: Economically Sustainable Solution for Safe Drinking Water Supply for Chronic Kidney Disease of Unknown Etiology Affected Areas in Sri Lanka

Chronic Kidney Disease with unknown etiology (CKDu) is one of the crucial health issues in North Central, Uva, North Western, North, Central, and Eastern Provinces of Sri Lanka and incapacitates the kidney function. The main source for the CKDu has not yet been identified, though many scientists believed that the number of certain drinking water quality parameters is changed due to the contamination of water sources by agricultural activities. Hence, the government of Sri Lanka introduces electrically driven Brackish Water Reverse Osmosis (BWRO) plants with a capacity of 10 tones/day to supply safe drinking water for the impacted community though it is an energy-intensive process. Concurrently, a smaller version of an electrically driven BWRO plant was introduced to the rural farming community for their domestic use. However, it was not practically worked out due to various reasons such as high cost, unavailability of electrical power supply for those villages. In this study, an economical air operated domestic use BWRO plant with zero-emission was designed. This anticipated system significantly reduces the government expenditures to subsidize the water purification cost by 50% of the existing expenses. Besides, simple payback time was found to be 2.5 years, and the benefit-cost ratio to be more than 1. Evaluating the performance with the conventional values, it comprehends with more sustainable and economically viable system compared to the existing method of water purification.

Fluoride Excess Removal from Brackish Drinking Water in Senegal by Using KSF and K10 Montmorillonite Clays

Fluoride excess in drinking water is noticed in many countries around the world and particularly in Senegal where, in addition to fluoride excess, high levels of salinity are also encountered. In order to reduce fluoride excess in drinking water in the groundnut basin of Senegal, two types of clays namely montmorillonite KSF and montmorillonite K10 as well were used as adsorbent materials. The results show that the pH which was initially alkaline becomes acidic varying from 2.80 to 6.80. The pseudo first-order kinetic model fit well with the adsorption experiments for KSF montmorillonite (r2 = 0.96), while for K10 clay the same model describe the experiments with slight differences (r2 = 0.90). The KSF clay has a better fluoride adsorption capacity compared to that obtained with K10 clay due to the presence of a great level of calcium oxide in the montmorilonite KSF clay.

Study and Proposal for a Hyperfluorinated Brackish Water Treatment System in the Fatick Region, Case of Diouroup (Senegal)

Groundwater is the main resource for human consumption in many countries, especially in developing countries. This groundwater is often brackish and hyperfluorinated, which leads to diseases such as dental and bone fluorosis, etc. The water from the Diouroup water drainage facilities, like those from many other water drainage facilities in the regions of Fatick, Kaolack, Diourbel and the area of Touba, is facing this problem. To solve these problems, several physicochemical and membrane methods have been implemented. In this work we have briefly outlined some of these methods and we have chosen one of them, low pressure reverse osmosis. In addition, this technique is very simple to operate and maintain. Reverse osmosis provides good quality water in a single step, without the need for additional sterilization or remineralization treatments. We then carried out simulations with the Reverse Osmosis System Analysis (ROSA) software. For reasonable operating parameters, we have noticed a low feed pressure of 11.58 bars, a good average flow of raw water of 27.79 L/m2/h and a recovery rate of the first pass of 75.01%. The results obtained also showed a good quality of the permeate which respects the recommendations of the World Health Organization (WHO) on drinking water. The fluorides of 0.59 mg/L have a recovery rate of 90.8% while the chlorides of 59.09 mg/L have a recovery rate of 92.12% as for the Total Dissolved Solids of 184.90 mg/L for an abatement of 92%. Finally, the low energy consumption of the process makes it possible to consider it in coupling with an electric supply by photovoltaic solar collectors for isolated sites.

Study on brackish water treatment technology

Based on the characters of deep well water quality in Fenxi Mining Group in Liulin, the feasibilities of two treatment technologies which use electrodialysis and reverse osmosis are analyzed. Through analyzing and comparing, reverse osmosis technology has several advantages, such as good treatment effect, convenient operating management and low run cost.

