Differing Water Quality Research Articles

Canopy temperature as a measure of salinity stress on sorghum

A complete understanding of plant response to combined water and salinity stress is desirable. Previous growth chamber and greenhouse experiments with sorghum and maize indicate that soil salinity, by negatively affecting growth processes, may reduce consumptive water use, thus prolonging the supply of available soil moisture. In the present field experiment, canopy temperature measurements were used to examine the effect of soil salinity on the plant-soil water relations of sorghum (Sorghum bicolor L. cv. Northrup King 1580). An infrared thermometer was used to measure canopy temperature during a 9-day period including two irrigations in plots of various salinities. The salinity treatments were created by a dual line-source sprinkler irrigation system, which applied waters of different quality. Excess irrigation allowed soil moisture to be uniform across the salinity treatments at the beginning of the measurement period. Consumptive water use and soil salinity were measured to quantify the salinity and water treatments. Grain and dry matter yields provided measures of plant response. Canopy temperature measurements were sensitive enough to detect differences across the salinity treatments when soil moisture was uniform for several days following irrigation. However, over the 9-day measurement period, plants in the low-salt plots used more water than plants in the high-salt plots. This differential water use eventually offset the salinity-induced stress, with the result that temperature differences were eliminated. Differences in temperature were observed again following irrigation. The results demonstrate that canopy temperature can be used as a tool to detect salinity stress on sorghum. Timing of measurements with regard to irrigation is identified as a key factor in detecting temperature differences that can be attributed to the presence of soil salinity.

High Energy Electron Beam Irradiation: An Advanced Oxidation Process for the Treatment of Aqueous Based Organic Hazardous Wastes

Abstract Advanced oxidation processes for the removal and destruction of hazardous organic chemicals in water and wastewater is a research area of increasing interest. Advanced oxidation processes generally consider the hydroxyl radical, OH-, the major reactive transient species. A novel process under development, utilizing high energy electrons, extends this concept to include the simultaneous formation of approximately equal concentrations of oxidizing and reducing species. Irradiation of aqueous solutions results in the formation of the aqueous electron, e−aq, hydrogen atoms, H-, and OH-. These reactive transient species initiate chemical reactions capable of destroying organic compounds in aqueous solution. This paper presents data on the removal of six common organic contaminants that have been studied at the Electron Beam Research Facility. The removal and the factors affecting removal were determined. This study focuses on halogenated ethenes, benzene and substituted benzenes. Removal is described in waters of different quality, including potable water, and raw and secondary wastewater. Removal efficiencies ranged from 85 to >99% and varied with water quality, solute concentration, dose and compound.

An evaluation of hamster, rat, and mouse sperm-cell motility in media formulated with water of different qualities

The in vitro motility of caudal epididymal spermatozoa from four hamsters, four rats, and four mice was compared in modified Tyrode's medium (TLP-PVA) prepared with water of three qualities: (1) Sigma tissue culture water, 18 m omega, high quality (HQ); (2) deionized distilled water, 4.5 m omega prior to distillation, intermediate quality (IQ); and (3) tap water, low quality (LQ). The objective was to evaluate the in vitro bioassay potential of spermatozoa from these species, in terms of relative sensitivities to toxins in different qualities of water. An average sperm motility index (SMI) was calculated per treatment at 2, 4, and 6 hr, where SMI = fpm2 x % motility. Hamster SMI could be used to discriminate between HQ and IQ media at 4 and 6 hr (P less than 0.001), while rat SMI could be used to discriminate between HQ and IQ media at 6 hr (P less than 0.05). Mouse SMI did not differ between HQ and IQ media. The ability to discriminate between extremes in quality. HQ or IQ vs LQ, was equal between species (P less than 0.001). These results suggest that hamster spermatozoa provide the more sensitive in vitro bioassay model, while rat and mouse spermatozoa may be used for assay of extremes in water quality.

Double line-source sprinkler system for determining the separate and interactive effects of water and salinity on forage corn

The line-source sprinkler system provides a water application pattern which is uniform along the length of the plot and continuously variable across the plot. A double line-source system is described which makes it possible to determine simultaneously the response functions for two factors — salinity and water — and their interaction, on a relatively small area. It is based on two parallel sprinkler lines with overlapping wetting, supplied with water of different quality. The lines are fitted with groups of sprinklers with a range of nozzle sizes to produce different rates of water application. This modified line-source technique has the following advantages: (i) it produces a wide range of water application amounts in combination with a large gradient in water salinity; (ii) different rates of water application are obtained between the two lines within each salinity level; and (iii) on the side of the lines where no overlapping occurs, the use of different rates results in the application of the same amount of water at different distances from the line-source. This is in contrast to the common line-source arrangement, in which the amount of water falling at a given distance from the line is always the same. A study using the double line-source system was carried out to determine the interactive effects of water and salinity on forage corn.

