Ahmed A. Abdelhafez

By Ahmed A. Abdelhafez, Mohamed H.H. Abbas and Jianhua Li

Production of biochars from agricultural wastes reduces significantly the volume and weight of the wastes, and hence, it can be considered as a promising means for managing the agricultural wastes. Biochar has received great interest during the last few years, due to its beneficial role to mitigate CO2 emission through enhancing the long-term carbon sequestration. The effects of biochar on soil properties vary widely, depending on the characteristics of soil and the biochar. Most types of biochars are of alkaline nature and of high C content. Addition of biochar to the soil can improve the cation exchange capacity enrich soil with the nutrients and enhance the microbial growth, and improve some soil physical properties such as water retention and aggregation. For contamination control, biochars have proven to be a suitable tool for controlling the contaminants in the environment. The high surface area, porous structure, alkaline nature, and the presence of functional groups characterized the biochar as alternative option for the remediation of heavy metal contaminated waters and soils. However, there is a lack of knowledge regarding the effects of biochar in the presence of mineral and/or organic fertilizers on the plant growth and nutrient transformation in soils. In addition, biochar is successfully used for treating the acid soils; therefore, future studies are needed to investigate the neutralization of alkaline performance of biochar to be used safely in alkaline soils.

Part of the book: Engineering Applications of Biochar

By Ahmed A. Abdelhafez, Xu Zhang, Li Zhou, Guoyan Zou, Naxin Cui, Mohammed H.H. Abbas and Mahdy H. Hamed

Part of the book: Applications of Biochar for Environmental Safety

By Ahmed A. Abdelhafez, Abdel Aziz Tantawy, Mohamed H.H. Abbas, Shawky M. Metwally, Amera Sh. Metwally, Aya Sh. Metwally, Rasha R.M. Mansour, Sedky H. Hassan, Hassan H. Abbas, Ihab M. Farid, Nermeen N. Nasralla, Ahmed S.H. Soliman, Mohammed E. Younis, Ghada S.A. Sayed, Mahfouz Z. Ahmed, Ehdaa Alaa Mohamed Abed, Ahmed Farouk Al-Hossainy, Heidi Ahmed Ali Abouzeid, Mahdy H. Hamed, Mahmoud I. El-Kelawy, Gamal Hassan Kamel, Hussein Ferweez and Ahmed M. Diab

In the late 1950s, residents of a Japanese fishing village known as “Minamata” began falling ill and dying at an alarming rate. The Japanese authorities stated that methyl-mercury-rich seafood and shellfish caused the sickness. Burning fossil fuels represent ≈52.7% of Hg emissions. The majorities of mercury’s compounds are volatile and thus travel hundreds of miles with wind before being deposited on the earth’s surface. High acidity and dissolved organic carbon increase Hg-mobility in soil to enter the food chain. Additionally, Hg is taken up by areal plant parts via gas exchange. Mercury has no identified role in plants while exhibiting high affinity to form complexes with soft ligands such as sulfur and this consequently inactivates amino acids and sulfur-containing antioxidants. Long-term human exposure to Hg leads to neurotoxicity in children and adults, immunological, cardiac, and motor reproductive and genetic disorders. Accordingly, remediating contaminated soils has become an obligation. Mercury, like other potentially toxic elements, is not biodegradable, and therefore, its remediation should encompass either removal of Hg from soils or even its immobilization. This chapter discusses Hg’s chemical behavior, sources, health dangers, and soil remediation methods to lower Hg levels.

Part of the book: Marine Pollution