Think the garbage you throw out is worthless? From waste disposal tycoons to scrap metal multimillionaires and recycling billionaires, an eye-opening number of people have become fabulously rich dealing with our refuse, proving that one person's trash is most certainly another person's treasure. Here are 15 of the most impressive success stories.

Thrown in at the deep end, North London-based Jacqueline O'Donovan took over her father's eponymous waste disposal company in 1990 at the age of 19 following his untimely death. At this point, the modest trash collecting firm had an annual turnover of $225,000 (£175k).

Together with her siblings, O'Donovan has built a thriving business with annual revenues exceeding $26 million (£20m) mainly through sheer hard work and dedication. Now a multimillionaire, London's queen of waste has won numerous business awards for her efforts.

From London's queen of waste to the Texan queen of trash, Maria Rios is the president and CEO of Nation Waste, the first female Hispanic-owned waste disposal company in the US. Rios had a tough start in life, escaping conflict-ravaged El Salvador at the age of 13 with her parents.

The family ended up in Houston, where Rios studied hard at school, and put herself through college. Upon graduation in 1997, the savvy entrepreneur founded her waste disposal business with a small bank loan, which paid for two garbage trucks. Nowadays, the firm has dozens of vehicles and turns over a cool $30 million (£23.3m) a year.

Politician Scott Wagner, who represents the 28th district in the Pennsylvania State Senate, has made enormous sums of money collecting and processing trash. The multimillionaire senator founded his garbage management company Penn Waste in 2000.

Since then, the company has grown spectacularly, expanding from Pennsylvania into neighbouring states. Penn Waste now processes 81,000 tons of trash a year, most of which is recycled and used to create green energy.

The late business whizz and philanthropist Percy Ross was best known for his Thanks a Million newspaper column and radio show, which donated cash to needy readers who wrote in and asked for assistance.

Ross didn't make his fortune from trash as such, but the deep-pocketed entrepreneur bought a company producing plastic garbage bags in 1959 and got rich as the business expanded, which gives him an honorary place in our round-up.

Canada's scrap metal king, Herbert Black has made hundreds of millions of dollars processing and repurposing rusty old pieces of metal. The Montreal entrepreneur's father Peter established the American Iron & Metal Company (AIM) in 1936.

In 1970, Herbert and his brother took control of AIM, transforming it into a multi-billion-dollar global enterprise. Herbert, who is notoriously litigious, has had his fair share of legal scrapes along the way, but is renowned for being ultra-altruistic, having donated millions to good causes.

A serial entrepreneur and real estate mogul, Sidney Torres IV is also known as the New Orleans trash king. The Louisiana business maestro made a very smart move when he set up SDT Waste & Debris Services in the aftermath of Hurricane Katrina.

Torres profited big-time from the massive clean-up operation and sold the company for millions in 2011. The trash tycoon, who has since moved into real estate developing, has even managed to bag several lucrative TV gigs along the way, including TLC's Trashmen and a house-flipping show on CNBC called The Deed.

Recycling entrepreneur and headline-grabbing philanthropist Chen Guangbiao realised he was on to a winner in 2003 when he made a small fortune selling on scrap iron retrieved from a demolition project in his adopted city of Nanjing in East China.

Chen, who is known for grand charitable gestures and OTT promos, founded construction waste company Jiangsu Huangpu Renewable Resources not long after, and by 2009 the firm was turning over almost $2 billion (£1.6bn) annually.

British steel magnate Jack Walker was worth almost $1 billion (£720m) at the time of his death in 2000. The Blackburn native started out in the scrap metal trade, transforming his Walkersteel company over the years into a key steel industry player.

Walker channelled a large chunk of his fortune into his beloved Blackburn Rovers Football Club, which he acquired in 1991. Thanks to Walker's cash, the club gained a promotion to the newly formed Premier League and went on to win the Premiership title in 1995.

Now worth in excess of $1 billion (£776m), Anatoly Sedykh heads Russia's leading manufacturer of train wheels and second largest pipe maker. The United Metallurgical Company (OMK) chairman was able to bankroll the company with money he made from scrap metal dealing.

In 1989, Sedykh secured a bumper loan from Russia's biggest bank Sberbank to fund a scrap metal recycling project, which netted him millions, enough cash to buy a controlling stake in 1999 in the Vyksunsky Metallurgical Plant, which later became OMK.

While Herbert Black is Canada's scrap metal king, Patrick Dovigi is the country's newly crowned king of waste and recycling. A former minor league hockey player, Dovigi eschewed a sports career for garbage, making his first forays into waste management in the early 2000s.

In 2007, the Ontario native established waste management and recycling firm Green For Life Environmental and hasn't looked back. The company now operates throughout Canada and parts of the US, and generates billions of dollars in revenue a year.

Yet another female entrepreneur who has been dubbed the queen of trash, Zhang Yin launched Ying Gang Shen, a paper recycling company back in 1985, using her entire life savings of $3,800 (£2.9k).

Zhang founded Nine Dragons Paper Holdings in 1995 and cornered the market by importing scrap paper from the US and turning it into cardboard boxes. Now China's biggest paper maker, the company generates billions of dollars in sales a year.

A college dropout from a family of garbage collectors, the late Wayne Huizenga, who passed away in March, co-founded Waste Management, Inc. in 1968, starting out with a single garbage truck that covered a small area of Chicago.

Huizenga didn't waste any time expanding the company, and by the early 1980s, his firm was one of the largest of its kind in the US. The garbage tycoon went on to found Blockbuster Video and car retailer AutoNation, and acquire several sports teams, including the Florida Marlins.

Like Anatoly Sedykh, entrepreneur Igor Altushkin figured out the best way to get rich in the chaos of 1990s Post-Soviet Russia was to deal in scrap metal, and he wasn't wrong, making a killing from the trade.

In 2004, the Ekaterinburg native founded the Russian Copper Company in his home town. The firm is now Russia's third largest copper producer with a turnover of just under $2 billion (£1.6bn) annually.

The billionaire founder of diversified metals and mining company Vedanta Resources, Anil Agarwal began his career as a scrap metal dealer in the early 1970s, gathering discarded cables from companies around India, then selling them on at a premium in Mumbai.

In 1976, Agarwal acquired his first metals firm and moved into manufacturing in the 1980s. A signatory of the Giving Pledge, the Indian tycoon has promised to donate 75% of his wealth to charity during his lifetime or at his death.

Anthony Pratt is the Executive Chairman of Visy Industries, the world's largest, privately-held 100% recycled paper and packaging company. The Melbourne firm was founded in 1948 by Anthony's father Richard.

Pratt assumed control of the company upon his father's death in 2009, and has since presided over an ambitious expansion plan, boosting the firm's revenues no-end, and basically making billions of dollars from other people's paper trash.