How does spirogyra get rid of waste

Subsequently, the algal strands consume oxygen for cellular respiration and produce carbon dioxide as a waste product. A spirogyra is plant-like because of the presence of chlorophyll which allows it to make its own food. Life cycle of Spirogyra is haploidic where the haploid vegetative filament represents a prolonged gametophyte generation and the brief sporophyte phase is represented by diploid zygospore zygote.

Spirogyra gets its food through photosynthesis. Predators are mayflies, midges, stoneflies, and other aquatic insects eat that algae, either living or in detritus. Spirogyra lives in freshwater habitats. It grows in fresh eutrophic water, water rich in nutrients. Some species of Spirogyra are used as a source of food in different parts of the world as they are rich in vitamins and minerals.

Green algae like Spirogyra are also an important part of the aquatic ecosystems as they are photosynthetic and thus provide oxygen to other organisms in the water. Spirogyra is named for the spiral arrangement of its chloroplasts. Its cylindrical cells connect end to end in long green filaments.

Cyanobacteria are bacteria that obtain their energy through photosynthesis. Small spherical heterocysts are present amongst the Rivularia filaments.

Spirogyra is a genus of green algae of the order Zygnematales. Spirogyra have a sprial arrangement of chloroplasts and are commonly found in fresh water ponds. The chloroplasts are ribbon shaped and usually arranged spirally, which results in the prominent characteristic green spiral on each filament. Their photosynthetic pigments are more varied than those of plants, and their cells have features not found among plants and animals.

Some protists are autotrophic, others are heterotrophic. Recall that autotrophs make their own food through photosynthesis or chemosynthesis see the Photosynthesis concepts. Photoautotrophs include protists that have chloroplasts, such as Spirogyra. Heterotrophs get their energy by consuming other organisms. The life cycle of Volvox is haplontic, i.

Volvox are among the most abundant creatures on Earth, growing wildly in lakes, puddles, and even aquariums. Just barely visible as a pale green dot to the human eye, under a microscope volvox look like hollow green spheres. Eight plates of illustrations in color together with photo- graphs, line drawings, the key, and descriptions are in- cluded for use as aids in the identification of the signifi- cant forms.

Six of the color plates of important algae are the work of artist-biologist Harold J. Walter, and were done under supervision of the author 16, The orig- inal six paintings are on display at the U.

Environmental Research Center in Cincinnati, Ohio. Figure 7. Figure 3. Figure 4. Figure 5. Figure 8. Figure 9. Figure Figure 6. The line drawings which are included as fig- ures throughout the manual were made by the writer and published previously in two taxonomic papers 18, The eight plates of algae in color represent four gen- eral areas of concern for plant operators; namely, water pollution, water treatment, sewage treatment, and water reservoirs.

Taste, odor, and filter clogging are the most troublesome problems faced by many operators in water treatment plants. In connection with water pollution, natural stream purifica- tion, and sewage treatment, the significant algae are those whose growth or survival is closely related to the amount and composition of sewage and other organic wastes in the water. Plates III and IV illustrate the contrasting fresh- water groups of clean water and polluted water algae. In the reservoirs and settling basins of water supply systems are encountered the drifting, swimming, and attached growths of algae which can become troublesome in the raw water and can cause nuisance conditions in the treat- ment plant.

Plates I and II illustrate respectively the plank- tonic and mat-forming algae of surface waters and the algae attached to the sides of reservoirs and settling bas- ins. Algae in water of high organic content are illustrated in plates IV, V, and VI, the fourth and fifth contrasting the algae associated with pollution of fresh and estuarine waters. The algae as illustrated on the plates are not shown in actual or relative size. Some of the forms illustrated are so minute as to be visible only under very high magnifi- cation of a compound microscope.

Other forms are large enough to be seen under lower magnification or even with the unaided eye. Thus, rather than having the same draw- ing scale for all of the algae, each is enlarged sufficiently to make clear its own particular characteristics. The mag- nification for each drawing is given with the species name in the list accompanying each plate. The eight color plates contain illustrations of of the algae referred to in this manual. Drawings and photo- micrographs of some other forms are also included in the manual as noted earlier.

The paintings and the drawings were prepared in such a way as to emphasize the char- acteristics most helpful in the identification of unstained material in water samples.

While illustrations may be a real aid in recognizing the various kinds of algae, an identification key is essential for distinguishing the many genera and species encountered. An original key, limited to the algae selected as most im- portant in water supplies, has therefore been prepared for this manual. Since many other algae may be associ- ated with these forms in the water, the supplementary use of additional treatises on algae would help to assure the greater accuracy in identifying the specimens.

