Comparison of different valent iron on anaerobic sludge digestion: Focusing on oxidation reduction potential,dissolved organic nitrogen and microbial community

• ORP value from −278.71 to −379.80 mV showed indiscernible effects on methane yield. • Fe(II) and Fe(III) promoted more degradation of proteins and amino acids than Fe⁰. • The highest enrichment of Geobacter was noted in samples added with Fe⁰. • Cysteine was accumulated during iron enhanced anaerobic sludge digestion. • Both iron content and valence were important for methane production. This study compared effects of three different valent iron (Fe⁰, Fe(II) and Fe(III)) on enhanced anaerobic sludge digestion, focusing on the changes of oxidation reduction potential (ORP), dissolved organic nitrogen (DON), and microbial community. Under the same iron dose in range of 0−160 mg/L after an incubation period of 30 days (d), the maximum methane production rate of sludge samples dosed with respective Fe⁰, Fe(II) and Fe(III) at the same concentration showed indiscernible differences at each iron dose, regardless of the different iron valence. Moreover, their behavior in changes of ORP, DON and microbial community was different: (1) the addition of Fe⁰ made the ORP of sludge more negative, and the addition of Fe(II) and Fe(III) made the ORP of sludge less negative. However, whether being more or less negative, the changes of ORP may show unobservable effects on methane yield when it ranged from −278.71 to −379.80 mV; (2) the degradation of dissolved organic nitrogen, particularly proteins, was less efficient in sludge samples dosed with Fe⁰ compared with those dosed with Fe(II) and Fe(III) after an incubation period of 30 d. At the same dose of 160 mg/L iron, more cysteine was noted in sludge samples dosed with Fe(II) (30.74 mg/L) and Fe(III) (27.92 mg/L) compared with that dosed with Fe⁰ (21.75 mg/L); (3) Fe⁰ particularly promoted the enrichment of Geobacter, and it was 6 times higher than those in sludge samples dosed with Fe(II) and Fe(III) at the same dose of 160 mg/L iron.     

Clean energy investment and financial development as determinants of environment and sustainable economic growth: evidence from China

Environmental Science and Pollution Research - Environmental sustainability has become one of the most common phrases in discussions about climate change. This study examines the impact of clean...     

Combined effects of air pollution in adulthood and famine exposure in early life on type 2 diabetes

Environmental Science and Pollution Research - Famine exposure or air pollution is linked to type 2 diabetes mellitus (T2DM). However, their combined effects on T2DM remain largely unknown. A total...     

What drives green development in China: public pressure or the willingness of local government?

Environmental Science and Pollution Research - With China already committing to peak carbon dioxide emissions before 2030 and achieving carbon neutrality before 2060, green development is urgent....     

实施清洁生产 创建绿色企业——开展清洁生产工作的几点体会

文章阐述了辽河油田公司开展清洁生产工作的基本情况,结合管理现状,分析总结了开展清洁生产工作的管理经验,阐述了通过科技进步所取得的清洁生产成绩,归纳整理出可借鉴的清洁生产审核经验,为清洁生产审核工作提供了有益的建议。     

石油化工企业灭火中的环境保护

从消防的角度对消防水的产生与特点进行探讨,阐述消防污水的产生与特点、灭火中应注意的问题以及消防污水紧急处置的措施,对石化企业的防火设计及消防监管提出了一些建议,阐明在消防灭火过程中,应树立强烈的环保意识,避免因火灾引发的突发环境事件造成政治、经济和社会方面的重大影响。     

Adaptation responses of microalgal-bacterial granular sludge to polystyrene microplastic particles in municipal wastewater

Environmental Science and Pollution Research - Microplastics are frequently detected in wastewater treatment plants, but the knowledge of their effects on microalgal-bacterial granular sludge...     

Nanotechnology-based controlled release of sustainable fertilizers. A review

The rising population is increasing food demand, yet actual crop production is limited by the poor efficiency of classical fertilizers. In particular, only about 40–60% of fertilizer nitrogen, 15–20% of phosphorus and 50–60% of potassium are used by crop plants, the rest ending polluting the environment. Nanofertilizers are promising alternatives. Here, we review plant nutrients, synthesis of zinc oxide nanoparticles, encapsulation of nanoparticles in fertilizers, and effect on plants.

     

Optimized ratoon rice system to sustain cleaner food production in Jianghan Plain,China: a comprehensive emergy assessment

Environmental Science and Pollution Research - Ratoon rice (RR) is regarded as a labor-saving and efficient approach to rice cultivation; however, sub-optimal production techniques (fertilization,...     

Measurement and identification of relative poverty level of pastoral areas: an analysis based on spatial layout

Environmental Science and Pollution Research - Pastoral areas are the key difficulty in China’s pursuit of common prosperity and a key region for China to build the northern ecological safety...