Evaluation of point-of-use treatments and biochar to reduce 1,2,3-trichloropropane (TCP) contamination in drinking water
Data files
Apr 11, 2024 version files 176.21 KB
Abstract
From the 1940s to the 1980s, 1,2,3-trichloropropane (TCP) was widely present as an impurity in soil fumigants to eliminate plant parasitic nematodes. TCP also saw wide usage as a degreaser and solvent in industrial processes. In rural agricultural regions with a history of fumigant use, TCP is a common pollutant in groundwater. As a potent suspected carcinogen (California MCL 5 ng/L), TCP poses a risk to communities reliant on domestic wells. Lacking the populations needed for more centralized water treatment facilities, these communities often use point-of-use (POU) treatment technologies or buy bottled water. In this study, we tested commercially available water pitchers equipped with carbon filters for point-of-use TCP treatment efficacy. As a less costly carbon alternative, we also tested low-cost, locally sourced biochar made from almond shells. Biochar could serve as a sustainable alternative to the current coconut and coal-based carbon feedstocks. Pitcher point-of-use filters removed at or above 98% of TCP in tap water derived from untreated groundwater during their lifetime of use. In our batch studies, almond biochar did absorb TCP at a lower efficiency than commercially available granulated carbon. Ultimately, the study's findings could assist affected communities and households in identifying efficient and cost-effective treatment technologies at the domestic well and household levels.
README: Evaluation of point-of-use treatments and biochar to reduce 1,2,3-trichloropropane (TCP) contamination in drinking water
https://doi.org/10.5061/dryad.d51c5b09f
Description of the data and file structure
This document encompasses both raw and processed data, alongside R analysis, pertaining to our research on the removal of 1,2,3-trichloropropane from drinking water through point-of-use and batch isotherm methods. Data sets are as Excel files.
Description of files, variables and units
The following excel files contain the data from isotherm and point of use experiments. Some spreadsheets contain multiple sheets. Variables are listed by sheet under "content" below.
1) BiocharIsotherm.xlsx:
Description: This spreadsheet holds the data for our Almond Biochar isotherm experiments. There are multiple tabs at the bottom of the spreadsheet. There are three sheets - ‘Data’ , 'Freundlich_Model' , and ‘Data_for_R.’
Content:
'Data' contains the following variables and units as column headings:
- Date: This states the month/day/year that we took the sample
- Flask code: This is a unique number that we assigned to each flask
- Char, F+cap+3b mass (g): This is the mass of the biochar, the flask, the cap and 3 glass beads in grams
- TCPsol+Char+F+cap+3b mass (g): This is the mass of the Spiked TCP solution, biochar, the flask, the cap and 3 glass beads in grams
- TCPsol volume (mL): This is the volume of the solution in mL
- Char mass (g): This is the mass of hte biochar used in grams
- BSK Labs TCP Concentration (µg/L ) a.k.a Ce: This is the measured TCP concentration at equilibrium in µg/L
'Freundlich_Model' uses the raw data to calculate qe for the isotherm. It contains the following variables and units as column headings:
- Sample date: This states the month/day/year that we took the sample
- Ce (µg/L): The equilibrium solution concentration with the units µg/L
- qe (µg/mg): The equilibrium sorbed concentration with the units µg/g
- log(Ce): The log of the Ce value
- log(qe): The log of the Ce value
- qe (µg/mg): The modeled log of the qe value
- Char mass (g): The mass of the biochar in grams
- Char mass (mg): The mass of hte biochar in milligrams
- Volume of solution (mL): The volume of the spiked TCP solution in mL
- Volume of solution (L): The volume of the spiked TCP solution in Liters
- Mean Ce: The mean Ce value if there were multiple trials with the units µg/L
- Mean Qe: The mean qe value if there were multiple trials with the units µg/mg
- SD Ce: Standard deviation of the Ce values, unitless
- SD Qe: Standard deviation of the qe values, unitless
- Log Ce Trial 1, Trial 2, Trial 3: Log of the Ce values from each of the three trials with units of log µg/L
- Log qe Trial 1, Trial 2, Trial 3: Log of the qe values from each of the three trials with units of log µg/mg
- Mean log Ce: Mean log of the Ce values from each of the three trials with units of log µg/L
- Mean log Qe: Mean log of the qe values from each of the three trials with units of log µg/mg
- SD logCe: Standard deviation of log of the Ce values from each of the three trials, unitless
- SD logQe: Standard deviation of log of the qe values from each of the three trials, unitless
'Data_for_R' is for processing and creating charts for publication (refer to R code). It contains the following variables and units as column headings:
- log(Ce): Log of equilibrium solution concentration with the units µg/L
- log(qe): Log of equilibrium sorbed concentration with the units µg/mg
2) BET_analysis.xlsx
Description: This data is from the BET analysis for the almond shell biochar that we used for the isotherm experiments. There is one sheet - ‘Data.’
