Reduction In Electrical Conductivity Research Articles

Biodesalination of saline aquaculture wastewater with simultaneous nutrient removal and biomass production using the microalgae Arthrospira and Dunaliella in a circular economy approach

Freshwater scarcity is escalating due to factors such as climate change, droughts, increased demand, population growth, and poor water management practices. A promising sustainable solution to this challenge is biodesalination using microalgae. We demonstrate that Arthrospira platensis and Dunaliella salina can thrive in saline aquaculture wastewater, reducing both its salinity and the concentration of nutrients. The salinity removal ability was quantified through measurements of electrical conductivity (EC) and ICP-OES, revealing reductions in EC by up to 45 % (from 31.5 to 17.2 ms/cm) for A. platensis and 35 % (from 31.5 to 20.5 ms/cm) for D. salina. FESEM indicated the formation of a salt layer on the surface of both microalgae, suggesting biosorption and bioaccumulation as likely mechanisms. FTIR spectroscopy analysis demonstrated the binding of functional groups within the cell wall of A. platensis and the cell membrane of D. salina with the ions present in the medium. Scaling up the cultivation of A. platensis in a photobioreactor under non-sterile conditions validated the processes' potential for industrial-scale biodesalination. Although the treated water did not reach the standards for irrigation or potable use, this approach provides a preliminary desalination step, reducing burden on subsequent treatments and simultaneously providing nutrient removal and biomass production.

Comparative Assessment of the Phytodesalination rates of Duckweed and Water Hyacinth in Brackish Water

Brackish surface water is a challenge for mostestuarinecommunities to meet the water requirement for agricultural purposes. Desalination plantson the other hand,are costlyandenergy consuming method to run. This research compares the possible use of duckweed andwater hyacinth for their Phytodesalinationrates of brackish water. Three replicates containing about 100 g of each aquatic macrophytes in a trough with 10 litres of brackish water (salinity 7.69 ppt) were studied daily for 6 days. Electrical conductivity (EC), pH, total dissolved solids (TDS) and salinity were the measured water parameters thereafter, the treatment means were calculated. Results showed that maximum reductions of most of the water parameter were observed after 3 days of the research for both aquatic macrophytes. A reduction of EC by 16.4 %, TDS by 16.3 % and salinity by 20.7 % for duckweed while for water hyacinth, a reduction of EC by 20 %, TDS by 19 % and salinity by 29.1 % were observed. Thereafter, both aquatic macrophytes started showing signs of nutrient starvation and a reduced rate of desalination. This can be addressed by removingthe spent and wilting aquatic plantsand re-introducingfresh onesin 3 days intervalsuntil desalination is achieved. Anova shows that there was significant difference between pre-and post-treatment values at 95 %confidence level in EC for both duckweed and water hyacinth treatment and also in TDS and salinity for water hyacinth treatment. This suggests potency of water hyacinth in the desalination of brackish water for crop irrigation and other agricultural purposes.

Development of data-driven models for the optimal design of multilayer sand filters for on-site treatment of greywater

Greywater, with limited content of pathogens, makes up more than half of the produced wastewater in urban areas. Given the high cost of wastewater management and treatment, it causes sense to collect greywater separately at the source and employ an on-site treatment system to increase opportunities for on-site water reuse. For this purpose, this paper aims to propose a multilayer granular filter as an inexpensive and simple on-site treatment method for greywater reuse. Furthermore, as determining the optimal structure of multilayer filters is a serious challenge, a simulation-optimization model is developed for determining the best filter configuration. An Artificial Neural Network (ANN) is trained based on experimental results to simulate the filter performance with different combinations of layers and the Genetic Algorithm (GA) is used to find the optimal thickness of different layers based on ANN simulation results. The proposed filter in this paper for greywater treatment consists of silica sand (in three different gradings) and activated carbon (with fixed grading) and treatment measures for evaluation of filter performance are considered as Chemical Oxygen Demand (COD) and Electrical Conductivity (EC). Due to difficulties in collecting, transferring, and storing the real greywater, synthetic greywater was used in this study. 49 experiments with different combinations of filter media thicknesses were performed and the performance of the filter was analyzed. Generally, three-layer filters perform better in COD and EC reduction, however, the average COD and EC elimination equals 36.3% and 15.1%, respectively, which indicates more efficiency of filter in COD reduction in comparison with EC. Based on the optimization-simulation model and experimental results, a filter consisting of 33 cm of fine sand, 20 cm of activated carbon, and 7 cm of medium sand results in the maximum efficiency and can reduce the COD and EC of greywater by 72% and 30%, simultaneously. According to the optimization outputs, the ideal filter can treat greywater up to having EC of 1000 μS/cm and COD of 321 mg/L, which is generally suitable for irrigation purposes.

