By Sally Brown, University of Washington
Abstracts of these resources are available in the searchable Information Portal offered to Northwest Biosolids members.
- Long-term impacts of infrequent biosolids applications on chemical and microbial properties of a semi-arid rangeland soil
- Phosphorus retention mechanisms of a water treatment residual
- Phosphorus losses from an irrigated watershed in the Northwestern United States: Case study of the Upper Snake Rock Watershed
- Drinking water treatment residuals: A review of recent uses
- Environmental benefits of biochar
This month’s library is an out and out promotion for our upcoming Biofest conference (September 9-11, Campbell’s at Lake Chelan, WA). The conference and this library feature Jim Ippolito, a professor of multiple talents at Colorado State University. Jim got his degrees in soils from Colorado State University and worked as a scientist for USDA ARS in Idaho before returning to CSU as an associate professor. He started his work with biosolids in graduate school studying biosolids impacts on dryland wheat…. Something that has relevance right here in WA State! He has gone on to work with metals and nutrients in biosolids and expanded to work with water treatment residuals and biochar. He is also known as an excellent teacher- read good speaker. The library this month presents a survey of his work.
The first piece is to prove that Jim has his biosolids ‘chops’. The paper presents results from a long-term study of biosolids applied to a semi-arid rangeland. Here plots received different rates of biosolids first in the early 90s and then half of those same plots got another shot (same rate) ten years later. Soil parameters, plant growth and diversity and microbial activity were measured. If you are thinking of using biosolids to restore rangelands, this paper is for you. Basic results, biosolids, long and short term, increased plant yield and improved some soil parameters (mainly nutrients, and water holding at higher rates). Increases were also seen at the higher application rates for microbial activity. While the species diversity (# of different kinds of plants) decreased, they conclude that a little less diversity is a small sacrifice for better vigor in general.
Jim also has a number of other papers about biosolids including work on metals and nutrients. At Biofest he’ll be talking about phosphorus- so the next two papers showcase some of his work on that topic. The 2nd paper describes a study testing what happens when you add a lot of P to an aluminum- based water treatment residual (WTR). The P sticks to the WTR. The authors looked at both P adsorption and the form of the P. They found that most of the P was adsorbed to the Al oxides with a little bit associated with calcium. So if you want to suck up P- this is one way to do it. The third paper focuses on P release from the Upper Snake River in ID. With concerns over P in biosolids and potential contamination of surface and ground waters, this study shows how P moves in an irrigated watershed. Water from the river is used to irrigate neighboring farmlands. The authors looked at water going to and coming from the farms as part of the P load of the river. They also measured the impact of mitigation strategies including sediment ponds. Currently total suspended solids and total P concentrations in return flow to the river exceed standards. Water returning to the river from the ponds showed both reduced TSS and TP. The authors conclude that conservation measures such as the ponds, if more broadly adopted, will mean that the water returning to the river meets TMDL standards.
The last two papers are really useful survey papers that Jim was first author on. The first goes into detail on uses for WTRs and the second details the environmental benefits of biochar. Biochar for many years was the universal answer to whatever ailed. Bringing soils back to life, sequestering contaminants and carbon, saving the universe …. You name it. Jim has done a significant amount of work with biochar and has enough perspective to see the pluses and minuses of this amendment. While a topic of his scheduled talks, for those that attend the conference, it might make sense to pick his brain on this topic. For those not able to attend, this is a really good basic paper on a topic that still comes up regularly.
Hopefully this library has provided you with even more reason to attend this year’s Biofest. It also includes some useful information even if you can’t come to the conference. Did I mention that Jim looks a whole lot like Robert Downey Jr? Looks, knowledge, and personality, can’t ask for more than that in a keynote.