Field Water Samples Research Articles

A guanidinium-rich polymer as a new universal bioreceptor for multiplex detection of bacteria from environmental samples

Protamine, a guanidinium rich polymer, is proposed as a universal bioreceptor for bacteria, towards rapid and handheld bacteria detection from complex environmental water samples without the need for specific antibodies or primers. Escherichia coli K12, Salmonella Typhimurium, and Staphylococcus aureus (MSSA) were assayed, representing gram-negative, gram-positive, rod- and round-shaped bacteria. Samples and the protamine conjugated fluorescent particles were sequentially loaded to the paper microfluidic chips and flowed through the channels spontaneously via capillary action. The particles were aggregated via protamine-bacteria membrane interactions and unbound particles were rinsed via capillary action. A low-cost smartphone fluorescence microscope was designed, fabricated, and imaged the paper channels. A unique image processing algorithm isolated only the aggregated particles to detect all three bacteria (p < 0.05) with a detection limit of 101−102 CFU/mL. Protamine did not induce any particle aggregation with a model protein, algae, and virus. Successful bacteria detection was also demonstrated with environmental field water samples. Total assay time was < 10 min with neither extraction nor enrichment steps. In summary, a guanidinium-rich polymer showed a promise as a universal bioreceptor for bacteria and can be used on a paper microfluidic chip and smartphone quantification towards rapid and handheld detection.

Experimental investigation of competitive mechanisms of precipitation and dissolution due to seawater and low salinity water injection in carbonate reservoirs

The dissolution and precipitation mechanisms are very effective in the water injection process, especially at low salinity and smart water injection. In this research, the focus is on competition between dissolution and precipitation mechanisms in the presence of calcite rock samples at reservoir conditions (100 °c and 2500 psi). Static experiments were designed in two parts; a) mixing of incompatible brines for investigation of precipitation process and b) repeating the process in presence of reservoir rock samples for precipitation/dissolution competition. Incompatible real formation and sea water brines were used to determine maximum scale formation ratio and dominate scale types. Based on high pressure static experimental results, mixing ratio of 50% of the formation water, as the maximum-precipitate-producing ratio, has been considered as the desired ratio for the experiments with rock samples in this study. The synthetic water compositions were designed to have the dominant scales as those were found in initial experiments of oil field water samples. In the next stage, the compatibility experiments were carried out for the mixture of 20-times diluted seawater and formation water. This was followed by mixing experiments in presence of the reservoir rock in the reservoir condition. The results were interpreted with ICP, SEM and EDX. The results of water mixing experiments with rock sample showed that most of the precipitations were sulfate scales types as strontium and calcium sulfates precipitations were significant in the ratio of 50% of formation water. Both precipitation and dissolution were detected in all experiments based on change in ions, rock surface chemical analysis and scale properties. The concentration of Ca2+, Sr2+ and SO42− ions determines the dominant mechanism. For 20-times diluted sea water, dissolution was dominant mechanism despite the presence of sulfate precipitations. However, this mechanism was indicated in sea water with less impact. In the compatibility tests, Mg2+ ion did not contribute to the precipitation process. In the process of mixing in presence of reservoir rock, the Mg2+ concentration was reduced in the end of experiment. Increase in calcium ion and decrease in magnesium ion indicated ion exchange at calcite rock surface.

Performance and kinetic of pesticide residues removal by microporous starch immobilized laccase in a combined adsorption and biotransformation process

The control and removal of pesticide residues from possible pollution source by using improved methods without secondary pollution is essential for reducing its potential hazards to humans. In this work, a method of combining adsorption and degradation for the removal of pesticide residue was investigated based on the biodegradable microporous starch immobilized laccase (LA–MPS). Biosorbent of microporous starch (MPS) were prepared from maize starch by treating with glucoamylase and α-amylase to increase the specific surface area. Then, laccase with natural biological activity was immobilized on the surface of MPS, the prepared LA-MSP was characterized by SEM, FT-IR, activity assay and stability test. Moreover, LA–MPS coupled with mediators were applied to remove two typical triazine herbicides, atrazine and prometryn, in paddy field water sample. The physical action force between the LA–MPS and pesticide molecules resulted in the good adsorption of LA–MPS to the two pesticides. The apparent rate constants of laccase interaction with pesticide molecules were greatly improved by the adsorption process. Compared with natural degradation, the removal efficiency of atrazine and prometryn were increased by 61% in 7 days, which contributed by 43∼52% of degradation and 10∼38% of adsorption. These results indicated that the application of LA–MPS prepared by MPS sorbent was a feasible and green approach for the removal of pesticide residues in paddy field water sample.

Exploring a legendary giant squid: an environmental DNA approach

The giant squid, Architeuthis dux, has been reported for centuries, but its distribution and ecology have remained famously mysterious. We investigated the A. dux distribution in the Sea of Japan using the environmental DNA (eDNA) method, which has recently been considered as a useful technique for evaluating the distributions of rare species. To develop the eDNA method to detect A. dux, we first created a species-specific polymerase chain reaction (PCR) primer–probe and tried to detect the eDNA in the western region of the Sea of Japan where A. dux has recently been observed. We successfully collected and amplified the A. dux eDNA in our study area using field water sampling and real-time PCR measurements. A. dux eDNA was detected in winter but not in summer, reflecting the historical record of A. dux observations in the region. The use of eDNA techniques could be a potential method for monitoring "invisible" and rare organisms, even in open ocean habitats.

Seasonal variation of Leptospira species in pond and paddy field water samples in Thrissur district

Leptospirosis is an acute anthropozoonotic infection occurring worldwide caused by a pathogenic spirochete belonging to the genus Leptospira. The highest occurrence of leptospirosis in tropical countries is directly related to heavy rainfall and flooding. The changing rainfall pattern in the Western Ghats with rainless days during the monsoon months is reportedly affecting normal climatic condition of Kerala. Leptospires are able to survive in an environment with high humidity and moderate temperature.. The present study was undertaken to study the seasonal variation in occurrence of Leptospira spp. in pond and paddy field water in Thrissur district of Kerala. The samples were collected in two seasons i.e. monsoon (June to September) (Season-1) and summer (February to May) (Season-2) for the identification of Leptospira spp. The water samples were subjected to PCR for identification of the organism. The temperature and pH of water samples were recorded at the time of collection. The different physicochemical parameters of water in these two sources were in the range of pH (6.5- 7.9), conductivity (85- 150 µs/cm), salinity (0.02- 0.12 psu), turbidity (5-50NTU), dissolved oxygen (6-8 mg/L). Out of the 80 samples analysed, 52 (23 from monsoon and 29 from summer) samples detected 16Sr RNA at 430 bp and hence was positive for Leptospira species. The pathogenicity of the positive isolates were analysed by detecting the virulence gene viz., lipl 32, lipl 21 and lipl 41 respectively. The results revealed that out of the total isolates of Leptospira, 23 and 21 isolates were positive for lipl 21 and lipl 41 in monsoon and summer seasons respectively. Out of the total 85 paddy field water samples collected, 17 samples were found to be positive for Leptospira spp. The virulence gene lipl 21 was detected in three samples in summer season. However, lipl 32 and lipl 41 genes were not detected in any of the samples. The results of the present study demonstrated the ubiquitous nature of the organism in environment in the both seasons. The contaminated environment can hence be one of the sources for the increase in the frequency of human and animal leptospirosis in Kerala. Keywords: Leptospira spp., Leptospirosis, Paddy field water quality, lipl 32, lipl 21 and lipl 41

Copper Toxicity to Tropical Water Flea Daphnia carinata and Freshwater Micro-algae Scenedesmus