Floating Wetlands for Sustainable Drainage Wastewater Treatment

The preservation of water resources in modern urbanized society is a major concern. In this study, a floating constructed wetland (FWT) pilot plant was designed and constructed for the treatment of a polluted wastewater drain. A series of experiments were run continuously for a year in pilot-scale FWTs in a semi-arid area located in Egypt’s Delta. Four aquatic plant species (Eichhornia, Ceratophyllum, Pistia stratiotes, and Nymphaea lotus) were used to assess the performance of FWTs for pollutant removals, such as biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), electrical conductivity (EC), and total dissolved solids (TDS), from drainage wastewater to reuse the treated effluent in irrigation practices. The FWT systems were fed drainage tainted water on a weekly basis, and the concentrations and removal efficiency were assessed in the experiments. The average reduction in BOD, COD, TSS, TDS, TN, EC, and TP were 76–86%, 61–80%, 87–95%, 36.6–44.1%, 70–97%, 37–44%, and 83–96%, respectively. ANOVA with Post-HOC t-tests show that the Eichhornia, Pistia stratiotes, and Nymphaea lotus have the highest BOD and COD removal performance, whereas Pistia stratiotes and Nymphaea lotus have the highest TN and TP removal performance. In all cases, the Nymphaea lotus performed well in terms of pollutant removal. In addition, a design procedure for a FWT systems is presented. For wastewater treatment, FWT systems have proven to be a low-cost, long-term option.

Seasonal performance of aquatic macrophytes in improving physicochemical parameters of swine wastewater.

Swine wastewaters (SW) present organic load and nutrient content, what have caused degradation of water quality in many watercourses. Thus, the aquatic macrophytes represent an alternative for the depollution of these wastewaters, due to the high recovery power. The aim of this study was to evaluate the performance of the Eichhornia crassipes (Mart.) Solms, Pistia stratiotes L. and Salvinia auriculata Aubl. in improving the physicochemical targets of SW, as well as to quantify the total ammoniacal nitrogen (NH4+) and total phosphorus (total P) in the plant tissue of the macrophytes and the dry matter biomass (DMB) in two seasons of the year (spring and winter). The experiment was designed in a randomized block design, with 4 treatments (T) with 4 replicates: T1 = Control (without plants); T2 = E. crassipes; T3 = P. stratiotes; and T4 = S. auriculata, submitted to a SW diluted in 50% water. The monitoring is done in tanks during a period of 30 days of each season. Electrical conductivity (EC), dissolved oxygen (DO), turbidity, NH4+ and dissolved phosphorus (P) were analyzed in the SW. In the plants, the contents of NH4+, total P and DMB were determined. It was verified that, in the spring, the plants showed higher production of DMB and a more significant reduction of EC, NH4+ and P, when compared to the plants managed in the SW in the winter. E. crassipes was more efficient at removing P (39%) and total NH4+ (80.2%), and EC reducing (92%) of SW and DMB production in the spring. The results demonstrated that the NH4+ uptake by E. crassipes contributed to a considerable removal of NH4+ and P from SW.

