L8 - Wastewater Treatment Works

Question 1

what is urban stream syndrome

Answer 1

describes the degradation of streams in urban areas, characterised by increased runoff, altered hydrology, water pollution and stressed biodiversity

Question 2

how does impervious surface cover affect water quality and biodiversity

Answer 2

Impervious surfaces increase surface runoff, transport pollutants and debris, and elevate water quantity in streams, stressing or killing stream organisms

Question 3

what are the stages of wastewater treatment

Answer 3

1. Preliminary Treatment: Mechanical removal of coarse solids
2. Primary Treatment: Sedimentation to remove suspended solids
3. Secondary Treatment: Biological treatment to oxidize organic matter
4. Tertiary Treatment: Advanced treatment for nutrient removal and disinfection (optional)

Question 4

what % of pollutants does primary treatment remove

Answer 4

• Suspended solids: ~70%
• BOD: ~40%
• Phosphorus: ~30%
• Nitrogen: ~20%
• E. coli bacteria: ~90%

Question 5

what is the role of anaerobic bacteria in sludge treatment

Answer 5

anaerobic bacteria convert raw sludge into a stable product by breaking down proteins, fats and polysaccharides, producing methane and CO2

Question 6

what are the disposal methods for sludge

Answer 6

1. use as farmland fertiliser
2. landfill
3. incineration

Question 7

why is the river Medlock in greater Manchester significant for freshwater studies

Answer 7

It is highly urbanized with a history of industrial pollution, combined sewer overflows (CSOs), and nutrient discharges, making it a critical site for studying river management

Question 8

what were the results of the river Medlock study regarding water quality?

Answer 8

• Upstream sites (S1 & S2) had cleaner water and higher dissolved oxygen.
• Downstream sites (S3-S5) showed higher pollution from wastewater treatment works (WwTW) and CSOs.
• Phosphate levels remained high downstream, indicating ineffective treatment.

Question 9

what is the EU water framework directives classification of the river Medlock?

Answer 9

It is classified as a heavily modified water body with poor ecological potential due to hydromorphological alterations and diffuse pollution

Question 10

what are the dominant benthic macroinvertebrates phyla in the river Medlock

Answer 10

1. arthropoda (72%)
2. annelida (28%)

Question 11

what role did public perception play in the river medlock study

Answer 11

Public concerns about river pollution initiated the research, leading to partnerships and significant investments in improving water quality

Question 12

what is the correlation between physical and chemical variables and benthic invertebrates in the River Medlock?

Answer 12

Conductivity, discharge, and phosphate levels were key factors affecting invertebrate communities, with increased pollution downstream

Question 13

what are the benefits of river restoration efforts

Answer 13

• improved biodiversity
• removal of barriers like weirs
• enhanced ecological health and compliance with environmental standards

Question 14

how can the future of freshwater ecosystems be secured

Answer 14

1. Enforce effective policies and environmental regulations
2. Monitor and research ecosystems continuously
3. Collaborate with communities and research partners
4. Train skilled personnel for water management

Question 15

what is the importance is benthic macroinvertebrates in assessing water quality

Answer 15

They serve as bioindicators of pollution, with their diversity and abundance reflecting water quality changes

Question 16

how do CSOs affect water quality

Answer 16

CSOs release untreated sewage and stormwater into rivers, increasing BOD, nutrients, bacteria, and suspended solids, degrading water quality

Question 17

What improvements have been made in the River Medlock following the study?

Answer 17

Investments in CSOs and WwTW have improved water quality, though challenges remain with diffuse pollution and hydromorphological impacts