Monitoring of surface water pollution based on biological indicators (SMART)

1. Introduction

Within the scope of the SMART II project, a feasibility study to monitor surface water pollution based on biological indicators was carried out and will contribute as a chapter of my PhD work focusing on the correlation of water quality and agronomic risks and benefits for irrigated agriculture in Jordan.

  

2. Project area

The project area is located north of Amman, in a protected area of “The Royal Botanic Garden of Jordan (RBG)”. The RBG is a non-profit organization, founded in 2005. It is located in Tell Ar-Rumman, overlooking King Talal Dam (KTD). The Botanic Garden covers 180 hectares with more than 300 m of elevation change and is used as a demonstration site showcasing sustainable water management and energy strategies (Royal Botanic Garden, 2012). Every strategy used at the RBG should be replicable by the average Jordanian. Although an independent non-profit organization, the RBG is part of the “Biodiversity Strategy and Action Plan” prepared by Jordan's Ministry of Environment, to implement the 1992 “Convention on Biological Diversity”, ratified by the Kingdom in 1993. Their work is divided into four main components: Scientific research, Biodiversity conservation, sustainable living and education (Royal Botanic Garden, 2012).

The location of the RBG shows several advantages regarding the implementation of this study as it provides:

  1. a protected environment to place samplers for monitoring
  2. easy access to laboratories (RBG, Jordan University, Royal Scientific Society (RSS))
  3. inflow of treated wastewater from As Samra Treatment Plant
  4. use of the KTD surface water for irrigation purposes in the Jordan Valley (JV)
  5. objective of the RBG to be a demonstration site showcasing sustainable water management

 

3. Methodology

3.1         Biofilm monitoring

The method of biofilm monitoring is based on aquatic biofilms and is used to monitor surface water pollution. Biofilms have the ability to adsorb and incorporate material, they can be found at any surface exposed to water and they represent a microbial community with various inhabitants such as sessile bacteria, protozoa, fungi and algae (Fuchs et al., 1996).

 

They are, according to their structure, able to incorporate contaminants, to grow rapidly and they also offer an easy sampling possibility (Fuchs et al., 1996). Thus these aquatic microbial communities can be used as a pollutant-monitor (Fuchs et al., 1996). Due to their low cost, easy handling and low site-specific requirements, the method allows a high spatial resolution of monitoring. Furthermore, the analysis of the biofilm delivers reliable and time integrated results on sources and state of surface water pollution. The biofilm samplers were exposed at different sites within the surface water system for about 14 days, depending on the organic load of the water. During this time a biofilm grows on the surface of the collector and incorporates any particulate and dissolved pollution passing through. Afterwards the biofilm was transferred to a lab for the subsequent analysis of five heavy metals: Iron, Lead, Copper, Zinc and Cadmium.

For measuring, 2 different atomic absorption spectrometers were used: Perkin Elmer - AAS 1100 B, used for determinations in the mg L-1 range and a Perkin Elmer AAS SimAA 6000, measuring in the range of µm. Using those measurements, a geochemical index (Igeo) was calculated according to Müller`s (1981) formula (Muzungaire, L., 2012):

 

Igeo = log2 Cn · 1.5 Bn–1       

 

Cn = trace element concentration in the sediment at the particular station

Bn = geochemical background of the element (Turekian and Wedepohl, 1961)

 

 

Table 1: Mean values of geochemical index of Zarqa River and KTD reservoir (Feb. to Sep. 2012).

Metal

Igeo value

Igeo class

Pollution intensity

Iron

4.29

5

Highly polluted

Lead

0.88

1

Unpolluted

Copper

0.81

1

Unpolluted

Zinc

1.74

2

Unpolluted to moderately poluted

Cadmium

2.48

3

Moderately polluted

 

 

 

 

 

 

 

 

 

To be able to compare the biological findings with chemical analyses, three water samples have been taken at Zarqa River, KTD and at the RBG and analyzed for Nitrogen, Hydrogencarbonate, Carbon trioxide, Iron, COD, Nitrate, Sulfate and Total Phosphorous. The samples taken show a differing Iron content from 1.30 mg/l at Zarqa river, 0.490 mg/l at KTD reservoir and 1.55 mg/l at KTD reservoir within the area of the RBG (Wadi Tell Ar Rumann). Still, the maximum limit of 5 mg/l (regarding the Jordanian Standard 893/2006) is not reached.

 

 3.2 Macro-invertebrate survey

With the Macro-invertebrate survey, organisms are being used to determine the water. In the 1900s, the Saprobien Index was developed by Kolkowitz and Marsson. It is based on the observation that the biocoenosis of a water body varies in a predictable way with the organic load (Chorus et al., 1999). While some residents react more resistant to organic water pollution, others only can survive unpolluted or slightly polluted water as their range of tolerance is very different. These observations can be explained by the biology of the organisms, as for example some species need oxygen rich waters and will die with decreasing oxygen content. Other species require a high supply of nutrients, but they may be able to tolerate very low oxygen levels (Friedrich, G. et al., 1992). The occurrence and frequency of those organisms which react to organic pollution can be used to determine the grade of pollution if the tolerance ranges for each species are known.

