OVERCOMING THE BIGGEST TREATMENT CHALLENGES Extracting river pollutants using Amazonian plants Jonathan L Jones Senior Environment Officer WWT Wastewater 2019 Conference & Exhibition, National Conference Centre, Birmingham, 29 January 2019
Background The EU Water Framework Directive requires that all UK waterbodies achieve “Good Ecological Status” Ecological Based upon by 2027 (waterbodies are classified as opposite) Status or physical, chemical Potential and biological Study area status High The Fendrod River is currently failing for: Good Fish; Macroinvertebrates; Moderate Zinc; If one element Cadmium; Poor fails then that is Manganese; and the status of that Bad water body Poly-aromatic Hydrocarbons Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
Nant-Y-Fendrod catchment The river, which is approximately 4.5km in length, is a tributary of the main River Tawe, which in turn drains the Swansea Valley into Swansea Bay (an EU designated bathing water, SSSI and Commercial fishery) Situated in the heart of the South Wales Coal field; Location of historic metal smelting; During the 1800s, 60% of the world’s copper and zinc was smelted here due to an abundance of coal; Smelting waste was disposed of in-situ. *Geological map taken from http://www.bgs.ac.uk Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
Swansea Bay, River Tawe and Swansea Marina Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
Lower Swansea Valley during its industrial past Morfa Bank Works on the Lower Tawe Vivian & Sons Old Forest Works at Numerous Spelter works Swansea, later converted into Morriston occupying the valley Spelter Works . Reproduced from Col. floor in Morriston Grant Francis, ‘The Smelting of Copper in the Swansea District (1881) Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
So why is this work important? Failure to achieve Good Ecological Status may result in UK Government facing costly infraction proceedings. This would also represent a failure to protect our most vital natural resource. Environmental pollution is a global problem affecting human, animal and plant health, particularly in developing countries; Clean water is needed to support a healthy ecosystem; We need to develop sustainable treatment methods to effectively deal with problematic pollutants and overcome poor wastewater and river water quality; With enough research, treatment methods can be developed to utilise waste or problematic materials as a sustainable source of treatment media; This has implications for not only waste water treatment though drinking water too, especially in developing countries and those where water poverty is an issue. Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
Heavy metal pollution Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
Manganese Site Name Max/Min/Mean Zinc (µg/L) Cadmium (µg/L) (µg/L) 2400 4.28 563 Maximum Nant-Y-Fendrod d/s of 150 0.19 142 Minimum flood alleviation lake Mean *870.14 1.25 314.57 4320 12.9 Maximum 9.5 Nant-Y-Fendrod u/s of 183 0.19 Minimum 2.42 Nant-Y-Ffin 2039.28 1.25 Mean 5.67 2600 17.9 Maximum 21.8 Nant-Y-Ffin u/s of Nant-Y- 150 0.44 Minimum 2.18 Fendrod 870.14 5.2 Mean 5.84 4320 14.4 Maximum 9.87 Nant-Y-Fendrod d/s of 327 1.43 Minimum 3.13 Nant-Y-Ffin 2399.41 7.65 Mean 6.23 1080 9.18 Maximum 6.04 River Tawe d/s of Nant-Y- 11.9 0.111 Minimum 1.02 Fendrod Mean 78.34 0.93 1.87 Maximum 45.3 0.14 2.82 River Tawe u/s of Nant-Y- Minimum 5.29 0.11 1.07 Fendrod Mean 11.23 0.12 1.66 Maximum 27.4 6.41 5.65 Nant Bran u/s of Minimum 6.54 16.1 9.22 Nant-Y-Fendrod Mean 15.4 0.1 1.1 Maximum 29.2 6.68 10.7 Nant-Y-Fendrod u/s of Minimum 5.46 0.12 1.05 Nant Bran Mean 13.99 0.82 4.03 Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
Other sources of pollution Other than historical contamination, pollution sources that have been identified include fly-tipped waste, domestic sewage, contamination from highway drains, suspended solids from construction activities and contamination from incidents at food and chemical processors; GCMS Screening shows that chronic and acutely ecotoxic chemicals are entering the stream via the drainage system e.g. Bisphenol A, which is a widespread, problematic endocrine disruptor. Passive monitoring has further examined this. Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
Passive Monitoring using Diffuse Gradient in Thin Films and Chemcatcher DGT results identified using ICP-MS Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
Water hyacinth (Eichhornia crassipes) An aquatic plant which originated in the rain forests of the Amazon Basin and is native of Brazil; It is the world’s fastest growing free -floating hydrophyte; Its rapid growth produces dense mats that block water bodies causing flooding, navigation problems and interfere with crop irrigation, power generation and ecological status; Whilst the plant has a prolific growth rate and is deemed to be invasive, it is also an excellent accumulator of heavy metals and due to its abundance, presents an attractive low-cost, green remediation strategy; Images courtesy of Adobe stock photos Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
Phytoremediation Investigations Conducted at three levels, namely: A bench-scale study using polluted river water and synthetic solutions; An in-situ trial using Water hyacinth within the Fendrod river; and A bankside trial to pump and treat river water; Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
Bench-scale study Metal(loid) Percentage Percentage removal removal 7 hours 21 days Aluminium 63% 100% Table showing maximum percentage removal of metals observed in ten litre Zinc 62% 80% samples of polluted river water Cadmium 47% 100% exposed to water hyacinth plants over a period of just seven hours; Manganese 22% 100% Arsenic 23% 45% Column three shows results when Nickel 19% 50% extended to three weeks exposure (optimum time required reported in Cobalt 14% 100% literature): Initial metal concentrations, expressed in µg/L were as follows: Al – 89.82; Zn – 2020.33; Cd – 6.23; Mn – 421.83; As – 2.11; Ni – 3.99; Co – 1.66 Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
In-situ study Metal(loid) Percentage removal Assessed if the plants can 8 hours remove metal pollutants from actual river water in a dynamic Aluminium 18.23% flow setting; Titanium 10.41% An amount of removal was demonstrated given only a very Chromium 39.56% short exposure time under flow Zinc 12.22% conditions. Cadmium 15.47% Manganese 6.37% Arsenic 23% Nickel 7.18% Copper 12.81% Cobalt 21.39% Antimony 26.49% Lead 7.22% Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
Bank side study Metal(loid) Percentage removal Again assessed if the plants can remove metal pollutants from 8 hours actual river water in a dynamic Aluminium 24.58% flow setting without interference of dilution by surrounding river Chromium 22.57% water; Zinc 4.04% An amount of removal was Cadmium 6.72% again demonstrated given only a very short exposure time under Manganese 5.38% flow conditions and under sub- Arsenic 9.39% optimal climatic conditions (conducted in October); Nickel 5.76% Copper 10.76% Cobalt 6.88% Tin 8.32% Lead 25.54% Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
Comparison of all three studies This Venn diagram shows similarities and differences between metals removal during each of the studies Jonathan L Jones Wastewater 2019 Conference, National Conference Centre, Birmingham 29 January 2019
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