Effects of perennial aromatic grass species richness and microbial consortium on soil properties of marginal lands and on biomass production

AbstractThis study investigates the effects of perennial grass species richness levels and consortium of three bacteria on properties of a slightly alkaline soil and on biomass production of grasses. Four species of perennial aromatic grasses namely: vetiver (Vetiveria zizanioides), lemongrass (Cymbopogon citratus), palmarosa (Cymbopogon martinii), and citronella (Cymbopogon winterianus) were planted in all possible combinations at one, two, three, and four species richness levels in a randomized block design with three replications and two treatments, these were PGPR+ (with plant growth promoting rhizobacteria) and without (PGPR−). Species and richness level specific changes in soil physicochemical properties: electrical conductivity (EC); bulk density (BD); total soil organic carbon (TOC); available nitrogen (Nav), microbial colony forming unit (CFU); microbial biomass carbon (MBC), and enzymatic alkaline phosphatase (ALKP) and dehydrogenase activity (DHA) were observed. The highest reduction in soil pH and EC and increase in soil TOC, CFU, Nav, MBC, and enzymes activities were found at two species richness levels of vetiver and lemongrass in both PGPR+ and PGPR− plots followed by monoculture of vetiver. The highest annual total dry biomass 22.8 and 27.5 Mg ha−1 was produced by monoculture of vetiver in PGPR− and PGPR+ plots, respectively, with similar values at two species richness levels of vetiver and lemongrass in PGPR− and PGPR+ plots. The highest plant carbon was found in vetiver monoculture and two species richness levels of vetiver and lemongrass. The soil carbon sequestration potential was highest at two species mixtures of vetiver–lemongrass and lemongrass–palmarosa as well.

Effects of surface straw mulching and buried straw layer on soil water content and salinity dynamics in saline soils

Field experiments were conducted to evaluate the effects of wheat straw return methods, which included the use of surface straw mulch and a buried straw layer, on soil water content, electrical conductivity (EC), and sodium adsorption ratio (SAR) of saline sodic soils in an effort to identify useful ways for reducing soil salt accumulation and enhancing soil water content. The results showed that the straw return treatments were effective for inhibiting salt accumulation and soil water loss, resulting in a reduction of EC and SAR but an enhancement of soil water content. After a year-long experiment, compared with the treatment with no straw return, the straw burial and straw mulching treatments decreased the EC by 10.5% and 3.5%, reduced the SAR by 7.4% and 21.5%, and increased the soil water by 0.9% and 4.4%, respectively. Furthermore, the combined application of straw layer burial and surface straw return had a more significant effect than the individual treatments; the positive effect of straw return occurred mainly focused in the topsoil (0–40 cm) and decreased with increasing soil depth. Our results allowed us to conclude that burial of the straw layer was necessary to enhance the effects of surface mulch, and the combination of surface mulch (3.0 t ha−1 of wheat straw) and straw layer burial (6.0 t ha−1 of wheat straw) proved to be a better straw return method than the others.

Application of the epuvalisation technology for the tertiary treatment of secondary treated effluents using geranium plants

The effluent of secondary treatment process at Al-Quds University wastewater treatment plant was tertiary treated using an Epuvalisation technique in which geranium plants (Pelargonium hortorum) was employed as a treatment vehicle. The Epuvalisation system was installed in a greenhouse in which germanium was planted hydroponically in a closed-loop mode using secondary treated wastewater (TWW) and fresh water (FW) as a control. The water quality analysis results before and after the growing season of TWW showed a reduction of 23% and 41%, for BOD and COD, respectively. The electrical conductivity (EC) and total dissolved solids (TDS) for TWW demonstrated a reduction of 52% and 53%, respectively. Similar trend was observed for FW in which the reduction in EC and TDS were 48% and 49%, respectively. Furthermore, the percent reduction of the concentration of suspended solids, phosphate ions (PO4−3), chloride ion (Cl−), total nitrogen (TN), and potassium ion (K+) in TWW were found to be 95%, 89%, 60% 98% and 59%, respectively. Plant growth parameters (plant height, fresh and dry weight, number of branches and flowers number) of geranium revealed no significant difference between irrigation with TWW and FW. The chemical plant analysis of roots, leaves, stems and flowers revealed no significant difference between hydroponic plantation in TWW and in FW. From these results it is safe to conclude that the Epuvalisation technique is a promising technique for advanced wastewater treatment using ornamental plants such as geranium due to its simplicity, low cost and easy use.