微咸水灌溉下冬枣光合生理性状与光响应模型研究

【目的】研究不同灌溉水矿化度对冬枣光合生理性状的影响。【方法】基于大田试验,研究1g/L(S1)、2 g/L(S2)、3 g/L(S3)、4 g/L(S4)和5 g/L(S5)灌溉水矿化度下的土壤水盐分布规律与冬枣光合生理响应机制。【结果】叶片净光合速率、蒸腾速率和气孔导度均在3 g/L处理或4 g/L处理下达到峰值;与其他处理相比,4 g/L处理与5g/L处理灌溉水矿化度下的叶片叶绿素量、最大荧光效率和最大量子效率显著降低;与1g/L处理相比,3 g/L处理与4 g/L处理下的冬枣表观量子效率、最大净光合速率、光补偿点、暗呼吸速率显著升高,而光饱和点显著降低,3~4 g/L灌溉水矿化度虽然减小了冬枣的可利用光强范围,但提高了叶片的生理活性。【结论】在果实膨大期,灌溉水矿化度为1~3 g/L时,气孔限制是影响冬枣光合作用的主要因素,而当灌溉水矿化度超过4 g/L时,非气孔限制因素是导致叶片光能利用效率降低的主要原因。综合考虑土壤生态环境与冬枣生理过程,推荐采用3g/L矿化度的微咸水对冬枣进行灌溉。

微咸水灌溉下粉垄耕作土壤水盐运移特性

【目的】明确微咸水灌溉条件下粉垄耕作土壤水分入渗规律及水盐运移特征。【方法】基于室内土箱试验,分析3种微咸水矿化度(0g/L(S1)、3g/L(S2)和5g/L(S3))和2种耕作(粉垄耕作(FL)和传统翻耕(FG))条件下的土壤水分入渗特征和水盐运移规律。【结果】水分平均入渗速率和垂直湿润锋推进速率随着微咸水矿化度的升高呈先增大后减小的变化趋势,水平湿润锋运移速度随着微咸水矿化度的升高而持续增加。FL处理下的土壤水分入渗速率、湿润锋推进速率相比FG处理有明显提升。Kostiakov模型可较好地拟合2种耕作措施下的土壤累积入渗量与入渗时间之间的关系(R^(2)>0.99)。灌溉后20 d,FL处理下的土壤含水率均小于相同微咸水矿化度下的FG处理;同一耕作措施下,土壤含水率随着微咸水矿化度的升高而增加。【结论】微咸水灌溉与粉垄耕作对土壤水分入渗、土壤湿润锋运移和土壤水盐再分布具有改善作用。与灌溉前相比,灌溉后20 d,FL处理下的土壤平均脱盐率为42.95%~55.98%,而FG处理下的土壤平均脱盐率为32.34%~43.29%。随着矿化度的增加,FL处理下的平均土壤电导率相比FG处理分别下降22.38%、18.54%和15.68%。

微咸水-腐植酸肥耦合滴灌条件下钙镁离子质量浓度对灌水器堵塞的影响

【目的】探明腐植酸肥施用条件下不同钙镁离子质量浓度对灌水器堵塞物质形成的影响效应与作用机制。【方法】以微咸水中钙镁离子耦合腐植酸肥滴灌为研究对象,选取4种不同额定流量(1.6、1.1、1.4、1.75 L/h)的非压力补偿内镶贴片式灌水器(FE1—FE4),其中设置3组钙离子质量浓度微咸水处理,离子质量浓度分别为100、150、200 mg/L(G1、G2、G3),3组镁离子质量浓度微咸水处理,离子质量浓度分别为100、150、200 mg/L(M1、M2、M3),以地下微咸水灌溉为对照(CK),研究不同离子质量浓度的灌水器平均流量(Dra)、滴灌系统灌水器的堵塞率分布、灌水器堵塞物质干质量(DW)动态变化规律,并分析了灌水器内部堵塞物质矿物组分。【结果】与CK相比,G1、G2、G3、M1、M2、M3处理的Dra分别降低了21.58%~29.68%、35.02%~39.71%、45.62%~55.68%、14.25%~20.41%、24.89%~45.69%、35.22%~56.75%,堵塞物质干质量分别增加了124.62%~178.49%、174.23%~230.33%、235.59%~270.09%、67.14%~120.28%、136.96%~191.18%、203.54%~213.35%。与G1、G2、G3处理相比,质量浓度相同镁离子处理M1、M2、M3处理的堵塞物质干质量分别降低了16.41%~27.26%、4.77%~13.60%、6.82%~15.34%。【结论】钙镁离子质量浓度的增加均显著加剧了灌水器的堵塞;在相同离子质量浓度条件下,镁离子处理显著减少了灌水器内堵塞物质的总量,因此镁离子在一定程度上能够降低灌水器堵塞风险。

