Closed-loop biochar cascades

Collaborative research between the Ithaka Institute, the Rochester Institute of Technology and Cornell University focused on cascading uses of biochar is showing promising results. Wastewater from food processing plants often contains high chemical oxygen demand (COD) which can result in fines as municipal wastewater treatment systems must use significant amounts of energy to lower COD.  Certain biochars have been found to be effective in helping to reduce COD and sorb other nutrients found in food processing plants.  This project assessed the potential to use the char post-filtration as a soil amendment. In the first phase of this collaboration biochar was used to filter whey from a tofu manufacturing plant.  The second phase was aimed at determining the impact filtered char would have on plant growth in lettuce, basil and tomatoes.  Positive results were seen in the initial plant trials.  Filtered char increased the fresh weight of lettuce (38% increase over control bv) and basil (62% increase at 5% bv).  The filtered biochar also performed better than a commercially available char (13.8% increase for lettuce at 5%; 38% for basil at 5%).  Tomato trials were also conducted but were terminated before harvest.  The number of fruits from filtered char increased substantially over controls (104% at 5% to 128% at 20%) and over the commercially available biochar (59% at 5% to 84% at 20% over control).  Ongoing research is being planned on other chars and food/liquids waste streams including the use of spent brewers grain biochar to filter brewery waste water.  The results of these trials will be presented as well as further discussions on other closed loop, cascading use scenarios for biochar in filtration and plant trials.