New tech urged to abate paper making pollution
A petrochemical plant transforms its daily discharge of waste gas into a material for paper making in Central China's Henan Province
When Cai Lun invented the technique of paper making 1,900 years ago, he probably never expected that the development, for all the great achievements it has led to, would be responsible for extensive environmental degradation.
Today, the paper industry is blamed for huge timber consumption and the discharge of millions of gallons of toxic waste every year.
At a forum on the environmental issues facing the industry, held recently in Beijing, experts called for the adoption of technical innovation to combat pollution and the integration of tree planting into the production process.
Of the first batch of eight environmentally-friendly enterprises appraised by the State Environmental Protection Administration (SEPA) last year, two were paper makers - Gold East Paper Co Ltd and Kunshan Banknote Paper Mill in Jiangsu Province.
"Their achievements show that through technical innovation it is possible for the paper making industry to shake off its reputation as a destroyer of the environment and natural resources," said Li Xinmin, vice-director of SEPA's Pollution Control Department.
However, China's paper making industry is still facing an urgent need to reduce waste emissions and save natural resources, said Li.
"In 2004, of 41 industrial sectors, the discharge of waste water by the paper industry ranks second, only chemical plants discharge more," he added.
According to Li, the paper industry produces 3.18 billion tons of waste water and 1.48 million tons of COD (Chemical Oxygen Demand) each year, accounting for 16 per cent and 33 per cent respectively of the total released by Chinese industry.
Although the industry is such a major polluter, it only contributes 2.2 per cent of the country's economic growth.
Most of China's paper making enterprises are in a small scale, producing less than 10,000 tons per year, way below the world average of 40,000 tons.
The industrial structure also needs to be improved. Currently, at least half the country's domestic paper products are made from straw pulp, which cannot make a high-quality product. High-quality paper products made from timber pulp are mainly produced by joint enterprises or depend on imports.
"The paper industry consumes a lot of resources, especially timber," said Shen Hanyao, director of the Shanghai-based Warton Economic Institute. "Production of one ton of art paper needs 4-5 cubic metres of timber. China's timber resources are not enough to meet the demand."
Because of the insufficient timber supply, the government once advocated the use of straw pulp. But, the use of straw led to serious pollution.
One ton of pulp made from timber needs less than 30 tons of water and releases 30-50 kilograms of COD; one ton of pulp made from straw needs 200 tons of water and discharges 350 kilograms of COD.
Due to the unstable supply of straw, factories using straw pulp are small-scale and cannot afford the investment needed to install environmentally-friendly equipment. As a result, said Shen, the country's small paper factories have become big polluters.
According to an investigation by SEPA, the COD from small-and-medium paper-making factories is three times the national standard. In Henan Province, waste water released by about 300 small paper factories accounts for 34 per cent of the province's total.
Xu Daping, a professor at Beijing Forestry University, blames the country's shortfall in timber resources on the lack of financial incentives to plant trees, failure to protect forests and the widespread felling of primeval forests.
While China does not have enough timber to feed its own industry, exports continue to grow. "The export, even to countries which are rich in timber resources, aggravates the shortage of raw materials for the domestic paper industry," Shen said.
"We should increase the timber pulp used in paper making to improve paper quality and reduce pollution," said Pu Junwen, a professor at Beijing Forestry University.
"Planting trees is the first, vital step in paper making. The integration of tree planting and paper making is necessary for the country to develop its forestry resources and paper making industry. The planting of fast growing trees will not only help the paper industry, but also help the country save its natural forest resources, especially primeval forests," Pu said.
As even fast growing trees take years to reach maturity, new forests do not just spring up over night. Use of straw pulp cannot be given upin a short time and the search is on for other environment-friendly materials.
"Reed, bamboo and bluish dogbane can be considered for paper making," Pu said. "These kinds of raw materials can produce high-quality paper. What's more, alkali can also be retrieved to help protect the environment."
The country has rich bamboo resources. With plenty of experience in making paper from straw pulp, the industry can select new raw materials to make up the shortfall in timber.
Experts have also called for the increased use of recycled paper. In Japan, about 78 per cent of waste paper can be recycled, and in Germany the figure is 83 per cent. In China, only 30 per cent can be reused. In the United States, more than 50 kinds of paper products can be recycled, but in China, only books, cardboard boxes and newspapers can be recycled.
Shen suggested that heavier taxation on exported timber could help limit exports, and better protect China's own timber resources.
The country should take active measures to protect its forests and give priority to domestic demands, Shen said.
(China Daily 11/01/2005 page5)
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