An activated sludge plant (CSTR w/ recycle) has the following characteristics: Influent substrate concentration, So = 400 mg/L BODL (all soluble); influent VSS, Xvº = 0; effluent 3 substrate concentration, S = 10 mg/L BODL; flow rate, Q = 1000 m³/day; aeration basin volume, V = 200 m³; reactor MLVSS, Xy = 4,280 mg/L; average, steady-state oxygen uptake rate, Oxygen uptake rate (OUR) = 0.3 mg 02/L-min. The biomass viability (i.e., v = Xa/Xv) was measured using the oxygen uptake rate (OUR) technique and found equal to 0.926. An aliquot of mixed liquor was placed in a small reactor, aerated without any exogenous substrate addition (i.e., starvation conditions) and it's OUR was measured over time resulting in the following data: 0 1 2 3 4 5 6 8 10 Time (days) OUR (mg 02/L-min) 0.3 0.274 0.243 0.222 0.203 0.182 0.165 0.135 0.110 By use of the above data, the microorganism decay coefficient (b, day) can be estimated if you assume that a constant relationship exists between Xa and OUR, i.e., OUR = a Xa, where a = proportionality constant (g O2/g Xa - min). 1. Estimate b (1/d) by using the above data (Use regression). 2. Calculate the solids retention time for this plant. 3. Calculate the net biodegradable fraction of the viable biomass (fd).

If you are working at a sewage treatment plant, which microbial process(es) would you use to reduce nitrates in sewage before releasing into rivers? Why? denitrification; to reduce occurrence of HAB's nitrification; to make water richer in fertilizers when used by farmers nitroge fixiation; to increase dissolved oxygen in river water nitirification to convert nitrates to unusable nitrites; to increase algal growth in water

Leachate production is what

The graph is of initial velocity versus substrate concentration. Estimate Vmax from the direct graph of v versus [S] using the plot. Estimate KM from the direct graph of v versus [S] using the plot, also.

Drinking water can be obtained via (a) bottled spring water or (b) a sink-mounted reverse osmosis device. Briefly discuss two negative aspects of each, from a sustainability point of view.

Salt Treatment Tap Water Treatment Distilled Water Treatment   Which of these experimental conditions is hyprtonic and which is  isotonic?

Mentions the advantages of membrane bioreactors in water treatment

this resource can be replaced by natraul process and will never run out

(b) (c) Explain the biological requirements for microalgal growth and the main system components for a microalgal processing plant to produce biofuel. How is the system design dependent on its geographical location? A continuous microalgal production system is being developed using a raceway design to produce biofuel from CO2 sequestration. Calculate the area of the raceway (m²) to sequester 2000 tons of CO₂ per year if the growth rate is 75mg/L-day and estimate the amount of biofuel that could be produced. Clearly state any assumptions that you make.

Specify the equipment used to measures the temperature, turbidity and salinity of the water