An effluent stream sample (500 mL) from a metal-working facility contains 0.52 g nickel sulphate. (i) What is the nickel concentration of this effluent stream (in mg/L)? (ii) Would you regard this concentration as suitable for discharge to the local sewage system? (iii) How much total nickel (in kg) leaves the facility per year in this stream if ~1 ML of effluent is produced?

Among the treatment schemes depicted below, select all that are able to perform enhanched biological phosphorus removal. Group of answer choices

A waste stream is discharging into a river at a rate of 5 m3/s. Upstream of where the waste stream enters the river, the river has a streamflow of 100 m3/s with a nitrate concentration of 1 mg/L. Downstream of where the waste stream enters, the nitrate concentration has been measured to be 3 mg/L. What is the nitrate concentration in the waste stream? Assume no change in storage in the system.

Please upload your full solution to the following problem. A series of experiments was conducted in a batch reactor to assess the disinfection by chlorine of the protozoan Giardia lamblia. In each experimental run, the concentration of free available chlorine was varied and the time required to kill 99 percent of the organisms was determined. The results showed that a Ct value of 100 mg-min/L was sufficient to achieve 2-log removal. Assume that the Chick- Watson model holds with n = 1. A. What value is the psuedo-first order disinfection rate coefficient k (min ¹) when the chlorine concentration is 1 mg/L? B. At a chlorine concentration of 1 mg/L and a contact time of 10 minutes, what fraction of the G. lamblia organisms would be killed? C. At a chlorine concentration of 10 mg/L and a contact time of 5 minutes, estimate the fraction of the G. lamblia organisms that would be killed. 4

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.