ZINC MOVEMENT IN SEWAGE-SLUDGE-TREATED SOILS AS INFLUENCED BY SOIL PROPERTIES, IRRIGATION WATER QUALITY, AND SOIL MOISTURE LEVEL

A soil column study was conducted to assess the movement of Zn in sewage-sludge-amended soils. Variables investigated were soil properties, irrigation water quality, and soil moisture level. Bulk samples of the surface layer of six soil series were packed into columns, 10.2 cm in diameter and 110 cm in length. An anaer-obically digested municipal sewage sludge was incorporated into the top 20 cm of each column at a rate of 300 mg ha−1. The columns were maintained at moisture levels of saturation and unsaturation and were leached with two waters of different quality. At the termination of leaching, the columns were cut open and the soil was sectioned and analyzed. Zinc movement was evaluated by mass balance accounting and correlation and regression analysis. Zinc movement in the unsaturated columns ranged from 3 to 30 cm, with a mean of 10 cm. The difference in irrigation water quality did not have an effect on Zn movement. Most of the Zn applied to the unsaturated columns remained in the sludge-amended soil layer (96.1 to 99.6%, with a mean of 98.1%). The major portion of Zn leached from the sludge-amended soil layer accumulated in the 0− to 3-cm depth (35.7 to 100%, with a mean of 73.6%). The mean final soil pH values decreased in the order: saturated columns = sludge-amended soil layer > untreated soils > unsaturated columns. Total Zn leached from the sludge-amended soil layer was correlated negatively at P = 0.001 with final pH (r = −0.85). Depth of Zn movement was correlated negatively at P = 0.001 with final pH (r = −0.91). Multiple linear regression analysis showed that the final pH accounted for 72% of the variation in the total amounts of Zn leached from the sludge-amended soil layer of the unsaturated columns and accounted for 82% of the variation in the depth of Zn movement among the unsaturated columns. A significant correlation was not found between Zn and organic carbon in soil solutions, but a negative correlation significant at P = 0.001 was found between pH and Zn (r = −0.61).

The importance of borehole water and lick sites to Kalahari ungulates

The utilization by ungulates of two artificial waterholes supplied with borehole water of different quality was studied. The ungulates showed a preference for the fresher water. Blue wildebeest (Connochaetes taurinus) were found to be the most water-dependent species, while springbok (Antidorcas marsupialis), gemsbok (Oryx gazella), red hartebeest (Alcelaphus buselaphus) and steenbok (Raphicerus campestris) showed greater use of mineral lick sites at waterholes than of the water itself. The differences are probably due to the various abilities of the ungulate species to survive without drinking water, the mineral status of preferred habitats and ungulate feeding habits.

Soil Properties, Irrigation Water Quality, and Soil Moisture Level Influences on the Movement of Nickel in Sewage Sludge‐Treated Soils

AbstractA column study was conducted to assess the effects of soil properties, irrigation water quality, and soil moisture level on the movement of Ni in sewage sludge‐treated soils. Surface layer samples of six soil series were packed into 24 columns, 10.2 cm in diameter and 110 cm in length. An air‐dried, anaerobically digested sewage slude was mixed into the top 15 cm of soil at a rate of 300 Mg ha−1. The columns were maintained at moisture levels of saturation and unsaturation (16.7 kPa tension) and leached with two waters of different quality. The unsaturated columns were irrigated about every 12 d with 5.08 cm of water for 13 months. The saturated columns were leached for 7 months. At the termination of the experiment the columns were cut open and the soil sectioned into 3‐cm intervals the entire length of each column. Samples were extracted with water and 4 M HNO3 and analyzed for chemical constituents. Irrigation water quality did not affect the amount of Ni leached from the sludge‐amended soil layer nor the depth of Ni movement. Mass balance calculations showed that an average of 3.3% of sludge‐applied Ni leached from the sludge‐amended soil layer of the saturated columns compared to 10.7% for the unsaturated columns. An average of 96.7% of sludge‐applied Ni remained in the sludge‐amended soil layer of the saturated columns compared to 89.3% for the unsaturated columns. For the saturated columns an average of 74.9% of sludge‐applied Ni leached from the sludge‐amended soil layer was accumulated in the 0‐ to 3‐cm soil interval compared to 46.5% for the unsaturated columns. Nickel movement below the sludge‐amended soil layer for the saturated columns ranged from 3 to 15 cm with an average of 9 cm compared to a range of 3 to 45 cm and an average of 18 cm for the unsaturated columns. Correlation and regression analysis indicated that pH and soil texture were the soil properties that best predicted the depth of Ni movement.