京津冀平原非常规水资源利用前景分析及其生态环境效应

[研究目的]京津冀平原水资源严重短缺,供需矛盾十分突出,加大非常规水资源利用力度,形成多元供水格局,可有效缓解水资源供需矛盾,对支撑京津冀协同发展区社会经济协调发展和推动生态文明建设具有重要意义。[研究方法]文章系统开展非常规水资源供水方向、开发利用模式和供水规模分类数据统计,依据各省(直辖市)非常规水资源供水规划及配置目标,分析其开发利用前景及其生态环境效应。[研究结果]该区非常规水资源主要包括微咸水、再生水、淡化海水、雨洪水,其中微咸水主要分布于中东部平原的天津、沧州、衡水等地,供水前景为5.43×10^(8)m^(3);再生水利用以北京、天津等大中型及工业城市为主,供水前景为34.22×10^(8)m^(3);淡化海水利用以天津等滨海城市为主,供水前景为4.19×10^(8)m^(3);雨洪水利用较分散。[结论](1)微咸水用于农业灌溉存在土壤盐渍化风险,需加强水盐调控。(2)再生水用于河流生态补水,沿线地表水富营养化,地下水体未受到明显污染;地下水浅埋区开展再生水灌溉,会增加硝酸盐污染风险;建议将高风险的新兴污染物纳入再生水利用监控体系。(3)海水淡化尾液浓盐水、冷却热水可能改变天然海洋生态系统的分布、构成与多样性,应予以关注。(4)雨洪水利用可降低污水入河的水质风险,但过度利用可能影响区域生态系统的稳定性,建议城市区适度扩大利用。

基于响应面法的微咸水反渗透脱盐工艺优化

为应对淡水资源短缺,提高微咸水反渗透工艺的处理效果,设计了一种单级多通道低压反渗透(RO)中试装置,采用Box-Behnken响应面分析法(RSM)建立了微咸水RO淡化过程的模拟和优化模型.在不同的进料浓度,进水流量和浓淡水比例等工艺参数条件下,考察了系统的盐截留率和膜通量,分析和计算了系统的评价系数和单位能耗(SEC).结果表明,进料浓度和浓淡水比例是影响盐截留率的显著因素.低进料浓度、较高进水流量并不能显著提高盐截留率,反而会增加设备的单位能耗.在5000mg/L进料浓度的条件下,控制进水流量258.02L/h,浓淡水比例1.39时,脱盐效果最佳,评价系数达到10.58L/(m^(2)·h),单位能耗相对最低为5.15(kW·h)/m^(3).所建的RSM模型能够较好地模拟微咸水反渗透脱盐的过程,SEC预测精度良好,R^(2)值达到0.9925,盐截留率模型误差RMSE仅为0.36.RSM模型可以用于优化不同进料浓度下的操作条件,指导反渗透脱盐工艺的长期高效运行.

咸淡水组合灌溉对土壤盐分和棉花生长的影响

为揭示不同微咸水(农田排水)与淡水在“先咸后淡”的组合灌溉模式下对土壤容重、盐分迁移和棉花生长的影响。以淡水灌溉为对照(CK),设置7种不同微咸水、淡水组合灌溉(微咸水∶淡水=1∶14(T1)、2∶13(T2)、3∶12(T3)、6∶9(T4)、9∶6(T5)、12∶3(T6)),T7处理采用全额微咸水灌溉,于2022年4-9月进行了棉花田间试验。结果表明,采用微咸水灌溉造成土壤表层盐分积累,0~40 cm土层出现积盐现象,棉花生育期结束后,各处理与淡水对照(CK)比较,T1~T6在0~40 cm土层的电导率分别增加1.16%~26.61%,T7处理电导率增加86.40%;与淡水对照相比,组合灌溉后各处理土层0~40 cm土壤容重明显增加,土壤孔隙度降低,以全额微咸水灌溉T7处理最为显著(容重增加10.24%);微咸水组合灌溉有效提高棉花株高、叶面积指数、茎粗。合理利用微咸水组合灌溉能够为棉花生长提供良好的水盐环境,提高棉花产量,能够为极端干旱区合理利用微咸水提供一种新的灌水模式,为灌区发展节水灌溉及农业可持续发展提供理论支撑。