When acquainted with the nature of an identification key, an observer can make direct use of the device in de- termining the name of a particular form whose essential characteristics have been determined through study under a microscope. It is necessary, therefore, to know the es- sential characteristics which must be observed in any specimen before the key is used for its identification. The essential characteristics are considered under the follow- ing headings: 1, gross structure of the alga, including shape, size, and cell grouping; 2, cell structure; 3, spe- cialized parts of cells; 4, specialized parts of multicellular algae; and 5, measurements.

Hundreds of genera of algae are unicellular. Colonies in the form of threads filaments where the cells are arranged in a simple linear series or chain are distinctive and very common fig.

The threads may be isolated, or obviously grouped together as in Symploca fig. The branches may be attached to the primary thread singly alternate , in pairs opposite , or in groups of more than two whorled.

Microthamnion fig. II have alternate branching; Stigeodonium pi. II has, in part, opposite branching; and Chara pi. II has whorled branching. Chaetophora and Phormidium on plate II have filaments grouped together into larger growths. In a few cases the alga may be in the form of a con- tinuous, sometimes branching tube with no cell walls to divide the material into distinct units or cells.

The tube is described as being nonseptate having no transverse walls. Botrydium fig. In others such as Hydryrus fig. A few freshwater algae have cells forming dense, mas- sive strands, the strands being from a few to many cells thick and with central and marginal peripheral cells which differ from one another. Finally, a limited number of algae have cells arranged to form a flat or bent membrane, as indicated by Hildenbrandia on plate III.

In summary, the gross structural forms encountered among the algae include the unicell, colony, filament, tube, strand, and membrane. Within the protoplast, one or more separate bodies of green, yellow- green, brown, or some other color may be present. These are known as plastids or chromatophores.

In the blue- green algae Myxophyceae the pigments are not localized in plastids but are distributed throughout the whole proto- plast.

Some of the protoplasts may contain bodies other than plastids, such as nuclei, crystals, starch grains, oil droplets, called sap vacuoles, and spherical pyrenoids around which minute grains of starch collect.

The nucleus of the cell is present in all but the blue-green al- gae but seldom referred to in the manual, because it is colorless and difficult to observe without staining or other special treatment of the material. The walls of algal cells are commonly a thin, rigid mem- brane which is in contact with the outer edge of the proto- plast and completely surrounds it. Some of the swimming algae, such as Euglena on plate I, do not have a rigid wall and their protoplasts are therefore somewhat flexible, making them changeable in form.

In the green algae the cell wall is semirigid and composed of cellulose. In dia- toms the wall is very rigid and composed principally of silica that is sculptured with a regular, even pattern of lines and dots as illustrated by Diatoma and Nevicula on plate VIII. The outer matrix, when present, tends in most cases to be flexible, colorless, gelatinous material which has been secreted through the cell wall. It often changes with age to become pigmented, to show stratification, and to de- velop a semirigid surface membrane.

In most cases it as- sumes a form and structure characteristic for the particular alga of which it is a part. In Botryococcus pi. I its brown color partially hides the green plastids within the proto- plasts.

In Gonium pi. I it forms a sphere. Lyngbya and Tolypothrix on plate II and Microcoleus fig. Some cells have a gelatinous stalk, one end of which is attached to the cell and the other to some other object. Gomphonema and Achnanthes on plate II are shown with stalks. In many cases the cell may become detached from the stalk very readily.

Gompho- nema on plate IV is illustrated without the stalk, although it is generally present in this genus. Knobs or spines may be found extending from the cell wall, or the cells may have sharp spine-like ends. Knob-like swellings on the cell wall are shown on the large cell of Chlorococcum on plate IV.

Swimming motile cells are often supplied with one, two, or occasionally more than two flexible, whip-like hairs known as flagella, extending from the front anterior , side lateral , or back posterior of the algal cell. Lateral flagella are found in Merotrichia fig. A reduction in the illumination of the microscope field may help in making the flagella singular, flagellum visible.

Swimming cells may also con- tain a single, small, red or orange body called an eye spot in the protoplast. This eye spot is generally located near the anterior end. Several special terms are required in the description of a diatom cell. The wall frustule of the diatom is com- posed of two approximately equal halves, the one, like a cover epitheca , fitting with its edge over the edge of the other hypotheca.