Application of Electrodialysis Process for Reduction of Electrical Conductivity and COD of Water Contaminated By Composting Leachate

The presented paper describes an experimental study to reduce electrical conductivity (EC) of composting leachate-polluted water by using electrodialysis (ED) process. High efficiency, simple operation, low waste generation and selectivity are considered as major advantageous of applying ED process. Along with evaluation of ED method for desalination, the possibility of the process for COD (chemical oxygen demand) removal was also studied. The impact of- applied voltage, feed concentration and process time on ED performances were investigated. Increasing of the applied voltage and decrease of feed concentration enhanced the reduction of EC and improved the COD removal from the sample. At optimal condition (Voltage=10 Volt, feed solution=Cf/4 and time operation=120 min), the reduction of EC and COD removal were 92.7%, and 83.8%, respectively. Applying higher voltage and using more feed solution concentrations resulted in more energy consumption. The obtained results showed that ED method can be considered as an acceptable method to reduce salt and organic content.

A preliminary investigation on water quality of coalbed natural gas produced water for beneficial uses: a case study in the Southern Qinshui Basin, North China.

Coalbed natural gas (CBNG) is an important unconventional natural gas resource with large reserves in China and receives much attention these years. The CBNG production is accomplished by extracting large volumes of produced water from the aquifer. The CBNG-produced water is commonly managed by discharging into nearby disposal ponds in the Southern Qinshui Basin (SQB), which provides an opportunity for water source for nearby irrigation, livestock, wildlife, and human drinking water. However, utilization of this nontraditional water source in the SQB is hindered by limited knowledge of water quality, practically oxidation/reduction potential (OPR), electrical conductivity (EC), sodium adsorption ration (SAR), and trace element chemistry data. The objective of this study was to collect CBNG-produced water samples at discharge points in the SQB and investigate their water quality principally, including physicochemical parameters, major ions parameters, and trace element parameters. Discharge points were sampled from five main CBNG blocks in the SQB including SZ, ZZ, FZ, CZ, and PZ blocks from July 31, 2013 to August 11, 2014. A composite geochemical data was created with the test results from 145 produced water samples, resulting in information on 40 constituents/parameters. The resulting constituents/parameters were compared to common water use criteria of China to determine possible beneficial uses. Results suggest that the CBNG-produced waters from SQB are characterized by dominated Na-HCO3 type waters, with approximately 12% Na-SO4 and Na-Cl type waters. The observed TDS ranges from 615 to 4376mg/L with 91% are less than 3000mg/L, and Na+ and HCO3- are the dominating determinants of the TDS content. The EC values vary from 930 to 3844μS/cm, ranging from class 3 to class 5 based on the suitability for irrigation. The CBNG-produced waters in SQB generally exhibit higher SAR values (avg. 41.98). Among the 25 detected trace elements in CBNG-produced waters from SQB, elements of environmental concerns include aluminum, iron, selenium, barium, manganese, nickel, and plumbum because their concentrations exceed the related Chinese regulatory standards for human drinking. The commonly constituents exceeding standards for human drinking water, livestock water, poultry water, and irrigation water include fluorinion, pH, and TDS. Besides, targeted reduction of SAR and EC also needs to be treated for most of the produced waters if used for irrigation. In contrast, the CBNG-produced waters in SQB are the most suitable for livestock water, because approximately 88% of the CBNG-produced waters are suitable for livestock drinking if the fluorinion is reduced.