Sai Gon river is one most the most important river of South-eastern region of Vietnam by providing water resources and others vital natural services for millions of people in this area. In recent years, proportion with the sharply increasing of human activities in industry and agriculture, the river is continuously loaded with xenobiotics released by anthropogenic activities. Among pollutants, heavy metals are considered as the most toxic elements to aquatic living organisms and human health. The aim of this study is to assess the sensibility of freshwater microalgae Scenedesmus and water flea Daphnia carinata, two fresh water species from Vietnam to copper (Cu). After physical and chemical characterization, field water samples from upstream Sai Gon River was used as dilution water in toxicity tests. With water flea D. carinata, the EC50 value of 48h immobilization experiment was 1.90 µg/L. Growth inhibition of the Scenedesmus algae cells was determined following exposure for 72 h, and EC50 values was 78.2 µg/L. The results showed that Cu is highly toxic to both species, and water flea D. carinata was more sensitive than freshwater algae Scenedesmus. Based on the observed high sensitivity with Cu, both D. carinata and algae Scenedesmus are potential tools for the assessment of copper pollution in fresh water of Sai Gon river.

Smartphone-based Fluoride-specific Sensor for Rapid and Affordable Colorimetric Detection and Precise Quantification at Sub-ppm Levels for Field Applications

Higher levels of fluoride (F–) in groundwater constitute a severe problem that affects more than 200 million people spread over 25 countries. It is essential not only to detect but also to accurately quantify aqueous F– to ensure safety. The need of the hour is to develop smart water quality testing systems that would be effective in location-based real-time water quality data collection, devoid of professional expertise for handling. We report a cheap, handheld, portable mobile device for colorimetric detection and rapid estimation of F– in water by the application of the synthesized core–shell nanoparticles (near-cubic ceria@zirconia nanocages) and a chemoresponsive dye (xylenol orange). The nanomaterial has been characterized thoroughly, and the mechanism of sensing has been studied in detail. The sensor system is highly selective toward F– and shows unprecedented sensitivity in the range of 0.1–5 ppm of F–, in field water samples, which is the transition regime, where remedial measures may be needed. It addresses multiple issues expressed by indicator-based metal complexes used to determine F– previously. Consistency in the performance of the sensing material has been tested with synthetic F– standards, water samples from F– affected regions, and dental care products like toothpastes and mouthwash using a smartphone attachment and by the naked eye. The sensor performs better than what was reported by prior works on aqueous F– sensing.

Potential of the magnetic hollow sphere nanocomposite (graphene oxide-gadolinium oxide) for arsenic removal from real field water and antimicrobial applications

Potential of the magnetic hollow-sphere nanocomposite, graphene oxide-gadolinium oxide (GO-Gd2O3) for arsenic (As) removal from real field water with developing a continuous operating system and antimicrobial activity were investigated. The characterization results suggest that the prepared GO-Gd2O3 is a hallow sphere wool-like nanocomposite having 50.91 m2 g−1 surface area. The sorption studies revealed that a high adsorption capacity (216.70 mg g−1) can be achieved using GO-Gd2O3 (0.1 g L−1) at a pH of 6.0, and temperature of 293 K. The main and novel observations from the loading of Gd2O3 are that the GO adsorption efficiency, adsorbent separation rate from aqueous solutions, and the stability of the composite have been altered. Thus, the developed material can overcome the separation and stability issues associated with the bare GO, and exhibits an enhanced adsorption capacity toward arsenic was higher or comparable with existing magnetic material. In addition, the developed adsorption method was well applied for real field water samples collected from the mining area of South Korea where the GO-Gd2O3 can reduce the quantity of arsenic under the maximum accepted concentration of arsenic considered fit for drinking water stipulated by environmental protection agencies. Furthermore, the GO-Gd2O3 nanocomposite shows a high bacterial photocatalytic inactivation and was comparable with other reports.

