Growth and mineral accumulation in Eucalyptus camaldulensis seedlings irrigated with mixed industrial effluents

Effects of mixed industrial effluents on growth, dry matter accumulation and mineral nutrient in Eucalyptus camaldulensis seedlings were studied. The objective was to evaluate the adaptability of E. camaldulensis to effluent, tolerance to excess/deficiency of mineral elements and ultimately to determine suitable combinations of industrial/municipal effluent for their use in biomass production in dry areas. Different irrigation treatments were: T(1): good water; T(2): municipal effluent; T(3): textile effluent; T(4): steel effluent; T(5): textile effluent+municipal effluent in 1:1 ratio; T(6): steel effluent+municipal effluent in 1:2 ratio; T(7): steel+textile+municipal effluent in 1:2:2 ratio; and T(8): steel+textile effluent in 1:2 ratio. High concentrations of metal ions and low concentrations of Ca, Mg, K, Na, N and P in soil and seedlings of T(4) resulted in mortality of the seedlings within a few days. Addition of the textile/municipal effluent increased the survival time of the seedlings for two to three months in T(6), T(7) and T(8) treatments. Among the remaining treatments, the seedlings of T(2) attained 131 cm height, 1.97 cm collar diameter, 19 total branches and produced 158 g seedling(-1) of dry biomass at the age of 10 months. The seedling of T(3) produced the least growth and biomass. Growth equivalent to that of the seedlings of T(1) treatment was achieved when municipal effluent was mixed with textile effluent (T(5)). There was a decrease in soil pH, EC, SOC, NH(4)-N, NO(3)-N, PO(4)-P and basic cations and increase in the concentration of Cu, Fe, Mn and Zn with T(4) treatment. The reverse trend was observed in T(3) where a high concentration of Na might have reduced Mg and micronutrient concentration in seedlings potentially affecting root and leaf growth. Mixing of effluents may be useful in tree irrigation to increase biomass productivity, which is evidenced by improved growth in T(5) and survival in T(6), T(7) and T(8) treatments. Further, reduction of toxic concentration of metal ions in effluents may be helpful for a long-term field application.     

Use of tree seedlings for the phytoremediation of a municipal effluent used in dry areas of north-western India: Plant growth and nutrient uptake

Impacts of municipal effluent (ME) irrigation on soil physicochemical properties and its remediation by tree species were assessed with a view to utilize this resource in growing woodlot, controlling land degradation and improving environmental quality in suburban areas. Acacia nilotica L. (babool), Dalbergia sissoo L. (sissoo) and Eucalyptus camaldulensis seedlings planted in July 1998 were irrigated with ME at ½ PET (T₂), 1 PET (T₃), 2 PET (T₄), and with canal water at 1 PET (T₅). The control was soil without seedlings irrigated with ME at 1 PET (T₁). Application of ME increased minerals concentration from T₂ to T₄ in both soil and seedling in June 1999 and 2000. The increase in soil pH, EC, SOC was by <2.00-fold and availability of potassium (K), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) by >2-fold, NH₄–N by 10.44-fold and PO₄–P by 6.57-fold in T₄ than those in T₅ treatment in 2000. Available NH₄–N, PO₄–P, Mg and K were higher in 0–15 cm soil layer but continued irrigation and low soil carbon influenced leaching of NO₃–N, Na, Cu, Fe, Mn and Zn resulting their higher concentrations in 60–90 cm soil layer (P < 0.01). Lower soil nutrients in T₃ than in T₁ suggested soil amelioration by the planted seedlings and because of lowest concentration of most of the nutrients E. camaldlensis showed highest soil amelioration capacity. But nutrient utilization efficiency was highest in A. nilotica for K, Ca, Mg, Na, Fe, Cu and Zn, D. sissoo for N and P, and E. camaldulensis for Mn. Thus, planting tree seedlings, particularly E. camaldulensis, under ecological amelioration could in this way help in controlling land degradation and enhancing biomass and aesthetic benefits, although long-term application of effluent would lead to mineral/salt accumulation in soil and plants.     

