Purification of Produced Water from a Sour Oilfield in South Kuwait. 1. Oil-Water Separation and Industrial Salt Production

Produced water from an oil extraction site in South Kuwait was sampled after primary oil – water separation had been carried out. The produced water was filtered through a mixture of activated charcoal and esterified cellulosic material gained from spent coffee grounds as a tertiary adsorption treatment. The earth-alkaline metal ions and heavy metals were separated from the de-oiled produced water by addition of either sodium or potassium hydroxide in the presence of carbon dioxide or by direct addition of solid sodium carbonate. The resulting filtrate gave salt of industrial purity upon selective crystallization on evaporation.

Purification of Produced Water from a Sour Oilfield in South Kuwait. 2. Oil-Water Separation and Crystallization of Calcium Carbonate

Oil-water separation for produced water (PW) originating from an oil extraction site in South Kuwait was carried out using bleached, esterified cellulosic material from used coffee grounds. Thereafter, earth-alkaline metal ions, specifically calcium ions, of the de-oiled PW were removed by precipitation with sodium carbonate to give access to pure sodium chloride as industrial salt from the remaining PW. While the purity of the precipitated calcium carbonate (CaCO3) depends on the precipitation conditions, CaCO3 of up to 95.48% purity can be obtained, which makes it a salable product. The precipitation of CaCO3 decreases the amount of calcium ions in PW from 11,300 ppm to 84 ppm.

Variability in Quantity and Salinity of Produced Water from an Oil Production in South Kuwait

Produced water (PW) is the largest waste stream in the oil and gas industry. Water remains trapped for millions of years in the reservoir with oil and gas. When a hydrocarbon reservoir is infiltrated by a production well, the produced fluids commonly contain water. The understanding of this water’s constituents and volumes is vital for the sustainable continuity of production operations, as PW has a number of negative impacts on the infrastructure integrity of the operation. On the other hand, PW can be an alternative source of irrigation water as well as of industrial salt. Interestingly, both the quantity as well as the quality of PW do not remain constant but can vary, both progressively and erratically, even over short periods of time. This paper discusses such a situation of variable PW in an oil and gas operation in the State of Kuwait.

Effects of the Produced Water from a Sour Oilfield in South Kuwait on the Production Tubing

Kuwaiti oil production faces a growing challenge in the increasing quantities of produced water generated in the production of oil. The high water cut of the produced fluid from the wells and the high salinity of the produced water lead to significant degradation of subsurface equipment, specifically the production tubing. Debris generated through the degradation of the inner part of the tubing becomes a constituent of the scaling that deposits in the tubing and blocks the flow of the production fluid, inducing higher maintenance costs. This paper looks at the characteristics of the scaling in regard to the produced water and outlines the economic impact of the produced water induced degradation of the tubing structure.

Kidding after Transfer of in Vitro Produced Saanen Goat Embryos into Local Ukrainian Breed Recipients in Different Seasons

In recent years, the demand for goat products has been growing due to the fact that goat milk has a number of advantages over cow milk, for example, it is low in lactose, and is considered less allergenic and easier to digest. To increase production during both breeding and non-breeding seasons and reduce the price of dairy products, it is necessary to effectively use reproductive management and assisted reproductive technologies. In vitro embryo production makes it possible to obtain a large number of eggs from goats, which for some reason are unable to conceive, but have genetic value. Afterward in vitro produced embryos can be transferred into recipient goats of other less genetically valuable breeds, such as the Ukrainian local breed. Therefore, the aim of the present study was to investigate the effectiveness of transfers of in vitro produced embryos of Saanen goats into surrogate sires of the Ukrainian local breed in different seasons. All manipulations with animals were carried out following ethical standards (Strasbourg, 1986). Six Saanen goats were selected as the oocyte donors. After the hormonal stimulation oocytes were retrieved by laparoscopic ovum pick-up. In vitro produced embryos were transferred laparotomically into 24 recipients of Ukrainian local breed. Fifty days after embryo transfers, pregnancies were determined by ultrasound diagnostics. Although the embryo development rate in the breeding season was 20% higher than in the non-breeding season, there was no difference in pregnancy and kidding rates between seasons. In conclusion, the transfer of in vitro produced Saanen goat embryos to recipients of the Ukrainian local breed gives the opportunity to achieve pregnancy and kidding regardless of the breeding season, which will enable a faster and more efficient increase in the livestock of highly productive goats in Ukraine in the post-war period.

Kinetic Performance of Oil-field Produced Water Treatment by Biological Aerated Filter

The biological aerated filter （BAF） was used to treat the oil-field produced water. The removal efficiency for oil, COD, BOD and suspended solids （SS） was 76.3%-80.3%, 31.6%-57.9%, 8.6.3%-96.3% and76.4%--82.7%, respectively when the hydraulic loading rates varied from 016m·h^-1 to 1.4m·h^-1. The greatest partof removal, for example more than 80% of COD removal, occurred on the top 100cm of the media in BAF. The kinetic .performance of BAF indicated that the relationship of BOD removal efficiency with the hydraulic loadingrates, in biological aerated filters could be described by c1/c1=l-exp（-2.44/L^0.59）. This equation could be used topredict the B OD.removal efficiency at different hydraulic loading rates.

Flux enhancement during ultrafiltration of produced water using turbulence promoter

Concentration polarization and membrane fouling remain one of the major hurdles for the implementation of ultrafiltration of produced water. Although many applications for ultrafiltration were already suggested, only few were implemented on an industrial scale. Among those techniques, turbulence promoter can be more simple and effective in overcoming membrane fouling and enhancing membrane flux. As for the result that turbulence promoter increase fluid velocity, wall shear rates and produce secondary flows or instabilities, the influence of turbulence promoter was investigated on permeate flux during produced water ultrafiltration and the potential application of this arrangement for an industrial development. Experimental investigations were performed on 100 KDa molecular weight cut-off PVDF single-channel tubular membrane module using four kinds of turbulence promoters. It is observed that the significant flux enhancement in the range of 83%--164% was achieved while the hydraulic dissipated power per unit volume of permeate decreased from 31%--42%, which indicated that the using of turbulence promoter is more efficient than operation without the turbulence promoter. The effects of transmembrane pressure and cross-flow velocity with and without turbulence promoter were studied as well. Among the four kinds of turbulence promoters, winding inserts with 20.0 mm pitch and 1.0 mm wire diameter showed better performances than the others did.

Influences of water treatment agents on oil-water interfacial properties of oilfield produced water

The emulsion stability of oilfield produced water is related to the oil-water interfacial film strength and the zeta potential of the oil droplets. We investigated the effects of water treatment agents （corrosion inhibitor SL-2, scale inhibitor HEDP, germicide 1227, and flocculant polyaluminium chloride PAC） on the stability of oilfield produced water. The influence of these treatment agents on oil-water interfacial properties and the mechanism of these agents acting on the oilfield produced water were studied by measuring the interfacial shear viscosity, interfacial tension and zeta electric potential. The results indicated that the scale inhibitor HEDP could increase the oil-water interfacial film strength, and it could also increase the absolute value of the zeta potential of oil droplets. HEDP played an important role in the stability of the emulsion. Polyaluminum chloride （PAC） reduced the stability of the emulsion by considerably decreasing the absolute value of the zeta potential of oil droplets. Corrosion inhibitor SL-2 and germicide 1227 could decrease the oil-water interfacial tension, whereas they had little influence on oil-water interfacial shear viscosity and oil-water interfacial electricity properties.

First Global Carbon Dioxide Maps Produced from Tan Sat Measurements

1.The need for global carbon monitoring from space and the TanSat mission Global warming is a major problem,for which carbon dioxide（CO2 ）is the main greenhouse gas involved in heating the troposphere.However,the poor availability of global CO2 measurements makes it difficult to estimate CO2 emissions accurately.

Geochemical Characters of Water Coproduced with Coalbed Gas and Shallow Groundwater in Liulin Coalfield of China

To reveal the geochemical characters of water coproduced with coalbed gas and shallow groundwater,water samples were collected from 12 wells of coalbed methane and 7 wells of shallow groundwater.The pH,CODMn,fCO2,total dissolved solids （TDS）,total hardness,and concentrations of metasilicic acid,sodium and kalium,calcium ion,magnesium ion,ammonium iron,bicarbonate ion,carbonate,chloride,sulfate ion,nitrate ion,fluoride,lithium,zinc,nickel,manganese,iron,boron,barium,etc.of the samples were measured.Research results showed the following：（1） Concentrations of TDS,chloride,fluoride,sodium and kalium,ammonium,iron,and barium in the water coproduced with coalbed gas exceeded the national standards of China; however,physical,chemical,and biological properties of shallow groundwater could meet the national standard.（2） The water produced from coalbed contained mainly Na-Cl·HCO3,with average TDS of 4588.5 ppm,whereas shallow groundwater contained a mixture of chemicals including Na.Mg.Ca-HCO3·SO4 and Na.Mg-HCO3·SO4,with average TDS of 663.8 ppm.（3） In general,it was observed that bicarbonate and sodium accumulated in a reducing environment and deeper system,while depletion of hydrogen ions and dissolution of sulfate,calcium,and magnesium occurred in a redox environment and shallow system.（4） Sodium and kalium,ammonium,chloride,and bicarbonate ions were the main ions found in the study area.

