Converting food waste is not a rubbish idea(2)

Natural balance

Yu, 49, sees the world as a constant recycling of chemical elements. Nature works through the interaction of animals, plants and microbes, she said. Ideally, the three work consistently and reach a natural balance. But the natural process has been disrupted in China by the expanding gap between urban and rural areas, she said.

Consumption by urban dwellers increases rapidly as cities expand. Trash treatment facilities can't keep pace, so rubbish is transferred to outlying areas. As a result, huge cities are surrounded by rubbish landfills, as Wang's documentary shows.

But it's not just a useless mess. Yu said about 70 percent of China's urban trash is rich in organic compounds. The challenge is to distill the nutritious elements from them and put them to use.

The abundance of rich garbage material in urban areas contrasts with the poor soil in some rural areas, where peasants turn to chemical fertilizers to boost agricultural production. Such fertilizers can increase output in the short term; in the long term, they damage the soil and make it more barren.

Further, too much of certain elements in those synthetic fertilizers, such as nitrogen, enters the water supplies and becomes a source of pollution in the ecosystem. Some chemicals also can go into the vegetables and fruits, making them decay easily and harming people's health.

For Yu, the solution is to reconnect the ecological chain. The company collects the garbage in urban areas, processes it, makes it into organic fertilizers and sells them to the rural areas.

Business value

In addition to the goodwill factor, Yu's business plan has the potential of producing profits. China generates about 1 billion tons of rubbish a year, 10 million tons of it cooking waste. The most common ways of disposal are to burn it or bury it. Neither way creates any business value.

Many rubbish treatment companies depend on government subsidies as their main source of income. Goldenway says it can ask for fewer subsidies because it can realize income through the sale of its fertilizers.

And the company obtains the raw materials almost for free, providing a competitive edge. Goldenway sells fertilizer through big State-owned companies, such as Sinochem Group, and directly to the government, which distributes it to rural areas.

Unlike most fertilizers used in China, Goldenway's fertilizer is organic, which can make the soil healthier. Zhang Hailiang works a strawberry field on a farm in Changping, northwest of Beijing. When he started, he said, the soil was almost barren. "It was so hard that our tools broke when we tried to turn the area into a strawberry field."

After three years, the soil has recovered its quality and now produces strawberries. "The farmers all know that the organic fertilizer is useful," Zhang said. "Some even fight for it."