Invisible electronics: Metastable Cu-vacancies chain defects for highly conductive p-type transparent oxide

Non-stoichiometric copper chromium delafossite has lately attracted a high interest in the community of oxide materials due to its high p-type electrical conductivity and adequate transparency in the visible range. This study reports record electrical conductivity of Cu0.66Cr1.33O2 thin films deposited by chemical vapour deposition and investigates their properties. As-deposited samples show conductivities greater than 100Scm−1 and carrier concentrations around 1021cm−3, highest reported value for any non-intrinsically doped delafossite system. A new structural defect consisting in Cu-vacancies chains is identified. This defect, never observed or presumed before, heals upon annealing at 900°C under argon environment, resulting in an electrical conductivity's reduction of six orders of magnitude. Through a wide-range of structural, chemical and transport measurement techniques, a structure-defect-property correlation of this system is established and the metastability of the non-stoichiometry induced defects is investigated. The possibility of manipulating the defects and carrier concentrations through high-temperature annealing and the outstanding electrical properties associated with the large-scale deposition technique and moderate deposition temperature could be of great technological interest. This material could find important applications as hole injection or extraction layer in all-oxide photovoltaic and light emitting devices.

Microstructural, hydraulic conductivity and geochemical changes of drying mature fine oil sand tailings in column experiments

This study offers new insights into two-lift deposition of mature fine tailings under atmospheric drying. The interaction of newly added lift and former lift(s) was evaluated using column experiments in terms of volumetric water content, electrical conductivity (EC), hydraulic conductivity, geochemistry and microstructure. Water content and EC followed the same trend and decreasing of water content appears to be responsible for significant reduction in EC. Evaporation on top of the column reduced the water content to almost zero. The obtained results support the coupling between the hydraulic and chemical processes that should be considered by active operators.

Freeze–melting process significantly decreases phthalate ester plasticizer levels in drinking water stored in polyethylene terephthalate (PET) bottles

Bottled water consumption has increased significantly in recent decades. Eighty percent of bottled water is sold in plastic containers usually made from polyethylene terephthalate (PET). Trace leaching of phthalate esters (PEs) from these bottles into the water and their effects on human health has become a serious concern. In this study, the effects of freezing on the release of PEs from PET bottles have been investigated. Four common PEs were determined in bottled water samples before and after freezing–remelting by a dispersive liquid–liquid micro-extraction method and gas chromatography–mass spectrometry (GC/MS) analysis. PE levels after freezing–remelting of samples were significantly lower than before (mean ± SD = 0.71 ± 0.28 and 0.33 ± 0.003 ppb, respectively). Electrical conductivity (EC) also decreased after freezing–remelting of the water (mean ± SD = 260.2 ± 80.6 and 130.6 ± 17.4 μs/cm, respectively). Significant correlation has been detected between reduction in water EC and elimination of PEs from water. Dissolved minerals and contaminants in water concentrate and conglomerate in the center of the ice during the freezing process and form white sediments mainly of calcium bicarbonate after remelting of the water. It seems that calcium bicarbonate effectively adsorbs PEs and traps them in its structures. These sediments do not have significant gastrointestinal absorption and cannot pose health consequences. The freezing–remelting process could be introduced as an effective procedure for water treatment.

Optimizing Gypsum Levels for Amelioration of Sodic Soils to Enhance Grain Yield and Quality of Rice (Oryza sativaL.)

