s) You are setting up a composting batch and have 8 tonnes (metric tons) of poultry litter with a C:N of 14, a dry weight % of N of 2.7%, density of 500 kg/m³, and a moisture content of 33%. You are aiming for a C:N of 25:1 for optimal composting performance, so you are considering several options of other wastes to make up your batch. The following table shows the moisture content, C:N and cost per tonne of each material. You estimate that you will lose 20% of the initial mass during the composting process. Determine which would provide the best return on investment if you can sell your compost for $80/m³ and the density of the finished compost is 400 kg/m³. Waste Type Shredded newsprint Sawdust RDF Moisture content C:N 152 530 60 18 40 45 Dry % N 0.2 0.1 1.1 Cost/tonne $200 $110 $80

6-1. Assume that refuse has a C/N ratio of 24:1. If raw sludge with a C/N of 16:1 is to be added to refuse to reach a required C/N of 20:1, how much of each-refuse and sludge-is needed? (Note: Use a wet weight basis.)

A BOD test is run using 100 ml of treated waste H20 mixed with 200ml of pure water. The initial DO of the mixture is 9.0 mg/ml. After 5 days, Do id 4.0 mg/ml. What is the 5-day BOD of the waste water?

Do the needful

A BOD analysis was begun on Monday. Fifteen ml of waste with a DO of zero was mixed with 270 mL of dilution water with a DO of 9 mg/L. The sample was then put in the incubator. Since the 5th day fell on a long weekend (Friday) and lab personnel do not work on Saturday, the final DO did not get measured until Monday, the eighth day. The final DO was measured at 2.8 mg/L. However, it was discovered that the incubator was mistakenly set at 32 ºC. Assume k is 0.15 day-1 at 20 ºC and θ= 1.05. Determine the 5-day 20 ºC BOD of the sample. Also, what is the ultimate CBOD at 32 ºC and 20 ºC; Will it vary?

The City of Forty-Five (population 465,565) has requested your assistance in evaluating its solid waste collection system. Determine the mean time per collection stop plus the mean time to reach the next stop, the number of pickup locations per load, and the minimum number of trucks the city must own. The City of Forty-Five collection data are as follows: Average truck capacity = 12.5 m3; Average observed compaction ratio = 2.87 Crew size = 2;  Number of pickups = 1 /wk (no rear-of-house service) Average number of cans per stop = 2.63/wk at 0.1136 m3/can Average number of residents per stop = 5 Average uncompacted density = 105.76 kg/m3 Average transport time to disposal site including delays and dumping = 1.78 h/trip Average number of trips to disposal site = 2/d; Rest breaks = 2 at 28.0 min Average maintenance downtime = 37.0 min/d; Average workday = 8.00 h Average percent of trucks out of service for major repairs = 15.0% Number of workday per week = 5

If the BOD4 of a waste is 200.0 mg/L and the ultimate BOD is 270.0 mg/L, what is the rate constant at 10⁰C.

The majority of municipal solid waste is 64% paper. What ways would you suggest to reduce paper waste?

7. (B)

Urgent please