SolarSack Performance data, bacteria and virus

SolarSackAps

Fruebjergvej32100CopenhagenDenmark

Dateofpreparation:12-02-2021 Preparedby:CharlotteFrydenlundMichelsenVersion:2.0SeniorScienceManager

Performance Data SolarSack

1 Introduction This document describes the performance efficacy for SolarSack and the test procedures for performance testing and verification against bacteria and viruses.

The performance efficacy for SolarSack has been assessed according to international standards and is based on the guidelines of minimum performance criteria, Log Reduction Values, LRV (Table 1), set by the World Health Organization (WHO)1 and U.S. Environmental Protection Agency (US EPA)2 for removing or killing three different classes of microorganisms, i.e., bacteria, virus, and protozoan cysts, in waters of unknown quality. Table 1: Overview of performance criteria set by WHO and US EPA

Microorganism WHO LRV US EPA

LRV Comprehensive Protection Targeted Protection (*) (***) (**)

Bacteria ≥ 4 ≥ 2 ‘Protective’ in two microbial classes and

documented health gains

≥ 6

Virus ≥ 5 ≥ 3 ≥ 4

Protozoan cysts ≥ 4 ≥ 2 ≥ 2

2 Conclusion The test results presented in this document are summarized in Table 2 and show that the SolarSack performance exceeds the highest criteria set by WHO and US EPA for the removal of bacteria. In addition, SolarSack meets the ‘targeted protection’ criteria set by WHO (for bacteria and viruses), thus being comparable to the performance of filtration and chemical disinfection technologies evaluated by WHO1. Table 2: Summary of the performance tests of SolarSack

Microorganism Highest pre-treatment concentration

Post-treatment concentration after 4 hours

Reduction

LRV %

Bacteria

E. coli 6 x 107 CFU/100 ml <1 x 100 CFU/100 ml 7.8 >99.99999 Total Coliform 5.9 x 104 CFU/100 ml 1.9 x 100 CFU/100 ml 4.5 >99.99 Total Plate Count 1.49 x 106 CFU/ml 1 x 100 CFU/ml 6.2 >99.9999

Virus MS-2 2.8 x 106 PFU/ml 2.1 x 103 PFU/ml 3.1 >99.9

SolarSack PerformanceData Page2of15

3 Efficacy of SolarSack Table 3 summarizes the efficacy of SolarSack against different microorganisms, which is reported as the percentage of contaminant reduction, based on the Log Reduction Value calculated using the formula: LRV = Log10 (Cuntreated water / Ctreated water), where C = microbe concentration in water. The percentage of contaminant reduction is reported as:

1 LRV = 90% reduction 2 LRV = 99% reduction 3 LRV = 99.9% reduction 4 LRV = 99.99% reduction 5 LRV = 99.999% reduction 6 LRV = 99.9999% reduction 7 LRV = 99.99999% reduction

Table 3: Overview of performance tests at different test laboratories

Microorganism Pre-treatment concentration [CFU/100 ml]

Post-treatment concentration after 4 hours [CFU/100 ml]

Reduction Test laboratory

LRV %

Bacteria

Escherichia coli

6 x 107 <1 x 100 7.8 >99.99999 Ghana Standards Authority

6.0 x 105 <1.0 x 100 5.8 >99.999 Tanzania Bureau of Standards

2.1 x 106 [CFU/ml]

3.4 x 100 [CFU/ml] 5.6 >99.999 SolarSack in-house

laboratory

4.9 x 105 1 x 100 5.7 >99.999 Makerere University

2.7 x 105 <1 x 100 5.4 >99.999 Danish Hydro Institute

1.1 x 106 4.3 x 101 4.4 >99.99 University of Dhaka

1.8 x 103 <1 x 100 3.3 >99.9 University of Kyambogo

1.4 x 103 <1 x 100 3.1 >99.9 Federal Ministry of Water Resources,

Nigeria

1.1 x 103 <1 x 100 3.0 99.9 Technical University

of Denmark (DTU Energy)

>1 x 102 <1 x 100 >2.0 >99 Rwanda Standards Board


Table 3 continued: Overview of performance tests at different test laboratories

Microorganism Pre-treatment concentration [CFU/100 ml]

Post-treatment concentration after 4 hours [CFU/100 ml]

Reduction Test laboratory

LRV %

Bacteria, continued

Total Plate Count

1.49 x 106 [CFU/ml]

1 x 100

[CFU/ml] 6.2 >99.9999 Kenya Bureau of Standards

1.49 x 106 [CFU/ml]

