Organic waste model transforms Erhai Lake's water quality

Local officials said the ecological environment and water quality of Erhai Lake in Dali Bai autonomous prefecture, Yunnan province, have been greatly improved thanks to a complete industry chain model for organic waste resource utilization.

Erhai Lake sits 1,972 meters above sea level and covers roughly 250 square kilometers. The ear-shaped freshwater lake is one of the largest highland lakes in Yunnan.

According to officials at the province's agriculture and rural affairs department, five organic fertilizer processing plants and 25 livestock and poultry manure collection stations have been built in the Erhai Lake basin with support from the local government.

They provide a subsidy of 80 yuan ($11.2) per ton to enterprises that collect and turn livestock and poultry manure and other organic waste into resources. These enterprises collect and process more than 140,000 metric tons of such waste annually.

"There is a large number of livestock and poultry breeders in the Erhai Lake basin. If not collected, the manure may flow into the lake and pollute its water," said Liu Fei, executive deputy general manager of Yunnan Shunfeng Erhai Environmental Technology Corp, on Tuesday.

To encourage these breeders to participate in environmental protection action, the company classifies the manure into different quality grades and purchases it at prices ranging from 80 to 120 yuan per metric ton, he said.

"We collect them from 22,380 breeders daily," Liu said, adding that the manure is transformed into organic fertilizers and biogas using green and environmentally friendly technologies.

Statistics from the company show that it collects nearly 2,000 metric tons of organic waste every day from the basin, including livestock and poultry manure, crop straw, kitchen waste, and dead aquatic plants. It has an annual production capacity of over 800,000 metric tons of organic fertilizers and over 30 million cubic meters of biogas.

Liu added that organic fertilizers can improve soil fertility and promote the sustainable development of agriculture in an eco-friendly way.

This organic waste resource utilization model has been promoted nationwide as an exemplary case by both the Ministry of Ecology and Environment and the Ministry of Agriculture and Rural Affairs, local officials said.