Field experiment was conducted on a fine loamy, mixed, hyperthermic, highly sodic soil having pH (10.5), electrical conductivity (EC) (2.42 dS m−1), exchangeable sodium percentage (ESP) (89.0), organic carbon (OC) (0.80 g kg−1) and available nitrogen (94 kg ha−1) to determine the response of two rice (Oryza sativa L.) varieties (CSR 13 and Pant 4) to gypsum levels [(control, 15, 25 and 50% gypsum requirement (GR)]. The study revealed that all the growth parameters (plant height, number of tillers, dry matter accumulation, number of leaves/hill, leaf weight/hill and leaf area index), yield attributes (length of panicle, number of grains/panicle, test weight) and yields (biological yield, straw yield and grain yield) significantly increased with increasing doses of gypsum. Application of gypsum at 50% GR (15.4 t ha−1) was significantly superior over the control and 15% GR doses but at par with that of 25% GR. Significant reduction in soil pH (10.50 to 8.91), EC (1.43 to 0.48 dS m−1) and ESP (89 to 28.5) and increment in OC (0.8 to 1.2 g kg−1) and available N (94 to 190 kg ha−1) were recorded after three years of study with 50% GR level. Grain quality of rice in terms of N content in grain, grain length, length: breadth ratio, brown rice recovery, milled rice recovery, head rice recovery and gel consistency were higher with 50% GR as compared to control but statistically at par with that of 25% GR. There were significant varieties × gypsum interactions on number of effective tillers, dry matter accumulation, number of leaves/hill, leaf weight, number of panicles m−2, length of panicle, number of grains/panicle, test weight and grain yield indicating that the varieties responded to gypsum differently. Variety ‘CSR 13’ showed significant increase over ‘Pant 4’ in all the growth parameters and yield attributes except length of panicle.

Impacts on soil quality from long-term irrigation with treated greywater

Drought condition in many places leads to the imperative use of greywater for irrigation. There is a serious concern on the impact of such prolonged uses on soil sustainability. The objective of this study was to evaluate the long-term impacts of greywater irrigation on soil electrical conductivity (EC) and other soil quality parameters in field conditions. Six locations were monitored in this study where home gardens have been irrigated with treated greywater for 2 years. Results showed a general reduction in EC levels of soil samples along all depth intervals at all locations. The average soil EC before greywater irrigation was 0.97 dS/m and decreased to 0.41 dS/m, which may be due to the use of greywater as well as the rainwater effect. The reduction in soil EC and irrigation water quantity shows positive correlation (correlation coefficient r = 0.64). Calcium precipitation might also have a major role in soil EC reduction. Soil calcium content was 81 mg L−1 before using treated greywater and decreased to 43 mg L−1 after 2 years of treated greywater usage, which might have been caused by calcium carbonates (CaCO3) precipitation. The results of other soil chemical analyses clearly show that using treated greywater for irrigation has reduced the concentration of organic matters, K, Cd, Pb, P, Mg, Cl, Na, exchangeable sodium percentage, and sodium adsorption ratio after 2 years of application. Zn concentration increased from 11 to 15 mg L−1, and soil pH became slightly higher from 7.6 to 7.8.

Application of robust MFI-type zeolite membrane for desalination of saline wastewater

Zeolites are potentially a more robust desalination alternative as they are chemically stable and possess the essential properties needed to reject ions. This work proposes to use zeolite membranes for desalination of saline recycled wastewater for the possibility of avoiding the costly pre-treatment needed for polymeric reverse osmosis membranes. The MFI-type zeolite membrane was developed on a tubular α-alumina substrate by a combined rubbing and secondary hydrothermal growth method. The prepared membrane was characterised by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and single gas (He or N2) permeation, and underwent desalination tests with saline wastewater under different conditions. When saline wastewater was fed at 7MPa to the zeolite membrane it showed a salt rejection of 80% based on electrical conductivity (EC) and a flux of 4Lm−2h−1. A254 (organics absorption at the wavelength of 254nm measured by a HACH DR5000 spectrophotometer) removal exceeded 90%. Slightly lower salt removal and A254 results were observed when operating at a lower pressure of 3MPa. During batch concentration runs on the saline wastewater, the EC of the feed water increased from the initial value of 1770µScm−1 to 3100µScm−1 over the 48h test time which indicates that a 43% water recovery was achieved. EC reduction remained >70% and flux was maintained at around 2Lm−2h−1 throughout the test period, indicating that the membrane resisted organic fouling. Chlorine stability studies showed that a long-term (7 days) strong hypochlorite clean did not significantly alter the flux or rejection confirming the chemical stability of zeolite membranes. Overall, the zeolite membrane showed excellent chemical resilience and produced a desalinated product suitable for reuse applications (e.g. irrigation, residential or industrial). Fluxes, however, need to be improved to be competitive with current polymeric membranes as do rejections for higher purity water applications.