When the cell is lying in the micro- scope field so that these overlapping edges are visible, the diatom is said to be presenting its girdle view. If the cell is lying so that the top of the epitheca or bottom of the hypotheca is visible, the diatom is said to be present- ing a valve view. In Gomphonema on plate II the left hand cell is in girdle view and the right hand cell is in valve view. These views are shown together in Gompho- nema on plate IV.

When diatom cells are fastened to- gether into a filament or ribbon, it is the valve surfaces which are attached together, so that the diatoms in the colony are always seen in their girdle view. Thus, the two attached cells in Diatoma on plate VIII present the girdle view while the isolated cell to the left is shown in valve view.

In diatoms the wall markings and partial partitions, par- ticularly those visible in the valve view, are important in identification. The many fine lines or lines of dots punc- tae extending from the edge of the valve toward the center are known as striae, or when thicker, as costae. There may also be a longitudinal line called a raphe or true raphe extending from one end of the cell to the other but broken in the middle. If there is merely a clear space with no striae crossing it rather than a longitudinal line, the space is known as a false raphe or pseudoraphe.

Motile diatoms generally have a true raphe which is ap- parently associated with their ability to swim or crawl. Partial wall-like partitions are called septa and extend lengthwise or crosswise into the protoplast. They appear as coarser lines than the striae. Both diatoms have a true raphe.

The former also has transverse septa. Longitudinal septa are seen in the girdle view of Tabellaria on plate VIM. There are two major groups of diatoms, those circular in valve view, with radiating striae, and those elongate in valve view, with striae that tend to be transverse.

The former are known as centric diatoms, and the latter as the pennate diatoms. The end cells may be essentially the same as other cells of the filament, or there may either be a gradual or an abrupt decrease in width attenuation to a point or even to a long spine or hair. On plate II, Cladaphora and Lyngbya have terminal cells essentially like others in the filaments while Stigeoclonium shows gradual and Bulbochaete, abrupt attenuation.

Some of the filaments of blue-green algae have terminal cells which are swollen capitate or covered with a thick, cap- like or conical membrane calyptra. Some multicellular blue-green algae also have occasional special cells associated with the normal ones. One type, the heterocyst, generally is swollen, has a clear, color- less protoplast, and a thick wall with a knob-like thicken- ing on the inside at the place or places where the cell is connected to the adjacent cell or cells.

Another specialized cell, the resting spore akinete , is swollen, has a dense, granular protoplast and a thick wall. A number of other specialized cells may be encoun- tered in some of the algae, but these are too varied or too infrequently found to be dealt with here in detail. Many are reproductive cells figs. In some forms the sexual reproductive cells must be present before identi- fication of particular species can be made. These struc- tures are well described in other references 1,2.

A peculiar type of branching of filaments found in cer- tain blue-green algae requires explanation. It is called false branching and is formed when a thread of cells splits crosswise. One or both segments break through the sur- rounding sheath at this point and a portion moves out to the side of the original thread, thus giving the appearance of branching.

It is one one-thousandth of a millimeter or approximately one twenty-five thousandth of an inch. A linear scale on a glass disc ocular micrometer which can be placed on the interior shelf diaphragm of a microscope eye piece ocular can be calibrated in microns with the aid of a stage micrometer. The ocular micrometer can then be used to obtain measurements of algae. A Whipple microm- eter, used in plankton counting, can also be calibrated in microns and thus serves in a similar manner.

Example No. Unicellular or in loose irregular colonies; cell spherical; no outer matrix; no projections or markings on the wall; protoplast with one cup-shaped, green plastid, filling most of the cell; one prominent pyrenoid in side or base of plastid; no great variation in size of cells; diameter of cells microns. Short cy- lindrical cells in simple filaments which are aggregated to form a mat, with formless gelatinous matrix between them; ends of filaments rather abruptly attenuate, bent, capitate, and with a conical calyptra; protoplasts homo- geneous, blue-green throughout, no plastids; no hetero- cysts or akinetes.

Numerous cells united side by side into a ribbon; contact of adjacent cells is continuous from one end of cell to the other; cells with fine transverse striations in the wall but absent in a wide band across the center; pseudoraphe present, septa absent; valve view narrowly elliptical but with sides paral- lel much of the way; end capitate; girdle view rectangular; protoplast with two brown linear plastids, one on each side; cell length, microns.

Unicel- lular; protoplast with two brown lateral plastids and an- terior red eye spot; protoplast surrounded by a brown spherical lorica with internal swelling at posterior end and an opening surrounded by a thickened ring at anterior end through which extends one flagellum that is about twice as long as the lorica; cell very small, diameter of lorica 6 microns.

