Drainage waters

Water clarification Water, cooling Water desalination Water dispersions Water drainage Water fastness Water fluoridation... 

Bacterial remediation of selenium oxyanions in San Joaquin, California, drainage water is under active investigation (96,97), but has not yet been commercialized. Agricultural drainage rich in selenium is also typically rich in nitrates, so bioremediation must also include conditions that stimulate denitrification (98). Phytoextraction of selenium is also being tested, but is not yet being used on a large scale. 

Because gravity is too weak to be used for removal of cakes in a gravity side filter (2), continuously operated gravity side filters are not practicable but an intermittent flow system is feasible in this arrangement the cake is first formed in a conventional way and the feed is then stopped to allow gravity removal of the cake. A system of pressure filtration of particles from 2.5 to 5 p.m in size, in neutralized acid mine drainage water, has been described (21). The filtration was in vertical permeable hoses, and a pressure shock associated with relaxing the hose pressure was used to aid the cake removal. 

Examples of nir analysis are polymer identification (126,127), pharmaceutical manufacturing (128), gasoline analysis (129,130), and on-line refinery process chemistry (131). Nir fiber optics have been used as immersion probes for monitoring pollutants in drainage waters by attenuated total internal reflectance (132). The usefulness of nir for aqueous systems has led to important biological and medical appHcations (133). 

Drainage water from copper affects zinc in a similar way. Zinc sheets must never be fixed with copper nails, nor should copper roofs drain into zinc or galvanised gutters. Copper lightning arrestors provide further potential hazards to zinc work when a copper lightning strip has to pass over or near a zinc roof, it should be either well insulated or heavily tinned. 

Lee RW, Glater J, Cohen Y, Martin C, Kovac K, Milobar MN, Bartel DW (2003) Low-pressure RO membrane desalination of agricultural drainage water. Desalination 155(2) 109-120... 

Harrison RM, Radojevic M, Wilson SJ. 1986. The chemical composition of highway drainage waters IV. Alkyl lead compounds in runoff waters. Sci Total Environ 50 129-137. 

Macy, J. M., Lawson, S., and DeMoll-Decker, H., Bioremediation of Selenium Oxyanions in San Joaquin Drainage Water Using Thauera selenatis in a Biological Reactor System, Appl. Microbiol. Biotechnol., 40 588 (1993)... 

Foams for woodland and grass fire-fighting have been developed with low drainage (water loss from foam) and high expansion (volume of foam per volume of starting liquid), two parameters traditionally considered to be inversely proportional. The stabilizing additive is poly (methyl vinyl ether/maleic anhydride), thought to cross-react with fatty alcohol components of the foam base via the anhydride function. 

In this chapter we construct geochemical models to consider how the availability of oxygen and the buffering of host rocks affect the pH and composition of acid drainage. We then look at processes that can attenuate the dissolved metal content of drainage waters. 

In the calculation, reaction of 1 cm3 of pyrite consumes about 3.4 cm3 of calcite, demonstrating that considerable quantities of buffering minerals may be required in mineralized areas to neutralize drainage waters. 

As pH rises, the metal content of drainage water tends to decrease. Some metals precipitate directly from solution to form oxide, hydroxide, and oxy-hydroxide phases. Iron and aluminum are notable is this regard. They initially form colloidal and suspended phases known as hydrous ferric oxide (hfo, FeOOH n O) and hydrous aluminum oxide (HAO, AlOOH nH.2O), both of which are highly soluble under acidic conditions but nearly insoluble at near-neutral pH. 

To see how this process works, we construct a model in which reaction of a hypothetical drainage water with calcite leads to the precipitation of ferric hydroxide [Fe(OH)3, which we use to represent HFO] and the sorption of dissolved species onto this phase. We assume that the precipitate remains suspended in solution with its surface in equilibrium with the changing fluid chemistry, using the surface com-plexation model described in Chapter 10. In our model, we envisage the precipitate eventually settling to the stream bed and hence removing the sorbed metals from the drainage. 

Fig. 31.5. Minerals formed during reaction at 25 °C of a hypothetical acid drainage water with calcite (top), and fractions of the amounts of arsenite, arsenate, copper, lead, and zinc present initially in solution that sorb onto ferric hydroxide over the course of the reaction path (bottom). Bottom figure is plotted against pH, which increases as the water reacts with calcite.

Saiki, M.K. and T.P. Lowe. 1987. Selenium in aquatic organisms from subsurface agricultural drainage water, San Joaquin Valley, California. Arch. Environ. Contamin. Toxicol. 16 657-670. 

Skorupa, J.P. and H.M. Ohlendorf. 1991. Contaminants in drainage water and avian risk thresholds. Pages 345-368 in A. Dinar and D. Zilberman (eds.). The Economics and Management of Water and Drainage in Agriculture. Kluwer Acad. Publ., Boston. 

Fig. 1. Map of Ruttan mine site showing the drainage trenches in the tailings and flow direction of drainage water.

In forest ecosystems these symbols stand for CL(M) is critical load of a heavy metal (g ha-1 a-1) Mu is metal net uptake in wood biomass under critical loads conditions (g ha-1 a 1) Mle(crit) is critical leaching flux of metal with drainage water (from the uppermost 10 cm soil layer) (g ha-1 a-1). 

Ecosystem functioning Free metal ion concentration in soil solution re-calculated to total dissolved metal concentration in soil drainage water (in view of effects on soil microorganisms, plants and invertebrates) 1.7-20.4 1.3-3.2 ... 

Soil-related data (HM and BC content in soil parent materials) were included in calculations to account the values of HM weathering. Also we considered the influence of soil types on forest biomass productivity. Runoff data (at scale 0.5 x 0.50 were directly used to get input data on drainage water fluxes, Qie. Forest-type-related data (wood biomass growth and HM content in wood biomass) inserted into our database were subdivided depending on either coniferous, deciduous or mixed forests. 

Critical Loads of Heavy Metals Depending on ERA Endpoints The ecosystem characteristics of case study plots in various natural forests of the European part of Russia are shown in Table 4. Critical loads in an occasion of human health and ecotoxicological effects on biota (endpoints) have been accounted. Corresponding critical limits of HM concentration in soil drainage waters are presented in Table 1. 

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