葡萄花油田注入水杀菌剂的筛选及应用效果

介绍了葡萄花油田注入水杀菌剂的室内筛选实验，对杀菌剂与各水质处理站注入水的配伍性及杀菌效果进行筛选，有效提高葡萄花油田注水水质，防止管道堵塞、腐蚀，提高注水量，保证油田的连续生产。     

Application of bacteria involved in the biological sulfur cycle for paper mill effluent purification

In anaerobic wastewater treatment, the occurrence of biological sulfate reduction results in the formation of unwanted hydrogen sulfide, which is odorous, corrosive and toxic. In this paper, the role and application of bacteria in anaerobic and aerobic sulfur transformations are described and exemplified for the treatment of a paper mill wastewater. The sulfate containing wastewater first passes an anaerobic UASB reactor for bulk COD removal which is accompanied by the formation of biogas and hydrogen sulfide. In an aeration pond, the residual COD_organic and the formed dissolved hydrogen sulfide are removed. The biogas, consisting of CH₄ (80-90 vol.%), CO₂ (10-20 vol.%) and H₂S (0.8-1.2 vol.%), is desulfurised prior to its combustion in a power generator thereby using a new biological process for H₂S removal. This process will be described in more detail in this paper. Biomass from the anaerobic bioreactor has a compact granular structure and contains a diverse microbial community. Therefore, other anaerobic bioreactors throughout the world are inoculated with biomass from this UASB reactor. The sludge was also successfully used in investigation on sulfate reduction with carbon monoxide as the electron donor and the conversion of methanethiol. This shows the biotechnological potential of this complex reactor biomass.     

Biodegradation of nonylphenol polyethoxylates under sulfate-reducing conditions

Biodegradation behavior of nonylphenol polyethoxylates (NPEOs) under sulfate-reducing conditions was investigated. The results showed that NPEOs were readily degraded under sulfate-reducing conditions. These compounds were degraded via sequential removal of ethoxyl units to nonylphenol (NP) without forming carboxylated intermediates under sulfate-reducing conditions. The biodegradation of NPEOs under sulfate-reducing conditions was not inhibited even at very high initial concentrations of NPEOs. The maximum removal rate increased about 1.3 microM d(-1) for each 10 micromol increase in initial concentration. The decrease in temperature caused a sharp decrease in the removal efficiency of NPEOs. The temperature coefficient (Phi) for the biodegradation of NPEOs under sulfate-reducing conditions was 0.008. Severe accumulation of NP and short-chain NPEOs occurred when most NPEOs were removed and this accumulation led to an increase in the estrogenic activity. The highest estrogenic activity appeared on day 21 when the total concentration of these metabolites reached its top (18.03+/-4.73 microM). NP could inhibit the biodegradation of NPEOs under sulfate-reducing conditions only at relatively high concentration. These findings are of major environmental importance in terms of the environmental behavior of NPEO contaminants in natural environment.     

岭澳核电站二期凝结水处理系统重大技术改进

针对大亚湾和岭澳核电站一期凝结水处理(ATE)系统投运后蒸汽发生器(SG)中SO_4~(2-)明显增高并超标等问题,对岭澳核电站二期ATE系统中的前置阳床和氢型混床的尺寸、布水装置以及离子交换树脂和分离装置等进行了重大的技术改进,提高了混床离子交换的效果,减少了因强酸阳树脂在混床底部溶出硫酸根和碎树脂漏入热力系统,而降解分离出硫酸根进入SG的可能性,确保和改善了SG的水-汽品质.     

Effects of thaumasite on bond strength of reinforcement in concrete

The conditions necessary for the formation of thaumasite are well known and much work is in progress to identify concrete mixes resistant to thaumasite form of sulfate attack (TSA). However, there have been no data to indicate how TSA affects the nature and strength of the bond between reinforcement steel and concrete and hence the load capacity of reinforced concrete elements.

During works to repair and strengthen the thaumasite-affected Tredington–Ashchurch Overbridge in Gloucestershire, sections of column were removed and placed in storage. These column sections presented an opportunity to perform pullout tests on full size TSA-affected structural elements and unaffected control specimens from the same structure. In total 63 pullout tests were performed on plain round reinforcement bars embedded in two unaffected and four TSA-affected reinforced concrete elements. The sections were also characterised in terms of estimated in situ cube strength and depth of softened zone.

A statistical analysis of the experimental results indicates that the bond of the plain round reinforcement bars in the unaffected concrete exceeded that of the plain round reinforcement bars in the TSA-affected concrete. TSA reduced the mean experimental bond coefficient by 24% for corner bars and 10% for other bars, representing an average reduction in mean experimental bond coefficient of 15% for all bars.     