Optimal Ratios of Saline and Nonsaline Irrigation Waters for Crop Production

AbstractIncreased demands for freshwater in irrigated agriculture might be offset in some instances by substituting saline waters when they are available. The purpose of this paper is to present a quantitative method for determining the optimal mix of saline and nonsaline waters for crop production. Equal yield curves (isoquants), which quantify the extent of substitutability between waters of different qualities when constant yield is sought, were derived from crop‐water production functions for waters of different qualities computed from a previously published model. Isoquants were derived for several crops for relative yield (RY) values of 1.0, 0.9, and 0.8. The waters considered for mixing were nonsaline waters and waters of electrical conductivity (EC) equal to 4, 6, or 11 dS/m. Extending the supply of water by combining nonsaline and saline water is not always technically or economically feasible, and depends on specific crop and water pricing situations. The technical and economic feasibility of mixing waters of different quality increases as the EC of the saline water decreases, crop tolerance to salinity increases, desired RY decreases, or the relative price of saline to nonsaline water decreases.

SALINE IRRIGATION WATER

Irrigation is becoming a practical means to use saline waste water. The purpose of this paper is to determine the effects of saline irrigation water on soil chemical and physical properties of a Friona fine sandy loam (Petrocalcic Paleustoll). Field plots were furrow-irrigated for 4 years with two saline waters of different quality at three quantity levels. Irrigation was with either blow-down water from an electrical generating plant (ECW = 12 dS/m, SAR = 11) or city water (ECW = 1.5 dS/m, SAR = 4.5). Soluble salts increased in all irrigated plots, with the highest concentrations in plots irrigated with blow-down water. ECe values increased from 0.4 dS/m in the control (nonirrigated) plots to 6.0 dS/m in plots irrigated with high levels of blow-down water. Soluble Na, Ca, and SAR increased in all irrigated plots, with the highest values occurring in plots irrigated with high levels of blow-down water. Soluble Mg was greatest in the plots irrigated with city water. Hydraulic conductivities (K) were significantly reduced in the Ap horizons of plots irrigated with high and medium levels of blow-down water. K values ranged from 2 mm/30 min in the Ap horizon of high-irrigation, blow-down water plots to 37 mm/30 min in the control plots. K values for the B horizons, were less significantly affected by irrigation treatments. Bulk density and water retention were not significantly affected by irrigation treatments.

Viruses and bacteriophages

Many of the enteric viruses which are transmitted from person to person by thefecal-oral route are found in raw and treated wastewater, and because of their persistence under adverse conditions may also be found in slightly polluted waters. There is no routine examination procedure of water and wastewater for entero-viruses,mainly because of the cumbersome isolation techniques, high cost and the need for highly skilled laboratory personnel. Phages are specific to single species of bacteria, are known for many entericbacteria, and are very often used for final identification of enteric pathogenic bacteria. Coliphages are provalent in raw and treated sewage as well as in polluted water, where enteric viruses may also be found. Coliphages were often mentioned as possible viral indicators in polluted water.To be a perfect indicator, they should comply with minimum criteria as follows: (a) they should be present wherever human enteric viruses are present: (b) the coliphage numbers recovered should be equal to or larger than those of enteric viruses recovered: (c) the coliphages should be at least as resistant as enteric viruses to adverse environmental conditions: (d) isolation and quantification of the coliphage should be faster and less expensive than isolation of the enteroviruses. Comparative studies show that the coliphage to enterovirus ratio in wastewater is about 10 3:1. Levels of poliovirus 1 (attenuated) to coliphage f2 remained stable for a few months in oxidation pond effluents. f2 coliphage exhibited higher resistance to chlorination than poliovirus 1 (attenuated). When the two strains were kept in water of different quality, f2 survived longer. In addition, all coliphage counts were completed within 24 h. while those of enteroviruses required about a week. Results indicate very strongly that coliphages can be used as viral indicators and this is already the practice in a few European and other countries.