膜下滴灌微咸水棉花临界氮稀释曲线模型与氮肥用量推荐

为了优化膜下滴灌微咸水条件下棉花生产氮素管理,该研究于2017—2019年在新疆库尔勒市开展3 a定位施氮试验。以新陆中棉花为试验材料,设置施氮水平0(NF0)、150(NF1)、250(NF2)、300(NF3)、350(NF4)、450(NF5)kg/hm^(2),各试验处理灌水量均为487.5 mm,分析施氮量对棉花地上部干物质量、氮素累积吸收量、产量和氮肥利用效率的影响,构建了膜下滴灌微咸水棉花临界氮浓度稀释曲线模型。结果表明:棉花氮素累积吸收量随生育期进程的推进而增大,棉花临界氮浓度与最大地上部干物质量符合幂函数关系。氮肥农学利用率和表观利用率均与施氮量呈二次多项式关系,氮肥生理利用率和偏生产力均与施氮量呈线性关系。NF1、NF2和NF3处理的氮素营养指数均小于1,表明氮素营养供应不足,棉花生长受到氮素限制。NF4和NF5处理的氮素营养指数接近于1,说明棉花氮素营养状况较好,但NF5产量和氮素利用效率较低,NF4获得最高产量和较高的氮素利用效率。因此,南疆膜下滴灌微咸水棉花生育期推荐施氮量为350 kg/hm^(2)。该研究构建的临界氮浓度稀释曲线模型对田间施氮管理具有重要意义。

咸水层CO_(2)残余埋存机理的微观数值模拟研究

基于矿场岩心铸体电镜扫描图生成的二值化图片建立二维气液两相渗流模型,利用相场法研究微观条件下CO_(2)的赋存状态与埋存机理,并分析了储层润湿性、气液两相界面张力及地层水回流速度等因素对CO_(2)残余埋存效果的影响。结果表明:当地层水回流后,CO_(2)被大量封存下来,此时CO_(2)赋存状态主要以柱状、孤滴状和盲端状为主;地层水回流时的速度对于残余气饱和度影响较大,而储层润湿性与气液两相界面张力对于残余气饱和度影响较小。此研究对于从微观角度认识CO_(2)残余埋存机理具有指导意义。

新疆尉犁县绿洲区微咸水水化学特征及可利用潜力分析

为探明新疆尉犁县绿洲区微咸水水化学特征、成因及可利用潜力,促进非常规水资源利用与水资源优化配置,综合采用Piper三线图、描述性统计分析、Gibbs图、离子比值法、水均衡法等对研究区地下水进行分析计算。结果表明:研究区微咸水水化学类型主要为SO_(4)·Cl-Na、SO_(4)·Cl-Na·Ca、SO_(4)·Cl-Na·Mg型,蒸发浓缩作用是微咸水形成的主要因素,其次是岩石风化作用;微咸水分布面积3851.35 km^(2),占研究区总面积的56.18%,可利用量为19237万m^(3)/a,开利用潜力较大。

Production of Spirulina platensis Using Inexpensive Local Resources in Palestine

Spirulina platensis is a special and unique cyanobacteria that is produced worldwide with a varied cost of cultivation media. In this study, five main experiments with different treatments were performed to evaluate the possibility of using cheap aquaculture water for Spirulina production, to test if solutions made by plant ash (PAS) could be used for Spirulina production, to determine if brackish water (BW) and mining water have a good impact on Spirulina production, to create a medium composed of cheap chemicals and fertilizers to be used for Spirulina cultivation, and to test if a mixture made from local components could be used to produce Spirulina. All experiments were performed via growth and dry weight measurements, including determination of chemical and physical characteristics of the samples with a comparison with Zarrouk medium (ZM) as a reference for each experiment, and all experiments were performed for 21 days to determine the best media type that lasts longer for commercial purposes. In all experiments, pH values were between 8 and 11, and EC was between 9.8 and 30 ms/cm, while temperature was at 30°C and 35°C, and light was at 1500 and 5000 Lux for 16 h light and 8 h dark. Spirulina can grow in (FW). It can also grow in FW diluted with BW. Also a 3% PAS can be used as a source to cultivate Spirulina at a very low price compared to ZM. The chemical fertilizer formula was one of the best types among all treatments with a good price. A mixture of these local resources could be a very good cheap alternative source. The main result that was obtained from all experiments in this study is the ability of Spirulina to grow within a wide range of chemical parameters at a lower price.