TABLE 3: proportion of municipal authorities using various wastewater characteristics to CALCULATE SEWAGE SURCHARGES
spent wet grains is provided in Tables 1 and 2. Separation can be achieved with a variety of equipment, including centrifuges, screens, etc. (n = 71) (adapted from Garcia et al., 2016) Many distillers, especially small plants, do not yet AUTHORITIES do this. If you are sending your liquid byproducts WASTEWATER CHARACTERISTIC UTILIZING (%) (i.e., whole stillage or thin stillage) to the city water TSS — Total suspended solids 97.2 treatment system, there are many issues that you BOD — Biochemical oxygen demand 90.1 need to consider. FOG — Fats, oil, and grease 31.0 Public wastewater treatment authorities have TKN — Total Kjeldahl nitrogen 26.8 fee structures where non-residential customers COD — Chemical oxygen demand 21.1 (e.g., distilleries) are charged according to the TP — Total phosphorus 16.9 burden that they place on a wastewater treatment facility. One component of this fee is a surcharge 16.9 NH3 — Ammonia based on the specific chemical characteristics of CBOD — Carbonaceous biochemical oxygen demand 4.2 your wastewater. Municipal authorities periodically CI Demand — Chlorine demand 2.8 sample customers’ wastewater streams and analyze TOC — Total organic carbon 1.4 them for parameters such as biochemical oxygen Some of these properties are explained in Table 4. demand (BOD), total suspended solids (TSS), Source: Garcia, R .A., Nieman, C.M., Haylock, R .A., Rosentrater, K .A., Piazza, G.J. 2016. The effect of chicken blood and its components on wastewater characteristics and sewage surcharges. Poultry Science. 95(8):1950-1956 ammonia (NH3), and other chemical/physical properties. The specific chemical characteristics which are monitored vary by authority, and these so understanding how these fees are determined is not always parameters are then used, along with the volumetric output of clear. In a recent study (Garcia et al., 2016), data was gathered wastewater, to compute each customer’s fee. on the methods used to determine sewage surcharges for industrial Every city in the U.S. is unique, however, and each has its own customers. For each public sewage treatment authority, information rate structure. But a large proportion of U.S. wastewater treatment on the pollution characteristics measured, rates, and methods of authorities do not post their surcharge formulas on the Internet, computation were recorded and assessed. Overall, information was collected on 71 wastewater authorities throughout the U.S. TABLE 4: Information about the chemical characteristics used to determine surcharges from these municipal authorities is summarized in Table 3. Over 90% of the municipalities surveyed included both TSS and BOD in the determination of sewage surcharges. Between PROPERTY TYPICAL VALUES 21% and 31% used FOG, TKN and COD to determine fees. Less Is the amount of dissolved oxygen needed (i.e. than 20% of the municipalities used other chemical factors. Table demanded) by aerobic biological organisms to break Biochemical oxygen down organic material present in a given water sample 4 provides definitions of these terms. demand (BOD) at a certain temperature (20oC most often) over a specific time period (5 days is common). In the national dataset of municipalities, there were multiple ways to calculate sewage surcharges. For 60 of the 71 (84.5%), Is a measure of the amount of oxygen that can be consumed by reactions in a measured solution. It surcharge formulas were expressed with this type of formula: Chemical oxygen is commonly expressed in terms of mass of oxygen
general definitions of parameters used to assess the PROPERTIES of WASTEWATER EFFLUENTS
consumed per volume of solution, which in SI units is milligrams per liter (mg/L). A COD test can be used to quantify the amount of organics in water.
Total suspended solids (TSS)
Is the dry-weight of suspended particles (not dissolved particles) in a sample of water that can be trapped by a filter, and is analyzed using a filtration apparatus.
Total phosphorus (TP)
Phosphorus compounds originate from the cereal grains, and are concentrated during fermentation.
Nitrogenous compounds originate from the cereal grains, and are concentrated during fermentation.
Total Kjeldahl nitrogen (TKN)
Is the total nitrogen bound in organic substances, nitrogen in ammonia (NH3-N), and in ammonium (NH4+-N) in the chemical analysis of soil, water, or wastewater (e.g. distillery effluent). Nitrogenous compounds originate from the cereal grains, and are concentrated during fermentation.
Fats oil and grease (FOG)
These are oils that accumulate in the stillage, and are concentrated during fermentation. They originate from the cereal grains that are used.
Si = V × (Bi − Ci) × D × Ei(1) Where: • Si is the surcharge for a given wastewater characteristic i (US $) (See Table 3 for the typical characteristics) • V is the total volume of wastewater discharged during the billing period (gallons) • Bi is the measured concentration of the wastewater characteristic i in the discharged wastewater (mg/L) • Ci is the allowable concentration of the wastewater characteristic i (mg/L) • D is a unit conversion factor (typically 8.34 lb · L/mg · gal) • Ei is a cost factor for the wastewater characteristic i (US $/lb)
The magazine for craft distillers and their fans.