<1 x 100

[CFU/ml] 6.2 >99.9999 Tanzania bureau of Standards

>3 x 102 <1 x 100 >2.5 >99 Rwanda Standards Board

Total Coliform

5.9 x 104 1.9 x 100 4.5 >99.99 Kyambogo University

3.6 x 103 1 x 100 3.6 >99.9 Federal Ministry of Water Resources,

Nigeria

4.35 x 102 <1 x 100 2.6 >99 Uganda Ministry of

Water and Environment

Virus

MS-2 bacteriophage

2.8 x 106

[PFU/ml] 2.1 x 103

[PFU/ml] 3.1 >99.9 National Food

Institute, DTU (DTU Food)

MS-2 coliphage 1.75 x 108

[PFU/ml] 5.73 x 104

[PFU/ml] 3.5 >99.9 University of Copenhagen

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4 Test procedures The performance tests of the SolarSack have been conducted at different independent test laboratories to evaluate the efficacy of SolarSack to remove natural microbiological contaminants as well as indicator microorganisms from different water sources. Prior to each performance test a thorough instruction in the correct usage of the SolarSacks was given to the laboratory personnel, to make sure that the tests represent an estimate of the SolarSack effectiveness in actual use with an exposure time of 4 hours under sunny conditions. The performance tests included both natural contaminated water sources with different physicochemical quality as well as challenge testing with microbial spiked test waters with turbidity up to 60 NTU (for E. coli), thus spanning a range of different pre-treatment


concentrations. Furthermore, the test conditions included both natural weather conditions as well as simulated solar irradiation conditions, following the WHO recommended solar simulation settings, delivering an irradiant range of 300nm – 800nm, equivalent to 550W/m2. The performance tests have been carried out with replicates of different SolarSack units and with appropriate controls. Bacterial analysis: Organism tested:

- Escherichia coli (laboratory strain) - Escherichia coli (enterotoxigenic, ETEC) - Total coliform bacteria - Total plate count

The analytical methods used for enumerating E. coli and total coliform bacteria before and after water treatment in the SolarSacks include the membrane filtration methods, ISO 9308-14 (for the majority of tests) and APHA 92225, the U.S. EPA approved Colilert method6 and standard spread plate methods7 with selective culture media. The analytical method used for enumerating TPC is ISO 62228. Virus analysis: Organism tested:

- MS-2 bacteriophage - MS-2 coliphage (ATCC # 15597-Bl)

The analytical method used for enumeration of MS-2 before and after SolarSack treatment was based on the plaque assay described in the standard operating procedure developed by Cefas International Centres of Excellence9 with Salmonella typhimurium WG49 or E. coli (ATCC # 15597)as the host strain, respectively. The method was adapted to the SolarSack setup using MS-2 spiked test water.


5 References

1. WHO, 2019. Results of Round II of the WHO International Scheme to Evaluate Household Water Treatment Technologies. https://www.who.int/water_sanitation_health

2. US EPA, 1987. Guide Standard and protocol for testing microbiological water purifiers. https://nepis.epa.gov/

3. WHO, 2014. General Testing Protocol #10: Solar (UV and heat) Batch Systems (with or without pre-filtration and/or disinfection addition). https://www.who.int/

4. ISO 9308-1:2014. Water quality – Enumeration of Escherichia coli and coliform bacteria. Part 1: Membrane filtration method for waters with low bacterial background flora. https://www.iso.org/standard/55832.html

5. APHA 9222. Membrane filter technique for members of the coliform group. American Public Health Association. Standard method for the examination of water and wastewater, 21st edition, 2005.

6. IDEXX laboratories. Colilert test kit for detecting total coliforms and E. coli in water. https://www.idexx.com/files/colilert-procedure-en.pdf

7. Koch A.L, 2007. Chapter 9: Growth Measurement. In: Methods for general and molecular microbiology. American Society for Microbiology Press, Washington, D.C., pp 172–199

8. ISO 6222:1999. Water quality — Enumeration of culturable micro-organisms — Colony count by inoculation in a nutrient agar culture medium. https://www.iso.org/standard/28960.html

9. CEFAS, 2007. Enumeration of male-specific RNA bacteriophages in bivalve molluscan shellfish. Cefas Standard Operating Procedure. Weymouth, UK.


6 3rd Party Certificates of Analysis

6.1 Ghana Standards Authority: Certificate of Analysis


6.2 Kenya Bureau of Standards: Certificate of Analysis


6.3 Makerere University: Certificate of Analysis


6.4 Danish Hydro Institute: Certificate of Analysis


6.5 Uganda Ministry of Water and Environment: Certificate of Analysis


6.6 Rwanda Standards Board: Certificate of Analysis



6.7 Federal Ministry of Water Resources: Certificate of Analysis


6.8 Tanzania Bureau of Standards: Certificate of Analysis


Documents

SolarSack Performance data, bacteria and virus