EFFECT OF WASTE SULFITE LIQ
Aggregati R. B. ALDERFER, Soil Conservation
articles M. F. GRIBBINS AND D. E. HALEY The Pennsylvania State College, State College, Pa.
Service,
U. S. Department of Agriculture, State College, Pa.
the most important methods for producing arood for paper manufacture involves the digestion of chips by a sulfite solution. As a result the lignin of the wood is rendered soluble and leaves cellulose as a residue. After digestion is completed, the spent liquor, usually referred to as nmste sulfite liquor, is a dark colored solution consisting mainly of lignin sulfonate, some carbohydrate materials which lvere originally present in and dissolved from the wood, and a small amount of ash-forming elements. The utilization of waste sulfite liquor, instead of its discharge into streams, is an involved problem worthy of serious study. I t has been estima,ted that the annual discharge of waste sulfite liquor in the United States approximates 27,000,000 tons, representing more than 1,500,000 tons of lignin ( 6 ) . These figures are in substantial agreement with more recent estimates submitted by Bollen (a). Various investigations leading to the utilization of this material over a long period have not met with any considerable degree of success, although some progress has been made. A series of investigations was therefore undertaken to study the possibilities of this waste material, including its effect on soil structure and plant growth. In the past the bulkiness of the waste product, together with the presence of certain deleterious components, has constituted an obstacle to its possible use as a soil amendment. Kow, however, it is being modified by chemical treatment which eliminates the more deleterious components, and is being concentrated by multiple-effect evaporation to a finished solution (Clarion extract) containing 50% dissolved solids. This material, as prepared by the Castanea Paper Company, was used for the experimental work and approximated 6% of ash, 4% nonfermentable carbohydrates, 5y0fermentable carbohydrates, and 35% lignin. The carbohydrate and lignin fractions were determined by the Partansky and Benson methods ( 4 ) . Although the material contains some calcium, potassium, sulfur and certain other elements essential to plant growth, it would not be classed as a fertilizer. Its lignin and carbohydrate fractions, hovever, offer possibilities as agents for improving the structural properties of soils through bacterial action and add to the humus supply through the formation of bacterial protein-lignin complexes. EFFECT ON FRESHLY PLOWED SOILS
The first series of experiments included the addition of Clarion extract to freshly plowed soils of the Hagerstown series. The solution was diluted and enough of the material was used per acre t o supply 5 tons of total solids. When thoroughly dry, the soil was cultivated and planted to tobacco. The beneficial effect of these treatments on the aggregation of soil particles was marked and was apparent long after the crop was harvested. Through the bacterial decomposition of sugar in the soil, Peele (6) was able t o show an increase in soil aggregation. It 272
would appear, therefore, that, in addition t o the lignin, the carbohydrates present in the liquor must have played a part in the results obtained. These treated soils were supplemented with a 3-8-12 fertilizer mixture applied a t the rate of 1000 pounds per acre. From 4 to 6 units of, nitrogen, however, should have been used; for while the yields were satisfactory, the plants showed some symptoms of nitrogen deficiency as they approached maturity. The soil organisms which effect decomposition were competing with the tobacco plants for this element. This biological effect should be given due consideration when this waste material is applied to soils. GREENHOUSE TESTS
