A systematic review of water treatment with Moringa oleifera seeds: comparative analysis of jar testing methodologies and results
Data files
Jun 05, 2026 version files 101.39 KB
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PLOSwater_CollectedData_CSV_JJR_040626.csv
23.22 KB
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PLOSwater_ConflictOfInterest_Data_CSV_JJR_040626.csv
32.81 KB
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PLOSwater_ResearchQuality_Data_CSV_JJR_040626.csv
11.46 KB
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PLOSwater_RiskOfBias_Data_CSV_JJR_040626.csv
22.53 KB
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README.md
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Abstract
This systematic review aims to assess the reliability of contemporary research on water treatment with Moringa oleifera seeds. Academic databases were browsed on a yearly basis (2014 – 2024); identification and screening were conducted between July 17th 2023 and December 9th 2024. Primary research reports featuring jar testing with M. oleifera seed coagulant were included for data collection. Thirty-five fields were used to collect data. Data was synthesised by establishing causality between independent variables and outcomes. Conflict of interest, research quality and risk of bias were assessed using modified Cochrane tools. Fifty non-duplicate publications were identified. Of these, 25 were included for data collection. In total, 511 data points were collected and synthesised. No conflicts of interest were found. Sixteen reports received “lower” or “lowest” research quality judgements. Six reports received “high risk of bias” judgements. Bias risk was most commonly associated with experimental design and missing data. Inadequate standardisation in test water preparation, M. oleifera seed coagulant processing and jar test parameters affected treatment efficacies in unpredictable ways. Researchers who used M. oleifera seed coagulants at appropriate concentrations and adhered to the three-stage model of coagulation, flocculation and sedimentation achieved turbidity reduction rates of 80 – 96%. Turbidity and microbiological reduction rates were comparable in three reports, but microbiological testing was uncommon. Based on their properties, M. oleifera cationic proteins are theorised to be lectins with hevein-like binding domains. These findings are significant because this technology has been in development for at least forty years and remains experimental due to perceived unreliability, unclear safety limits and limited innovation. Suggestions for future research and standardisation are made throughout this review. If the technology is found to be a safe, effective and sustainable method of water purification, it may support Targets 6.1, 6.a and 6.b of the United Nations sustainable development goals.
Dataset DOI: 10.5061/dryad.m37pvmdgw
Description of the data and file structure
This dataset contains the data, assessments and judgements required to replicate analyses and syntheses in the manuscript titled "A systematic review of water treatment with Moringa oleifera seeds: comparative analysis of jar testing methodologies and results" (Russell, Paterson and Pritchard, 2026).
The table titled "PLOSwater_CollectedData_CSV_JJR_040626.csv" contains data collected from the 25 reports included in the systematic review; all of these reports conducted jar testing with coagulant(s) produced from the seeds of the tree species Moringa oleifera. A total of 511 data points were collected using 35 data fields. Data fields pertain to experimental design, methods of analyses and results. The data collection process was conducted in duplicate to ensure accuracy. The table concludes with comments on experimental outcomes (positive/negative) and concerns regarding experimental design. These data and comments were used in the synthesis of the systematic review; therefore, the authors chose to include the comments in the data table to allow third-party researchers to replicate the synthesis. Within the table, data fields are arranged into nine categories:
1. Test water properties: Type(s) of test water; Method(s) of adjusting test water turbidity; Pre-treatment turbidity; Pre-treatment pH.
2. M. oleifera seed handling: Source(s) of MO seeds; Method of species verification; Age of MO seeds at time of testing; Storage conditions of MO seeds.
3. M. oleifera seed processing: MO seed primary processing methods; MO seed defatting methods; MO seed secondary processing methods; MO seed tertiary processing methods; Final MO seed coagulant type(s).
4. Coagulant dosing concentrations: MO seed coagulant dosing concentration(s); Use of negative control (i.e. 0 mg/L); Use of positive control; Positive control dosing concentration(s).
5. Microbiological methods: Test organism species; Test organism concentration(s); Test organism recovery method(s).
6. Jar test operational parameters: Coagulation parameters; Flocculation parameters; Sedimentation parameters; Water sampling depth; Method(s) of data/statistical analysis.
