Living with pollution
During the first half of 2014, 63.6% of the days registered a pollution level over the limit in 13 cities in the Beijing-Tianjin-Hebei region. Only 36.4% of the days registered a pollution level below or at the limit for healthy air. The main pollutants were PM2.5 and PM10. In that region, the average PM2.5 concentration was 100 mg/cubic meter, and the average PM10 concentration was 174 mg/cubic meter.
In 2013, the annual average PM2.5 concentration in that region was 106 mg/cubic meter.
As of the end of March, 2014, China has 3,622 sewage treatment plants with a daily treatment capacity of 153 million cubic meters.
Director of water policy research center at Qinghua University, Fu Tao, estimates that by 2015, the annual amount of wet sludge with a water content of 80% produced by all sewage treatment plants will reach 33,590,000 tons. A 2013 analysis of China’s sludge treatment showed that 67% were buried in landfills, 12% were used as compost, and treatment of 18% of sludge was unaccounted for.
According to the deputy director of the Environmental Sciences and Engineering Academy of Tianjin University, Ma Degang, sludge contains large amounts of pathogenic bacteria, parasitic larvae, copper, zinc, mercury and chromium.
Yet, 80% of sludge in China are not treated.