Content:
‘Data’ contains the following variables and units as column headings:
- Relative Pressure (p/po)
- Quantity adsorbed (cm^3/g)
3) PlasticGlass.xlsx
Description: This Excel spreadsheet contains data from a batch isotherm experiment investigating the sorption of TCP to plastic containers. It compares the concentration of TCP in a solution stored in plastic containers to that stored in glass containers. The purpose is to quantify, if any, TCP absorption by the plastic. There are two sheets: ‘Data’ contains the data points from our experiment and ‘Data_for_R’ has the data organized for import into R (see provided R code).
Content:
‘Data’ contains the following variables and units as column headings:
- Ce: The equilibrium solution concentration with the units µg/L
- Qe: The equilibrium sorbed concentration with the units µg/g
- Solution volume: Volume of the solutions that we used with the units mL
- bottle mass: the mass of the containers we used with the units g
- % reduction: This is a calculated value Ce-Co/Co unitless
- Average percent reduction: Calculated mean of % reduction values
‘Data_for R’ contains the following variables and units as column headings:
- Ce: The equilibrium solution concentration with the units µg/L
- Qe: The equilibrium sorbed concentration with the units µg/g
4) Plastic_ttest.xlsx
Description: This uses the Plastic dataset (PlasticGlass.xlsx) for import t-test in R. There are two sheets: ‘Data’ contains the data points from our experiment and ‘Data_for_R’ has the data organized for import into R (see provided R code). There are two sheets - ‘Data’ and ‘Data_for_R’
Content:
‘Data’ contains the following variables and units as column headings:
- Ce: The equilibrium solution concentration with the units µg/L
- Qe: The equilibrium sorbed concentration with the units µg/g
- Solution volume: Volume of the solutions that we used with the units mL
- bottle mass: the mass of the containers we used with the units g
- % reduction: This is a calculated value Ce-Co/Co unitless
- Average percent reduction: Calculated mean of % reduction values
‘Data_for R’ sheet contains the following variables and units as column headings:
- ContainerType: Specifies either glass or plastic container was used
- TCPppb: Provides the equilibrium concentration in ppb
5) MEL.xlsx
Description: This data is for the effluent concentration for different check points along the manufacturer's estimated lifetime (MEL) of three pitcher point of use filters and for a control group. Data is shown on the first sheet 'Data' as well as data formatted for R plotting 'Data_for_R'
Content:
‘Data’ contains the following variables and units as column headings:
- 0% MEL: The filter is new
- 25% MEL: 25% of the filter lifetime has passed
- 50% MEL: 50% of the filter lifetime has passed
- 75% MEL: 75% of the filter lifetime has passed
- 100%MEL: 100% of the filter lifetime has passed
- 125% MEL: 125% of the filter lifetime has passed
- Mean 0%, SD 0%, Trial 1, Trial 2, Trial 3: The mean and standard deviation of the three trails for effluent sampled at a MEL of 0%
- Mean 25%, SD 25%, Trial 1, Trial 2, Trial 3: The mean and standard deviation of the three trails for effluent sampled at a MEL of 25%
- Mean 50%, SD 50%, Trial 1, Trial 2, Trial 3: The mean and standard deviation of the three trails for effluent sampled at a MEL of 500%
- Mean 75%, SD 75%, Trial 1, Trial 2, Trial 3: The mean and standard deviation of the three trails for effluent sampled at a MEL of 75%
- Mean100%, SD 75%, Trial 1, Trial 2, Trial 3: The mean and standard deviation of the three trails for effluent sampled at a MEL of 100%
- Mean125%, SD 125%, Trial 1, Trial 2, Trial 3: The mean and standard deviation of the three trails for effluent sampled at a MEL of 125%
- Percent reduction C = (Co-Ce)/Co: These columns state the percent reduction using the formula C = (Co-Ce)/Co where Co is the concentration of the control and Ce is the concentration of the effluent for three types of filters: PPOU1, PPOU2, PPOU3
‘DataSummary’ contains the following variables and units as column headings: (note that Data Summary has the same information form the sheet ‘Data’ however it is in longform)
- Mean Ceffluent Concentration (ppb) from 0-100MEL
- POU1, 0, 25, 50, 75, 100, Mean: This is the Effluent concentration in µg/L at different checkpoints along the MEL for pitcher 1
- POU2, 0, 25, 50, 75, 100, Mean: This is the Effluent concentration in µg/L at different checkpoints along the MEL for pitcher 2
- POU3, 0, 25, 50, 75, 100, Mean: This is the Effluent concentration in µg/L at different checkpoints along the MEL for pitcher 3