Bioflocculant Produced by Klebsiella sp. MYC and Its Appli-cation in the Treatment of Oil-field Produced Water

Seventy-nine strains of bioflocculant-producing bacteria were isolated from 3 activated sludge samples. Among them, strain MYC was found to have the highest and stable flocculating rate for both kaolin clay suspension and oil-field produced water. The bacterial strain was identified as Klebsiella sp. MYC according to its morphological and biochemical characteristics and 16SrDNA sequence. The optimal medium for bioflocculant production by this bacterial strain was composed of cane sugar 20 g L^-1, KH2PO4 2 g L^-1, K2HPO4 5 g L^- 1, （ NH4）2SO4 0.2 g L^-1, urea 0.5 g L^- 1 and yeast extract 0.5 g L^- 1, the initial pH being 5.5. When the suspension of kaolin clay was treated with0.5% of Klebsiella sp. MYC culture broth, the flocculating rate reached more than 90.0% in the presence of 500mg L^-1 CaCI2, while the flocculating rate for oil-field produced water was near 80.0% in a pH range of 7.0 - 9.0 with the separation of oil and suspended particles from the oil-field produced water under similar conditions. The environment-friendly nature of the bioflocculant and high flocculating rate of the strain make the bioflocculant produced by Klebsiella sp. MYC an attractive bioflocculant in oil-field produced water treatment.

High in vitro survival rate of sheep in vitro produced blastocysts vitrified with a new method and device

Background:To advance the use of embryo vitrification in veterinary practice,we developed a system in which embryo vitrification,warming and dilution can be performed within a straw.Ovine in vitro produced embryos(IVEP)were vitrified at either early(EBs:n=74)or fully expanded blastocyst stage(FEBs:n=195),using a new device named"E.Vit",composed by a 0.25-m L straw with a 50-μm pore polycarbonate grid at one end.Embryos at each stage(EBs and FEBs)were vitrified by either Two-step(TS)or Multi-step(MS;6 different concentrations of vitrification solutions)protocol.Non-vitrified embryos(n=102)were maintained in in vitro culture as a control.Warming consisted of placing the straws directly into 1.5 m L tubes containing a TCM-199 solution with three decreasing concentrations of sucrose.Blastocyst re-expansion,embryo survival and hatching rate were evaluated at2,24 and 48 h post warming.The number of apoptotic cells was determined by TUNEL assay.Results:Blastocyst re-expansion(2 h)after warming was higher(P<0.05)in FEBs group,vitrified with the MS and TS methods(77.90%and 71.25%,respectively)compared with the EBs group(MS:59.38%and TS:48.50%,respectively).Survival rates of vitrified FEBs after 24 h IVC were higher(P<0.001)in both methods(MS and TS)than vitrified EBs(MS:56.25%;TS:42.42%)and was higher(P<0.05)in the MS method(94.19%)compared with those in TS(83.75%).After 48 h of culture the hatching rate for FEBs vitrified in MS system(91.86%)was similar to control(91.89%),but higher than FEB TS(77.5%)and EBs vitrified in MS(37.5%)and TS(33.33%).Number of apoptotic cells were higher in EBs,irrespective of the system used,compared to FEBs.The number of apoptotic cells in FEBs vitrified with MS was comparable to the control.Conclusions:A high survival rate of IVP embryos can be achieved by the new"E.Vit"device with hatching rates in vitro comparable with control fresh embryos.This method has the potential for use in direct embryo transfer in field conditions.

