{"title":"ASSESSMENT OF HEAVY METALS IN HYDROCHAR PRODUCED BY HYDROTHERMAL CARBONIZATION OF DAIRY MANURE","authors":"B. Brian HE, Zheting BI, Lide CHEN","doi":"10.15302/j-fase-2023507","DOIUrl":null,"url":null,"abstract":"<List> <ListItem><ItemContent> ● Content of heavy metals in hydrochar varies considerably, from 50% to 100%. </ItemContent></ListItem> <ListItem><ItemContent> ● Concentrations of heavy metals in hydrochar can be higher than those in the dairy manure. </ItemContent></ListItem> <ListItem><ItemContent> ● Concentrations of heavy metals in hydrochar are far below the regulatory level. </ItemContent></ListItem></List> Hydrochar produced from dairy manure is a regulated biosolid if being promoted for agricultural applications thus must have the properties that comply with all environmental standards and government regulations, including the levels of heavy metals (HMs). In this study, systematic research was conducted on HM levels in hydrochar from dairy manure and on the effects of processing conditions, including processing temperature (180–255 °C), holding time (30<i>–</i>120 min) and solid content of manure slurry (2%<i>–</i>15%), through a central composite design and statistical analyses. It was found that HMs can be retained in hydrochar, ranging from 40% to 100%. The processing temperature and solid content in the feed were the most influential process parameters that affected HMs retention in hydrochar. Statistical analysis showed that there was no single optimal point to minimize HMs retained in hydrochar, but there were minimization points at given processing time and solid content. Most HMs concentrations were higher in hydrochar than those initially in dairy manure but were greatly below the thresholds as set by the US government regulations. Thus, hydrochar is feasible for use as a phosphorus-enriched organic fertilizer and/or soil amendment for agricultural applications without serious concerns about HMs it might contain.","PeriodicalId":12565,"journal":{"name":"Frontiers of Agricultural Science and Engineering","volume":"9 1","pages":"0"},"PeriodicalIF":3.6000,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Frontiers of Agricultural Science and Engineering","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.15302/j-fase-2023507","RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRONOMY","Score":null,"Total":0}
引用次数: 0
Abstract
● Content of heavy metals in hydrochar varies considerably, from 50% to 100%. ● Concentrations of heavy metals in hydrochar can be higher than those in the dairy manure. ● Concentrations of heavy metals in hydrochar are far below the regulatory level. Hydrochar produced from dairy manure is a regulated biosolid if being promoted for agricultural applications thus must have the properties that comply with all environmental standards and government regulations, including the levels of heavy metals (HMs). In this study, systematic research was conducted on HM levels in hydrochar from dairy manure and on the effects of processing conditions, including processing temperature (180–255 °C), holding time (30–120 min) and solid content of manure slurry (2%–15%), through a central composite design and statistical analyses. It was found that HMs can be retained in hydrochar, ranging from 40% to 100%. The processing temperature and solid content in the feed were the most influential process parameters that affected HMs retention in hydrochar. Statistical analysis showed that there was no single optimal point to minimize HMs retained in hydrochar, but there were minimization points at given processing time and solid content. Most HMs concentrations were higher in hydrochar than those initially in dairy manure but were greatly below the thresholds as set by the US government regulations. Thus, hydrochar is feasible for use as a phosphorus-enriched organic fertilizer and/or soil amendment for agricultural applications without serious concerns about HMs it might contain.
期刊介绍:
Frontiers of Agricultural Science and Engineering (FASE) is an international journal for research on agricultural science and engineering. The journal’s aim is to report advanced and innovative scientific proceedings in agricultural field including Crop Science, Agricultural Biotechnology, Horticulture, Plant Protection, Agricultural Engineering, Forestry Engineering, Agricultural Resources, Animal Husbandry and Veterinary Medicine, Applied Ecology, Forestry and Fisheries. FASE is committed to provide a high level scientific and professional forum for researchers worldwide to publish their original findings and to utilize these novel findings to benefit the society.