Clarion extract was then used on tobacco seedbeds under greenhouse conditions and t o increase the quantity of fertilize? applied, noting the ultimate effect on seedling growth and on the aggregat,ion of soil particles. A 4-8-12 fertilizer mixture was applied at the rate of 1500 pounds per acre. The soil used was obtained from plot 2, tier 111, of the Jordan fertility plots, and had received no fertilizer treatment for 58 years with the exception of nitrogen as dried blood which had been applied in alternate years over this period. When the extract was applied a t the rate of 2.5 tons of total solids per acre a few days before seeding, a good yield of tobacco seedlings was obtained, and the absorption of both nitrogen and potassium was satisfactory. The dry weight of seedlings over an area of 2 square feet amounted to 33 grams and contained 4.98% nitrogen and 8.31% potassium (S). On the other hand, germination failed when sufficient material was applied to supply 5 tons of total solids per acre. This was due principally to a lack of aerat,ion because of a temporary physical cementing effect on the upper soil layer by the undecomposed material. Samples taken from these soils after 8 weeks, as indicated by samples 2 and 3 of Table I, showed a marked aggregation of soil particles, The degree to which the particles of the original untreated field soil were aggregated into good tilth-producing crumbs, following the addition of the extract, was determined by structural stability and permeability measurements ( 1 ) . Stability reflects the degree to which the clay, silt, and fine sand have been aggregated into larger water-stable granules. A high stability index indicates that much of the silt and clay (two soil particle sizes present in high quantity in the Hagerstown silty clay loam soil) have been aggregated into large, stable granules or crumbs. The latter tend to produce a good tilth, whereas the soil in a dispersed condition results in poor structure or tilth. The stability index is the sum of the positive differences between the percentage of soil existing in the various larger size classes (>0.02 mm.) by aggregate and mechanical analysis. Probable permeability is represented by the percentage of the soil which consists of either aggregates or stones large enough
INDUSTRIAL AND ENGINEERING CHEMISTRY
March, 1944
OF WASTESULFITE LIQUORTREATMENT TO SOIL STRUCTURE TABLEI. RELATION
Treat-
Prob-
1
Untreated
58.5
30.1
2
2.5
62.8
58.1
3
5
64.9
64.6
Gravel
Coarse Sand
Sampled after Plant Harvest 5.07 Aggregate 8.54 1.75 Mechanical 6.43 8.01 Aggregate 23.89 1.81 4.58 Mechanical 11.78 Aggregate 23.20 2.43 3.73 Mechanical
Sampled in Early Spring Aggregate 4.92 4.32 2.61 2.05 Mechanical 2 5 55.8 29.3 Aggregate 6 64 4.45 5 3.47 2.00 Mechanical 8.81 8.81 6 5 61.2 49.1 Aggregate 3.72 2.59 Mechanical 7 10 64.3 69 1 Aggregate 17.06 18.06 3.42 1.36 Mechanical a Dissolved solids in the form of concentrated extract. 4
Untreated
50 9
20 5
d S
273 sented by sample 7, Table I) produced 24 grams (dry weight) of seedlings having a nitrogen content of 3.84% and a potassium content of 7.27% (3). RESULTS WITH MANURE AND FERTILIZER
An effort was next made to ascertain the effect of Clarion extract on soil aggregation when used alone, with rotted manure, with fertilizer, or with both. Boil was obtained from a different 11.24 62.80 15.82 0.90 3.36 24.39 45.62 21.97 part of the plot previously men18.18 58.95 11.38 0 20 3.35 23.59 45.62 21.97 tioned. The experiment w w 31.46 44.52 6.22 0!18 conducted under greenhouse con4.56 21.54 45.62 21.97 34.00 27.60 3.09 0.19 ditions over a 2-month period. 3.11 24 52 45.62 21.97 The treatments and results are given in Table 11. The mechanical and aggregate analyses were conducted on composite samples taken from duplicate plots of the same treatment. The results show a marked effect of the extract on the aggregation of soil particles, which was intensified by supplemental fertilizer treatments. These studies indicate that a n excellent soil structure may be obtained through the judicious use of the sulfite liquor. There is a marked increase in probable permeability which, in turn, is brought about by the considerable increase in the number of waterstable granuIes produced as shown by aggregate analysis. If this material is to be used as a soil amendment, the quantity to apply must be watched carefully, and intimate mixing with the soil particles must be insured. A few weeks at least should elapse before crops are seeded on soil so treated, in order t o provide a suitable interval for soil organisms to decay the less resistant materials. T o ensure more rapid and thorough decomposition of these materials, the addition of an ample quantity of a well balanced fertilizer mixture should precede the treatment. This mixture should carry from 40 to 60 pounds per acre of readily available nitrogen when the equivalent of 5 tons of dissolved solids are used. Such an application should prevent serious competition between the soil organisms and