Sea salt aerosol groundwater salinization in the Litorale Romano Natural Reserve (Rome, Central Italy)

A yearly survey in a piezometric network was realized in the Litorale Romano Natural Reserve (Rome, Central Italy), collecting water table and chemo-physical data. Monthly chemo-physical surveys highlighted a groundwater salinization variability in a coastal unconfined aquifer. The aquifer is mostly composed by aeolian sands of a still preserved dune ridge environment, on which a pine forest develops. The groundwater salinity variability resulted is connected to the wind pattern and rainfalls. In fact, wind speed higher than 4 m/s is responsible for generating sea salt aerosols (SSA) from sea surface. A statistical analysis was performed for wind with a speed higher than 4 m/s, to detect wind orientation. The dry deposition of SSA on the tree foliage appeared correlated to the westerly winds, blowing in the springtime. When the rainy season occurs, the SSA is washed out from the trees and it is directed to groundwater, where an enhancement of the Electrical Conductivity (EC) values is noticed. Whenever rain events occur and winds are not westerly, a dilution of groundwater salinity takes place and consequently a reduction of EC. Chemical analyzes were realized as well. They confirmed that groundwater of piezometers located close to the coast line is enriched of SSA elements.

전기동력학 기술을 이용한 시설재배지 토양 염류제거 실증 연구

본 연구에서는 높은 농도의 염류가 집적된 시설재배지 토양의 제염을 위해 전기동력학적(EK) 기술을 적용한 파일럿 규모(<TEX>$2{\times}3{\times}0.2m^3$</TEX>, <TEX>$W{\times}L{\times}D$</TEX>)의 실증시험을 실시하였다. 실험 전 토양의 전기전도도(EC)는 약 9 dS/m였으며, 토양내 주요 염류는 <TEX>$Ca^{2+}$</TEX>, <TEX>$Cl^-$</TEX>, <TEX>$SO_4^{2-}$</TEX> 이온이었다. 2주간의 EK 처리 후 토양의 EC는 실험 전에 비해서 52% 감소하였으며, 이 중 대부분은 초기 1주일 이내에 제거되었다(47%). 이는 주로 <TEX>$Na^+$</TEX>와 <TEX>$Cl^-$</TEX>의 제거에 의한 것으로 보이며, 주요 염류 이자 토양에 대해 높은 흡착능을 가지는 <TEX>$Ca^{2+}$</TEX>와 <TEX>$SO_4^{2-}$</TEX>이온은 상대적으로 제거율이 낮았다. EK 실험이 진행되는 동안 토양의 온도는 전류의 세기에 따라 증가하여 최대 <TEX>$50^{\circ}C$</TEX>까지 증가하였다. 따라서 작물이 재배 중인 토양의 원위치 EK 적용을 위해서는 토양의 온도 상승을 제한하기 위해 전류를 조절할 필요가 있다. 결론적으로 EK 기술을 이용하여 경작 중이거나 휴경 중인 시설재배지 토양의 원위치 염류 제거가 가능할 것으로 판단되며 효율적인 탈염을 위해서는 적절한 운전 전략이 요구된다. A pilot-scale electrokinetic (EK) separation field test (<TEX>$2{\times}3{\times}0.2m^3$</TEX>, <TEX>$W{\times}L{\times}D$</TEX>) was performed in a greenhouse to remove salts from saline soil. Initially, the greenhouse soil had high electrical conductivity (EC), about 9 dS/m, and contained mainly <TEX>$Ca^{2+}$</TEX>, <TEX>$Cl^-$</TEX> and <TEX>$SO_4^{2-}$</TEX> ions. After 2 weeks of EK treatment, the soil EC was reduced to 52% compared with its initial value. The EC reduction was mostly achieved within the first week (47%) due to removal of <TEX>$Na^+$</TEX> and <TEX>$Cl^-$</TEX> ions, but ions with a high adsorption capacity such as <TEX>$Ca^{2+}$</TEX> and <TEX>$SO_4^{2-}$</TEX> ions were difficult to be removed. During the EK test, the soil temperature increased and it reached around <TEX>$50^{\circ}C$</TEX> at some regions. For in situ application to soils in cultivation, the current should be controlled to limit increases in temperature, especially near the cathodes. In conclusion, the in situ EK technique is feasible for the restoration of saline greenhouse soils in or no cultivation and an appropriate strategy is necessary for more effective remediation.

