Integrated Wastewater Treatment In PRD

By Zeng Sasha, Liang Xiangjing 14 June, 2017

CT Environmental Group's Liang & Zeng elaborate on how a plant in Guangzhou leads in wastewater treatment

Editor’s note: Generating nearly one tenth of China’s GDP, the Pearl River Delta (PRD) Region is one of the most developed regions in the country. However, rapid economic boom over the past few decades also came at environmental costs. According to the Pearl River Commission, secondary industry accounted for about 46.3% of total wastewater discharged in the delta region. Polluting industries such as textile manufacturing are in particular in the spotlight. Zengcheng – a district within Guangzhou city – that hosts over 4,000 textile manufacturing companies, in particular denim clothes, accounts for 70% of China’s or 30% of the world’s total productions. Xintang, one township in Zengcheng, is even famed as ‘Jeans Capital of the World’. In Greenpeace’s 2010 exposé, shocking images of blue-coloured wastewater entering local rivers and toxic working environment in those jeans factories revealed the dirty secret of the fashion industry.
The Guangdong government has set the target of eliminating Grade V+ surface water bodies in PRD by 2020. Effluents from wastewater treatment plants are also required to meet more stringent limits in relevant discharge standards. Improving sludge treatment and recycling is also a key task in the following years. All these will require better monitoring and more investment towards infrastructure and new technologies. According to the 13FYP, the total investment needs on wastewater treatment and recycling infrastructure across China during 2016-2020 are expected to be RMB564.4 billion (USD82 billion). Guangdong will need RMB39.8 billion (≈USD5.8 billion). The government has been promoting PPP (public-private-partnership) models, in order to mobilise more private investment to fill the finance gap.

Yonghe Wastewater Treatment Plant in Zengcheng, Guangzhou is regarded as one of the key pollution control projects by both the Xintang town government and the Zengcheng municipal government. With a total floor space of 234mu (approx. 0.16 km²), the plant serves a total neighbouring area of up to 32.38 km², reaching the Guanghui Expressway in the north, the Guangzhou-Shenzhen Railway in the south, the Xin-xin highway in the west, and the Sha-ning highway in the east.

Phase 1 to 3: different PPP models

Phase 1 and Phase 2 of the project adopt the Build-Operate-Transfer (BOT) business model. The project is funded and operated by Guangzhou Haitao Environmental Protection Technology Company Limited (“Haitao”), a wholly-owned subsidiary of CT Environmental Group Limited (“CTEG”).

Phases 1 & 2 adopt the Build-Operate-Transfer business model with a treatment capacity each of 50,000 m³/day

The two phases were designed to process municipal wastewater with a treatment capacity of 50,000 m³/day each (the total capacity of 100,000 m³/d), and have commenced operation since 2010 and 2012 respectively. These two phases adopt the modified Anaerobic/Anoxic/Oxic (A/A/O) treatment process and the sludge generated is treated and recycled as nutritious soil in the qualified sludge treatment and disposal workshop within the plant.

Phase 3 treats wastewater from 18 textile co’s in the region funded under the Build-Own-Operate business model

In order to assist the local government in actualising the centralised treatment of printing and dyeing wastewater from the manufacturers in the Sha Pu Area, Phase 3 of the industrial wastewater treatment project was later initiated and funded by Haitao. The Phase 3 facility commenced trial operation in 2013 and up to now has been receiving and treating wastewater from 18 textile companies in the target region. The facility adopts the Anoxic/Oxic (A/O) plus final sedimentation treatment process and after tertiary treatment combines the effluent with those from Phase 1 and 2 before discharge.
Phase 3 was funded by Haitao under the Build-Own-Operate (BOO) business model and is dedicated to centralised treatment of industrial wastewater from the bleaching and dyeing manufacturers in Sha Pu area of Xintang town. This phase is considered one of the quintessential win-win solutions for environmental pollution control based on the partnership between private capital and public sector.

Coordination with local government

There is only one discharge outlet for the whole plant and the discharged water is required to achieve the higher standards between First Grade A level of “Discharge standard of pollutants for municipal wastewater treatment plant (GB18918-2002)” and First grade for the second category pollutants in session II of “Discharge limits of water pollutants (DB44/26-2001)”, i.e. between the applicable national standard and provincial standard.

Discharged water is required to achieve the higher standards between the applicable national standard & provincial standard

As a compulsory requirement by the Guangzhou Municipal Environmental Protection Bureau (Guangzhou EPB), a real-time online automatic monitoring system was installed on the discharge outlet. This system samples and tests the effluent every 2 hours and transmits the results to an online monitoring platform every 10 minutes, so as to ensure the consistent monitoring of the effluent quality. The system is operated and maintained by a third party authorised by the Guangzhou EPB.

The dyeing sludge produced by the treatment system in the Phase 3 facility is transferred to Haitao’s sister companies – Heyuan Solid Waste Centralised Disposal Center Co., Ltd. and Qingyuan Lvyou Environmental Protection Technology Co., Ltd., which are also wholly-owned subsidiaries of CTEG and qualified for comprehensive treatment and disposal of sludge, for eventual recycling into construction materials. At last, according to the urban river remediation plan of the local government, the effluent water is pumped to a watercourse circa eight kilometres away from the wastewater treatment plant as supplemental water to improve the water quality of the watercourse before it flows into the upstream of Dongjiang River.
Thanks to strong support from the local municipal engineering and planning department, Haitao was able to lay wastewater collection main pipes along the nearby highway and railway, as well as sub-pipes connected to the textile manufacturers. Under the BOO business model, Haitao signs service contracts with every manufacturer individually. Among other terms, the treatment tariff is determined based on the quality of wastewater produced, i.e. the nature of the production. The daily processing volume is agreed on based on the scale of the production in those factories. Moreover, manufacturers must notify Haitao in advance if there are to be any substantial changes in their productions.