16.45 3.69 26.15 3.95 29.64 3.89
60.89 20.54 37.11 22.07 32.66 22.36
8.71 46.62 4.63 45.62 2.36 45.62
0.34 21.97 0.21 21.97 0.36 21.97
to effect optimum moisture-permeability relations. A high probable permeability figure represents a condition in which a greater percentage of the soil consists of particles having diameters >2 mm., which if arranged properly will render the soil readily permeable to air and moisture. The probable permeability figure is the sum of the aggregate analysis percentages for particles greater than 0.2 mm. Soil structure refers to the arrangement of soil particles and may be characterized as to whether it is satisfactory or unsatisfactory for plant growth by the degree of permeability of the soil to air and moisture. I n order to ensure a more or less thorough decomposition of the carbohydrates present, soils were intimately mixed with varying quantities of the Clarion extract and placed in heaps outside the greenhouse. They were exposed to the weather from November, 1941, to March, 1942. A sample of the untreated soil was exposed to the same weather conditions for the same time. At the end of the period samples w%re taken for aggregate analysis; the results are represented by samples 4, 5, 6, and 7 in Table I. The yield of seedlings produced on these treated soils and the intake of nitrogen and potassium were obtained a t the end of 8 weeks. A plot which had r e c e i v e d rotted manure at the rate TABLE11. EFFECTOF WASTESULFITELIQUORON SOILSTRUCTURE AS INFLUENCED BY MANURE AND FERTILIZER TREATMENT of 20 tons and a 4-8-1 2 fertilizer Treatment per Acre mixture at the rate FytilProbMeMaizer Staable Coarse dium Fine of 1000 pounds Sample W.S.L.a, nure, (4-8-121, bility PermeGravel, Sand, Sand, Sand, Silt, Clay, per acre, produced NO. tons tons lb. Index ability Analysis % % % % % % seedlings w h i c h , 1-14 0 0 0 52.24 18.63 Aggregate 5.37 3.87 9.39 62.49 17.85 1.03 3.82 Mechanical 1.37 3.06 20.63 48.70 22.42 over a 2 square 2-15 2.5 0 0 60.23 32.33 Aggregate 6.96 5.08 20.29 56.78 10.17 0.39 2.92 Mechanical 1.29 3.14 21.53 48.70 22.42 foot area, 5-18 5.0 0 . 0 61.61 42.49 Aggregate 10:02 7.77 24.70 48.00 8.94 0.57 amounted to 22 Mechanical 3.46 1.67 3.24 20.51 48.70 22.42 grams (dry 8-21 0 10 0 48.59 20.44 Aggregate 7.01 4.12 9.31 57.03 21.56 0.98 Mechanical 3.19 1.74 3.57 20.38 48.70 22.42 weight) and had a 9-22 2.5 10 0 59.03 37.14 Aggregate 8.79 5.70 22.65 50.59 11.61 0.33 nitrogen content Mechanical 2.79 1.28 3.05 21.58 48.70 22.42 10-23 5.0 10 0 62.07 45.35 Aggregate 10.59 7.89 26.87 45.60 8.61 0.43 of 1.71% and a Mechanical 3.52 1.93 3.84 19.59 48.70 22.42 potassium content 11-24 0 10 1000 51.47 20.42 Aggregate 6 . 4 2 4.24 9.76 59.93 18.80 0.86 of 6 . 3 0 % . O n 3.06 Mechanical 1.35 3.15 21.32 48.70 22.42 3-16 2.5 0 1000 53.19 25.73 Aggregate 5.58 4.63 15.52 56.34 16.86 1.07 the other hand, Mechanioal 3.01 1.27 2.94 21.66 48.70 22.42 the c o m p o s i t e d 6-19 5.0 0 1000 64.07 50.81 Aggregate 13.65 8.55 28.61 42.14 6.64 0.41 Mechanical 3.92 1.11 3.09 20.76 48.70 22.42 soil receiving the 12-25 2.5 1000 59.82 38.12 Aggregate 8.98 6.07 23.07 50.58 10.75 0.54 extract at the rate lo Mechanical 3.13 1.34 2.55 21.86 48.70 22.42 of 10 tons of total 13-26 5.0 Aggregate 14.12 7.60 25.34 44.99 7.08 0.87 lo 1000 63.17 47.06 Mechanical 4.31 1.26 2.87 20 44 48.70 22.42 solids per acre and a similar fertilizer a Dissolved solids in the form of the concentrated extract, treatment (repre8
INDUSTRIAL AND ENGINEERING CHEMISTRY
214
crop plants for the mineral nutrients present. It should also contribute to the formation of humus, since most of the humus found in soils results from a combination of lignin with bacterial proteins. ACKNOWLEDGMENT
Vol. 36, No. 3
LITERATURE CITED
(1) Aldeifer, R. B., and Merkle, F. G., Soil Sci., 51, 201 (1941). (2) Bollen, W. B., Pacific Pulp & Pupel. Ind., 16, 30 (1942). (3) Gribbina, M. F., Ph.D. thesis, Pa. State College, 1942.
(4) Partansky, A. M., and Benson, H. K., Paper Trade J., 101, 29-35 (1936).
The work reported in this paper was made possible through a fello~shipestablished at The Pennsylvania State College by the Castanea Paper Company, of Johnsonburg, Pa.
