// let's assume you have the csv data in $csv

// you create the new arrays to hold the results
$col1 = array();
$col2 = array();

// explode the csv data into an array
$csv_exploded = explode("\n", $csv);

// loop over the lines from $csv
foreach($csv_exploded as $line)
{
  // explode the line into the two part you want
  $data = explode("/* your seperator here */", $line)

  // and store them
  $col1[] = $data[0];
  $col2[] = $data[1];
}