Evaluation of Heavy Metals and Pesticide Residues in Dendrobium officinale Produced in Guangxi

[Objectives]To establish a method for the determination of heavy metals and pesticide residues in Dendrobium officinale produced in Guangxi and its culture substrate.[Methods]The contents of five heavy metals(Pb,Cd,As,Hg and Cu)were determined by the atomic absorption spectrophotometric(AAS)method;residues of 9 organochlorine pesticides(α-BHC,β-BHC,γ-BHC,δ-BHC,p,p′-DDT,p,p′-DDE,p,p′-DDD,o,p′-DDT and pentachloronitrobenzene)were determined by gas chromatography(GC).[Results]The contents of five heavy metals in the medicinal materials of D.officinale produced in Guangxi were 0.96,0.21,0.021 mg/kg,and not detected,and 0.35 mg/kg.The contents of five heavy metals in the culture substrate were 0.03,0.19,0.21,0.004 and 1.80 mg/kg,respectively;the content of 9 organochlorine pesticide residues in the sample was not detected.[Conclusions]The detection results of heavy metal content and organochlorine pesticide residues in D.officinale produced in Guangxi and its substrate are consistent with the limit requirements of the Chinese Pharmacopoeia.This experiment is expected to provide reliable data reference for ensuring the safety of the drug resources of D.officinale in Guangxi.

Electromotive Force for Solid Oxide Fuel Cells Using Biomass Produced Gas as Fuel

The electromotive force （e.m.f.） of solid oxide fuel cells using biomass produced gas （BPG） as the fuels is calculated at 700-1,200 K using an in-house computer program, based on thermodynamic equilibrium analysis. Tour program also predicts the concentration of oxygen in the fuel chamber as well as the concentration of equilibrium species such as H2, CO, CO2 and CH4. Compared with using hydrogen as a fuel, the e.m.f. for cells using BPG as the fuels is relative low and strongly influenced by carbon deposition. To remove carbon deposition, the optimum amount of H2O to add is determined at various operating temperatures. Further the e.m.f, for cells based on yttria stabilized zirconia and doped ceria as electrolytes are compared. The study reveals that when using BPG as fuel, the depression of e.m.f, for a SOFC using doped ceria as electrolyte is relatively small when compared with that using Yttria stabilized zirconia.

POLY (β-HYDROXYALKANOATES): NATURAL BIOCOMPATIBLE AND BIODEGRADABLE POLYESTERS PRODUCED BY BACTERIA

A wide variety of different types of microorganisms are known to produce intracellular energy and carbon storage products, which have been generally described as being poly (β-hydroxybutyrate), PHB, but which are, more often than not, copolymers containing different alkyl groups at the β-position. Hence, PHB belongs to the family ofpoly (β-hydroxyalkanoastes), PHA, all of which are usually formed as intracellular inclusions in bacteria under unbalanced growth conditions. Recently, it became of industrial interest to evaluate these PHA polyesters as natural biodegradable and biocompatible plastics for a wide range of possible applications, such as surgical sutures or packaging containers. For industrial applications, the controlled incorporation of repeating units with different chain lengths into a series of copolymers is desirable in order to produce polyesters with a range of material properties because physical and chemical characteristics depend strongly on the polymer composition. Such 'tailor-made' copolymers can be produced under controlled growth conditions in that, if a defined mixture of substrates for a certain type of microorganisms is supplied, a well defined and reproducible copolymer is formed.

Fermented Corn Flour Poisoning in Rural Areas of China Ⅲ. Isolation and Identification of Main Toxin Produced by Causal Microorganisms

Flavotoxin A was isolated from Pseudomonas cocovenenans subsp. farinofermentans culture in semisolid potato-dextrose-agar medium, which was isolated from fermented corn meal that had caused food poisoning outbreaks in China. The isolation, purification, and chemical structure of this toxin were studied. The NMR spectra, the uv spectra, and molar extinction coefficients, and the mass spectra of Flavotoxin A are in good agreement with those reported for bongkrekic acid. Therefore, Flavotoxin A and bongkrekic acid are the same organic chemical compound; the molecular formula is C_(28)H_(38)O_7. The oral LD_(50) of the purified Flavotoxin A in mice was 3.16mg/kg (1.53-6.15mg/kg). The existence of bongkrekic acid in toxic fermented corn samples collected during food poisoning outbreaks was also confirmed. It is concluded that bongkrekic acid has played an important role in the outbreaks of fermented corn poisoning. 1989 Academic Press, Inc.