Referring to the key, lines 1a and 1b at the beginning are then com- pared to one another and with the essential characteristics of the specimen. At the end of the line which agrees with the specimen is a number. Turn to the place in the key where this same number is listed on the left hand side of the page and is divided into lines a and b.

Repeat the above process and continue until a name for the alga rather than an additional number is given at the end of the line. Thus, in determining the name of Example No.

The appro- priate lines are as follows: 1b, 2b, 3b, b, b, b, b, b, b, b, b, b, b, b, b, b, b, b, b, b, b, b, b, b, b, b, b Chlorella pyrenoidosa. Three manuals on algae in water supplies have been published abroad, one in Dan- ish 20 , one in Japanese 21 , and one in German TABLE 1. The fresh-water algae of the United States. McGraw-Hill, N. A treatise on the British freshwater algae. New and revised ed. West and F.

Press, Cambridge, England, p. Revision of the coccoid Myxophyceae. Drouet and W. The Characeae of Indiana. Fay K. Nomenclatural changes in two genera of diatoms. Ruth Patrick. Notulae Naturae, Acad. Natural Sci.

Philadelphia, No. Synopsis of North American Diatomaceae. Part II, Naviculatae, Surirellatae. Philadelphia The genus Euglena. Mary Gojdics. Press, Madison, Wise.

The algae of Illinois. Tiffany and M. A preliminary study of the algae of northwestern Minnesota. Minnesota Acad. Algae of the western Great Lakes area.

Cranbrook Inst. Bacillariophyta Diatomeae. Heft 10 in A. Pascher, Die Susswasser-Flora Mitteleuropas. Gustav Fisher, Jena, Germany, p. The marine and fresh-water plankton.

State Univ. Press, East Lansing, Mich. Revision of the classification of the Oscillatoriaeceae. Monograph 15, Acad. Philadelphia, p. Revision of the Nostocaceae with cylindrical trichomes.

Hafner Press, Riverside, N. Algae of importance in water supplies. Plans for a manual with keys and color plates. News Bull. Palmer and C. Public Wks. With 6 color plates. Algae of Marion County, Indiana.

A description of thirty-two forms. Additional records for algae, including some of the less common forms.

Dansk Planteplankton. The easy classification of important microorganisms in Japanese water supplies. Japanese Waterwks. In Japanese. Das Phytoplankton des Susswassers. Band 16, Teil In Die Binnengewasser by A. Schweizer- bart'sche Verlagsbuchhandlung, Stuttgart, Germany. Alga name. Plate number or figure number. Achnanthes: D 59 lanceolata microcephala II minutissima Achnanthidium breviceps var. YG YG BG C,PE. G PE,SP BG PI BG PI A. Fl SP The flow of water in a stream is constantly subjecting any area to a passing mass of water causing all ingredients to be resupplied to that area from the water upstream.

Turbulence in a stream is almost al- ways sufficient to prevent the formation of stratification such as we find in lakes. This is one of the most important differences between a stream and a lake. Even when a river is deep, there tends to be a condition of complete circulation 1.

The stream bottom affects the condition of the water constantly and in many ways. It is releasing or receiving materials from the water, including silt, min- erals, alkalies, acids, nutrients, and living or dead organ- isms or organic debris. The exchange of materials varies with the geologic nature of the bottom, the depth and rate of flow of the water, the temperature, and other factors. A stream also contains a mixture of the waters from its trib- utaries, which may often be quite different from one an- other.

Contours of the stream channel change from place to place; shallow flowage and backwater alternate with swift water and with deep pools. Current velocities vary. Different geological formations may follow one another in quick succession. Clean, hard bottoms may give way to soft mud deposits and vice versa. Wastewaters from hu- man habitations and industries bring about sudden and often catastrophic changes.

Stream levels rise and fall ac- cording to the amount of rainfall 2. Thus, conditions in a stream tend to be very unstable at any location, in this way also making it different from a lake. Streams are rarely entirely destitute of raw materials, as may be the case in some lakes, and probably on the whole are better supplied with nitrogenous compounds 3. Streams undefiled by anything other than natural enrich- ment will contain at most only a few ppm of CO2.

This is one of the reasons why they fail to develop large crops of algal growths 2. There is little correlation between the seasonal flux in chemical conditions and the seasonal con- dition of plankton production. Stream temperature affects plankton profoundly. Light is as important in streams as it is in lakes, but light in streams may more often be reduced due to greater turbidity.