Long-term monitoring of sulfonamides and tetracyclines in manure amended soils and leachate samples - A follow-up study

Antibiotics can be detected in manure and digestate samples worldwide. As manure is a frequently used fertilizer, antibiotics are found in soil and leachate samples. Only little is known about the long-term fate of antibiotics in the soil environment. One shortcut is the lack of appropriate monitoring studies. Here we present the results of an unequalled soil monitoring study over 18 years from an agricultural field site in Lower Saxony (Germany). Sulfonamides and tetracycline are mainly fixed in the upper soil layer. Contents showed a sharp decrease below sampling depth of 30 cm (plough depth). Sulfaguanidine and sulfamethazine (SMZ) were detected down to 90 cm. Water samples taken below the field site revealed the transfer of sulfonamides into leachate. High variances were observed between sampling points emphasizing the need for sampling strategies for environmental studies. In addition, field lysimeters with defined input of sulfonamides enabled a long-term monitoring and mass balance of antibiotic transfer into leachate over 10 years. SMZ showed the highest mobility with concentrations up to 65 ng L−1. Less than 0.5% of the applied SMZ was transferred into the leachate. Data of lysimeter and field water samples support the theory of a steady state process with a continuous input of sulfonamides such as SMZ into leachate. Soils contaminated with antibiotics can be a long-term source for the input of antibiotic active compounds into deeper soil layers and groundwater.

Development of a rapid screening test for Karenia mikimotoi by using loop-mediated isothermal amplification and lateral flow dipstick

As a bloom-forming dinoflagellate, Karenia mikimotoi is toxic and globally distributed. Frequent outbreaks of K. mikimotoi blooms usually lead to the mass mortality of pelagic and benthic marine life, resulting in large economic losses. Therefore, the simple, rapid, and highly effective monitoring of K. mikimotoi is crucial to minimize the damage caused by this alga. This study aimed to establish a convenient, cost-effective, and efficient molecular detection technique through loop-mediated isothermal amplification (LAMP) combined with chromatographic lateral flow dipstick (LFD) for the daily monitoring and real-time detection of K. mikimotoi. The internal transcribed spacer (ITS) and large subunit (LSU) rDNA sequences of K. mikimotoi were used to design and screen an optimal primer (KmLF3) and a detection probe (KmLF3HP). The optimized LAMP conditions were as follows: dNTP concentration, 1.2 mM; betaine concentration, 1 M; ratio of the inner primer to the outer primer, 8:1; magnesium ion concentration, 8 mM; amplification temperature, 59 °C; and amplification time, 60 min. Cross-reactivity tests confirmed the specificity of LAMP–LFD. The detection limit of LAMP–LFD for K. mikimotoi genomic DNA was 1.70 × 10−4 ng μL−1, which is 100 times lower than that of conventional PCR. The detection limit of LAMP–LFD for the recombinant plasmid containing the LSU rDNA of K. mikimotoi was 6.21 × 103 copies μL−1, which was 10 times more sensitive than that of LAMP followed by agarose gel electrophoresis and SYBR Green I dye staining and 100 times lower than that of conventional PCR. The practicability of LAMP–LFD was validated by testing with simulated field-water samples, displaying a detection limit of 10−1 cells mL−1. In conclusion, the developed LAMP–LFD is a specific, sensitive, and accurate detection method and may be competent for the field detection of K. mikimotoi.

The Bayes Recognition Model for Mine Water Inrush Source Based on Multiple Logistic Regression Analysis

Accurate recognition of water inrush sources is important in mine water hazard control. In this study, 118 water samples of four water types in the Qinan coal mine were analysed by multiple logistic regression, and the 12 water samples that did not meet the requirements were removed. The remaining 106 were used as training samples to establish a Bayes recognition model (BRM). In addition, the BRM was used to complement multiple logistic regression analysis (MLRA) to discriminate other water samples in the mining area. The recognition accuracy of the combined model was 95.28%. The results from the model were consistent with the field water samples and showed that the combined MLRA-BRM approach fully considers the hydraulic relationships between different aquifers and a mixed water inrush source. Moreover, the MLRA-BRM combination improved water inrush source recognition accuracy and was more reliable than using MLRA or BRM alone.

