Water-Energy Nexus in the Antofagasta Mining District: Options for Municipal Wastewater Reuse from a Nearly Energy-Neutral WWTP

Author:

Campo Giuseppe1ORCID,Ruffino Barbara12ORCID,Reyes Arturo3,Zanetti Mariachiara1

Affiliation:

1. DIATI—Department of Environment, Land and Infrastructure Engineering, Politecnico di Torino, 10129 Torino, Italy

2. CleanWaterCenter@PoliTO, Politecnico di Torino, 10129 Torino, Italy

3. Departamento de Ingeniería en Minas, Universidad de Antofagasta, Antofagasta 1240000, Chile

Abstract

The region of Antofagasta is the mining hearth of Chile. The water requirement of the local mining sector is 65% of the total water uses, with a water consumption of approx. 9 m3/s in the year 2020. That determines an important pressure onto freshwater, which can only be alleviated by resorting to desalination or reuse of treated wastewater. At present, an amount equal to 90% of the wastewater generated in the city of Antofagasta is discharged into the ocean, after undergoing only preliminary treatments. The wastewater treatment plant (WWTP), which includes a conventional activated sludge (CAS) process, has a very low treatment capacity, insufficient to serve the whole population. A new WWTP will be built with the twofold aim of (i) purifying the totality of the wastewater generated from the city (approx. 320,000 equivalent inhabitants, e.i.), and (ii) allowing the reuse of 100% of the treated wastewater in the local mining sector, in agreement with the goals of the Chilean government. The new Antofagasta WWTP will include preliminary treatments and a conventional activated sludge (CAS) process with a higher treatment capacity. This study integrates a number of modeling tools, namely the Activated Sludge Model n.3 (ASM3), the Takacs model, and some stoichiometric and energy balances, to assess the impact that some changes, possibly introduced into the project of the new WWTP, could determine on its energy and environmental sustainability. Specifically, through an energy-economic-environmental (3-E) analysis, the original scheme of the planned WWTP was compared with three scenarios, of which Scenario 1 introduces anaerobic digestion (AD) of secondary sludge, Scenario 2 concerns primary sedimentation and AD of both primary and secondary sludge, and, finally, Scenario 3, other than primary sedimentation and AD, also includes a pre-denitrification process. The results of the study demonstrated that all the changes introduced by Scenario 3 were of capital importance to promote the transformation of the WWTP into a nearly energy-neutral water resource recovery facility (WRRF). Specifically, the processes/operations introduced with Scenario 3 can reduce the electric energy demand from external sources to only 20% of that of the original scheme, and consequently avoid the emission of 4390 tons CO2-equivalent/y.

Funder

European Commission

Publisher

MDPI AG

Subject

Water Science and Technology,Aquatic Science,Geography, Planning and Development,Biochemistry

Reference67 articles.

Cited by 2 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3