上海地区大型公共建筑中水工程成本效益分析

Cost-benefit analysis of treated wastewater reuse for large public building in Shanghai

针对上海地区大型公共建筑中水回用问题,采用蒙特卡罗模拟技术,对其全生命周期成本效益进行了分析,并讨论了水价对中水工程成本效益的影响.成本计算结果表明生物接触氧化工艺在全生命周期内总成本集中在240.27～276.00万元之间.不同水价方案计算结果表明,在上海现行水价的条件下,生物接触氧化工艺全生命周期效益主要集中在-53.98～-37.54万元之间,50年内不存在投资回收期;当水价为3.8元/t时,生物接触氧化工艺的全生命周期效益主要集中在23.03～51.94万元之间,投资回收期为18～19a;当水价为6.10元/t时,工程效益主要集中在192.47～263.36万元之间,投资回收期为4～5a.因此单从中水工程的成本效益角度来看,上海现行水价偏低,中水回用工程缺乏推广优势,建议适当提高水价或对中水回用工程进行补贴.

For the issues of treated wastewater reuse in large public building in Shanghai,analysis of the cost and benefit of the project of treated wastewater reuse was performed based on life cycle assessment and Monte Carlo simulation. The cost of the biological contact oxidation treatment process in life cycle concentrated in a range of 2.4027～2.7600 million yuan. At current water price in Shanghai,the whole lifecycle expected benefits mostly ranged from -539.8～-375.4 thousand yuan and return period of investment did not exist within 50 years. When the price is 3.8 yuan per ton,the benefits raise to 230.3～519.4 thousand yuan and cost could be recovered within 18～19 years. If the tariff reached 6.10 yuan per ton,1.9247～2.6336 million would be achievable and the payback time would reduce to 4～5 years. Consequently,in terms of the cost and benefit of the project of treated wastewater reuse,the present water price in Shanghai was so cheap that it did harm to the promotion of treated wastewater reuse. So the suggestion had been proposed that raising the water price appropriately or subsidizing the project.