A meta-analysis of water quality and aquatic macrophyte responses in 18 lakes treated with lanthanum modified bentonite (Phoslock®)

WATER RESEARCH

卷:97

Article

Spears, Bryan M.¹  Mackay, Eleanor B.²  Yasseri, Said³  Gunn, Lain D. M.¹  Waters, Kate E.¹  Andrews, Christopher¹  Cole, Stephanie⁴  De Ville, Mitzi²  Kelly, Andrea⁵  Meis, Sebastian^1,6  Moore, Alanna L.¹  Nurnberg, Gertrud K.⁷  van Oosterhout, Frank⁸  Pitt, Jo-Anne⁹  Madgwick, Genevieve¹⁰  Woods, Helen J.¹  Lurling, Miquel^8,11 

[1] Ctr Ecol & Hydrol, Penicuik EH26 0QB, Midlothian, Scotland

[2] Lancaster Environm Ctr, Ctr Ecol & Hydrol, Lib Ave, Lancaster LA1 4AP, England

[3] Inst Dr Nowak, Mayenbrook 1, D-28870 Ottersberg, Germany

[4] Environm Agcy, Red Kite House,Howbery Pk, Wallingford OX10 8BD, Oxon, England

[5] Broads Author, Yare House,62-64 Thorpe Rd, Norwich NR1 1RY, Norfolk, England

[6] Lanaplan GbR, Lobbericher Str 5, D-41334 Nettetal, Germany

[7] Freshwater Res, 3421 Hwy 117, Baysville, ON P0B 1A0, Canada

[8] Wageningen Univ, Dept Environm Sci, Aquat Ecol & Water Qual Management Grp, POB 47, NL-6700 AA Wageningen, Netherlands

[9] Environm Agcy, Stn Rd, Haddiscoe NR31 9JA, Great Yarmouth, England

[10] Nat England, Shaftesbury Rd, Cambridge CB2 2DF, England

[11] Netherlands Inst Ecol NIOO KNAW, Dept Aquat Ecol, POB 50, NL-6700 AB Wageningen, Netherlands

关键词: Geo-engineering;    Recovery;    Ecology;    Water quality;    Aquatic macrophyte;    Lake;    Management;    Remediation;    Lake restoration;    Eutrophication control;   

DOI  :  10.1016/j.watres.2015.08.020

来源: Elsevier

【 摘 要 】

Lanthanum (La) modified bentonite is being increasingly used as a geo-engineering tool for the control of phosphorus (P) release from lake bed sediments to overlying waters. However, little is known about its effectiveness in controlling P across a wide range of lake conditions or of its potential to promote rapid ecological recovery. We combined data from 18 treated lakes to examine the lake population responses in the 24 months following La-bentonite application (range of La-bentonite loads: 1.4-6.7 tonnes ha(-1)) in concentrations of surface water total phosphorus (TP; data available from 15 lakes), soluble reactive phosphorus (SRP; 14 lakes), and chlorophyll a (15 lakes), and in Secchi disk depths (15 lakes), aquatic macrophyte species numbers (6 lakes) and aquatic macrophyte maximum colonisation depths (4 lakes) across the treated lakes. Data availability varied across the lakes and variables, and in general monitoring was more frequent closer to the application dates. Median annual TP concentrations decreased significantly across the lakes, following the La-bentonite applications (from 0.08 mg L-1 in the 24 months pre application to 0.03 mg L-1 in the 24 months post-application), particularly in autumn (0.08 mg L-1 to 0.03 mg L-1) and winter (0.08 mg L-1 to 0.02 mg L-1). Significant decreases in SRP concentrations over annual (0.019 mg L-1 to 0.005 mg L-1), summer (0.018 mg L-1 to 0.004 mg L-1), autumn (0.019 mg L-1 to 0.005 mg L-1) and winter (0.033 mg L-1 to 0.005 mg L-1) periods were also reported. P concentrations following La-bentonite application varied across the lakes and were correlated positively with dissolved organic carbon concentrations. Relatively weak, but significant responses were reported for summer chlorophyll a concentrations and Secchi disk depths following La-bentonite applications, the 75th percentile values decreasing from 119 mu g L-1 to 74 mu g L-1 and increasing from 398 cm to 506 cm, respectively. Aquatic macrophyte species numbers and maximum colonisation depths increased following La-bentonite application from a median of 5.5 species to 7.0 species and a median of 1.8 m to 2.5 m, respectively. The aquatic macrophyte responses varied significantly between lakes. La-bentonite application resulted in a general improvement in water quality leading to an improvement in the aquatic macrophyte community within 24 months. However, because, the responses were highly site-specific, we stress the need for comprehensive pre- and post-application assessments of processes driving ecological structure and function in candidate lakes to inform future use of this and similar products. (C) 2015 The Authors. Published by Elsevier Ltd.

【 授权许可】

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