7. Results: turbidity: Optimal turbidity reduction rate: MO seed coagulant(s); Optimal dose for turbidity reduction: MO seed coagulant(s); Optimal turbidity reduction rate: chemical coagulant(s); Optimal dose for turbidity reduction: chemical coagulant(s); Gravitational settling rate.
8. Results: other: Test organism concentration change: MO seed coagulant(s); Test organism concentration change: control sample(s); pH change: MO seed coagulant(s); pH change: chemical coagulant(s); Changes to dissolved residue concentrations.
9. Outcomes: Turbidity; Microbiology; pH; Dissolved residues; Additional notes.
Author comments are exclusively contained within the “Additional notes” field at the conclusion of the table.
The table titled "PLOSwater_ConflictOfInterest_Data_CSV_JJR_040626.csv" contains conflict of interest statements, funding statements, acknowledgement statements and data pertaining to author affiliations and institutes for each of the 25 reports included in the systematic review. The table concludes with conflict of interest judgements and judgement reasoning for each report. This assessment was conducted using Cochrane tools modified for in vitro laboratory studies. Conflict of interest judgements were used in the synthesis of the systematic review.
The table titled "PLOSwater_ResearchQuality_Data_CSV_JJR_040626.csv" contains 11 signalling questions which were used to assess the quality of research of each of the 25 reports included in the systematic review. Each question is designed so that an answer of "yes" indicates positive research quality, "unclear" indicates minor quality loss and "no" indicates significant quality loss. Each report was assessed identically using all 11 signalling questions. Justification for answers of "unclear" and "no" are provided within the table. Reports are allocated an overall Quality Score (QS) and corresponding Quality Judgement (QJ) at the conclusion of the table. This assessment was conducted using Cochrane tools modified for in vitro laboratory studies. Research quality judgements (and associated reasoning) were used in the synthesis of the systematic review. The following signalling questions were used to assess research quality:
Q-Q1: Are procedures fully described?
Q-Q2: Are procedures appropriate?
Q-Q3: Is the sample size/number of replicates appropriate?
Q-Q4: Do procedures include appropriate control groups?
Q-Q5: Are procedures applied identically to all groups?
Q-Q6: Are procedures replicable?
Q-Q7: Is analysis fully described?
Q-Q8: Is analysis appropriate?
Q-Q9: Is analysis applied identically to all groups?
Q-Q10: Are pre-treatment data fully reported?
Q-Q11: Are post-treatment data fully reported?
The table titled "PLOSwater_RiskOfBias_Data_CSV_JJR_040626.csv" contains 10 signalling questions, categorised into three bias domains, which were used to assess the risk of bias of each of the 25 reports included in the systematic review. Within each bias domain, questions were answered sequentially (e.g. B-Q1.1, B-Q1.2 and then B-Q1.3). Each answer was then applied to the flow chart corresponding to its bias domain (see supporting figures “S1”, “S2” and “S3” within the manuscript). By answering all signalling questions within a bias domain, the corresponding flow chart was used to determine a risk of bias judgement for that bias domain (B-J1, B-J2 and B-J3). The table concludes with overall risk of bias judgements (B-J4) for each included report, as determined by the "Overall risk-of-bias judgement criteria" at the end of the table. This assessment was conducted using Cochrane tools modified for in vitro laboratory studies. Risk of bias judgements (and associated reasoning) were used in the synthesis of the systematic review. The following bias domains and signalling questions were used to assess risk of bias:
Bias domain 1: Risk of bias due to experimental design and confounding factors
B-Q1.1: Does the design of the experiment preclude bias?
B-Q1.2: Are confounding factors identified, measured, controlled and reported?
B-Q1.3: Do negative control data suggest confounding?
Bias domain 2: Risk of bias due to missing data
B-Q2.1: Are results data fully reported?
B-Q2.2: Are data pertaining to confounding factors fully reported?
B-Q2.3: Are missing data likely to affect the perception of treatment efficacy?