Usage of sewage effluent in irrigation of some woody tree seedlings. Part 3: Swietenia mahagoni (L.) Jacq.

A pot experiment was investigated to study the effect of sewage irrigation treatments (primary and secondary effluents) compared with tap water on the growth and chemical constituents of mahogany seedlings (Swietenia mahagoni (L.) Jacq.) as well as soil chemical properties. The experiment was conducted at a greenhouse in the nursery of Timber Trees Research Department of Sabahia, Horticultural Research Station in Alexandria, Egypt, from June 2003 to December 2004 for three irrigation periods (6, 12 and 18 months). The sewage effluent waters were taken from oxidation ponds located in New Borg EL-Arab city and used directly for irrigation.The primary effluent treatment was superior than other treatments in improving the growth parameters (plant height, stem diameter, leaf area, leaves number, fresh and dry weights of leaves, shoots and roots and shoot/root ratio) and showed the highest concentration and total uptake of N, P, K, Cd, Ni, Pb and Fe in plant parts, followed by secondary effluent then tap water. The data revealed that soil salinity in terms of electrical conductivity of saturated paste (EC), CaCO₃%, organic matter% and soluble anions and cations were influenced significantly by primary or secondary effluent treatment. The data also showed that the use of sewage effluent for irrigation increased N, P, K and DTPA-extractable-heavy metals (Cd, Cu, Ni, Pb, Fe, Mn and Zn). The effects of sewage effluent on growth parameters and elements content in plant parts and treated soil were more pronounced as water treatments were used for long period.The results suggested that the use of sewage effluent in irrigating mahogany trees grown on calcareous sandy loam soil was an important agriculture practice for improving soil properties, increasing fuel and timber production, and is an economic and safe way to dispose wastewaters.     

Phosphorus and micronutrient metal uptake by some tree species as affected by phosphate and lime applied to an acid sandy soil

Summary The effects of added P and lime on Douglas fir and Scots pine seedlings, and poplar and willow cuttings growing in a podzolic soil (pH 3.8, 90 ppm total P) were studied in pot experiments. Conifer dry weights responded best to P applied in the absence of lime, whereas liming to pH 4.3 promoted the P response of the broadleaved species. Normal rates of P, and of lime (broad-leaved species), by promoting growth, also raised total contents of P and metals (Zn, Mn, Cu, Fe) in the various plant parts (stems, foliage, roots), but generally lowered the metal concentrations. The results strongly suggest that P interfered with the root to shoot translocation of Cu, Fe and Al (Al only estimated in Scots pine), but not with that of Zn and Mn. It is postulated that internal plant tolerance (promoted by P) plays a more important part in neutralizing toxic metal concentrations (Zn, and possibly also Fe) in the soil than do exclusion mechanisms. High applications of P without Cu may depress growth, as demonstrated for willow. Water-soluble soil P data may be misinterpreted if other limiting soil factors (pH, Cu status) have not been eliminated.     

Effects of nitrogen and water addition on trace element stoichiometry in five grassland species

A 9-year manipulative experiment with nitrogen (N) and water addition, simulating increasing N deposition and changing precipitation regime, was conducted to investigate the bioavailability of trace elements, iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn) in soil, and their uptake by plants under the two environmental change factors in a semi-arid grassland of Inner Mongolia. We measured concentrations of trace elements in soil and in foliage of five common herbaceous species including 3 forbs and 2 grasses. In addition, bioaccumulation factors (BAF, the ratio of the chemical concentration in the organism and the chemical concentration in the growth substrate) and foliar Fe:Mn ratio in each plant was calculated. Our results showed that soil available Fe, Mn and Cu concentrations increased under N addition and were negatively correlated with both soil pH and cation exchange capacity. Water addition partly counteracted the positive effects of N addition on available trace element concentrations in the soil. Foliar Mn, Cu and Zn concentrations increased but Fe concentration decreased with N addition, resulting in foliar elemental imbalances among Fe and other selected trace elements. Water addition alleviated the effect of N addition. Forbs are more likely to suffer from Mn toxicity and Fe deficiency than grass species, indicating more sensitivity to changing elemental bioavailability in soil. Our results suggested that soil acidification due to N deposition may accelerate trace element cycling and lead to elemental imbalance in soil–plant systems of semi-arid grasslands and these impacts of N deposition on semi-arid grasslands were affected by water addition. These findings indicate an important role for soil trace elements in maintaining ecosystem functions associated with atmospheric N deposition and changing precipitation regimes in the future.     

