Environmental Technology & Innovation最新文献

Soils contaminated with microplastics have disorganized pore structure, which reduces soil fertility. However, few studies have focused on morphological characteristics and connectivity of soil pores under microplastic enrichment. This study evaluates how different concentrations of polyvinyl chloride microplastics (0 %, 2 %, and 4 %) affect the pore structure characteristics (pore distribution and porosity, pore characterization parameters, and pore connectivity) of soils with different textures (sandy, sandy loam, and loamy). Computed tomography were used to reassemble images of soil micropores following microplastics enrichment. The pore network model, Euler characteristics number, and tortuosity were used to characterize the complexity of connected pores. The results revealed that the effects of microplastics on pore structure varied substantially depending on soil texture, with sandy and sandy loam soils rapidly reducing or eliminating connected pores after introducing microplastics. However, loamy soils could still maintain a certain degree of pore connectivity. Adding microplastics reduced the porosity of all three soils, with sandy soil showing the most significant drop (89.51 %) at 4 % microplastics concentration dramatically. The overall impact of microplastics on the pores of loam soil is minimal. As the microplastics abundance increased, the pore network model of loam-connected pores became simpler. Under a 4 % microplastics enrichment, the loam soil’s Euler characteristic number of connected pores grew by 91.17 % In summary, even though the overall structure of the pores of soils of different textures differed due to microplastics addition, microplastics deposition would still severely disrupt the connectivity of soil pores and reduce soil infiltration capacity regardless of soil texture.

Layered double hydroxides (LDH) are widely used in a variety of industries due to their unique structural characteristics. It is essential to comprehend the environmental behavior and toxicological impacts of these substances to address potential risks caused by LDH release into the environment. In this study, CuFe and Cobalt (Co)-doped CuFe LDHs were synthesized and their toxicities to Chlorella vulgaris were investigated. In the scanning electron microscope images, the Co-doped and undoped catalysts appeared as uniformly dispersed flakes. The X-ray diffraction pattern of the Co-doped CuFe LDH confirmed the successful incorporation of Co into the crystalline lattice of the LDH. The growth of C. vulgaris was negatively affected by the presence of 1 mg/L LDHs, with membrane damage and cell wrinkling observed with 20 mg/L. The CuFe LDH-exposed algae exhibited a significantly greater decline in chlorophyll content compared to that of the Co-doped LDH-exposed algae. However, superoxide dismutase activity was elevated in algal cells exposed to the Co-doped CuFe LDH. Catalase activity increased up to 20 mg/L, followed by a decline at higher doses in CuFe LDH-exposed cells. From an ecological perspective, the lack of increased toxicity after Co doping is favorable for aquatic life. The extensive characterization, together with a rigorous toxicity assessment, provides new information about the environmental safety of cobalt doping to aid in the development of safer and more sustainable LDH-based products.

Bio-based fertilizers (BBFs) are an increasingly important source of nutrients in agriculture, promoted by the new EU fertilizer regulation aiming to enable a circular bioeconomy. Predicting the mineralization-dependent nutrient release of BBFs is critical for their appropriate use and to minimize environmental losses. We assessed mineralizable nitrogen (N) and carbon (C) of a representative selection of 32 BBFs and evaluated a set of chemical extraction methods to predict their N mineralization dynamics. In 84-day aerobic incubations, cumulative mineral N release varied between −13 and 100 % of amended N. Mineralized C ranged from 10 % to 117 % of amended C. Based on the dynamics of N and C mineralization, BBFs were classified into five significantly different groups. Among the tested chemical indicators of N mineralization from BBFs, cold and hot water presented the lowest extraction intensities, followed by hot potassium chloride and hot sulfuric acid extractions, while C:N ratio is based on total contents. Mineral N released almost immediately was best predicted by cold water extractable N, while hot sulfuric acid extractable N and C:N ratio predicted N released after the first two weeks and after 84 days, respectively. The combination of these three indicators was able to discriminate BBFs into four out of five mineralization classes. Such a cost-effective yet accurate estimation of N mineralization dynamics from BBFs can therefore be used as a basis to inform farmers on suitable timing and amount of BBF application, improving the synchrony between N release from BBFs and crop N demand.

