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51.
A start‐up study for biohydrogen production from palm oil mill effluent (POME) is carried out in a pilot‐scale up‐flow anaerobic sludge blanket fixed‐film reactor (UASFF). A substrate with a chemical oxygen demand (COD) of 30 g L?1 is used, starting with molasses solution for 30 days and followed by a 10% v/v increment of POME/molasses ratio. At 100% POME, a hydrogen content of 80%, hydrogen production rate of 36 L H2 per day, and maximum COD removal of 48.7% are achieved. Bio‐kinetic coefficients of Monod, first‐order, Grau second‐order, and Stover‐Kincannon kinetic models are calculated to describe the performance of the system. The steady‐state data with 100% POME shows that Monod and Stover‐Kincannon models with bio‐kinetic coefficients of half‐velocity constant (Ks) of 6000 mg COD L?1, microbial decay rate (Kd) of 0.0015 per day, growth yield constant (Y) of 0.786 mg volatile suspended solids (VSS)/mg COD, specific biomass growth rate (μmax) of 0.568 per day, and substrate consumption rate of (Umax) 3.98 g/L day could be considered as superior models with correlation coefficients (R2) of 0.918 and 0.989, respectively, compared to first‐order and Grau's second‐order models with coefficients of K1 1.08 per day, R2 0.739, and K2s 1.69 per day, a = 7.0 per day, b = 0.847. 相似文献
52.
Philip L. Cadwallader 《新西兰海洋与淡水研究杂志》2013,47(1):101-103
Gravel occurred in. the stomachs of 17.8% of 924 Galaxias vulgaris and 2.8% of 430 Philypnodon breviceps taken from the Glentui River, Canterbury, between June 1970 and November 1971. It is suggested that differences in feeding habits and feeding locality are responsible for the difference in occurrence of gravel in the stomachs of the two fish species. Galaxias vulgaris feeds in the water column in riffles and, being a drift feeder, is more likely to ingest inedible material by accident than is P. breviceps, which feeds on the bottom in sheltered or quiet stretches of the river. 相似文献
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54.
Carla G. B. Brenner Carlos A. Mallmann Daniel R. Arsand Francieli M. Mayer Ayrton F. Martins 《洁净——土壤、空气、水》2011,39(1):28-34
In this work, an analytical methodological study was carried out to determine the antimicrobials sulfamethoxazole and trimethoprim, as well as their metabolites, in hospital effluent. The determinations were conducted by liquid chromatography tandem mass spectrometry using a hybrid triple quadrupole‐linear ion trap mass spectrometer (LC‐QqLIT‐MS). The data acquisition was made in selected reaction monitoring (SRM) mode, in which two SRM transitions were monitored to ensure that the target compounds were accurately identified by the information dependent acquisition (IDA) function. The limits of detection (LOD) and quantification (LOQ) were 0.25 and 0.80 µg L?1 for sulfamethoxazole and 0.15 and 0.50 µg L?1 for trimethoprim. The linear range for the SMX was 0.8–100.0 µg L?1 and TMP was 0.5–100.0 µg L?1 on the basis of six‐point calibration curves generated by means of linear regression analysis. The coefficients of the correlation were higher than 0.999, which ensured the linearity of the method. The average concentration of sulfamethoxazole and trimethoprim found in hospital effluent was 27.8 and 6.65 µg L?1, respectively. The analytical methodology employed allowed two metabolites to be identified, N4‐acetyl‐sulfamethoxazole and α‐hydroxy‐trimethoprim. Fragmentation pathways were proposed. 相似文献
55.
应用水文地球化学模拟和室内模拟耦合方法,对引起地热尾水回灌堵塞的问题进行研究。结果显示,回灌过程中化学结垢的主要类型为碳酸盐。影响碳酸盐堵塞的因素主要为温度、C02脱气、混合程度、pH以及矿化度。随着温度、pH、C02分压的增大CaC03结垢趋势增加;当360％的原水和40％的尾水混合时,CaC03的沉淀量达到最大;而矿化度的影响主要体现在盐效应和同离子效应。运用朗格利尔指数和雷兹诺指数对CaCO3沉淀程度进行计算,结果表明,在研究区内多数井中存在中低程度的CaCO3结垢。 相似文献
56.
