Biogeochemistry

Agroecosystems make up a significant portion of terrestrial ecosystems and receive a disproportionally high amount of terrestrial nitrogen inputs from fertilizer, leading to nitrogen loss and associated environmental problems. Integrated crop livestock systems, such as pasture-integrated crop rotations, may be more environmentally sustainable however the long-term effects of this management practice on soil microorganisms and nitrogen transformations are not well understood.
Soil organic matter (OM) stratification and macro and micro fauna are both good indicators for the evaluation of soil ecological functioning, which is interrelated with nutrient cycles. To the best of the authors’ knowledge, responses of the degree of OM stratification with soil depth expressed as a ratio, and belowground biota to forest degradation and land cover changes have received little attention, particularly in northern Iran.
Soil contamination by potentially toxic elements (PTEs) has led to adverse environmental impacts. In this review, we discussed remediation of PTEs contaminated soils through immobilization techniques using different soil amendments with respect to type of element, soil, and amendment, immobilization efficiency, underlying mechanisms, and field applicability. Soil amendments such as manure, compost, biochar, clay minerals, phosphate compounds, coal fly ash, and liming materials are widely used as immobilizing agents for PTEs.
In the last decades, energy scarcity has become an important issue globally. Renewable energy sources have gained importance due to limited fossil fuel reserves and increased concerns on climate change. In this regard, municipal wastewater is a remarkable energy source since huge amounts of wastewater are generated and treated all over the world every day. Conventional activated sludge (CAS) process, which has been in use for more than a century, is the most widely applied treatment method for municipal wastewater.
In the last decades, energy scarcity has become an important issue globally. Renewable energy sources have gained importance due to limited fossil fuel reserves and increased concerns on climate change. In this regard, municipal wastewater is a remarkable energy source since huge amounts of wastewater are generated and treated all over the world every day. Conventional activated sludge (CAS) process, which has been in use for more than a century, is the most widely applied treatment method for municipal wastewater.