With its direct or indirect reliance on agriculture for a living, the Indian economy is heavily dependent on this industry. Food insecurity is a result of decreased agriculture productivity due to growing contamination and pollution. Biochar is an organic carbon bound environment friendly material known for enhancing soil functions and plant growth. On the other hand, compost is an organic, nutrient-rich product that is formed by an aerobic process and is used as an amendment. Both of these have numerous benefits as amendment in the soil-plant system. This is a complete study on the effects of applying biochar and compost separately and in combination at ratios of 0 %, 1 %, and 2 % in a cadmium contaminated soil (0 mg/kg, 4 mg/kg and 8 mg/kg Cd). Their effect was studied on the soil characteristics, seed germination, morphology, photosynthetic pigments, oxidative stress, enzymatic and non-enzymatic antioxidant activity in spinach plant grown in contaminated soil in Chhattisgarh state, India. The results depicted that combination of biochar and compost was beneficial in improving soil-plant productivity. Compost and biochar mixtures improved the soil quality and decreased Cd concentration. When comparing the biochar-compost combination to either biochar or compost alone, the plant morphological changes and chlorophyll content increased to a greater extent in their combined application. Proline content and enzymatic activities were similarly enhanced in the biochar-compost mixture. Their amendment showed effective potential in improving spinach growth and development in the polluted soil.

Biostimulants emerged as a versatile tool to modify plant biological processes, by enhancing growth, improving nutrition, increasing stress tolerance, and enhancing crop quality. Among various biostimulant compounds, chitin and gelatin have shown promise in promoting plant growth and enhancing microbial communities. In this study, we investigated the biostimulant effects of chitin, gelatin, and their mixture on cucumber plantlets and associated rhizosphere microbial communities during plantlet production. Cucumber seeds were sown in seedling substrate amended with gelatin, chitin, or a mixture of both biostimulants. Plants were grown at 25°C/21°C with a 16/8 h photoperiod and 75 % humidity. Unamended samples served as controls, while urea was used as a mineral fertilizer control. After 8, 11 and 15 days, rhizosphere samples were collected, DNA was extracted, and the bacterial and fungal communities were assessed by high-throughput sequencing of the 16 S rRNA gene and the ITS region, respectively. Our findings revealed that the application of these biostimulants significantly improved cucumber plantlet growth, with the most pronounced effects 15 days after germination. Gelatin had significantly superior performance compared to chitin. The microbial communities with those amendments were enriched with microbes of genera Cellvibrio, Catenulispora, Arthrobacter, Mortierella, and Penicillium, all known for their production of hydrolytic enzymes such as chitinases, cellulases, and proteases. Overall, this research contributes to a deeper understanding of the biostimulant-mediated interactions between plants and their associated microbial communities, offering potential applications to enhance crop productivity, especially at the plantlet stage while promoting circular economy and environmental sustainability in agriculture.

Stacking edge-of-field practices may improve nutrient removal from crops. To examine the effects of stacking edge-of-field conservation practices, a woodchip bioreactor (WBR) and saturated riparian buffer (SRB) were installed in series by intercepting tile flow from a field having a drainage water management system. Nutrient monitoring from 5 years evaluated nutrient export annually and based on the precipitation intensity. Drainage water was monitored for total suspended solids (TSS), nitrate-N, total-P, total-N, and ortho-P at the inlet and outlet of WBR and control structure of SRB. Nutrient export reductions of WBR and SRB were determined for precipitation events that were categorized as low <12.7 mm, mid 12.7–25.4 mm, high 25.4–50.8 mm, and very high >50.8 mm. Over the five seasons, nitrate-N export was reduced 88 % at the WBR outlet and 78 % at SRB outlet when used in a stacked series configuration. The efficacy of edge-of-field practices was affected by the intensity of precipitation events. The low and mid-intensity precipitation events generated 67 % of the total discharge from the subsurface drainage system which accounted for 74 % of the influent nitrate-N. During low and mid-intensity precipitation events, discharge was reduced by 58–65 %, nitrate-N was reduced by 49–88 % and total-P was reduced by 65–73 % by using stacked practice of WBR and SRB. During high and very high-intensity precipitation events only nitrate-N export was reduced by 61–66 %. This indicates that when designing stacked edge-of-the-field practices the cumulative effect of the practices and their performance during different precipitation events should be taken into account when managing conservation practice-based cropping systems.

This study modified and integrated a bioimaging method of hybridization chain reaction fluorescence in situ hybridization (HCR-FISH) into a pipeline for assessing biofouling on stainless steel (SS). A modified protocol of double-labeling HCR-FISH was directly applied to two surface types of SS grade EN 1.4404 to detect localized bacteria and sulfate-reducing bacteria (SRB) by targeting bacterial 16 S rRNA genes and dissimilatory sulfite reductase (dsrB) genes, respectively. The protocol was first validated using microbial pure cultures and materials before being integrated into a biofouling assessment pipeline of SS in a laboratory-scale brackish water circuit, incorporating electrochemical, surface, and molecular biology characterization analyses. The double-labeling HCR-FISH improved bioimaging of surface biofilm morphology and microbial distribution, surpassing monochrome staining methods. This method was compatible and complemented other microscopy techniques and molecular biological analyses, providing additional insights into the biofilms and deposits on the alloy surfaces. The implemented assessment pipeline for biofouling determination frequently detected the ennoblement phenomenon in the evolution of marine biofilm on SS surfaces. However, within the experimental timeframe, microbial activities in the brackish seawater circuit did not flourish significantly, resulting in minimal impact on the steel material. Additionally, surface type and roughness may correlate with microbial adhesion, biofilm growth, and the deformation of passivation layers in SS. Despite abundant sessile bacteria, particularly opportunistic microorganisms, on the steel surfaces, no direct correlations with biodeterioration phenomena or influences of surface roughness of an alloy and the presence of biofilm were conclusively established.