Mineral Elements in Root of Wild Saposhnikovia divaricata and Its Rhizosphere Soil

Mineral elements are important components of medicinal herbs, and their concentrations are affected by many factors. In this study, Ca, Mg, Na, K, Fe, Mn, Cu, and Zn concentrations in wild Saposhnikovia divaricata and its rhizosphere soil collected from seven locations at two different times in China were measured, and influences of rhizosphere soil on those minerals in plant were evaluated. The results showed that mean concentrations of eight minerals in plant samples decreased in the order: Ca > Mg > Na > K > Fe > Zn > Mn > Cu, and those in the soil samples followed the following order: Na > Fe > Ca > K > Mg > Mn > Zn > Cu. Mean concentrations of Ca, Na, Mg, and K in plants were higher than those in soils, while higher mean concentrations of the other four minerals were found in soils. It was found that there was a positive correlation of Mg, Na, and Cu concentrations in the plant with those in the soil respectively, but a negative correlation of Mn concentration in plant with that in the soil. Except Ca, K, and Mn, the other five minerals in plant were all directly affected by one or more chemical compositions of soil. The results also indicate that pH value and concentrations of total nitrogen, Mg, Mn, and Cu in soil had significant correlations with multimineral elements in plant. In a word, mineral elements uptake of S. divaricata can be changed by adjusting the soil fertility levels to meet the need of appropriate quality control of S. divaricata.     

Phytoremediation of the toxic effluent generated during recovery of precious metals from polymetallic sea nodules

Recovery of metals from the polymetallic sea nodules at the pilot plant at National Metallurgical Laboratory, Jamshedpur, India has generated a highly toxic effluent. This effluent contains several metals like Mn, Cu, Zn, Fe, Pb, Cr, and Cd that pollute the neighboring water bodies when discharged. Hence detoxification of this effluent was practiced using two plants: Lemna minor and Azolla pinnata for 7 days. During investigation A. pinnata removed 96% of Mn, 97% of Cu, 98% of Zn, 70% of Fe, 96% of Pb, 93% of Cr, 78% of Cd, and was comparatively more effective than L. minor which removed 94% of Mn, 86% of Cu, 62% of Zn, 74% of Fe, 84% of Pb, 63% of Cr, 78% of Cd. During the 7 days of experiment chlorophyll content decreased by 51% and 59% in A. pinnata and L. minor respectively. Based on our findings we can suggest that these two plants have wide range of metal retention potentialities hence can be of routine use for purification of toxic effluents.     

Trace elements in the hydrologic cycle of a forest ecosystem

Summary Concentrations of Cu, Fe, Mn, and Zn were measured in bulk atmospheric precipitation, throughfall, stemflow, and soil solutions at 10−, 15−, 25−, and 30-cm depths, in aEucalyptus globulus forest in the Berkeley hills, California, during the 1974–75 wet season after each main storm event. Litter and plant samples were analyzed. There was some similarity in the behavior of Cu, Fe, and Zn, but Mn behaved differently. Mn and Zn are largely deposited on the forest canopy by impaction during dry-deposition episodes, whereas most of the Cu and Fe input occurs in rain. For the hydrologic components measured, concentrations of Cu and Fe increase in the order: precipitation<throughfall<stemflow <soil solutions. For Zn the order is: precipitation<stemflow<throughfall<soil solutions. Concentrations of Cu, Zn, and Fe in the soil solution fluctuate with downward movement of wetting fronts and are negatively correlated with pH. Concentrations of Fe in soil solution are about 10 times greater than those of throughfall and stemflow; the corresponding relative differences for Cu and Zn were much less. Plant uptake of Mn exceeds that of Cu, Zn, and Fe. The increases in Mn concentrations from precipitation to throughfall and stemflow are much greater than those for Cu, Zn, and Fe because precipitation has very low Mn concentrations. The concentration series for Mn is: precipitation<soil solutions<throughfall<stemflow. Concentrations of Mn in the soil solution are negatively correlated with pH. During the dry summer Mn accumulates in the soil, but is quickly flushed by early rains of the wet season.     

Heavy metals in water,sediments, fish and plants of river Hindon,U.P., India

We analysed the concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in the water, sediments, fish and plants of the River Hindon, U.P., India, at seven sampling stations, in the year 1982. Considerable variation in concentration between water, sediments, fish and plants were noted. The concentration in the water was in the order Fe > Zn > Cr > Mn > Cu > Pb > Ni > Co > Cd, in the sediments, Fe > Mn > Zn > Ni > Cr > - Co > Cu > Pb > Cd; in a fish (Heteropnuestes fossilis) Fe > Zn > Mn > Pb > Ni > Co > Cu > Cd > Cr, and in a plant (Eicchornia crassipes) Fe > Mn > Zn > Ni > Cu > Cr > Pb > Co > Cd.     

关帝山云杉次生林树木更新与土壤养分的空间关联性

参照CTFS(Center for Tropical Forest Science)技术规范在山西关帝山4 hm²样地(GDS 样地)190个采样点进行调查,研究样地更新苗的分布,以及土壤有机质、有效氮、有效磷、有效钾等养分及pH值等14个土壤指标的空间格局,分析树木更新与土壤养分分布的空间关联性,探究云杉次生林树木更新格局的形成机制。结果表明: 土壤有效氮、有效钾、有效铜、有效铁、有效锰、有效镍及有效锌含量低的斑块中更新苗存活数量较多,且除有效钾外其他6个土壤养分因子与地径(GD)相对较大的Ⅱ(2.5 cm相似文献   

Effect of submergence on availability of certain plant nutrients in three Ultisol catenas

Soil samples from surface and sub-surface horizons in the well-drained and poorly-drained members of three soil catenas were incubated under submergence or at field capacity to study the effects of these incubation conditions and prior natural drainage on the solubility of four plant micro-nutrients. Iron, Mn, Zn and Cu were extracted by water using a 11 water:soil ratio. The four micronutrient metals were also extracted by DTPA solutions buffered at either pH 5.3 or pH 7.3 to compare the effectiveness of these two extractants under these incubation conditions with acid soils. Generally the extractability of the nutrients was much affected by the horizon (A, E or B) with A horizons having the greatest amounts of all nutrients and undergoing greater changes in water- and DTPA-extractability during incubation. Soil drainage class (wellvs. poorly drained) had few effects. Incubation moisture regime had major effects on water extractable Fe and Mn with lesser effects on Zn and Cu. Submerged soils generally had the greatest levels of water extractable nutrients, though rice uptake did not reflect this. DTPA at pH 5.3 extracted 2 to 3 times as much Fe, Mn, Zn and Cu as did DTPA at pH 7.3 and about 50 to 100 times as much as did water. Correlations between DTPA extractable nutrients and rice uptake were significant only for Fe and Cu and declined during incubation. The changes in all variables during incubation were complex, being related to soil properties such as organic matter content, pH and mineralogy as well as to incubation conditions.     

镁肥对马尾松幼苗生长与叶片元素积累的影响

为了探讨上杭种源马尾松Pinus massoniana叶营养与生长对不同镁肥水平的响应,以其优良种源1年生苗为材料,设置4个镁肥梯度(42 g·m-2、85 g·m-2、170 g·m-2、339 g·m-2),测定移栽1年后苗木生长指标及叶内营养含量。结果表明,施镁能够促进元素P、K、Ca、Fe、Cu、Zn积累,抑制N、Mg、Mn积累;镁施肥量为85 g·m-2时,对N、Mg、Mn积累的抑制作用不显著,对P、K、Ca、Fe、Cu、Zn积累的促进作用最大,苗木生长最好,为最佳施肥量。施镁并不能促进苗木对镁的吸收,而是改变了营养供应的土壤环境,从而改变植物对其他营养的吸收比例,进而影响植物的生长。苗木的生长与Fe、P、K的关系最为密切,其次是Mg、Mn、Ca、N、Cu、Zn。     

Effects of soil acidification on the chemical extractability of Fe,Mn, Zn and Cu and the growth and micronutrient uptake of highbush blueberry plants

Summary The effects of soil acidification and micronutrient addition on levels of extractable Fe, Mn, Zn and Cu in a soil, and on the growth and micronutrient uptake of young highbush blueberry plants (Vaccinium corymbosum L. cv. Blueray) was investigated in a greenhouse study.Levels of 0.05M CaCl₂-extractable Fe, Mn, Zn and Cu increased as the pH was lowered from 7.0 to 3.8. However, the solubility (CaCl₂-extractability) of Fe and Cu was considerably less pH-dependent than that of Mn and Zn. With the exception of HCl-and DTPA-extractable Mn, micronutrients extractable with 0.1M HCl, 0.005M DTPA and 0.04M EDTA were unaffected or raised only slightly as the pH was lowered from 6.0 to 3.8. Quantities of Mn and Zn extractable with CaCl₂ were similar in magnitude to those extractable with HCl, DTPA and EDTA whilst, in contrast, the latter reagents extracted considerably more Cu and Fe than did CaCl₂. A fractionation of soil Zn and Cu revealed that soil acidification resulted in an increase in the CaCl₂- and pyrophosphate-extractable fractions and a smaller decrease in the oxalate-extractable fraction.Plant dry matter production increased consistently when the soil pH was lowered from 7.0 to 4.6 but there was a slight decline in dry matter as the pH was lowered to 3.8. Micronutrient additions had no influence on plant biomass although plant uptake was increased. As the pH was lowered, concentrations of plant Fe first decreased and then increased whilst those of Mn, and to a lesser extent Zn and Cu, increased markedly.     

Effect of Trichoderma asperellum strain T34 on iron, copper, manganese, and zinc uptake by wheat grown on a calcareous medium

Rhizosphere microbes may enhance nutrient uptake by plants. Here we studied the effect of Trichoderma asperellum inoculation on the uptake of Fe, Cu, Mn, and Zn by wheat (Triticum aestivum L) grown in a calcareous medium. To this end, an experiment involving two factors, namely Fe enrichment (ferrihydrite enrichment and non-enrichment of the growing medium), and inoculation/non-inoculation with Trichoderma asperellum strain T34, was performed twice under the same conditions. The increase in Fe availability as a result of ferrihydrite enrichment did not enhance plant dry matter production. The effect of T34 on the concentration of Fe, Cu, Mn and Zn, and the total amount of Cu, Mn, and Zn in the aerial parts differed depending on the degree of ferrihydrite enrichment. Inoculation with T34 increased Fe concentration in Fe-deficient media, thus revealing a positive effect of this microorganism on Fe nutrition in wheat. However, T34 significantly decreased the concentration and total amount of Cu, Mn, and Zn in the aerial parts, but only in ferrihydrite-enriched medium. This adverse effect of T34 on Cu, Mn, and Zn uptake by wheat plants may have been related to conditions of restricted availability where potential competition for nutrients between microorganisms and plants can be more marked.     

Trace elements in aerial parts and rhizosphere of <Emphasis Type="Italic">Thymus pannonicus</Emphasis> All.

This paper brings out the results of the study on the levels of selected trace elements (Cu, Fe, Mn, Zn and Cr) in aerial parts of Thymus pannonicus All. (Lamiaceae) and rhizosphere soil from twelve locations in Serbia. Prior to assays by flame and flameless atomic absorption spectrometry, samples were subjected to microwave-assisted acid digestion. Real and potential acidity of soil samples were also measured. Obtained results for soil samples, although slightly higher for some elements (Cu: 12.38–45.18 mg/kg; Fe: 22102–46193 mg/kg; Mn: 776.95–4901.27 mg/kg; Zn: 62.27–214.02 mg/kg; Cr: 48.86–69.13 mg/kg), were found to fit into biogeochemical background. Element contents in plant samples differed depending on collecting site (Cu: 5.26–14.07 mg/kg; Fe: 25.92–1454.07 mg/kg; Mn: 89.29–278.25 mg/kg; Zn: 1.81–10.64 mg/kg; Cr: 1.11–3.51 mg/kg), which can be partly explainable by different nutrient availability influenced by soil acidity. Zinc levels in T. pannonicus were below expected and seem to be strongly influenced by plant physiological properties.     

Genetic and functional diversity of Bacillus strains in the soils long-term irrigated with paper and pulp mill effluent

The genetic and functional diversity of Bacillus and Bacillus-derived genera was analyzed in soil samples collected from three different fields near Century Paper Mill, Lal Kuan, Uttarakhand, India. Two had been subjected to concentrated and diluted effluent irrigation for the past 25 years and were designated as a concentrated effluent irrigated field (CEIF) and a dilute effluent irrigated field (DEIF), respectively. The field irrigated with fresh water was designated as a water irrigated field (WIF). Increase in pH, Na and Zn content and decrease in Fe content was observed due to effluent irrigation. The population count of Bacillus and Bacillus-derived was maximum in DEIF followed by WIF and CEIF. Variations in plant growth-promoting traits and extracellular enzymes were observed among the isolates from the three different field soils. Based on the amplified ribosomal DNA restriction analysis (ARDRA) with three restriction enzymes, all the selected 104 isolates were clustered into 14 groups. The sequencing of the representative isolates revealed that the majority belonged to the genus Bacillus, while three isolates belonged to Paenibacillus, Lysinibacillus and Orthinibacillus. There were a few species like Orthinibacillus contaminans, B. oleronius, B. safensis, B. methylotrophicus, B. stratosphericus, B. aryabhattai, B. asahii and B. bataviensis that were prevalent only in DEIF and CEIF but not in WIF field soil. The diversity index parameters like the Shannon Index, indices of species richness and species evenness based on biochemical profiling and ARDRA profiling revealed that Bacillaceae members in the fresh water irrigated field were diverse.     

EDTA-Facilitated Phytoremediation of Soil with Heavy Metals from Sewage Sludge

The objective of this research was to determine the effect of the chelate EDTA (ethylenediaminetetraacetic acid), which is used in phytoremediation, on plant availability of heavy metals in liquid sewage sludge applied to soil. Sunflower (Helianthus annuus L.) was grown under greenhouse conditions in a commercial potting soil; the tetrasodium salt of EDTA (EDTA Na₄) was added at a rate of 1 g kg^-1 to half the pots. Immediately after seeds were planted, half of the pots with each soil (with or without EDTA) were irrigated with 60 ml sludge, and half were irrigated with 60 ml tap water. For the subsequent five irrigations, plants in soil with EDTA received either sludge or tap water containing 0.5 g EDTA Na₄ per 1000 ml, and plants in soil without EDTA received sludge or tap water without EDTA. Of the four heavy metals whose extractable concentrations in the soil were measured (Cu, Fe, Mn, and Zn), only Zn had a higher concentration in sludge-treated soil with EDTA compared to sludge-treated soil without EDTA. The concentrations of Fe, Cu, and Mn were similar in sludge-treated soil with and without EDTA. Of the three heavy metals whose total concentrations in the soil were measured (Cd, Pb, Cr), Pb (<10 mg kg^-1) and Cd (< 1 mg kg^-1) were below detection limits, and Cr was unaffected by treatment. The concentration of all measured elements in plants (Cd, Cu, Fe, Zn, Pb) was higher than the concentrations measured in the soil. With no EDTA, sludge-treated plants had a higher concentration of the five heavy elements than plants grown without sludge. Cadmium was lower in sludge-treated plants with EDTA than plants with EDTA and no sludge. After treatment with EDTA, the concentrations of Cu, Fe, and Zn were similar in plants with and without sludge. Lead was higher in plants with EDTA than plants without EDTA, showing that EDTA can facilitate phytoremediation of soil with Pb from sewage sludge.     

Micronutrient status of the rice plant

Summary Soil solution Zn, Cu, Mn and Fe concentrations which were monitored throughout the growing season were found to be representative for flooded rice culture. Plant Zn, Cu, Mn and Fe contents of top, middle and bottom leaves as well as whole plants were also measured periodically throughout the growing season. These data were found to be within reported ranges for rice plants grown on flooded soils. Simple regression analyses were performed between plant micronutrient contents for each plant part sampled and the corresponding soil solution values. Results showed that the most promising portions of the rice plant to sample for accurate assessment of plant response to changes in soil solution micronutrient concentration as a function of time are as follows: (a) for Zn, bottom leaf; (b) for Cu, top or bottom leaf, whole plant; (c) for Mn, top leaf and (d) for Fe, bottom leaf or whole plant. re]19750915     

Performance of an ecological treatment system at three strengths of dairy wastewater loading

Ecological treatment systems, which rely on renewable resources, have successfully treated municipal and industrial effluents with reduced costs compared to conventional methods, but their capacity to treat dairy wastewater is unknown. In order for ecological treatment systems to be practical for agriculture they must be able to treat a significant portion of a dairy's daily wastewater production. In this study, the impact of three strengths of dairy wastewater on effluent water quality was assessed. Three ratios of wastewater and city water—(1) one part wastewater:three parts city water, (2) one part wastewater:one part city water, and (3) two parts wastewater:one part city water—were each pumped into an ecological treatment system. Influent and effluent water samples were analyzed for PO₄-P, TP, TN, NH₄-N, NO₃-N, total suspended solids (TSS), and carbonaceous biochemical oxygen demand (CBOD₅). Influent dairy wastewater volumetric loading rates were much greater than those of municipal wastewater. Regardless of influent wastewater strength, concentrations of all measured variables were significantly reduced between the influent and effluent of the ecological treatment system. At the lowest wastewater strength, PO₄-P was reduced 39%, TN 83%, and NH₄-N 89%, while at the highest wastewater strength, PO₄-P was reduced 41%, TN 79%, and NH₄-N 70%. Increased wastewater strength required greater aerobic treatment volume to reduce concentrations of NH₄-N and CBOD₅.     

Comparison of the vibration mode of metals in HNO3 by a partial least-squares regression analysis of near-infrared spectra

The near-infrared (NIR) spectra of such metals as Cu(II), Mn(II), Zn(II) and Fe(III) in HNO(3) in the 700-1,860 nm region were subjected to a partial least-squares regression analysis and leave-out cross-validation to develop chemometric models. The models yielded a coefficient of determination in cross validation of 0.9744 [Cu(II)], 0.9631 [Mn(II)], 0.9154 [Zn(II)] and 0.741 [Fe(III)]. The regression coefficients for Cu(II), Mn(II) and Zn(II), but not for Fe(III), showed strong negative peaks at around 1,050-1,200 nm, a zone where spectral bands have been reported to decrease with increasing pH value. A positive peak at around 710-750 nm, which may have been due to water absorption, was observed in regression coefficients of Cu(II), Mn(II) and Zn(II) but not in Fe(III), while a negative peak was observed in that for Fe(III) at around 710-750 nm. These results indicate that the divalent cations [Cu(II), Mn(II) and Zn(II)] showed different absorption in the NIR region from the trivalent cation [Fe(III)], suggesting that the vibration mode of water, which mirrors the interaction between cations and water, may be influenced by valency.