Kajian Kualitas Perairan Laut Sekitar Muara Sungai Jelitik Kecamatan Sungailiat – Kabupaten Bangka

Jelitik River is the main river and economic artery of Sungailiat District, Bangka Regency. Currently around the Jelitik River there is a Jelitik Fishing Port and is developed as an industrial area. In addition to the problems of sedimentation problems with the development of industrial estates and the presence of sand mining rich in tin ore on land and on the high seas it is feared that it will reduce the quality of the environment, especially the surrounding sea water. Therefore, this study is needed in order to find out the quality of waters in this estuary which can be used as a basis or baseline for the initial environment of this region if later this area will be developed as a port or industrial area. The method used in this study is field observation, water sampling, and laboratory analysis. Therefore, as an initial step, it is necessary to identify the quality of the waters in this estuary which can be used as the basis or initial environmental baseline of this area if later this area will be developed as a port or industrial area. Based on observations in the field of laboratory analysis of water samples, generally the quality of seawater around the estuary of Jelitik River still meets seawater quality standards both for port activities, marine tourism and for biota. Some parameters that exceed the quality standard include total suspended solid (TSS) which reaches 250 mg/l, total dissolved solids (TDS) which reaches 24,700 mg/l and nitrate content which reaches 0.38 mg/l. BOD value is 4.7 mg / l and COD is 46.4 mg / l, these parameters are still below the existing sea water quality standard.

The spatial distribution of nitrate and phosphate in Sempor Reservoir, Kebumen Regency, Central Java

Sempor Reservoir is used for irrigation, domestic, industrial, and tourism purposes, as well as hydroelectric power plant and inland fish farming in pens. The land use in its catchment area is mainly plantation (74%) and, followed by, rice field (8.13%), dry farmland (7.74%), and settlement (5.69%). Agricultural activities, both in irrigated and rainfed farming systems, apply fertilizers to maintain crop quality, but when these substances washed away by surface runoff and transported through the drainage system, they end up increasing nutrients in water bodies. Excess nutrients like nitrate and phosphate induce a rapid growth of algae and aquatic plants, disrupting the ecosystems. This study was designed to identify the spatial distribution of nitrate and phosphate in Sempor Reservoir by field observation, water sampling, and laboratory analysis. The water was collected from 25 sampling points distributed at the outlet (close to the spillway), in the middle and the upstream of the reservoir, and around the fish pens (near the check dam). The results showed that nitrate was present on the reservoir water surface and at a depth of 1 meter at varying concentrations, i.e., <0.01-0.36 mg/L. The phosphate levels were <0.01-0.31 mg/L on the surface and <0.01-4.78 mg/L at a depth of 1 meter. The upstream had very high nitrate concentrations both on the surface and at a depth of 1 meter, while the outlet had very high content only at a depth of 1 meter. As for phosphate, very high concentrations were identified in the middle surface of the reservoir (near the pier) and at 1m depth around the fish pens.

