Miss professor need before 12 central time
giants2018
Chapter12.pptxChapter 12 – Solid & Liquid Wastes
Learning Objectives
By the end of this chapter, the reader will be able to:
Describe trends in the production of solid waste
Discuss methods for source reduction of solid waste
Discuss the role of landfills for disposing of solid waste
Describe methods for primary, secondary, and tertiary sewage treatment
Discuss hazards of poorly designed solid waste disposal sites and improperly processed sewage
Two Major Challenges
Disposal of Solid Wastes
History of disposal methods
Challenges of growing volume of waste
Proposed solutions
Treatment & Processing of Liquid Wastes
Human solid wastes (sewage)
Animal wastes
~4.5 pounds per person, per day
Hierarchy for Managing Waste
Source Reduction (best)
Recycling
Energy Recovery
Disposal (worst)
Hierarchy for Managing Waste
Source Reduction (best)
Recycling
Energy Recovery
Disposal (worst)
Reducing the amount of waste created
Strategies:
Reusing/donating items
Buying in bulk (less packaging)
Reducing packaging (e.g. water bottles)
Redesigning products
Reducing toxicity of materials produced
Hierarchy for Managing Waste
Source Reduction (best)
Recycling
Energy Recovery
Disposal (worst)
Sorting and processing recyclable products into raw materials
Then remanufacturing with the recycle materials
Benefits:
Preventing emissions
Saving energy
Supplying valuable raw materials
Creating jobs
Conserving resources
What’s the recycling rate in Houston?
Only 6%... The “diversion rate” is 19%,
but 13% of this is yard waste
One Bin to Rule Them All..?
Houston has an abysmal recycling rate – approximately 17 percent diversion rate (only 6 percent came from recycling, the rest from yard waste disposal)
Compared to San Francisco at ~80 percent diversion rate
In 2013, the City of Houston won a $1M grant under a program to spur municipal innovation – the Bloomberg Philanthropies Mayors Challenge
Awarded for a “One Bin” approach to recycling – all trash (recyclable and not) would be combined in one bin
Sounded a lot like… trash, actually
One Bin to Rule Them All..?
One bin program looked a lot like a Dirty MRF (materials recovery facility)
The vendor for the City of Houston claimed it was not just a MRF
A Clean MRF accepts only recyclables
Can recover from 5 to 45% of materials as recyclables
The rest is still landfilled
In the end, Mayor Sylvester Turner decided against a one bin approach, and opted for a more traditional approach to recycling with separate waste and recycling streams
Hierarchy for Managing Waste
Source Reduction (best)
Recycling
Energy Recovery
Disposal (worst)
Convert non-recyclable waste materials into energy (heat, electricity, or fuel), called “waste-to-energy”
Processes:
Combustion
Gasification (convert to gas without combustion)
Pyrolization (decomposition of organic materials)
Anaerobic digestion
Landfill gas
Hierarchy for Managing Waste
Source Reduction (best)
Recycling
Energy Recovery
Disposal (worst)
Treatment to reduce volume & toxicity
Can be physical, chemical, or biological
Landfills are the most common form of waste disposal
Methane gas may be produced and trapped (form of energy recovery)
Wastes & the Three P’s
Population
Pollution
Poverty
Hazardous Wastes
Regulated by the Resource Conservation and Recovery Act (RCRA) of 1976
Characterized by the following four traits:
Ignitability
Reactivity
Corrosivity
Toxicity
Additionally, RCRA includes listed hazardous wastes
CERCLA (what is this act usually referred to as?)
Provided for the clean-up and remediation of sites with hazardous waste
Household Hazardous Waste (HHW)
In general, legal for most households to dispose of HHW as normal, municipal solid waste
Modern landfills are designed to handle normal amounts of HHW
Some examples:
Paints/solvents
Motor oil, gasoline
Pesticides
Products with Mercury
Batteries
Aerosols
Cleaning agents
2nd Major Problem – Treatment & Processing of Liquid Waste
What do we already know about this?
Pliny, the Elder
Philosopher, author, military commander
Most notable for writing Naturalis Historia, a 37-book encyclopedia
Commented in Natural History that Roman sewage systems, among all the things the Romans had accomplished, were “the most noteworthy of all”
Roman Sewer Systems
Poorer quality water from aqueducts was used for latrines and public baths
Sewers covered by stones that flushed waste from latrines and bath houses to nearby rivers (in Rome, the Tiber)
First sewers built between 800 and 735 BCE
Latrines – public and private – were built
Around 100 AD, homes were directly connected to sewage systems
By then, after 900 years of development, the sewage system was very efficient
Cloaca Maxima – one of the earliest sewage systems; drained low-lying marshes, as well as sewage from Rome
Waste and Antimicrobial Resistance (AR)
What is antimicrobial resistances?
Scope of the problem
Accounts for ~50,000 deaths in United States and Europe
Estimates as high as 700,000 worldwide
Projected to be as high as 10M by 2050
Pharmaceutical waste and agriculture animal waste are major contributors to the issue
Pharmaceutical Waste
Waste can include pharmaceutical drugs, such as antibiotics
Minor source of pharmaceutical waste is from patients disposing drugs
Major sources is from the production of the active ingredients in drugs
India exports ~20% of the world’s generic drugs; China exports more than 60% of active pharmaceutical agents
Hyderabad, India has 90 pharmaceutical companies that discharge ~400,000 gallons of wastewater daily
Antibiotics in India’s Wastewater
Antibiotics in India’s Wastewater
Ciprofloxacin was found at concentrations higher than patient’s blood
As high as 31 mg/L
In one day, as much ciprofloxacin was disposed of in Hyderabad’s water as used in Sweden for 5 days (to treat ~44,000 individuals)
Researchers found drug-resistant genes in downstream sites
Almost 2% of DNA samples had resistant genes
Not just India…
Tamiflu in the Rhine River
Tetracycline & penicillin in China
Bacitracin in Norway
Hospital waste water throughout the world
Antibiotics and Farm Animals
~80% of antibiotics (by weight) are given to farm animals
Administered in low doses in food and water
Promotes growth and to prophylactically avoid infections that would be rampant in the modern factory farm
Natural Resources Defense Council report found that the FDA had allowed 30 potentially harmful antibiotics (18 classified as “high risk” by the FDA) to be used as additives to animal food and water
A review in 2001 found that 26 of the 30 did not even meet 1973 safety criteria
None of the 30 would meet current guidelines
However, 28 are still approved for use, 9 of which are still being actively marketed
The European Union has banned all antibiotic use as growth promoters
Denmark has banned all prophylactic use
Questions?
