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As a far-reaching initiative in China's air pollution control and energy transition efforts, the clean heating policy has sparked considerable debate in both academia and practice regarding its effectiveness in reducing carbon emissions. This study uses panel data from 15 prefecture-level cities in northern China from 2013 to 2023 and constructs a multi-period difference-in-differences model to empirically examine the impact of the clean heating policy on regional carbon emissions. The results are summarized as follows: (1) The policy effectively promotes the reduction of regional unit GDP and per capita carbon emission intensity in Northern China, but it has no evident effect on regional total carbon emissions. (2) The policy can exert the multiplier effect of the central government funds and structural effect to facilitate regional low-carbon transformation, but no significant Porter effect has been observed. (3) The carbon reduction effects exhibit significant regional heterogeneity. The policy has a more significant effect on carbon emissions of nonprovincial capital cities, coal-resource cities, and regions without coal power output, but it may significantly increase emissions in coal power-exporting regions. The clean heating policy should continue to be vigorously implemented, but its implementation strategy should be optimized by strengthening the transmission mechanism and addressing regional differences.

Since the discovery of anaerobic ammonium oxidation bacteria, commonly known as AnAOB in the early 1990s, more than a quarter century has passed and partial nitrification/anammox process for sewage treatment is still mainly in lab and pilot-scale research phase with few plants in operation. The main challenges for that are enrichment, grow and how to keep AnAOB in the reactor on low-strength wastewater treatment, such as in anaerobically treated domestic sewage. Another important aspect is need for continuous supply of nitrite and how to minimize nitrite consumption by others than anammox. In addition to that other minor control parameters play an important role, such as hydraulic and sludge retention time, dissolved oxygen, temperature, pH, etc. This paper presents a detailed review of essential process parameters and identifies gaps and solutions for effective implementation of the anammox process highlighting the different factors that suppress AnAOB growth, along with the aspects favouring activity and immobilization. Reactor start-up and operation, bacteria inhibition and conversion of emerging-pollutants is also investigated, with their effect on AnAOB and their removal. The main conclusions are the sustainability evaluation, which found that the process reduce the overall GHG emissions compared to conventional nitrogen removal processes; a possible microbial pathway that could be involved for simultaneous organics, nutrients and emerging-pollutants removal; and, finally, a novel concept of a three-stage treatment process in two up-flow anaerobic sludge blanket-based system is proposed.

Two independent experiments were performed to investigate role of NO in 5-aminolevulinic acid-mediated resistance to lead toxicity in barley plants. Lead toxicity significantly resulted in reduction of plant growth, Fv/Fm, total chlorophyll, leaf water potential, and Ca²⁺ as well as K⁺ potassium levels. Concurrently, it resulted in elevated levels of leaf MDA, H₂O₂, EL, Pb, and NO in comparison to control group. Both ALA (50 µM and 100 µM; ALA1 and ALA2) treatments enhanced plant growth parameters and elevated leaf K⁺ and Ca²⁺ levels, while simultaneously decreasing leaf Pb, H₂O₂, and MDA concentrations in comparison to Pb-stressed plants. A second experiment was conducted to ascertain involvement of nitric oxide in mitigation of Pb stress in barley seedlings by ALA, utilizing nitric oxide scavenger C₁₄H₁₆N₂O₄.K (cPTIO) in conjunction with ALA treatments. ALA-induced tolerance to Pb stress was entirely negated by administration of cPTIO (C₁₄H₁₆N₂O₄.K), which significantly decreased concentrations of endogenous nitric oxide. The findings indicated that ALA improved resistance of barley seedlings to Pb toxicity via activating endogenous nitric oxide. This was corroborated by elevation of H₂O₂ and MDA levels, with a reduction in SOD, CAT, and POD activities. The application of cPTIO along with ALA, led to growth inhibition and a notable increase in leaf Pb concentrations. Both ALA and nitric oxide collaboratively enhanced Pb tolerance in barley.

The cultivation of Daucus carota L. (carrot)  on soils polluted with trace elements (TE) constitutes an innovative phytomanagement approach, combining significant ecological and economic benefits. This plant species exhibits a notable capacity to extract trace elements from the soil while generating valuable biomass, primarily intended for hydrodistillation to produce high-quality essential oils (EO). Carrots exhibit an enhanced capacity to accumulate cadmium in their leaf tissues, with a high bioconcentration factor (BCF = 1.71), as well as significant zinc accumulation. Furthermore, the cultivation of this biennial plant promotes an increase in soil microbial biomass, as assessed by phospholipid fatty acid (PLFA) content, specifically enriching populations of Gram- bacteria, Gram+ bacteria, and saprotrophic fungi, thereby contributing to the modulation of microbial dynamics and the alleviation of stress within soil microbial communities. The EO extracted from carrot seeds contain TE concentrations below the quantification limit compared to other commercially available EO. Chemical analysis of the EO reveals a composition similar to that of commercial oils, with the major components being carotol (27.53%), an oxygenated sesquiterpene, and sabinene (26.08%), a monoterpene hydrocarbon. These EO have been extensively evaluated for their biological properties, demonstrating significant antifungal activity against Fusarium culmorum (IC50 = 0.57 ± 0.11 mg/ml) and Zymoseptoria tritici (IC50 = 1.09 ± 0.12 mg/ml), as well as antigermination activity against Blumeria graminis spores (IC50 = 1.47 ± 0.15 mg/ml). Additionally, these EO exhibit notable herbicidal properties, particularly in inhibiting root elongation and germination of the monocots species Lolium perenne (ryegrass) and the dicots species Lactuca sativa (lettuce). These findings highlight the potential of carrot as a tool for phytoremediation and the production of high-value bioactive compounds.