黄土区小流域植被类型对沟坡地土壤水分循环的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 黄土区小流域植被类型对沟坡地土壤水分循环的影响 DOI: 10.5846/stxb201902120248 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 基金面上项目（41771311）；国家自然科学基金国际（地区）合作与交流项目（41561144011）；国家自然科学基金（41807066） Effects of vegetation types in small watershed on soil water cycle in gully-slope land of loess region Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:沟坡作为黄土丘陵区小流域水土流失最为活跃的区域，探究不同下垫面植被类型下的土壤水分循环特征对于沟坡地植被恢复具有重要意义。基于氢氧同位素示踪技术，通过野外水样采集和室内同位素分析旨在揭示植被类型对沟坡地土壤水分循环的影响机制。结果表明：（1）各水体氢氧同位素均遵循：降水 > 刺槐林地土壤水 > 草地土壤水 > 地表水 > 地下水，降水的变异系数最大，地表水和地下水的变异系数较小。（2）草地土壤水主要以降水补给为主，所占比例为59.12%，刺槐林地土壤水则以深层土壤水的上升补给为主，所占比例为60.97%。短阵性暴雨条件下，草地土壤水运移速率较刺槐林地高约1 cm/d，且主要发生在0-50 cm土层。（3）土壤水的垂向运移为地下水的主要补给形式，草地土壤水对地下水的补给比例为51.64%，约比刺槐林地高0.52%。表明植被类型对土壤水分循环特征具有一定的影响，刺槐林对深层土壤水分利用强度较大，可能加剧深层土壤干层化，而草地更有利于降水入渗以及地下水补给，该研究可为小流域沟坡的生态修复和综合治理提供科学依据。 Abstract:The gully-slope land is the most active area of soil erosion in small watershed of loess hilly region. It is of great significance to explore the characteristics of soil water cycle under different underlying vegetation types for vegetation restoration on gully-slope land. Based on the hydrogen and oxygen isotope tracer technique, the mechanism of vegetation types affecting soil water cycle in gully-slope land was revealed through field water sample collection and indoor isotope analysis. The results were: (1) The hydrogen and oxygen isotope concentration in the five water bodies decreased in an orderly way, with precipitation being observed to have the greatest amount, followed by soil water of black locust forest, then soil water of grassland, then surface water, finally groundwater. The coefficient of variation of precipitation was the largest, and the coefficient of variation of surface water and groundwater was smaller. (2) Soil water in grassland was mainly recharged by precipitation, accounting for 59.12%. Soil water in black locust forest was mainly recharged by the rising of deep soil water, accounting for 60.97%. Under the condition of short-burst rainstorm, the water transport rate of grassland soil was about 1 cm/d higher than that of black locust forest. And the main transport ranges of soil water in two vegetation types were 0-50 cm. (3) The vertical migration of soil water was the main form of groundwater recharge. The groundwater recharge ratio by soil water of grassland was 51.64%, which was about 0.52% higher than that of black locust forest. It indicated that the vegetation type had certain influence on the characteristic of soil water cycle. Black locust forest had a strong utilization of deep soil water, which might aggravate the dried soil layer of deep soil. And the grassland was more conducive to precipitation infiltration and groundwater recharge. This study can provide a scientific basis for ecological restoration and comprehensive management of gully-slope land in small watershed. 参考文献 相似文献 引证文献

Effects of Temperature, Growth Media, and Photoperiod on Growth and Toxin Production of Azadinium spinosum.

Azaspiracids (AZAs) are microalgal toxins that can accumulate in shellfish and lead to human intoxications. To facilitate their study and subsequent biomonitoring, purification from microalgae rather than shellfish is preferable; however, challenges remain with respect to maximizing toxin yields. The impacts of temperature, growth media, and photoperiod on cell densities and toxin production in Azadinium spinosum were investigated. Final cell densities were similar at 10 and 18 °C, while toxin cell quotas were higher (~3.5-fold) at 10 °C. A comparison of culture media showed higher cell densities and AZA cell quotas (2.5–5-fold) in f10k compared to f/2 and L1 media. Photoperiod also showed differences, with lower cell densities in the 8:16 L:D treatment, while toxin cell quotas were similar for 12:12 and 8:16 L:D treatments but slightly lower for the 16:8 L:D treatment. AZA1, -2, and -33 were detected during the exponential phase, while some known and new AZAs were only detected once the stationary phase was reached. These compounds were additionally detected in field water samples during an AZA event.

Performance of a novel magnetic solid-phase-extraction microsphere and its application in the detection of organic micropollutants in the Huai River, China