Haitao also coordinates with the local govt to prevent illegal discharge actions from enterprises

At the same time, in coordination with the local government and the environmental protection department, Haitao is able to obtain the monthly water consumption volume of its customers through flow meter readings. If the monthly wastewater discharge volume of the manufacturer is less than 95% of its monthly water consumption, then Haitao will charge the wastewater treatment fees based on 95% of the water consumption volume. This in a way acts as a powerful constraint on any illegal discharge actions from those enterprises.

Beyond wastewater treatment – sludge treatment & deodorisation

Furthermore, the volume of sludge generated from municipal wastewater treatment plants is ever increasing in Guangzhou, driving the demand of municipal sludge treatment and disposal to an unprecedentedly high level. In order to address the sludge issue as well as embrace the market opportunity, Haitao invested in a municipal sludge treatment and disposal facility within the wastewater treatment plant. The facility adopts an aerobic fermentation treatment process to compost the municipal sludge before turning it into nutritious soil, so as to achieve harmless disposal of sludge. The daily treatment capacity of municipal sludge is 900 tons.
Haitao has also set up three sets of biofilter deodorisation systems to collect and treat odour produced during wastewater treatment and sludge treatment processes in an effort to improve surrounding environmental quality. Additionally, two deodorisation systems were installed at the sludge dehydration workshop, using liquid spray deodorisation techniques to effectively reduce the offensive odour produced during the treatment process. The plant also pays attention to afforestation through setting up a greenbelt area to enhance ambient air quality.

Such a market-oriented model can be beneficial to the plant, govt, enterprises & the environment

By adopting a market-oriented operational model, this plant, especially in Phase 3, shows how professional environmental solution providers can maximise its value in pollution control with proactive coordination and effective supervision from the local government. It also helps relieve manufacturing companies from the burden of in-house wastewater treatment. Such a model is beneficial to the sustainable development of all parties in the region in the long run.

Further Reading

• 2016 State of Environment Report Review – The signs are positive for China’s environment in 2016. Groundwater quality improved after 5 years of decline though there is mixed news for rivers & lakes. Is the tide turning in China’s ‘war on pollution’?
• Environmental Law: 2 Years On – China’s new Environmental Protection Law has been in force more than two years now. Has it been enforced? What has the impact been? Who has been hit? Professor Wang Canfa from the University of Political Science and Law in Beijing reviews
• 12FYP Water Quality Report Card – Bao Hang & Deng Tingting from Greenpeace East Asia share key findings from their report on provincial performance in the 12FYP. Which provinces met water quality targets? Which failed?
• No Safe Haven For Polluters – As affluent eastern Chinese provinces are cleaning-up, companies are relocating to inland provinces with more lenient regulations. China Water Risk’s Hubert Thieriot explores this pollution haven effect & why it can be a short-sighted strategy
• Flushing With No Water – 2.4bn people still lack clean sanitation but flushing toilets may not be the answer with limited or no access to water. Derek Lam expands on an affordable alternative – a waterless, chemical-free toilet system named DEHTLET

PRD & regional action

• Pearl River Delta: 5 Water Must-Knows – China’s Pearl River Delta generates 9% of GDP but water challenges lurk behind the dazzling economic success. Don’t know what these are? China Water Risk’s Feng Hu shares 5 water must-knows for the region
• Why Should PRD Business Lead In Water Stewardship? – With the Pearl River Delta set to lead China’s economic growth, China Water Risk’s Feng Hu & the Alliance for Water Stewardship’s Zhenzhen Xu explain why business should adopt water stewardship to ensure continued prosperity
• Water Stewardship In Industrial Parks: TEDA Pilot – Industrial parks generate 22.5% of China’s GDP but can this last given water security and pollution concerns? An Chen, from the TEDA Eco Center & Zhenzhen Xu from the Alliance for Water Stewardship show how the Tianjin Economic-Technological Development Area leads in mitigating these risks

Wastewater in China & treatment

• Wastewater: Good To The Last Drop – Happy World Water Day! In the year of wastewater, we look at China’s management of the ‘waste’. Plus, what does the 13FYP hold? Action; given rising wastewater discharge & low re-use rates
• 8 Things To Know About Recycling Water – Recycling water could alleviate some of China’s water challenges. Yet, only 10% of its treated wastewater is recycled. Not sure what reclaimed water is? Check out China Water Risk’s 8 things you should know
• Cost-Effective Carbon Reduction In Wastewater Treatment – The wastewater industry consumes a lot of energy. Xylem’s Lu Shuping shows how its rapid expansion makes it ripe for attractive energy savings opportunities, especially in China
• T Park: Waste-to-Energy In Hong Kong – Hong Kong’s increasing waste load by 2030 will put tremendous pressure on its management capability.  Veolia’s Nina Cambadelis introduces T PARK, a state-of-the-art sludge treatment facility that turns waste into energy while achieving ‘zero wastewater discharge”
• Treating Landfill Black Water – Landfill leachate, a highly polluting effluent, is now under new China EPA standards. Regular treatment has limitations but EWS:AOx™ by OriginClear is versatile alternative as its Jean-Louis Kindler, Nicholas Eckelberry and Stephen Jan show
• Changing Filters: Benefits of AFM vs Sand – Sand filters are the primary means of treatment but there are performance & stability issues. Dr Howard Dryden, inventor of the up-cycled AFM® filter tells us how his filter means lower costs & bacteria & longer life

PPP’s in China

• Water PPPs To Lead In China – All new water & wastewater projects in China need to follow the Public-Private-Partnership (PPP) model. Will this mean big change and how have other water-related projects been funded in China? China Water Risk’s Yuanchao Xu takes a look