硫酸盐还原菌生物膜下钢铁腐蚀研究概况

本文从菌种的分离,提纯,活化及初步鉴定,生物膜与腐蚀的关系,生物膜下细菌腐蚀机理,与生物膜有关的测量方法,生物膜检测及控制等方面介绍了硫酸盐还原菌生物膜对钢铁文化馆的研究概况。     

Effects of altered groundwater chemistry upon the pH-dependency and magnitude of bacterial attachment during transport within an organically contaminated sandy aquifer

The effects of a dilute (ionic strength = 5 × 10⁻³ M) plume of treated sewage, with elevated levels (3.9 mg/L) of dissolved organic carbon (DOC), upon the pH-dependency and magnitude of bacterial transport through an iron-laden, quartz sand aquifer (Cape Cod, MA) were evaluated using sets of replicate, static minicolumns. Compared with uncontaminated groundwater, the plume chemistry diminished bacterial attachment under mildly acidic (pH 5.0-6.5) in-situ conditions, in spite of the 5-fold increase in ionic strength and substantively enhanced attachment under more alkaline conditions. The effects of the hydrophobic neutral and total fractions of the plume DOC; modest concentrations of fulvic and humic acids (1.5 mg/L); linear alkyl benzene sulfonate (LAS) (25 mg/L); Imbentin (200 μg/L), a model nonionic surfactant; sulfate (28 mg/L); and calcium (20 mg/L) varied sharply in response to relatively small changes in pH, although the plume constituents collectively decreased the pH-dependency of bacterial attachment. LAS and other hydrophobic neutrals (collectively representing only ∼3% of the plume DOC) had a disproportionately large effect upon bacterial attachment, as did the elevated concentrations of sulfate within the plume. The findings further suggest that the roles of organic plume constituents in transport or bacteria through acidic aquifer sediments can be very different than would be predicted from column studies performed at circumneutral pH and that the inorganic constituents within the plume cannot be ignored.     

A pilot-scale evaluation of magnetic ion exchange treatment for removal of natural organic material and inorganic anions

The objective of this research was to evaluate a magnetic ion exchange process (MIEX) for the removal of natural organic material (NOM) and bromide on a continuous-flow pilot-scale basis under different operating conditions and raw water characteristics. The most important operating variable was the effective resin dose (ERD), which is the product of the steady-state resin concentration in the contactor and the regeneration ratio. The raw water employed in this study had a moderate concentration of ultraviolet (UV)-absorbing substances and dissolved organic carbon (DOC), and a low turbidity, alkalinity, and concentration of competing anionic species. Experiments were conducted using the ambient raw water and raw water spiked with bromide, chloride, and sulfate. Substantial removal of UV-absorbing substances and DOC was achieved at ERDs as low as 0.16mL/L. Moderate bromide removal was achieved, depending on the ERD. Increasing the sulfate concentration resulted in decreased removal of UV-absorbing substances, DOC, and bromide. Consistent results were observed between the continuous-flow pilot plant tests and batch equilibrium studies.     

Characterisation of acid mine drainage in a high rainfall mountain environment, New Zealand

The Stockton coal mine lies at 700-1100 m above sea level in a mountainous orographic precipitation zone on the West Coast of the South Island of New Zealand. Rainfall exceeds 6000 mm/year and arrives with frequent flood events that can deliver > 200 mm/day. Streams vary in discharges by up to two orders of magnitude over a time scale of hours. Pyritic waste rock at the mine interacts chemically with even the most intense rainfall, and almost all runoff is acidic to some degree. In the most intense rain event recorded in this study (> 10 mm/hour), dilution of acid mine drainage (AMD) occurred and pH rose from 3 to > 5 over several hours, with stream discharge at a monitoring point rising from < 0.5 to > 100 cumecs. However, most rain events of similar magnitude are less intense, longer duration, and only raise AMD pH to ~ 4 with similar high discharges. Results presented here for Stockton confirm that it is the intensity of rain events on the hourly scale, rather than the total amount of rainwater delivered to the site, that governs the amount and composition of AMD generated during flood events. Stream discharge loads of dissolved iron and aluminium range from ~ 20 to 1000 kg/hour. Dissolved sulfate and acidity loads are typically ~ 500 kg/hour but can exceed 20 tonnes/hour in rain events.First flush effects observable elsewhere around the world involving peak metal loads following dry periods or seasonal changes are not obvious at Stockton due to the high and variable rainfall environment. Dissolved Fe concentrations may be limited in runoff waters by precipitation of jarosite and schwertmannite, especially when rainfall is sufficiently intense to raise pH to 4 or higher. These minerals are widespread in the exposed waste rock on site. Likewise, precipitation of alunite may occur as pH rises in rain events, but no field evidence for this has been observed.     

Effects of chloride and sulfate on the rate of oxidation of ferrous ion by H2O2

The rates of oxidation of Fe(II) by H(2)O(2) in the presence of sodium perchlorate, sodium nitrate, sodium chloride and sodium sulfate salts (0-1M) have been compared in the study. Experiments were carried out in a batch reactor, in the dark, at pH <3, 25+/-0.5 degrees C and at controlled ionic strength (< or =1M). The experimental results showed that the rates of oxidation of Fe(II) in the presence of chloride, nitrate and perchlorate were identical. In the presence of sulfate, the rate of oxidation of Fe(II) was faster and depended on the pH and the concentration of sulfate. The pseudo second-order rate constants for the reaction of H(2)O(2) with Fe(2+), FeCl(+) and FeSO(4) were determined as 55+/-1, 55+/-1 and 78+/-3 M(-1) s(-1), respectively.