摘要:

The use of dual media filtration for treating Tigris River raw water is considered a new technique in Iraq. More than forty test runs employing different dual media filter configurations were conducted. A pilot plant designed to operate similarly to the full scale water treatment plant was used for this purpose.

ISSN:0360-1226    

DOI:10.1080/10934528909375467

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The parent aromatic hydrocarbon, benzene, has been and still is used in industry on a large scale, although the use of it is generally avoided because of its adverse health effects. Hence, it is still possible to come across a number of benzene intoxication cases, due to its technically inappropriate way of use.

ISSN:0360-1226    

DOI:10.1080/10934528909375468

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A method for the determination of lead in waters and sediments by electrothermal atomization atomic absorption spectrometry was developed. The method was applied to Lake Donner in California. Lead concentrations on the surface water were below the detection limit of 2.0 μg/L, at a depth of 14.5 feet were in the 35–41 μg/L range, and in the sediments were in the 0.012–0.032% range.

ISSN:0360-1226    

DOI:10.1080/10934528909375469

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Studies indicated that duckweed absorbed mercury in water (e.g. lakes) strongly and that after three days it contained up to 2000 ppm of mercury by weight of duckweed. The uptake of mercury was little affected by acidity at pH 4.0 and pH 5.0. The presence of copper ion suppressed the mercury uptake significantly. The presence of 1.0 mM EDTA in solution also suppressed the mercury uptake significantly. Further 10 mg of humic acid in 400 mL solution suppressed the mercury uptake to some degree, probably by complexing the mercury.

ISSN:0360-1226    

DOI:10.1080/10934528909375470

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0360-1226    

DOI:10.1080/10934528909375471

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Solutions (5 × 10‐5M) of humic‐like model compounds, chiefly, hydroxybenzoic and cinnamic acids, were tested for their ability to inhibit the growth of hydrilla (Hydrilla verticillataRoyle). This is a perennial, adventitious plant that has the ability to occupy the top meter of water in sub‐tropical and temperate zones and eliminate benthic or rooted plants through shading. Humic acid and a naturally occurring soils extract have the ability to inhibit the growth of this plant (total organic carbon 0.4 mg/L), and the humic‐like models were tested for comparison. None appeared to be as effective as the natural product. Chelation does not appear to be the explanation for inhibition, though there was a good negative correlation between the degree of growth inhibition and the pKAof the model compound.

ISSN:0360-1226    

DOI:10.1080/10934528909375472

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A systematic methodology for mathematically simulating photosynthetically driven DO variations in the mid‐Passaic River system is presented and discussed. A steady‐state model for BOD‐DO dynamics, calibrated and verified to data from two stream surveys conducted during the Summer and Fall of 1983, is first presented. Diurnal DO fluctuations due to algal photosynthetic activity are then simulated by Fourier series. The resultant models display good correlation to the data.

ISSN:0360-1226    

DOI:10.1080/10934528909375473

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Dry matter yield, heavy metals and Al accumulation by seven forage grasses, bermudagrass (Cynodon dactylon). Kentuckty 31‐tall fescue (Festuca arundinacea),oat (Avena sativa), orchardgrass (Dactylis glomerata),perennial ryegrass (Lolium perenne), triticale (×Triticosecale Wittmack) and winter wheat(Triticum aestivum) were investigated on three different Alabama acid mine spoils. The objective was to study the growth response (dry matter basis) and metal accumulation at different clipping dates to determine which grasses may be effectively used to lower metal levels in the acid spoils during reclamation. The grasses were clipped at 47, 58, 68 and 83 days after planting and dry matter yield and tissue levels of metals determined. Bermudagrass grew best on all spoils and clipping intervals did not generally influence dry matter yield and metal accumulation. The other grasses had late (oat only) or early restricted growth and were not considered effective for use in reclamation of spoils studied due to poor growth. The bermudagrass accumulated high total levels of Mn (when all 4 clippings were considered) and lower levels of Al compared to the other grasses. It is recommended as a good crop to lower metal levels on acid spoils similar to those used in this study before planting less tolerant but more economic crops and/or trees especially where liming of the spoils to reduce availability may not be feasible.

ISSN:0360-1226    

DOI:10.1080/10934528909375474

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0360-1226    

DOI:10.1080/10934528909375466

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor