% TN = volume of HCL (sample - blank) x Normality of HCL x meq. wt. of N / wt. of soil. The resulted value multiplied by 100. Where, meq. weight of N = 0.014 g.

Total P (ppm) = ppm P from calibration curve xAxB / wt. xV

where, A= Total volume of the digest

B = Volume made for measurement

wt = Amount of the test material taken

V = Volume of digest used for measurement

Generally TKN (Total Kjeldahl N) will be done - As Kanhaiya pointed out this includes both Organic N and Ammonia N. Nitrate and nitrite N may be reported as TON (total oxides of N r total oxidised N).

So TKN + TON is equivalent to Org N, NH4-N, NO3-N, NO2-N).

Hi,

Many Thanks for all. But I mean about data, analysis formulas and how to calculate and draw charts in Excel ...

Best Regards,

CALCULATIONS FOR PHOSPHORUS MANAGEMENT IN WASTEWATER: Examples for consultants and regulators Dr Robert Patterson FIEAust, CPSS, CPAg Lanfax Laboratories Armidale NSW 16th December 2016 Technical Note: T16-1 Calculations for P management in wastewater Lanfax Laboratories. Armidale 16th December 2016 Page 1 of 8 CALCULATIONS FOR PHOSPHORUS MANAGEMENT IN DOMESTIC WASTEWATER Dr Robert Patterson, Lanfax Laboratories, Armidale NSW 1. Introduction Phosphorus (as phosphate PO43-) is present in domestic wastewater (50% orthophosphate, 40% polyphosphate; 10% organic phosphates) and most passes through treatment systems such as septic tanks and aerated treatment systems (AWTS) in the effluent (discharge) without any significant lowering of the concentration. A minor component (6 to have a high P sorption (>6000 kg/ha) to both have ‘minor limitations’. Without any priority ranking of the soil features, there seems to be a problem with the Guidelines authors’ understanding of P sorption as more or less important than the other parameters. For Councils to simply take the discounting as mandatory (it is a guideline only), it would be preferable that they understand the specific soil test parameters. A blanket discount of measured P sorption cannot be justified, even on the basis of ultra-conservative issues. 5. Measurement of phosphorus sorption capacity P can be present in the soil in three forms: solution where the P is readily available to plants; labile P, more plentiful than solution P, that is not strongly adsorbed to the soil and may move into solution quickly; and non-labile P in adsorbed forms that is unavailable to plants. It is the non-labile P, the largest fraction of soil total P that is of interest in maximising the retention of P in the land application area and so prevent its loss to the wider environment. Phosphorus sorption isotherms relate mathematically the amount of P sorbed by soil to the concentration remaining in corresponding equilibrating solutions under a specified set of conditions (Rayment & Lyons, 2011). For agricultural purposes, the agronomist needs to know how to maintain a workable level of plant available P in the soil to avoid P deficiency in the pasture or crop. The phosphorus soption isotherm, as set out in Rayment & Lyons (2011) Method 9I1 provides a phosphate sorption index, reported as an index without units. Method 9I2 describes a P buffer index (PBI) that includes extractable P and P sorption for equivalent soil content of 20-160 mg P/kg in five increments. Method 9J leads to the construction of a phosphate sorption curve using equilibrating solutions yielding 2.5-250 mg P/kg. These methods provide valuable insight into the requirements of plant available P and fertiliser strategies but are poorly related to soil retention of P. Allen et al., (2001), indicated three other single point indices, plus variations, for deriving P sorption for fertiliser application, yet found these methods underestimated the total amount of P sorbed. The work by them was not suitable for adsorption rates for wastewater disposal. Holford ((1979) stated that in his research on 30 Australian soils, ‘there was no correlation at all between any of the buffering indices and phosphate uptake on these soils. His results suggest that a 4 to 5 point isotherm, giving final solution concentrations up to and including 5 mg P/L, is adequate to determine the most useful buffering indices’. This concentration is well below domestic wastewater (10 mg P/L) and shows how the indices are related to plant available P rather than immobilisation of P for environmental protection. In a wastewater treatment system, the desired outcome is to understand the capacity of the soil to bind P to prevent its movement out of the land application area, not the minimum concentration to support vigorous plant production. The two purposes are at opposite ends of the soil P sorption spectrum. Thus, the equilibrating solutions, used to determine a numerical value for the P sorption of a soil from effluent, are higher than used for agriculture (Patterson, 2001), and equilibrating solutions up to an equivalent of 1500 mg P/kg are required, six-fold higher than the Methods referenced above. The Guidelines state that “a simple test to distinguish soils on the basis of high and low P retention is described in Rayment & Higginson (1992)”, a book superseded by Rayment and Lyons (2011). The problem with this statement is that it is unclear as to whether the reference is to Method 9I1, 9I2 or 9J. Just knowing whether the value is high or low is insufficient, since later in the Guidelines (page 113) and Table 6 specific guidance values for minor, moderate and major limitations are given. Method 9I uses only one solution to give the phosphate buffer index, originally used for wheat-growing soils – that is, sufficient P in solution to sustain a wheat crop. Method 9J is used to derive an equilibrium P concentration, not the ultimate potential for P sorption. Do the regulators know which one applies? If so, it would be convenient for the laboratories and consultants to have some direction so as not to waste valuable resources on tests that have no meaningful value. But the regulators may not know which test, or amended test is applicable. Calculations for P management in wastewater Lanfax Laboratories. Armidale 16th December 2016 Page 5 of 8 DEC (2004) also simply refers to P sorption as high, moderate and low for slight, moderate and severe limitations respectively (Table 2.2) without any definitive numerical value in sorption as kg P/ha. The document makes no reference to a suitable P sorption test method, so across a number of consultants, a range of uncorrelated values may be submitted to rank as meaningless low, moderate or high. How can you calculate an area without numerical P sorption values? Patterson (2001) defined a modified P sorption index for domestic wastewater using five equilibrating solutions, a soil to solution ratio of 1:10 and a 17-hour equilibration period. The residual P in solution, that which has not been adsorbed by the soil, is measured and used to calculate the P sorption capacity. This method is similar to Methods 9I and 9J in Rayment & Lyons (2011), except the equilibrating solutions are many times higher. Figure 1 shows a typical low level P sorption capacity and Figure 2 a high P sorption capacity. The closer the measured curve to the straight line of the standards, the higher the potential P sorption. Rayment & Lyons (2011) suggest that the steeper the slope, the lower the plant available P in the soil. Higher P sorption characteristics are often measured in soils high in iron or aluminium. Blast furnace slag can be added to increase the P sorption in a low P sorption soil. Other high P sorbing products/soils can be sourced to add to the land application area, or incorporate in the trenches. The MEDLI Model (Model for Effluent Disposal using Land Irrigation) (DSITI, 2015) uses the multi-point form of the Freundlich isotherm to describe the equilibrium between adsorbed and soil solution P. MEDLI version 2 is for “designing and analysing effluent disposal systems for rural industries, agri-industrial processors (e.g. abattoirs) and sewage treatment plants using land irrigation”. In a similar approach to Figures 1-4, the user must provide numerical values as input to the modelling of plant available P in the soil solution and P adsorption. The P sorption curve is derived using six or more equilibrating solutions, together with measuring extractable P to give the Y-axis starting point. Burkitt et al., (2008) dispute the addition of the exchangeable P to the soil buffering measures. While MEDLI is used extensively in Queensland for domestic wastewater assessments, possibly for dubious reasons, the model parameters are only specific for kikuyu and tropical pasture, ryegrass and temperate pasture and sorghum pasture, with no suggested inputs for lawns and small domestic irrigation areas. A significant data set is required to run MEDLI, a costly exercise for domestic systems. Figure 1 Low level P sorption Figure 2 High level P sorption Note: the calculated P sorption capacities, in Figures 1-4, are for an equivalent depth of soil of 1 m, for an assumed bulk density of 1400 kg/m3. It will be necessary to alter the P sorption capacity for shallower or deeper soils. While P sorption can occur in a period of a few hours or days, desorption (the loss of soluble P from the adsorbed site) is a lengthy process that requires specific soil conditions and whether iron, aluminium or calcium ions are involved. The testing with elevated P concentrations accounts for a desorption that may have occurred during the testing, particularly that due to the high strength equilibrating solution. Figure 3 Psorbed (mg P/kg) against log C (ug P/L) Figure 4 Psorbed (mg P/kg) against log C (ug P/L) In Figures 3 and 4, the curve is extrapolated to the X-axis to determine the critical P concentration for agricultural purposes (soil solution P for adequate plant growth). The phosphate buffer index is taken as the slope of the line. standards 0 250 500 750 1000 1250 1500 1750 250 500 750 1000 1250 1500 P sorbed (mg/kg) Conc. P calibrating solution (mg/L) P-isotherm Example of low level P sorption Calculated P sorption kg/ha =2100 standards 0 250 500 750 1000 1250 1500 1750 250 500 750 1000 1250 1500 P sorbed (mg/kg) Conc. P calibrating solution (mg/L) P-isotherm Example of high level P sorption Calculated P sorption kg/ha =9900 y = 256.96x - 900.96 R² = 0.9842 0 300 1.00 10.00 P sorbed (mg/kg) Log10 final supernatant concentration ug/L P-isotherm Example of low level P sorption y = 455.89x - 1351 R² = 0.9718 0 250 500 750 1000 1.00 10.00 P sorbed (mg/kg) Log10 final supernatant concentration ug/L P-isotherm Example of high level P sorption Calculations for P management in wastewater Lanfax Laboratories. Armidale 16th December 2016 Page 6 of 8 6. P in wastewater P, as the anion phosphate (PO43-), exists in several forms in wastewater. Inorganic phosphate from laundry detergents and household cleaning products: Orthophosphate, sometimes referred to as soluble reactive P (SRP); and the polyphosphates made up of chains of phosphates such as pyrophosphate and tri-polyphosphate (TPP). These polyphosphates are unstable in water and break down into orthophosphate. This contribution is about 85% of the household’s wastewater flow. Organic phosphate sourced from human excreta (faeces and urine) and food wastes (kitchen sink). Nearly all (80-100%) the phosphates in domestic raw wastewater are present in the effluent from septic tanks (Crites and Tchobanoglous 1998). The same applies to aerated wastewater treatment systems (AWTS) unless there is an active means of removing P, which in most cases, there is not. When plant removal, precipitation and P sorption are taken into account, it is possible to design a land application area that can minimise the risk of transport of P outside the buffers to the area. The most likely cause of P moving off-site is through hydraulic failure and surfacing of effluent from trenches, or failed irrigation systems connected to AWTS. Erosion of surface soils removes soil particles to which P is adsorbed as well as the P in organic matter. Because orthophosphate is an ion (an anion to be correct), it is free to move with the percolating effluent through all the soil pores – macropores and micropores. As the water carrying the ions passes P sorbing properties, the phosphate ion is attracted and rapidly immobilised (adsorbed). Thus, all of the wetted zone from the effluent has the potential to immobilise the phosphate, not just the zone around roots or macropores, but throughout the soil profile. 7. Uptake of phosphorus by plants How much P a plant will uptake from the soil is related to the type of plant, its vigour and the availability of P in the soil and other growing conditions such as plant available water (PAW), balance of other nutrients (N, K, S, Ca), as well as temperature and sunlight. Moody (2011) suggests that biologically available P consists of dissolved reactive P (DRP) as dissolved and colloidal organic and inorganic P, and bioavailable particulate P (BPP) as that which is immediately available to microorganisms. The methods used to determine these fractions are not in routine use in Australia even though these fractions are important to agriculture and environmental risk analysis. While single point P sorption index is applicable to growing crops it does not quantify the immobilisation of P in wastewater management. In Section 1, the uptake used for modelling purposes was 30 kg P/ha, a value commonly attributed to grasses growing under favourable conditions, that is, no limiting P concentration in the soil water, adequate nitrogen, adequate plant available water and favourable weather. Since the effluent application area is not usually water limited, and has a mixture of nitrogen, P, potassium and sulphur (although imbalanced), the growth of plants is more akin to irrigated agriculture. Perhaps the need to mow the effluent application area more often than non-effluent areas is a practical expression of the greater plant production expected. The NSW Guidelines (p.153) suggest 2-4 mg P/m2.day is the rate of plant uptake of P, equating to 4.3 – 14.6 kg P/ha, in the effluent application area. AS/NZS 1547:2012 does not provide any guidance on plant uptake of P, as if it is not a limiting factor to land application area assessment. DEC (2004) Table 4.2 (p. 42) tabulates the P removed in effluent irrigated kikuyu and perennial rye as 60 kg and 48 kg P/ha respectively, about 0.3-0.4% of dry matter. No data are available for a typical domestic effluent irrigation area, but both grasses are used in domestic lawn mixtures. The significant difference between the NSW Guidelines and DEC (2004) is not readily explained. The most important consideration is that the effluent disposal area (surface or sub-surface) is an irrigated pasture, not a rain-fed pasture, so comparisons of P loading rates with other effluent re-use projects is more reliable as to the performance of the land application area. Comparing the domestic irrigation with commercial piggery wastewater is not a reasonable road to take. The second important aspect is that P is an essential plant macro-nutrient and where water and other nutrients are not limited, greater vegetation mass will be produced. That’s why the production of vegetation with effluent will produce more grass than rain-fed areas, and uptake more P and other nutrients. Removing those cut grasses harvests the P for use in other areas, such as composting for garden use. Sergeant (2009) indicated that for the establishment of perennial pasture, an initial application rate of 20-30 kg P/ha was required at establishment and thereafter on an annual basis. The effluent application area needs to be considered a perennial pasture, with mowing replacing hungry mouths. To reverse-engineer the size of the effluent irrigation area, using the 0.3-0.4% P in grasses/pasture/lawns, then to remove the calculated P load in Calculation A1 (1.825 kg P), one has to remove 608 kg dried grass per year. When effluent reuse data show 20 t/ha grass production (APL 2010, Table 14.4), then 304 m2 of irrigation area is required, without accounting for any P sorption. When only the difference between half of the P sorption (2000 kg P/ha) is taken into account in Calculation A3, then 260 m2 of irrigation area is required to produce 520 kg grass. The question to ask is whether the effluent irrigation area can produce that mass of grass. Calculations for P management in wastewater Lanfax Laboratories. Armidale 16th December 2016 Page 7 of 8 8. Improving soil phosphorus sorption capacity When the soil in a land application area, whether for surface irrigation or sub-soil drainfields, has a low P sorption capacity a large area is required for assimilation of that P to minimise risk of loss off site. If the calculations in A2 and A3 were applied to Figures 1 and 2, then the required land application areas would be 253 m2 and 80 m2 respectively. Thus, the actual determination of P sorption is required to address the P assimilation. Amelioration of effluent for the surface soil for irrigation or the trench for sub-surface disposal is always an opportunity. Adding aluminium or iron to increase the P sorption will only make the soil very acid and impede plant nutrition and needs to be done with cation. Adding calcium in the form of agricultural lime (calcium carbonate) or gypsum (calcium sulphate) is preferred. Lime will slowly increase the pH of the soil (make more alkaline) but gypsum has almost no effect upon shifting pH. Application rates of up to 0.5 kg/m2 (5 tonne/ha) of lime/gypsum can be applied. For irrigation areas, the lime/gypsum is simply spread on the surface and allowed to wash into the soil. Holford (1983) showed that for acid soils, the addition of lime increased the exchangeable phosphate (plant nutrition) while also increasing sorptivity. He also showed that for very acid soils (pH

The disposal of untreated industrial wastewater into water bodies causes excessive growth of algae and aquatic plants due to the presence of nutrients e.g. phosphorus and nitrogen in the untreated industrial wastewater. This results in deterioration of the water quality causing eutrophication of the water body.

Nitrogen and phosphorus needs to be removed from the wastewater if it is to be discharged into water body. The concentration of phosphorus (mg/L) and nitrogen (%) in the wastewater can be calculated as follows:

Phosphorus:

Plot a standard graph of concentration of phosphorus at various spectrop photometric absorbances and find the gradient of the graph. To find total phosphorus in wastewater the following formular can be applied:

📷📷×📷×📷

Phosphorus can be removed by passing the wastewater across an adsorber filled with activated alumina adsorbent.

Nitrogen:

Titrate the wastewater sample against 0.1M hydrochloric acid and record the titre value. Calculate the volume equivalent of the titre value in relation to Nitrogen. Measure and record the total volume of the wastewater and the 0.1M Hydrochloric acid used. The concentration of nitrogen in the form of free ammonia in the wastewater can be calculated from the formular:

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Nitrogen can be removed by passing the wastewater across an adsorber filled with zeolite adsorbent.