Tur- bidities of more than 30 ppm are high enough to cut off sunshine almost completely except for a shallow layer very close to the surface 2. Although some plankton occur even in very muddy streams, turbidity usually seems to be the major limiting factor in algal growth 4. Wind action appears to be of little significance in streams. Area and depth of a stream show little relation to plankton produc- tion 2. Speed of the current and the nature of the bot- toms are the factors which most affect the plants and animals of a stream.

But for most organisms, small, local variations, such as the difference in the current at the edge and in the middle of the stream, are more important than the general condition 5.

Attached algae in fast currents take full advantage of the water in their reproduction. Due to the mixing caused by the current, these algae are able to disperse their re- productive units into a high percentage of rock fissures, cracks, scratches, and roughened areas to permit subse- quent growth from the colonizing cells to cover almost all of the available surfaces.

The complete stream has three horizontal areas: 1. The upper or mountain course, with swift current, especially after a rain. Stones are rolled along the bottom. Its valley is V-shaped, with unstable banks. However, some streams may arise instead from springs, lakes, or from drainage of low-lying land. The middle course is located over the foothills. It has lost some of its velocity but is still rapid enough to carry sand, silt, and mud in suspension and to roll pebbles.

Its main work is transportation. Its valley has a broad, open section, stable sides, and less erosion than in the first area. The lower course meanders lazily over a plain. It has lost much of its velocity and much of its power of transportation. It lays down part of its load as beaches, sand banks, and large flat plains of deposition, spreading aluvium over a wide flood plain or delta 5. The algae, especially of swift running streams, are more distinctive than those of any other type of aquatic habitat and include a larger percentage of genera and species restricted to that particular habitat 7.

In swift water the characteristic algae are those with holdfast cells or similar structures. The freshwater red algae Lemanea and Sachena grow in rapid torrents and waterfalls. Batrachospermum develops attached in cool, slightly alkaline, rapid waters of small streams.

The most common attached alga in temperate zone streams is Cladophora, often extending many feet with the current. In very shallow waters flow- ing from springs, Vaucheria grows attached, forming large mats. In this rushing water of the rapids, the stones are thickly overgrown with mosses and algae. Diatoms which attach themselves to stones by means of gelatinous masses or stalks include Achnanthes, Cocconeis, Cymbella, and Comphonema 8.

Stones in lakes, on the other hand, exhibit much smaller growths 1. Other algae without holdfast cells may be present on various substrata, in spite of the current, due to copious secretion of mucus in which the cells are imbedded. Attached and unattached des- mids, diatoms, blue-green and green algae are often pres- ent 3. Thus, in the swift current are found encrusting algae such as Hildenbrandia, attached algae in which the greater part projects into the current, and algal forms held in place by the mucus 7.

During the winter, ice is responsible for scouring at- tached algae from rocks and other bottom materials. An- chor ice may form in the beds of rapid streams. The sur- face water may not freeze because of its motion, but freez- ing may occur on the bottom where the current is re- tarded.

It congeals in semi-solid flocculent masses which, when attached to the stones, often bring them up and cause them to be carried away. Thus, the organisms in the stream bed are deprived of their shelter and exposed to new perils 9. The algae of areas of slower current are for the most part unattached forms behaving as planktonic algae. These are, in general, distinct from those of ponds and lakes and are often designated by the terms potamoplankton or rheoplankton 3.

Since the possibilities of a good seed bed are more remote than in lakes and ponds, the streams depend upon their tributaries, backwaters, and ox-bows for the source of most of their plankton. The plankton that has become entirely adapted to river conditions is much less rich in species than is the truly limnetic plank- ton.

The multiplication of the algal constituents, whatever the source, may take place as they are carried downstream. In general the less rapid the stream the greater the number of plankton. Slow-moving areas in streams may often be covered with blooms in summer, in many instances, uni- algal growths of Chlamydomonas, Euglena, diatoms, or blue-green algae 3. Unattached, filamentous algae may form mats or blankets. The current is slower at the bottom, around stones, and along the sides of the stream.

Many algae increase in these areas of slow current, and some of them move into the area of faster current 9. In lakes and ponds the algae for the most part are ones not found in the benthos. In streams there is a greater variety of microscopic organisms in the littoral environment than in the channel proper.