Oilfield produced water treatment in internal-loop airlift reactor using electrocoagulation/flotation technique

Oilfield produced water is large quantities of salty water trapped in underground formations and subsisted under high temperatures and pressures that are brought to the surface along with oil during production. Produced water(PW) contains a lot of pollutants such as hydrocarbons and metals, this water must be treated before disposal. Therefore, different techniques are being used to treat produced water. Electrocoagulation is an efficient treatment technique involving the dissolution of anodes and formation of electro-coagulants, while the simultaneous generation of H_2 bubbles at the cathode leads to the pollutant removal by flotation. Electrocoagulation(EC)method is one of the most promising and widely used processes to treat oilfield produced water. In the present work, a conventional internal-loop(draught tube) airlift reactor was utilized as electrocoagulation/flotation cell for PW treatment by inserting two aluminum electrodes in the riser section of the airlift reactor. The EC airlift reactor was operated in a batch mode for the liquid phase. Different experimental parameters were studied on the oil and turbidity removal efficiencies such as current density, initial pH, electrocoagulation time, and air injection.The experimental results showed that mixing of the oil droplets in the PW was accomplished using only the liquid recirculation resulted by H_2 microbubbles generated by EC process which enhanced the oil removal. The experimental results further showed that the EC time required achieving ≥ 90% oil removal efficiency decreases from 46 to 15 min when operating current density increases from 6.8 to 45.5 mA·cm^(-2). This reactor type was found to be highly efficient and less energy consuming compared to conventional existing electrochemical cells which used mechanical agitation.

Texture Characteristics of Thin Grain Oriented Silicon Steel Sheet Produced by Cross Shear Rolling

Commercial grain oriented silicon steel was cold rolled to thickness from 0.06 to 0.10 mm by cross shear rolling, then annealed in vacuum or a hydrogen atmosphere furnace. Deformation textures of the sheets were researched by ODF method and reverse pole figure quantitative analyses. The results indicate that: in the condition of the cross shear rolling, the deformation texture of rolled sheet is generally similar to that of conventional rolled sheet, however, the texture distribution through the thickness is asymmetrical. With mismatch speed ratio increasing, the amount of Goss texture increases. With reduction ratio increasing, the intensity of γ-fiber becomes strong.

Time-Resolved Optical Emission Spectroscopy Diagnosis of CO_2 Laser-Produced SnO_2 Plasma

The spectral emission and plasma parameters of SnO2 plasmas have been investigated. A planar ceramic SnO2 target was irradiated by a CO2 laser with a full width at half maximmn of 80 ns. The temporal behavior of the specific emission lines from the SnO2 plasma was characterized. The intensities of Sn I and Sn Ⅱ lines first increased, and then decreased with the delay time. The results also showed a faster decay of Sn I atoms than that of Sn II ionic species. The temporal evolutions of the SnO2 plasma parameters （electron temperature and density） were deduced. The measured temperature and density of SnO2 plasma are 4.38 eV to 0.5 eV and 11.38×1017 cm 3 to 1.1×1017^ cm-3, for delay times between 0.1 μs and 2.2 #s. We also investigated the effect of the laser pulse energy on Sn02 plasma.

Characteristics of dissolved inorganic carbon in produced water from coalbed methane wells and its geological significance

Based on long-term dynamic tracing of dissolved inorganic carbon(DIC)and stable carbon isotope(δ13CDIC)in produced water from 20 coalbed methane(CBM)wells in western Guizhou,the spatial-temporal dynamic variations ofδ13CDIC of the GP well group produced in multi-layer commingled manner were analyzed,and the relationship between the value ofδ13CDIC and CBM productivity was examined.The produced water samples of typical wells in the GP well group were amplified and sequenced using 16S rDNA,and a geological response model ofδ13CDIC in produced water from CBM wells with multi-coal seams was put forward.The research shows that:δ13CDIC in produced water from medium-rank coal seams commonly show positive anomalies,the produced water contains more than 15 species of methanogens,and Methanobacterium is the dominant genus.The dominant methanogens sequence numbers in the produced water are positively correlated withδ13CDIC,and the positive anomaly of v is caused by reduction of methanogens,and especially hydrogenotrophic methanogens.Vertical segmentation of sedimentary facies and lithology in stratum with multi-coal seams will result in permeability and water cut segmentation,which will lead to the segmentation ofδ13CDIC and archaea community in produced water,so in the strata with better permeability and high water cut,theδ13CDIC of the produced water is abnormally enriched,and the dominant archaea is mainly Methanobacterium.In the strata with weak permeability and low water cut,theδ13CDIC of the produced water is small,and the microbial action is weak.The shallow layer close to the coal seam outcrop is likely to be affected by meteoric precipitation,so theδ13CDIC of the produced water is smaller.The geological response model ofδ13CDIC in produced water from multi-coal seams CBM wells in the medium-rank coal reveals the geological mechanism and microbial action mechanism of theδ13CDIC difference in the produced water from the multi-coal seams CBM wells.It also provides effective geochemical evidence for the superimposed fluid system controlled by sedimentary facies,and can also be used for the contribution analysis of the produced gas and water by the multi-layer CBM wells.