Urgency for sustainable development in coastal urban areas with reference to weather pattern, land use, and water quality

Water pollution is one of the most critical problems affecting mankind. Weather pattern and land use of catchment area have significant role in quality of water bodies. Due to climate change, there is frequent variation in weather pattern all over the world. There is also rapid change in land use due to increase in population and urbanization. The study was carried out to analyze the effect of change in weather pattern during the monsoon periods of 2008 and 2012 on water quality of a tropical coastal lake system. The nature and extent of variation in different water quality parameters namely electrical conductivity (EC), magnesium (Mg), sodium (Na), chloride (Cl), sulphate (SO4), turbidity, Secchi disk depth, biochemical oxygen demand (BOD), phosphate (PO4), calcium (Ca), and water temperature as well as the effect of various land use activities in the lake basin on water quality have also been studied. There is significant reduction in precipitation, EC, Mg, Na, Cl, SO4, turbidity, and Secchi disk depths whereas a significant rise in the BOD, PO4, Ca, and water temperature were observed in 2012. This significant reduction in electrical conductivity during 2012 revealed that because of less precipitation, the lake was separated from the sea by the sandbar during most of the monsoon period and thereby interrupted the natural flushing process. This caused the accumulation of organic matter including phosphate and thereby resulting reduction in clarity and chlorophyll-a (algae) in the lake. The unsustainable development activities of Thiruvanathapuram city are mainly responsible for the degradation of water bodies. The lack of maintenance and augmentation activities namely replacement of old pipes and periodical cleaning of pipe lines of the old sewer system in the city results in the bypass of sewage into water bodies. Because of the existence of the old sewerage system, no effort has been taken by the individual establishment/house of the city to provide their own treatment system for sewage and sullage and the untreated wastes are discharged into these old sewer pipes and ultimately the wastes reach the water bodies. In this context, decentralized treatment of sewage, sullage, and garbage by individual houses/establishments/hotels/hospitals is a better option for the developing countries. With the rapid developmental activities, and due to the variation of precipitation due to climate change, it is highly essential to provide proper waste treatment/augmentation facilities in urban lake system because a slight variation in the weather pattern can result in serious implications in the already polluted water bodies.

Early udder inflammation in dairy cows treated by a homeopathic medicine (Dolisovet®): a prospective observational pilot study

Mammary inflammation in dairy cows is a widespread problem in dairy farming resulting in significant economic and welfare concerns. Dolisovet (Belladonna 1dH, Calendula MT, Echinacea 1dH, Dulcamara 1cH) a homeopathic medicine, licensed in France and indicated for the restoration of mammary function in cows is presented as a 10 g tube of ointment for intramammary use. A prospective, uncontrolled, observational pilot study involving the collection and analysis of data from 31 udder quarters identified as being inflamed by an automated milking system (AMS) was conducted to evaluate the effect of Dolisovet on selected parameters of mammary inflammation. Inflamed quarters were identified when milk quality started to deteriorate, via an alert generated by the AMS, on the basis of electrical conductivity (EC). Milk yield and EC were retrieved five to seven days prior to the AMS alert, on the day of and for the following seven days. Dolisovet was administered twice daily for two consecutive days, commencing on the day of the AMS alert. A significant reduction in EC was observed 4-7 days following the first treatment. An increase in milk yield was also observed following the first treatment. Dolisovet may have a beneficial therapeutic effect in the early stages of udder inflammation and for restoring udder health and function. This medicine may be an effective first line treatment for sub-clinical bovine mastitis, reducing the need for antibiotics. Randomised, controlled studies should be undertaken to further investigate this possibility.