Aquatic insects were sampled from selected sites along the project area and identified to order, family and, if possible, to the genus or species. A total of 6 orders and 26 families were found, whereas the families are: Diptera, Ephemeroptera, Hemiptera, Odonata, Trichoptera and Coleoptera. The organisms were given values from 0 to 10 according to the organism's tolerance to the water quality. Organisms rated with 1 or 2 are intolerant organisms which will not survive waters with poor conditions while organisms rated with values 9 or 10 are tolerant and will survive in waters of poor quality. The tolerance values of the organisms found range from 2 (Dixidae) to 9 (Libellulidae). In KTD Reservoir as well as in Zarqa River, the tolerance values ranged from 4 to 9, with a high percentage around a tolerance value of 6 and no species with a low pollution tolerance. This is an indicator for a moderate to polluted water quality as organisms, which settle here, have a higher tolerance to pollution. Within the area of the RBG (Wadi Tell Ar Rumann), species with a tolerance value of 2 were found indicating good to moderate water quality, even if some species also showed a value of 6. Based on the results of Wadi Tell Ar Rumann, no indicators for organic pollution have been identified, whereas Al Zarqa River shows a reduced invertebrate community indicating the organic loading of the water.

 

4. Material and Methods

Benthic macro invertebrates usually occur in all kind of freshwater environments. They usually settle down in a specific environment which fits to their needs and are likely to be exposed to environmental changes due to pollution or stress. Their life span is quite long and if an environmental impact occurs, it is likely that the community will not recover that fast and the stress will be detected.

Biweekly field trips were conducted to sample aquatic insects in Wadi Tell Ar Rumman from January 2012 to March 2013. Insects were sampled using an aquatic net from collection sites selected along the stream according to distinct characteristic (e.g. lentic versus lotic sections, muddy versus vegetated substrates). Several samples were taken at each location to ensure the representativeness of the biological community in each stream.

 

The collected insects were placed in a plastic bag or plastic container and then taken to the laboratory for picking, sorting and counting the collected. The samples were preserved in 75% alcohol and transferred into small vials (figure 8). Insects will be identified to order, family and, if possible to the genus or species according to the availability of references. Labels containing data about the site, date and identification were printed for the samples. The collected insects were briefly described, photographed

and the necessary illustrations helping in identification of the specimen were added. Afterwards the macro invertebrates are being identified under a stereo microscope with the help of identification keys. With a stereo microscope having a magnification range between 7 x to 30 x, organisms may be identified to taxonomic level such as family or genus (NYSDEC Stream Biomonitoring Unit, 2013).

 

The sampling campaign was necessary to identify the impact of the pollution in the surface water. The fauna in flowing water is usually more sensitive to pollution impacts than standing or slow flowing water and pools and thus, if possible, was applied during the sampling campaign even if most of the locations were in slow flowing areas.

 

Interaction with working groups

 

This feasibility study to “monitor surface water pollution based on biological indicators” contributed to Work Package 5, D501 and will be an own standing deliverable, D502.

A draft of the deliverable 502 has been submitted. Nevertheless, this report (as part of my PhD work) is still at the stage of work in progress. A contribution to deliverable 501 “Report on water resources pollution from urban areas in the LJV” has been submitted.

 

References

Barbour, M.T., J. Gerritsen, B.D. Snyder, and J.B. Stribling (1999): Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers: Periphyton, Benthic Macroinvertebrates and Fish, Second Edition. EPA 841-B-99-002. U.S. Environmental Protection Agency; Office of Water; Washington, D.C.

Chorus, I., Bartram, J. (1999): Toxic Cyanobacteria in Water: A guide to their public health consequences, monitoring and management. E & FN Spon, an imprint of Routledge, WHO.

Friedrich, G. et al. (1992): Water Quality Assessments - A Guide to Use of Biota, Sediments and Water in Environmental Monitoring - Second Edition. ISBN 0 419 21590 5 (HB) 0 419 21600 6 (PB).

Fuchs, S. et al. (1996): Biofilms in Freshwater Ecosystems and their Use as a Pollutant Monitor. Water Science and Technology, Volume 34, No. 7-8, pp. 137-140, 1996.

Muzungaire, L. (2012): Preliminary investigation of biomagnifications of trace metals in the Okavango River, North-eastern Namibia. Research Journal of Agricultural and Environmental Management Vol. 1(2), pp. 034-042, December, 2012.

Turekian and Wedepohl (1961): EarthRef.org Reference Database (ERR). Development and Maintenance by the EarthRef.org Database Team.