QUALITY OF IRRIGATION WATER AND EFFECTS OF SULFURIC ACID AND GYPSUM ON SOIL PROPERTIES AND SUDANGRASS YIELDS

The effects of irrigating a soil over a 3-year period with three waters of different qualities were evaluated in terms of chemical characteristics of the soil profile. The salinity content of the waters ranged from ECw of 3.2 X 103 to 0.55 X 103 millimhos per centimeter. The use of these waters resulted in different soil salinity contents, e.g., values of ECe X 103 for the surface 30 centimeters ranged from 3.50 to 2.13 for the high to low salt waters, respectively. Exchangeable sodium percentage (ESP) ranged from 18.4 to 24.0 in the surface 30 centimeters of soil, being highest with the lowest salinity water. The effects of relatively low rates of 93 percent H2SO4 (2.24 tonnes/hectare) and gypsum (3.84 tonnes/hectare) were evaluated in terms of plant yields and soil chemical properties over an additional 2-year period. Sudangrass (Sorghum sudanese) yields increased with decreasing salinity of the waters. Yields were increased significantly by H2SO4 and gypsum with all three waters the first year, but only with H2SO4 the second year. Significant negative correlations of ECe and ESP of the soil at depths of 0 to 30 and 30 to 60 centimeters with crop yields were found. Soil salinity and ESP were reduced significantly by both amendments one season after application. Sulfuric acid was generally superior to gypsum in terms of yield increases and soil improvement. This study demonstrated the usefulness of low rates of soil-applied amendments. Of particular interest is sulfuric acid, which gave significant results at a lower per-hectare rate than gypsum, and which is often available as a low-cost by-product.

Infiltration as Influenced by Irrigation Water Quality

AbstractAfter 19 months of irrigation with waters of different quality, columns of Heimdal loam cropped to alfalfa had infiltration rates that were correlated better with irrigation water sodicity and salinity than with soil surface (0–76 mm) or column average (0–530 mm) exchangeable sodium and soil salinity. Two sets of irrigation water parameters were tested: (i) total cation concentration (Cc) in molc m‐a (meq liter−1) and sodium adsorption ratio (SARc) of the irrigation water in equilibrium with solid phase CaCO3 at a PCO2 of 0.07% based on ion activities corrected for ion pairing; and, (ii) total cation concentration of the irrigation water as prepared and the adjusted sodium adsorption ratio based on the calculated pH of the water in equilibrium with CaCO3. On the basis of multiple linear regression analyses, the best correlation was obtained with the lime‐equilibrated water parameters (R2 = 0.87). The corresponding relationship between infiltration rate (I) in mm hour−1 and the chemical parameters was I = 6.80 − 1.10 SARc + 0.79 Cc. Cation concentration greatly affected infiltration rates even at low SAR levels (2<SAR<5). Apparently, the mechanical action of the applied water greatly enhances the effects of exchangeable sodium and soil solution concentration on swelling and dispersion at the soil surface which, in turn, has a large effect on infiltration rates.

Some relationships between quality of irrigation waters and chemical characteristics of irrigated soils of the Nagaur district, Rajasthan

Studies were conducted on the effects of waters of different quality on the chemical characteristics of 74 surface and subsurface soils of the Nagaur district, Rajasthan. The electrical conductivity (EC) of the saturation extract of these sandy and loamy sand soils were found to be less than that of the irrigation water. Correlations were observed between EC and the constituent ions (Na +, Ca 2+ and Mg 2+ of the irrigation water and of the saturation extract of the soil samples. The pH values of the irrigation water and soil suspensions also showed a positive correlation. The carbonate and bicarbonate ion concentrations in both the irrigation water and the saturation extract of the soils correlated with their respective pH values. EC of both the irrigation water and the saturation extract from surface and subsurface soil layers correlated with total cations. Correlations between the chemical characteristics of the irrigation water and the saturation extract of the soils are of limited value for prediction purposes, due to other factors operating under field conditions.

Analyses of Benthic Community Structure in a Reservoir by Use of Diversity Indices

Benthic macroinvertebrate and physicochemical collections were made monthly in four bays of Keystone Reservoir, Oklahoma, from early November 1965 through October 1966. Benthic community structures were subjected to species diversity analyses and the results were related to selected physicochemical estimates. A total of 25 benthic macroinvertebrate species were collected. There was a high, inverse correlation between diversity (d) and conductivity, and between d and depth. There was a direct, high correlation between conductivity and depth. There were significant differences in annual diversity (d) between bays which differed in water quality. Diversity indices were an easy and reliable method of determining long-term effects of waters of different qualities on the benthic fauna within reservoirs. The method should be of equal value when used on an entire reservoir, or in making comparisons between reservoirs.