Fate and toxicity of spilled chemicals in groundwater and soil environment I: strong acids

Abstract

We reviewed the chemical/physical properties, toxicity, environmental fate, and ecotoxicity of strong acids in soil and groundwater environments. We recommend that sulfuric acid and hydrofluoric acid be classified as chemicals of priority control based on volumes used, toxicity, carcinogenicity, and past significant spill events. Understanding the behavior and transport of spilled strong acids in soil and groundwater environments requires a multi-disciplinary approach, as they can undergo a variety of geochemical and biochemical reactions with complex geomedia. The toxicity of spilled acid is dependent on the characteristics of the geomedia exposed to the acid and the amount of residual protons following acid–substrate interaction. Soil texture, cation exchange capacity, mineral composition, bedrock type, and aluminum content may be important factors affecting the toxicity of spilled acid in soil-groundwater environments. We expect that the results of this study will contribute preliminary data for future research on chemical spills.

Environmental Impacts of Graphite Recycling from Spent Lithium-Ion Batteries Based on Life Cycle Assessment

“…With a pK a value of 1.92 at 25 °C, sulfuric acid is classified by the international agency for research on cancer as a group I carcinogen. 25 Additionally, sulfuric acid has a high toxicity, with LC 50 values (lethal concentration 50) of 1.67 and 2.9 mg•L −1 for fish and aquatic invertebrates after 48 h. 25 Regarding the GWP, a reduction of 31.1% achieved (to 1.99 kg•CO 2 equiv.•kg graphite −1 ) makes this procedure more competitive against virgin battery-grade graphite (either synthetic or natural). So, at this point, the following question arises: is it worth using so many toxic components to obtain marginal improvements in the graphite quality and its electrochemical performance?…”

“…As shown in the materials and energy inputs in Table , some of the approaches rely on the use of extremely large amounts of inorganic acids, making the process not only environmentally but also economically nonviable. The excessive use of inorganic acids can also seriously threaten human, animal, and plant life, so limiting their use should be a priority. Green chemistry principles also encourage the reduction of hazardous chemical syntheses and the design of synthetic methods for maximizing incorporation of all materials used during the process into the final product, that is, atom economy .…”

“…In eight of the 18 impacts, the reductions exceed 50%, with special improvements in categories related to toxicity (terrestrial acidification and ecotoxicity, fine particulate matter formation, freshwater ecotoxicity, marine ecotoxicity, and human noncarcinogenic toxicity). With a p K a value of 1.92 at 25 °C, sulfuric acid is classified by the international agency for research on cancer as a group I carcinogen . Additionally, sulfuric acid has a high toxicity, with LC 50 values (lethal concentration 50) of 1.67 and 2.9 mg·L –1 for fish and aquatic invertebrates after 48 h .…”

“…Graphite recycling/regeneration has been accomplished through diverse approaches, including hydrometallurgical methods based on acid–base leaching processes (for example by using acids HCl or H 2 SO 4 ) , or a pyrometallurgical process where graphite is treated under temperatures above 1000 °C so that the residual metals, metal oxides, and binders are gasified and the graphite structure is repaired . In the former, the use of inorganic acids encompasses serious environmental human and environmental safety issues, while large amounts of energy are required to power smelting furnaces in the latter. Some companies such as Umicore are applying the pyrometallurgical process to recover high-value metals from batteries …”

Thermoelastic pulsed laser ablation of silver thin films with organic metal–SiO2 adhesion layer in water: application to the sustainable regeneration of glass microfluidic reactors for silver nanoparticles

“…In this case, the system should be extensively rinsed with water after successful cleaning. In the context of a sustainable technology, the scientific community has been investigating methods to eliminate the use of acid solutions in experimental protocols dedicated to chemical synthesis, purification, or cleaning processes [17][18][19][20][21].…”