Total Residual Chlorine Chlorine is a common wastewater disinfectant. Residual chlorine in effluent is toxic to fish in receiving streams and so must be removed with a dechlorinating chemical, such as sulfur di-oxide. Many NPDES permits place limitations on the amount of total residual chlorine (TRC) that can be discharged after dechlorination. Often, a permit…
Immediate first aid should be given to any cut or abrasion that occurs at a wastewater treatment facility. A physician should treat more serious injuries. Proper sampling techniques should prevent breakage and spillage. Sample bottles should have a wide mouth opening and, whenever possible, should be plastic. If glass containers are required, the glass should…
1. A water storage tank is 35 feet in diameter and 65 feet high. WIth no water entering the tank, the water level dropped 14 feet in 5 hours. Find the average flow for water leaving the tank in gallons per minute. 2. If two pumps transfer 120 gpm each how long will it take…
1. Possible types of atmospheric hazards found in manholes include _. a. explosion b. oxygen deficiency c. toxic gas d. all the above 2. The flushing water pressure in a water-lubricated wastewater pump should be _ the pump discharge pressure. a. 10 psi less than b. 5 psi less than c. 5 psi more than…
1. A well operated digester normally receives sludge at about _ % volatile solids and reduces it to about _ % volatile solids. a. 70 – 75%, 25 – 30% b. 90 – 95%, 45 – 50% c. 90 – 95%, 25 – 30% d. 70 – 75%, 40 – 45% 2. Chlorine applied minus…
pH In a laboratory, pH meters are generally calibrated once in the morning and once in the afternoon. In the field, calibrate for each set of samples or whenever field conditions change. Calibrate to two points that bracket the expected sample pH and are at least 3 pH units apart using the following sequence: *…
Toxins are chemicals or chemical mixtures that, under certain circumstances of exposure, present an environmental or human health risk. Toxins include metals, hydrocarbons, and synthetic organic chemicals. Concentrations of toxins in wastewater can be a concern in industrialized areas or where monitoring data indicate potential toxicity. Storm water contributions to CSOs in urbanized areas can…
pH Measurement of pH is one of the most important and frequently used tests in water/ wastewater analysis. Practically every phase of water supply and wastewater treatment is pH dependent. At a given temperature, pH indicates the intensity of the acidic or basic character of a solution. A solution’s pH is the outcome of the…
Bacteria are simple, unicellular organisms. Most bacteria range in size from 0.1 micrometers (µm) to 15 µm, and the shape of most bacteria is rod (bacillus), spherical (coccus), or spiral (sprillium). Bacteria are ubiquitous in nature, and most are harmless. They reproduce asexually, usually by splitting in half, and may be found as individual cells,…
1. How many gallons does a 400 foot long section of 24-inch pipe hold? 2. The distribution system has 3 storage tanks. Each tank is 50 feet square and 30 feet deep. What is the maximum storage volume of the distribution system in gallons? 3. Find the perimeter of a circular sedimentation basin if the…