- Mean Percent removal from 0-100MEL
- POU1, 0, 25, 50, 75, 100, Mean: This is the removal percentage at different checkpoints along the MEL for pitcher 1, unitless
- POU2, 0, 25, 50, 75, 100, Mean: This is the removal percentage at different checkpoints along the MEL for pitcher 2, unitless
- POU3, 0, 25, 50, 75, 100, Mean: This is the removal percentage at different checkpoints along the MEL for pitcher 3, unitless
‘Data_for_R’ contains the following variables and units as column headings:
- MEL: Manufacturers estimated lifetime where a=0, b=25, c=50, d=75, and e=100
- Group: This column states the pitcher type
- trial1, trail2, trail3: This is the removal percentage from trial 1, 2 or 3
- MeanRemPer: This is the Mean removal percentage of the three trials, unitless
- Sd: This is the standard deviation of the removal percentage of the three trials, unitless
- Se: This is the standard error of the removal percentage of the three trials, unitless
6) kwMEL.xlsx:
Description: This dataset complies the information needed to perform a Kruskal Wallis test in R. It compares three filter brands' Manufacturers' Estimated Lifetime (MEL) data for the point-of-use filtration Experiments. There are four sheets - ‘Data’ , ‘DataSummary’ , ‘kwtest’, and ‘Data_for_R’. Note that ‘Data’ and ‘DataSummary’ are the same as in the file MEL.xlsx (see above)
Content:
‘kwtest’ contains three columns:
- PPOU1, PPOU2, PPOU3: These are the mean removal percentages for TCP over the course of the filter’s lifetime (MEL 0-100) for pitchers 1,2,3, unitless
'Data_for_R' contains two columns:
- MeanRemPercentage: This is the mean removal percentage for TCP over the course of the filter’s lifetime (MEL 0-100), unitless
- Group: This states which pitcher is being tested 1, 2, or 3
7) boxplotMEL.xlsx
Description: This dataset uses mean effluent concentrations from MEL.xlsx prepared to visualize the data with a box plot in R. This was not used for the final manuscript but just for a quick visualization.
Content:
‘Data_for_R’ contains two columns:
- Group: This gives the Pitcher type (there are three trials)
- Concppb: This states the mean TCP concentration in the effluent for the MEL from 0-100.
8) anovaMEL.xlsx
Description: This dataset uses data from MEL.xlsx but prepared for conducting a one-way ANOVA test in R.
Content:
‘Data_for_R’ contains two columns:
- MeanRemPercentage: This is the mean removal percentage for TCP over the course of the filter’s lifetime (MEL 0-100), unitless
- Group: This states which pitcher is being tested 1, 2, or 3
9) FlowRate.xlsx
Description: This is the raw and processed data for the flow rates of the three different brands of POU pitcher filters. This was completed in triplicate thus POU1a, POU1b, and POU1c are three different replicates of the same pitcher type. FlowRate.xlsx has three sheets
Content:
‘Data’ contains the following columns and units
- Liters collected: This field states how many liters had passed through the filter when we took a sample
- MEL: This states how far along the lifetime of the filter, we were when we timed the flow (o, 25, 50, 100 or 125)
- POU1: This gives volume data in Liters for Pitcher 1
- POU2: This gives volume data in Liters for Pitcher 2
- POU3: This gives volume data in Liters for Pitcher 3
- Note: there are three trials, thus the a, b and c.
‘Transformed’ contains the following columns and units
- Filter type: This gives the Pitcher type (either 1, 2, or 3)
- % MEL stage: This states how far along the lifetime of the filter, we were when we timed the flow (o, 25, 50, 100 or 125)
- Filter 1, Filter 2, Filter 3: This is the flow rate in L/sec for each of the trials for a given pitcher
- Mean flow rate in L/second: This is the mean rate in L/sec for the trials
- Standard deviation of flow rates: This is the standard deviation of flow rates, unitless
‘Data_for_R’ contains the following columns and units
- POUType: This gives the Pitcher type (either 1, 2, or 3)
- MEL_stage: This states how far along the lifetime of the filter, we were when we timed the flow (o, 25, 50, 100 or 125)
- Filter 1, Filter 2, Filter 3: This is the flow rate in mL/sec for each of the trials for a given pitcher
- mean_ml_per_sec: This is the mean rate in mL/sec for the trials
- Sd: This is the standard deviation of flow rates, unitless
- Se: This is the standard error of flow rates, unitless
Code/Software
The provided R file 'TCP_ManucsriptData_2024' is the script used for making the charts and statistical comparisons in the manuscript. RStudio version 2023.06.0+421-06-05 was used.
Methods
This data set was collected throughout the study. Both raw and processed data sets are shown.