Henan Wastewater Treatment Plant, Yiyang Subdistrict, Henan Province, China

The Henan wastewater treatment plant is located in Yiyang Subdistrict, part of Huangchuan County in Xinyang City, Henan Province, China. It serves a population of 160,000, classifying it as a medium-to-large agglomeration under Chinese wastewater management frameworks. The plant is situated inland, approximately 115 km east of the nearest coast, and its operations are integral to the local urban water infrastructure. As a facility serving 160,000 people, the plant is expected to meet China's Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (GB 18918-2002), which mandates secondary treatment with nutrient removal for plants of this scale. The regulatory framework also requires compliance with effluent limits for chemical oxygen demand, ammonia nitrogen, and total phosphorus to protect receiving waters. The plant likely employs conventional activated sludge or similar biological treatment to meet these standards. The plant discharges treated effluent into local watercourses that ultimately drain into the Huai River basin, a major river system in eastern China. The Huai River flows eastward into Hongze Lake and then into the Yellow Sea. The plant's operations help protect downstream water quality in the Huai River watershed, which supports agriculture, fisheries, and domestic water supply for millions of people.

The plant's treated effluent enters local waterways that feed into the Huai River basin, one of China's major river systems. The Huai River flows through Henan, Anhui, and Jiangsu provinces before reaching Hongze Lake and eventually the Yellow Sea. The watershed supports extensive agricultural irrigation and is ecologically important for migratory birds and freshwater fisheries. Protecting water quality in this basin is critical due to its dense population and intensive land use.