Soil respiration (R_s) and its temperature and water sensitivities play a vital role in understanding the processes and mechanisms of carbon (C) cycling in half plastic film mulching (M_m) field. A two-year field experiment was conducted to investigate the responses of R_s and its components, including respiration from roots (R_r) and soil free-living microbes (R_m), to soil temperature (ST) and water content (SWC) amidst environmental changes. Results showed that M_m significantly stimulated the cumulative CO₂ emissions of R_m (CE-R_m) and R_r mainly due to the prominent increase of them in rows without plastic film in M_m. This was attributed to more favorable microclimatic conditions under M_m for microbes and roots growth, identified by improved SWC, dissolved organic C (DOC) and total nitrogen (DTN), microbial biomass C (MBC) and nitrogen (MBN) contents, enzyme activities and functional genes abundances associated with C degradation. The combination of ST and SWC can help to more accurately predict the seasonal R_r and R_m variation than solely ST or SWC. M_m considerably increased the temperature sensitivity of R_m and the water sensitivities of R_m and R_r probably due to the improved soil C and nitrogen substrates for microbes and roots indicated by growing DOC and DTN contents. This study indicated that the M_m could sustain crop yield without increasing environmental impacts because there was no significant difference for CE-R_m per unit of grain yield produced between M₀ and M_m.

Approximately 3.2 billion cubic meters of untreated sewer overflow water is discharged into U.S. lakes and rivers every year during high-intensity precipitation events posing both environmental and public health challenges. A decentralized, end-of-pipe sewer overflow treatment system would eliminate detrimental overflow effects by handling peak wet-weather flow and associated pollutant loadings. In this study, an overflow treatment system comprised of suspended solids removal followed by chemical oxidation was assessed. Three different suspended solids removal technologies were employed to determine their compatibility with subsequent ozonation and to estimate the treatment cost to meet Clean Water Act discharge permit requirements for biochemical oxygen demand (BOD), total suspended solids (TSS), and Escherichia coli (E. coli) in approximately 30 minutes of total treatment time. Both cloth media filtration with ozonation and chemically enhanced primary treatment with ozonation met permit limits for BOD, TSS, and E. coli, while conventional primary treatment only met permit limits for BOD and TSS, ostensibly due to lower TSS removal by conventional primary treatment. Initial suspended solids removal was a key parameter for effective, subsequent ozonation to remove BOD, achieve disinfection, and decrease operating costs. The estimated, simple operating cost was competitive with conventional activated sludge ($0.10/m³ water treated, 2022 dollars). A full-scale decentralized, end-of-pipe treatment system could be operated as a “peaker facility” to handle large flows during storm events but remain idle during dry weather periods.

Excessive chemical fertilizers harm the environment, economy, and health, while compost and its extracts provide a sustainable solution. Consequently, the development of liquid organic amendments with biofertilizing and antioxidant capabilities is of significant interest in intensive agriculture. To achieve this, four Compost Extraction Protocols (CEP1–4) were applied to different compost to obtain a range of aqueous extracts. These treatments varied in temperature, incubation duration, and agitation. The raw materials for the compost used were Agri-food Waste (AW), Sewage Sludge (SS), Vegetable Waste (VW), and Olive Mill Waste (OMW). The extracts were characterized in physicochemical terms and their potential to promote radicle germination in cucumber and lettuce seeds. Additionally, counts of microbial groups associated with biofertilizing capacity were conducted. Three extracts were chosen based on the germination index to conduct an in vivo bioassay on seedlings. Finally, oxidative stress in radicles and seedlings resulting from the preceding tests was evaluated by quantifying malondialdehyde (MDA), total phenolic compounds (TPC), and ascorbate-glutathione cycle enzymes. The results established that protocols with milder temperatures, such as CEP1 and CEP4, yielded aqueous compost extracts with good biofertilizing and antioxidant properties, although the effect was dependent on crop sensitivity. Specifically, the extracts selected for the seedling trial, OMW-A CEP4, AW-A CEP1, and especially AW-A CEP4, demonstrated a remarkable biofertilizing and antioxidant properties in lettuce, by increasing growth parameters and TPC while decreasing MDA. The results indicate that aqueous compost extracts are a suitable alternative to reduce the consumption of chemical fertilizers.