( 5 ) Peele, T. C., J. Am. SOC.Agron., 32, 204 (1940). (6) Phillips, Met et al., J. Agl.. Research, 53,209 (1936).
JOURNAL Series Paper 1156, Pennsylvania Agricultural Experiment Station.
Basicitv Factors of Limestone and Lime J
EVALUATkON AS NEUTRALIZING AGENTS RICHARD D. HOAK, C. J. LEWIS, AND WILLARD W. HODGE’ Mellon Institute of Industrial Research, Pittsburgh, P a .
A procedure is presented for determining basicity factors as a menns for comparing the relative neutralizing values of limestones and limes. This method should be useful in water, sewage, and industrial waste treatment plants. Basicity factors are applied to the neutralization of waste liquor from the sulfuric acid pickling of steel. A procedure is given for the rapid determination of the acid value of such P liquor, in terms of sulfate ion, with high precision and an accuracy of 0.2%. A nomograph is presented from which the pounds of neutralizing agent per gallon of liquor can be read directly where the basicity
factor of the agent and the acid value of the liquor have been determined. Where waste pickle liquor is neutralized with limestone or lime the settling rates of the sludges produced are similar to those of water suspensions of the neutralizing agents alone. Increments in temperature and dilution increase sludge settling rates but not enough to justify their use economically. Such rates decrease with increases in pH, but are usually determined by the requirements of neutralization. A brief summary is given of the economic factors involved in deciding whether to use limestone, quicklime, or hydrated lime.
T
limestone and lime. Sulfuric acid was employed to decompose the samples because the spent liquor from the sulfuric acid pickling of steel is a typical acid industrial waste to demonstrate the practical application of the method. The pulverized limestone was guaranteed 100% through 30 mesh. A portion of this material was ground until it all passed 100 mesh, t o obtain greater homogeneity, and samples were analyzed by the standard chemical method. The average results on three samples follow:
HE basicity factor of a n alkaline agent is a measure of
the available alkalinity of the agent that avoids dependence upon chemical analysis, which may not reflect the true value of the substance in the application intended. Although the method of determining basicity factors is not novel, the procedure has been developed as a means for determining the relative reactivity of related agents or of the same agent in different physical states. The user can then select from a number of possibilities t h a t agent best suited to his purpose. The application of basicity factors to a n actual problem is illustrated by the treatment of spent pickling liquor. This procedure should be adaptable to ascertaining the acid value of most waste acid liquors not containing metals whose hydroxides are soluble in excess sodium hydroxide. BASICITY FACTOR O F LIMESTONE
Basicity factors are of particular utility in evaluating the available alkalinity of limestone and lime because the chemical analysis of these substances is time consuming and the results give limited information concerning the reactivity of the material. (Unless otherwise indicated, “basicity factor” will be used i n this paper to represent grams of calcium oxide per gram of alkaline agent.) The method evolved for determirting t h e basicity factor of limestone or lime reflects the value of the substance as a neutralizing agent under the conditions of use. I n the development of the procedure, samples of Bellefonte pulverized limestone and of shaft-kiln and rotary-kiln lime produced from the same source were selected as representative of good grades of high-calcium 1 Department of Chemical Engineering, West Virginis University, Morgantown. W. Va. (Advisory Fellow, Mellon Institute).
Calcium oarbonate CaCOa Magnesium carboGate, MgCOx Metal oxides, Rz03 Acid-insoluble Moisture at 120’ C. Total Ignitionloss at l l O O o C .
92.80% 2.07 0.74 4.20
0.05 __
99.86 42.03
Basicity factors were determined on a series of samples of different particle size prepared by grinding portions of the original 30-mesh material until all the portions passed through a given standard screen.
PROCEDURE. Weigh accurately a 2-gram sample of pulverized limestone, representative of its condition a t the time of use, into a 500-ml. Erlenme ’er flask containing 10 ml. of distilled water. Run in from a kuret the amount of 0.5 N sulfuric acid estimated to decompose the sample completely and add 30-35 ml. in excess. Boil the sample, adding water to make up evaporation loss, until decomposition appears to be complete. Cool to room temperature, wash down the inside of the flask, add two drops of phenolphthalein, and titrate to the usual end point with 0.5 N sodium hydroxide. Calculate the net acid required in terms of equivalent calcium oxidz. When several samples are run a t the same time, it is convenient to condense a part of the water vaporized during boiling by circulating cold water through narrow U-tubes inserted two
