Worksheet Grade 9 English Language Arts
Turning Biosolids into Fertilizer: A Grade 9 Vocabulary Worksheet
A grade 9 vocabulary and comprehension worksheet on how a fictional water reclamation facility recovers nutrients from wastewater and turns them into fertilizer.
Objectives
- Students will define technical vocabulary related to wastewater treatment and nutrient recovery using context clues.
- Students will trace how a treatment plant recovers nutrients from wastewater and returns them to agricultural use.
- Students will apply the passage's removal-rate figure to a new hypothetical scenario.
Vocabulary
- Effluent
- Effluent is the cleaned water that leaves a treatment plant at the end of the process. It is tested carefully before being released to a river, lake, or the ocean.
- Biosolids
- Biosolids are the nutrient-rich solid material left over after sewage sludge has been treated and made safe. Many farms use treated biosolids as fertilizer for their fields.
- Secondary treatment
- Secondary treatment uses billions of helpful microbes that eat the dissolved waste in the water. The plant keeps the microbes supplied with air, then settles them out, leaving much cleaner water.
Also: BOD
Teacher overview
Environmental biotechnology puts living microorganisms to work solving practical problems, and one of its clearest examples is a wastewater plant that turns a treatment byproduct into fertilizer. This worksheet builds vocabulary and comprehension skills around a short passage describing that process, then asks students to apply the passage's key figure to a new scenario. A common misconception this worksheet addresses is the assumption that biosolids are simply sludge removed from water and discarded; the passage and questions are built to correct that by tracing exactly how the material is recovered, stabilized, and reused.
Student Worksheet
Read the passage below, then answer the questions that follow. Elm Fork Water Reclamation Facility is a fictional plant used for this worksheet.
Recovering Nutrients at Elm Fork
At Elm Fork Water Reclamation Facility, engineers do not treat wastewater as trash. They treat it as a resource with more than one useful product. The facility's secondary treatment stage uses billions of naturally occurring microorganisms. These microorganisms consume the organic material in wastewater. That is the same biological process at work in a compost pile, but it happens in large aeration basins under close control. Secondary treatment must bring effluent down to a monthly average of 30 mg/L or less of both BOD and TSS. That is a removal of roughly 85 percent from the raw sewage, which typically enters the plant carrying 200 to 300 mg/L of BOD. The microorganisms responsible for that removal settle out as solids, called sludge, once they have consumed what they can. Elm Fork does not send this sludge to a landfill. Instead, it further treats and stabilizes it into biosolids, then blends the finished product into a nutrient-rich fertilizer sold to regional farms. The nitrogen and phosphorus once considered pollution in the wastewater return to farmland instead. That closes a loop between a city's drains and its fields.
Based on how the passage uses the word "effluent," what does it most likely mean?
Based on how the passage describes microorganisms consuming it, what does BOD most likely measure?
According to the passage, secondary treatment must bring effluent down to what monthly average for BOD and TSS?
According to the passage, roughly what percentage of BOD is removed from raw sewage during treatment?
The passage compares secondary treatment to a compost pile. In your own words, explain what makes that comparison accurate.
Why does the passage describe biosolids as part of "a resource" rather than only "trash"?
Define "stabilized" as it is used in the passage, based on context clues.
Using details from the passage, explain how nitrogen and phosphorus "return to farmland" after starting out in wastewater.
A fictional new water reclamation facility processes raw sewage carrying 250 mg/L of BOD. It removes 85 percent of the BOD. About how many mg/L remain in its effluent? Does that meet the 30 mg/L standard described in the passage?
In two or three sentences, explain why calling this process "water reclamation" rather than "waste disposal" reflects what actually happens at Elm Fork.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Answer Key
- Answer: Effluent is the treated water that leaves the plant, since the passage discusses bringing "effluent" down to a specific standard after treatment.
- Answer: BOD measures the organic material in wastewater that microorganisms consume, since the passage describes microorganisms consuming the organic material that BOD represents. Strictly, BOD (biochemical oxygen demand) measures the oxygen those microorganisms use while breaking the material down, so it serves as an indirect measure of how much organic material is present.
- Answer: A monthly average of 30 mg/L or less for both BOD and TSS. The passage states this directly.
- Answer: About 85 percent. The passage states secondary treatment removes roughly 85 percent of the BOD present in raw sewage.
- Answer: Accept reasoned answers. A strong response notes that, like a compost pile, secondary treatment relies on naturally occurring microorganisms breaking down organic material, just carried out in a controlled facility instead of a backyard bin.
- Answer: Because the facility recovers and reuses the biosolids as fertilizer rather than discarding them, turning a treatment byproduct into something with value instead of waste meant only for a landfill.
- Answer: "Stabilized" means treated further so the material is safe and consistent enough to be processed into a usable product, based on the passage's description of the sludge being further treated and stabilized into biosolids before becoming fertilizer.
- Answer: The nitrogen and phosphorus originally in the wastewater end up inside the sludge removed during treatment; once that sludge is stabilized into biosolids and turned into fertilizer and sold to farms, the same nutrients are applied to fields instead of remaining in the water.
- Answer: About 37.5 mg/L would remain (250 mg/L multiplied by 0.15), which does not meet the 30 mg/L standard described in the passage, meaning this fictional facility would need additional treatment.
- Answer: Accept reasoned answers. A strong response notes that "waste disposal" implies simply getting rid of something, while "water reclamation" reflects that the facility recovers usable water and nutrients from what enters as wastewater.
Differentiation
Support (below grade level)
Provide a short glossary defining "effluent," "BOD," "biosolids," and "secondary treatment" before reading, and allow items 5, 6, and 10 to be answered orally instead of in writing.
Extension (above grade level)
Ask students to work out, using only the passage, what might happen to Elm Fork's fertilizer product if the incoming wastewater carried an unusually high BOD level one month, and to explain their reasoning using the passage's removal-rate figure.
ELL supports
Pre-teach "microorganism," "organic," "recover," and "nutrient" with simple definitions and an image of a treatment basin before reading. Allow items 1, 2, 3, 4, and 7 to be answered with short phrases rather than full sentences.