Variations in phosphorus (P) speciation were compared for two types of pilot scale wetlands: a blast furnace slag‐based constructed wetland (SCW), and a gravel‐based constructed wetland (GCW). Synthetic secondary effluent was used as the influent of the wetlands, which contained 1.1 mg/L P with more than 95% present as soluble reactive P (SRP). However, dissolved organic phosphorus (DOP) and particulate phosphorus (PP) emerged in the water along both wetlands. The levels of these three P species varied between the two wetlands. The GCW was more efficient than SCW at removing SRP, but showed a different trend. SRP decreased continually in the SCW, while it increased at the end of the GCW due to biological release. DOP was constant in SCW and GCW, and the mean value was 0.023 and 0.020 mg/L, respectively. The mean values of PP in the GCW ranged between 0.093 and 0.216 mg/L; much higher than the 0.05 ± 0.01 mg/L measured in the SCW. Sequential extractions showed that iron bound PP (Fe‐PP), aluminum bound PP (Al‐PP), organic PP (Org‐PP) and occluded PP (Oc‐PP) were the major components of PP at most locations of the GCW. Fe‐PP decreased from 0.53 to 0.14 mg/L in the upper layer, with DO steady at about 0.15 mg/L at the bottom. Oc‐PP increased at each layer. Al‐PP and Org‐PP were steady in the first 140 cm of the GCW, but decreased sharply at the end. Considering the variation of SRP, DOP and PP fractionations, it can be seen that PP exchanged intensively with SRP in the GCW, and might act as an intermediate in the P removal process. Part of the SRP was first transformed into PP, and then absorbed by substrates or deposited in the wetlands. P removal was mainly via Ca precipitation in the SCW, but involved multiple mechanisms in the GCW, such as precipitation, adsorption and biological interactions. The multiple P removal mechanisms might be the reason for the low proportion of SRP, and the better P removal efficiency observed in the GCW. 相似文献
57.
Analyses of 67 samples collected from 25 bore wells and 42 dug wells in the basaltic aquifer at Tuppa, New Nanded, Maharashtra, India over a period of three years revealed that groundwater from this region shows higher content of TDS, Cl, TH, Ca, Mg and SO4 The geochemical characteristic of groundwater is related to pollution. The source of this pollution is effluent from industries. The effluent is discharged in a stream flowing through this area. The effluent is also discharged in the injection wells. The result of this is that pollutants have entered into the aquifer system and flowed farther in the eastern direction. The zone of pollution has an aerial extent of more than 38 km2. The values of molar ratios of effluent sample are either the same or a little higher than the samples from the polluted zone, suggesting that industrial effluent, probably, is the source of pollution in this region. The people from this region have already stopped using water from these polluted wells, which forms the only source of drinking water in the area. 相似文献
58.
污水渗滤土地处理系统中水力停留时间与出水效果的讨论 总被引：6，自引：0，他引：6
污水渗滤土地处理系统中，水力停留时间与出水效果之间的关系，直接涉及到系统的大小与出水效果之间的关系。一般认为各污染组分的去除率与水力停留时间之间符合一级反应动力学方程，从微生物生长动力学角度出发，就此问题做了进一步讨论。结果表明，各污染组分的出水浓度与水力停留时间之间的关系严格地说，是一处类指数关系，它实际是一条直线和一条负指数曲线叠加而成，而并非纯指数关系，实际应用结果表明，不同系统的处理效率可以通过一级反应速率常数KT进行对比评价。提高系统的处理效率可以围绕反映系统净化能力的综合指数KT，从提高系统内微生物活性的角度出发，以减小系统的占地及投资。． 相似文献
59.
Assessment of heavy metal accumulation in macrophyte, agricultural soil, and crop plants adjacent to discharge zone of sponge iron factory 总被引：1，自引：0，他引：1
The present study deals with the characterization of effluent released from sponge iron industries and distribution of heavy
metals in soil and macrophytes near to effluent discharge channel. Apart from this, accumulation of heavy metals in nearby
soil and vegetation system irrigated with effluent-contaminated water is also the subject of this study. Physico-chemical
analysis of effluent reveals that the concentration of total suspended solids (TSS), total hardness (TH), iron (Fe2+), and oil and grease are greater than the IS (1981) norms for discharge of water into inland water body. The soil along the sides of the effluent channel also shows higher
concentration of heavy metals than the background soil. The enrichment of the heavy metals are in the order of Chromium (Cr) > Iron
(Fe) > Manganese (Mn) > Zinc (Zn) > Copper (Cu) > Cadmium (Cd). Macrophytes growing along the sides of the effluent channel
also show significant accumulation of heavy metals almost in the same order as accumulated in soil. Higher uptake of heavy
metals by these varieties reveals that these species can be used for future phytoremediation. The effluent as well as contaminated
water is extensively used for irrigation for growing vegetables like tomato (Lycopersicon esculatum) in the surrounding areas. Heavy metal accumulation in this agricultural soil are in the sequence of Cr > Fe > Mn > Zn > Cu > Cd.
More or less similar type of accumulation pattern are also found in tomato plants except Fe and Zn exceeding Cr and Mn. Transfer
Factor of heavy metals from soil to tomato plants (TFS) shows average value of <1, suggesting less uptake of heavy metals from soil. Among the plant parts studied, fruit shows
least accumulation. Although tomato plants show some phenotypic changes, the survival of tomato plants as well as least accumulation
of metals in fruit reveals their tolerance to heavy metals. Therefore it may be suggested that this plant can be grown successfully
in the heavy metal contaminated soil. Further research work on in situ toxicity test will be necessary in order to identify
the most resistive variety on this particular type of contaminated site. 相似文献
60.
厌氧氨氧化工艺及其应用前景 总被引：1，自引：0，他引：1
阐述厌氧氯氧化工艺的原理、发展过程、主要特点，并从工艺的先进性、适用性和可行性方面等对工艺的应用前景进行了探讨。对工艺中存在的问题也提出了相应的改进措施及建议。 相似文献