Solid phase extraction has been increasingly applied for the detection of organic micropollutants (OMPs). However, time-consuming and high-cost disadvantages also limit the widespread use of this method, especially for the extraction of large-volume field water samples. In this study, a gas chromatography-mass spectrometry (GC-MS) method based on the magnetic microsphere (M150) solid-phase-extraction (MSPE) was established to investigate the OMPs in source water throughout the whole Huai River. In brief, the results demonstrated that the extraction efficiency of the M150 was superior to that of C18 and HLB for the selected OMPs, including species of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), phthalate esters (PAEs) and nitrobenzenes (NBs), and the method detection limits of M150 for these OMPs were comparable to those of C18 and HLB. The optimized conditions of extraction and elution were the 100 mg/L dosages of microspheres, extraction time of 60 min and pH of 2, and the eluent with a similar polarity, hydrophobicity and molecular structure to the OMPs rendered higher elution efficiencies. A total of 21 types of OMPs affiliating to PAHs, OCPs, PAEs and NBs were detected by the established method, with the total concentrations of 505–2310 ng/L in source water of the Huai River. Spatial differences of the OMPs were also observed, demonstrating the link between pollutant profiles and geographical locations. This study provides an alternative to enrich OMPs in filed water samples, and it reveals pollutant profiles of source water throughout the whole Huai River.

Interaction of Surface Water and Groundwater Influenced by Groundwater Over-Extraction, Waste Water Discharge and Water Transfer in Xiong’an New Area, China

Understanding the interaction of surface water and groundwater affected by anthropogenic activities is of great importance for water resource and water quality management. The Xiong’an New Area, located in the North China Plain, has been designated a new building area by China’s government. Groundwater has been over pumped and artificial water was transferred to meet the water supply in this region. Therefore, the natural interaction of surface water and groundwater has been greatly changed and there has been a complex impact of the groundwater from anthropogenic activities. In this study, we used water chemical ions and stable isotopes of δ2H and δ18O to assess the interaction of surface water and groundwater in the Xiong’an New Area. We carried out field surveys and water sampling of the Fu River (domestic waste water discharge), Lake Baiyangdian (artificial water transfer), and the underlying groundwater along the water bodies. Results show that the artificial surface water (discharged and transferred) became the major recharge source for the local groundwater due to the decline of groundwater table. We used groundwater table observations, end-member mixing analysis of the stable isotopic composition and chloride tracers to estimate the contributions of different recharge sources to the local groundwater. Due to the over pumping of groundwater, the lateral groundwater recharge was dominant with a contribution ratio ranging from 12% to 78% in the upper reach of the river (Sections 1–3). However, the contribution of lateral groundwater recharge was estimated to be negligible with respect to the artificial water recharge from Lake Baiyangdian. Seepage from the Fu River contributed a significant amount of water to the connecting aquifer, with a contribution ranging from 14% to 75% along the river. The extent of the river influence into the aquifer ranges as far as 1400 m to the south and 400 m to the north of the Fu River. Estimations based on isotopic fractionation shows that about 22.3% of Lake Baiyangdian water was lost by evaporation. By using the stable isotopes of oxygen and hydrogen in the lake water, an influencing range of 16 km west of the lake was determined. The interaction of the surface water and groundwater is completely changed by anthropogenic activities, such as groundwater over pumping, waste water discharge and water transfer. The switched interaction of surface water and groundwater has a significant implication on water resources management.

Ultrasound-assisted synthesis of thermosensitive nanovesicle for direct trap and release of analgesic drugs in biofluid and sewage

An environmentally friendly thermosensitive nanovesicle-cloud point microextraction technique has been developed with the assistant of ultrasonic waves to determine analgesic drugs with a broad range of polarity in field water and human urine. Based on thin-film hydration, the conformation of nanovesicles formed by a binary mixing system with the nonionic surfactants was evaluated using regular and cryogenic transmission electron microscopy. The multilayered nano-spherical structure was able to capture polar and nonpolar compounds simultaneously. Analgesic drugs (acetaminophen, salicylic acid, ketoprofen, diclofenac, indomethacin, ibuprofen, and mefenamic acid) were detected by ultra-performance liquid chromatography coupled to photodiode array detection. Under optimal conditions including the type and ratio of surfactants, sonication time and sonication temperature, linear calibration curves were obtained over the range of 50–8000 μg L−1. The coefficient of determination (R2) ranged from 0.9953 to 0.9995, with detection limits of 10–100 μg L−1. The relative standard deviations ranged from 3.2% to 12.7% for intraday precision (n = 5) and 2.5% to 14.1% for interday precision (n = 15). The relative recoveries obtained from one industrial wastewater sample and two field water samples ranged from 86.1% to 108.1%. In the human urine analysis, three volunteers ingested 1500 mg of acetaminophen. After 4 h, the concentration of acetaminophen in the urine was found to range from 87.0 to 197.9 mg L−1.

