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Topic review
Updated time: 22 Jun 2021
Definition: The Fenton process is an efficient treatment for removing many organics pollutants in aqueous systems at acidic pH (2.8-3.5). However, the in-situ application of this technology for soil remediation (where pHs around neutrality are required) presents important limitations, such as catalyst (iron) availability and oxidant (H2O2) stability. The addition of chelating agents (CAs) makes iron soluble at circumneutral pH by forming complexes with Fe, and thus, enabling Fenton reactions under these conditions. This strategy, called chelate-modified Fenton process (MF), can be employed to overcome the challenges identified in conventional Fenton.
Entry Collection : Environmental Sciences
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Topic review
Updated time: 20 May 2021
Submitted by: Fulvia Chiampo
Definition: The contamination of soil by heavy metals and metalloids is a worldwide problem due to the accumulation of these compounds in the environment, endangering human health, plants, and animals. Heavy metals and metalloids are normally present in nature, but the rise of industrialization has led to concentrations higher than the admissible ones. They are non-biodegradable and toxic, even at very low concentrations. Several techniques have been developed over the years: - physical remediation (e.g., washing, thermal desorption, solidification), - chemical remediation (e.g., adsorption, catalysis, precipitation/solubilization, electrokinetic methods), - biological remediation (e.g., biodegradation, phytoremediation, bioventing), and combined remediation (e.g., electrokinetic–microbial remediation; washing–microbial degradation).
Entry Collection : Environmental Sciences
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Topic review
Updated time: 18 May 2021
Submitted by: Sheng Li
Definition: Landscape integrated soil and water conservation (LISWC) is a system designed to conserve and reuse soil and water within the landscape by integrating multiple BMPs based on an understanding of the landscape processes and knowledge about the BMPs. On a typical sloping field in Atlantic Canada, an LISWC system can be established by integrating BMPs such as diversion terraces and grassed waterways, tile drainage, water retention structures, supplemental irrigation, conservative tillage practices and soil–landscape restoration.
Entry Collection : Environmental Sciences
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Topic review
Updated time: 06 Jul 2021
Definition: Mangrove forests play an important role in mitigating climate change but are threatened by aquaculture expansion (shrimp ponds). The change of land use from natural environments to productive uses, generates a change in the balance and carbon sequestration and storaging. In mangrove forest the carbon stocks are larger than in other tropical forest. Addtionally, soil mangrove forest represent 40-80% of Cardon stocks. These reasons are the evidence of mangrove forest need to be included in REED programs and conservation strategies.
Entry Collection : Environmental Sciences
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Topic review
Updated time: 25 Jun 2021
Submitted by: Fangzhou Zheng
Definition: Water-induced channel is one of the main forms of soil erosion in cultivated fields. Channelized erosion is often measured by the volume of the channels. Traditionally, the measurements were conducted with rulers or measuring tapes. However, these traditional methods are generally time- and labor-consuming and can cause soil surface disturbance. Close-range photogrammetry with a Consumer-Grade Camera (CGC-CRP) provides an alternative way of measuring channel volume and can overcome limitations of traditional methods and provides much higher spatial resolution. The optimum setting of the camera is with the image overlapping greater than 70% and with the shooting angle ranging from 60° to 80°. In addition, the channel orientation paralleled to the camera shooting direction is recommended.
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