The areas adjacent to the shores do not have any uni- formity of plankton. Even here the ever-changing cross- section of a stream does not permit the development of as characteristic a littoral flora and fauna as is found along the shores of lakes and reservoirs 2. The stream plankton is thus seeded with a great range and variety of organisms. It is not characterized by any species peculiar to it, nor by any precise assemblages of eulimnetic organisms.

It is subject to extreme fluctuations in quantity and constitution. The plankton production ap- pears to exhibit a series of recurrent pulses which vary from 3 to 5 weeks in duration 2. Normally, most of the growth of algae in the stream is planktonic. The planktonic organisms are usually dom- inated by rotifers and diatoms. There is a marked ten- dency of green algae and blue-green algae to appear in the warm months.

When streams are enriched, certain types of algae tend to occur in great abundance. These in- clude Stigeodonium, Cladophora, Ulothrix, Rhizodonium, Osdllatoria, Phormidium, Comphonema, Nitzschia, Navi- cula, and Surirella, all of which may be found in unen- riched streams but far less abundantly. We do not know why these particular genera are encouraged while others are not. Cladophora growths appear to be stimulated by the addition of phosphate to the water 4.

In the United States, the Southeast, the Northeast, the Southwest, and the upper and lower Mississippi River each have their characteristic diatom floras. Many individual rivers have characteristic plankton. Diatoms found in large numbers in all major drainage basins of the United States are Diatoma vulgare, Fragilaria crotonensis, Melosira am- bigua, Melosira granulata, and Stephanodiscus hantzschii. Astereonella formosa and Diatoma elongatum become abundant during cold water seasons.

The common blue-green algae, green algae, and pigmented flagellates of streams would include the forms listed in table 4 Six of these algae are shown in figures The total number of species for any river varied from about 70 to in a study made of nine streams in the eastern United States.

The mean for all of these rivers was 84, for the soft water ones, 89, and the hard water ones, Approximately 56 percent of the species were found in only one river and 73 percent occurred in one or two rivers. Less than 1 percent of the species occurred in all the rivers studied The impression concerning the abundance of algae in streams has changed in recent years.

Formerly, the unat- tached algae were considered to be so few that often they were recorded in numbers per liter or cubic meter rather than per ml. In such data, when converted to numbers per ml, the algae are generally recorded as fewer than Sampling sta- tions on 16 rivers were chosen where water samples were obtained at regular intervals for examination.

The number of sampling stations was soon increased to include other rivers, and the program was continued for several years Over a period of 2 years the average count was 3, algae per ml.

April, September, and October had the high- est counts. Some individual counts exceeded 20, Records compiled for the Public Health Service have been published covering a period from October 1, , to Sep- tember 30, In addition, an account of the prin- cipal diatoms of the major waterways of the United States has been published 14 and one on plankton population dynamics Concern for the quality of river waters increases as the many uses for these waters are intensified.

It is necessary to know the algal population of streams quantitatively and qualitatively, if we are to be concerned with assessing their value or their significance as stream purifiers, pollu- tion indicators, or as producers of excessive growths, their role in water treatment problems, and their function as the primary food producers for fish.

It can be important to know the algal population of a river before any major change is made in the use of the stream. Also, we need to know the algal population of rivers throughout the year and not merely for the warmer months. Determina- tion of the effect of particular factors on the biota of rivers will require detailed studies that should be planned for that particular purpose The communities of running water.

In Fundamentals of Limnology by F. University of Toronto Press, p. Whipple, C. Fair, and M. Algae of streams and rivers. Charles C. Thomas, Springfield, III. The enrichment of streams. In Eutrophication: Causes, Consequen-. Symposium, National Acad. Chapter 5 in Life in Lakes and Rivers by T. Macan and E. Collins, London, p.

The influence of water currents on the life functions of algae by J. New York Acad. The algae of different types of habitat. McGraw-Hill Book Co. Water habitats. Patrick and C. Academy of Natural Sciences of Philadelphia.

Monograph No. Needham and J. Viewpoint Society, New York, p. Plankton population dynamics. Public Health Publication No. National Water Quality Network-Supplement 2, 90 p. A study of the number and kinds of species found in rivers in East- ern United States. Natural Sciences of Philadelphia Algae in rivers of the United States.

Public Health Service Publication No. Dilute sulphuric acid 0. Interference from cations negatively impacted on biosorption of chromium. Immobilized algae on Amberlite XAD-8 in a glass column, gave better recovery of chromium in tannery effluent compared to a batch method with unimmobilized algae.

Fourier transform infra red FT-IR analysis of the two algae revealed the presence of carboxyl groups as possible binding sites.