Bactericidal efficacies of food additive grade calcium hydroxide toward Legionella pneumophila.

Food additive grade calcium hydroxide (FdCa(OH)2) in the solution of 0.17% was evaluated for its bactericidal efficacies toward Legionella pneumophila with or without sodium hypochlorite (NaOCl) at a concentration of 200 ppm total residual chlorine, at room temperature (RT) (25°C ± 2°C) and 42°C, either with or without 5% fetal bovine serum (FBS). Besides, FdCa(OH)2 in different concentration solutions were prepared in field water samples (hot spring and bath tab water) and evaluated for their bactericidal efficacies at 42°C. FdCa(OH)2 (0.17%) inactivated the L. pneumophila to the undetectable level (<2.6 log CFU/ml) within 5 min and 3 min, respectively, at RT and 42°C, with 5% FBS. At RT and 42°C, NaOCl inactivated L. pneumophila to the undetectable level within 5 min, without 5% FBS, but with 5% FBS, it could only inactivate this bacterium effectively (≥3 log reductions). Conversely, at RT and 42°C, the mixture of 0.17% FdCa(OH)2 and 200 ppm NaOCl could inactivate L. pneumophila to the undetectable level, respectively, within 3 min and 1 min, even with 5% FBS, and it was elucidated that FdCa(OH)2 has a synergistic bactericidal effect together with NaOCl. FdCa(OH)2 0.05% solution prepared in hot spring water could inactivate L. pneumophila to the undetectable within 3 min at 42°C. So, FdCa(OH)2 alone could show nice bactericidal efficacy at 42°C, even with 5% FBS, as well as in field water samples.

Multilayered surface for the interactive separation of perchlorate from aqueous medium

Environmental contextPerchlorate from rocket fuel plants or firework manufacturing units can seriously contaminate drinking water. We developed a separation skin on a microfiltration membrane and on sand that can remove perchlorate from water in the presence of competing ions. This method is suitable for a domestic water purification unit selective for perchlorate removal. AbstractThis study reports an interactive separation of perchlorate (ClO4−) by polyethyleneimine (PEI) and poly (styrene sulfonate) (PSS) deposited on a microfiltration membrane and on sand surfaces. The variation of the interaction with respect to deposition and feed variables was assessed. The 9 bilayered ((PEI/PSS) 0.15M NaCl, pH 6)) membranes showed a ClO4− rejection of ~80%. An increase in the feed concentration to 25mgL−1 reduced the rejection to 58%. With a feed pH from 4 to 10, the rejection varied between almost 100% and 16%. The presence of ions reduced the rejection percentage of ClO4− with the interference by the ions in the order of SO42−&amp;gt;HCO3−&amp;gt;NO3−&amp;gt;Cl−. The interference is attributed to the characteristics of the competing ions and the nature of the multilayers. A positive impact of post-treatment (98%) and capping layers on rejection percentage (80% to nearly complete) for synthetic and ClO4− contaminated field water samples is clearly established. The presence of competing ions is also accounted for by a capped membrane system. The selectivity of the competing ions increases with capping layers of 1M NaCl in the order of HCO3−&amp;gt;NO3−&amp;gt;SO42−. In the field water samples up to a SO42− concentration of 3.0mgL−1, the capping layers with 0.4M NaCl result in a near complete rejection of ClO4−, whereas further enhancement requires a capping layer of 1M NaCl. A sand filtration system was developed by incorporating the pre-optimised polyelectrolyte multilayer on sand. Deposition of a single bilayered PEI/PSS multilayer on sand effectively (nearly completely) removes ClO4−.