Bias domain 3: Risk of bias due to selective reporting of data
B-Q3.1a: Were data collected, analysed or presented using multiple methods in parallel?
B-Q3.1b: Do conclusions consider data generated by all parallel methods?
B-Q3.2: Are conclusions drawn from desirable data from a select sub-group or sub-groups?
B-Q3.3: Are conclusions made in omission of undesirable data from a select sub-group or sub-groups?
Assessments for conflict of interest, research quality and risk of bias were judged by two researchers in parallel using no automation tools; a third researcher was used to settle disagreements between the two principal judges.
Files and variables
File: PLOSwater_CollectedData_CSV_JJR_040626.csv
Description: Methodological and results data collected from 25 reports for the synthesis of the systematic review titled "A systematic review of water treatment with Moringa oleifera seeds: comparative analysis of jar testing methodologies and results" (Russell, Paterson and Pritchard, in review).
Variables
- Missing values indicated with "N/A"
- Alum - Aluminium sulphate (chemical coagulant)
- BOD - Biological Oxygen Demand (measure of dissolved residue concentration)
- CFU - Colony Forming Units (measure of microbiological concentration)
- COD - Chemical Oxygen Demand (measure of dissolved residue concentration)
- DOC - Dissolved Organic Carbon (measure of dissolved residue concentration)
- MO - Moringa oleifera (tree species)
- NTU - Nephelometric Turbidity Units (measure of turbidity in water)
- PAC - Polyaluminum chloride (chemical coagulant)
- RPM - Revolutions Per Minute (measure of mixing intensity of jar testing machine)
- TDS - Total Dissolved Solids (measure of dissolved residue concentration)
- TFC - Total Faecal Coliforms (measure of microbiological concentration)
File: PLOSwater_ConflictOfInterest_Data_CSV_JJR_040626.csv
Description: Conflict of interest assessments of 25 reports for the synthesis of the systematic review titled "A systematic review of water treatment with Moringa oleifera seeds: comparative analysis of jar testing methodologies and results" (Russell, Paterson and Pritchard, in review).
Variables
- Missing values indicated with "N/A"
- No abbreviations in table
File: PLOSwater_ResearchQuality_Data_CSV_JJR_040626.csv
Description: Research quality assessments of 25 reports for the synthesis of the systematic review titled "A systematic review of water treatment with Moringa oleifera seeds: comparative analysis of jar testing methodologies and results" (Russell, Paterson and Pritchard, in review).
Variables
- No missing values in table
- No abbreviations in table
File: PLOSwater_RiskOfBias_Data_CSV_JJR_040626.csv
Description: Risk of bias assessments of 25 reports for the synthesis of the systematic review titled "A systematic review of water treatment with Moringa oleifera seeds: comparative analysis of jar testing methodologies and results" (Russell, Paterson and Pritchard, in review).
Variables
- No missing values in table ("N/A" indicated non-applicable signalling question)
- Alum - Aluminium sulphate (chemical coagulant)
- BOD - Biological Oxygen Demand (measure of dissolved residue concentration)
- CFU - Colony Forming Units (measure of microbiological concentration)
- COD - Chemical Oxygen Demand (measure of dissolved residue concentration)
- DOC - Dissolved Organic Carbon (measure of dissolved residue concentration)
- MO - Moringa oleifera (tree species)
- NTU - Nephelometric Turbidity Units (measure of turbidity in water)
- PAC - Polyaluminum chloride (chemical coagulant)
- RPM - Revolutions Per Minute (measure of mixing intensity of jar testing machine)
- TDS - Total Dissolved Solids (measure of dissolved residue concentration)
- TFC - Total Faecal Coliforms (measure of microbiological concentration)
Code/software
All data tabulated in CSV file format.
CSV is an unformatted, open-access file format, considered near-universally accessible.
Access information
Other publicly accessible locations of the data:
- None
Data was derived from the following sources:
Twenty-five reports were subject to data collection & synthesis in this systematic review. No figures, tables or extended quotations were taken and used from any report into the manuscript. Summaries of data and short quotations fall under "fair use" copyright law for all included reports.