Smoothing the Phosphorus Resource Stress under the Socioeconomic Development in China.

Phosphorus (P) is the key in maintaining food security and ecosystem functions. Population growth and economic development have increased the demand for phosphate rocks. China has gradually developed from zero phosphate mining to the world's leading P miner, fertilizer, and agricultural producer since 1949. China released policies, such as designating phosphate rock as a strategic resource, promoting eco-agricultural policies, and encouraging the use of solid wastes produced in mining and the phosphorus chemical industry as construction materials. However, methodological and data gaps remain in the mapping of the long-term effects of policies on P resource efficiency. Here, P resource efficiency can be represented by the potential of the P cycle to concentrate or dilute P as assessed by substance flow analysis (SFA) complemented by statistical entropy analysis (SEA). P-flow quantification over the past 70 years in China revealed that both resource utilization and waste generation peaked around 2015, with 20 and 11 Mt of mined and wasted P, respectively. Additionally, rapidly increasing aquaculture wastewater has exacerbated pollution. The resource efficiency of the Chinese P cycle showed a U-shaped change with an overall improvement of 22.7%, except for a temporary trough in 1975. The driving force behind the efficiency decline was the roaring phosphate fertilizer industry, as confirmed by the sharp increase in P flows for both resource utilization and waste generation from the mid-1960s to 1975. The positive driving forces behind the 30.7% efficiency increase from 1975 to 2018 were the implementation of the resource conservation policy, downstream pollution control, and, especially, the circular agro-food system strategy. However, not all current management practices improve the P resource efficiency. Mixing P industry waste with construction materials and the development of aquaculture to complement offshore fisheries erode P resource efficiency by 2.12% and 9.19%, respectively. With the promotion of a zero-waste society in China, effective P-cycle management is expected.

Virtual sample generation empowers machine learning-based effluent prediction in constructed wetlands.

The design of constructed wetlands (CWs) is critical to ensure effective wastewater treatment. However, limited availability of reliable data can hamper the accuracy of CW effluent predictions, thus increasing design costs and time. In this study, a novel effluent prediction framework for CWs is proposed, utilizing data dimensionality reduction and virtual sample generation. By using four the machine learning algorithms (Cubist, random forest, support vector regression, and extreme learning machine), important features of CW design are identified and used to build prediction models. The extreme learning machine algorithm achieved the highest determination coefficient and lowest error, identifying it as the most suitable algorithm for effluent prediction. A multi-distribution mega-trend-diffusion algorithm with particle swarm optimization was employed to generate virtual samples. These virtual samples were then combined with real samples to retrain the prediction model and verify the optimization effect. Comparative analysis demonstrated that the integration of virtual samples significantly improved the prediction accuracy for ammonium and chemical oxygen demand. The root mean square error decreased by averages of 60.5% and 42.1%, respectively, and the mean absolute percentage error by averages of 21.5% and 23.8%, respectively. Finally, a CW design process is proposed based on prediction models and virtual samples. This integrated forward prediction and reverse design tool can efficiently support CW design when sample sizes are limited, ultimately leading to more accurate and cost-effective design solutions.

From full life cycle assessment to simplified life cycle assessment: A generic methodology applied to sludge treatment.

Life cycle assessment is widely used to evaluate sludge treatment methods. However, detailed life cycle assessment is time-consuming and resource-intensive. In addition, the complex characteristics of sludge and the variety of treatment methods increase the difficulty of sludge treatment life cycle assessment. There is an urgent need to develop simplified life cycle assessment models to allow rapid decision-making. This study proposes a simplified method of sludge treatment life cycle assessment based on logistic regression analysis. The simplified model relies on the total environmental impact and very few or even a single input parameters. Contribution and data quality analysis were introduced to identify key input parameters and to obtain model training data. The method was eventually applied to traditional sludge treatment methods, showing that it can quickly and accurately predict environmental impact. Representative analysis showed that the model would be affected by technology and energy structure modification. It is hoped that this study will provide a reference and new perspectives for a simplified life cycle assessment of sludge treatment.

Illuminating plant-microbe interaction: How photoperiod affects rhizosphere and pollutant removal in constructed wetland?

Rhizosphere is a crucial area in comprehending the interaction between plants and microorganisms in constructed wetlands (CWs). However, influence of photoperiod, a key factor that regulates photosynthesis and rhizosphere microbial activity, remains largely unknown. This study investigated the effect of photoperiod (9, 12, 15 h/day) on pollutant removal and underlying mechanisms. Results showed that 15-hour photoperiod treatment exhibited the highest removal efficiencies for COD (87.26%), TN (63.32%), and NO3--N (97.79%). This treatment enhanced photosynthetic pigmentation and root activity, which increased transport of oxygen and soluble organic carbon to rhizosphere, thus promoting microbial nitrification and denitrification. Microbial community analysis revealed a more stable co-occurrence network due to increased complexity and aggregation in the 15-hour photoperiod treatment. Phaselicystis was identified as a key connector, which was responsible for transferring necessary carbon sources, ATP, and electron donors that supported and optimized nitrogen metabolism in the CWs. Structural equation model analysis emphasized the importance of plant-microbe interactions in pollutant removal through increased substance, information, and energy exchange. These findings offer valuable insights for CWs design and operation in various latitudes and rural areas for small-scale decentralized systems.

Sulfate-reducing ammonium oxidation: A promising novel process for nitrogen and sulfur removal.

Sulfate-reducing ammonium oxidation (sulfammox), a novel and promising process that has emerged in recent years, is essential to nitrogen and sulfur cycles and offers significant potential for the elimination of ammonium and sulfate. This review discussed the development of sulfammox process, the mechanism, characteristics of microbes, potential influencing factors, applicable bioreactors, and proposed the research needs and future perspective. The sulfammox process could be affected by many factors, such as the NH4+/SO42- ratio, carbon source, pH, and temperature. However, these potential influencing factors were only obtained based on what has been seen in papers studying related processes such as denitrification, sulfate-reduction, etc., and have to be further tested in bioreactors carrying out the sulfammox process in the future. Currently, sulfammox is predominantly used in granular activated carbon anaerobic fluidized beds, up-flow anaerobic sludge blanket reactors, anaerobic expanded granular bed reactors, rotating biological contact reactors, and moving bed biofilm reactors. In the future, the operating parameters of sulfammox should be further optimized to improve the processing performance, and the system can be further scaled up for actual wastewater treatment. In addition, the isolation, identification, and characterization of key functional microbes and the analysis of microbial interrelationships will also be focused on in future studies to enable an in-depth analysis of the sulfammox mechanism.

Exploring the resilience of constructed wetlands to harmful algal blooms disturbances: A study on microbial response mechanisms.

Constructed wetlands (CWs) have emerged as a promising environmentally sustainable technique for wastewater treatment. However, the susceptibility of CWs to disturbances caused by harmful algal blooms (HABs) raises concerns. This study aimed to investigate the impact of HABs on the pollutants' removal performance of CWs and the response of rhizosphere microbial community. Results revealed that CWs possessed an adaptive capacity that enabled them to recover caused by HABs. The rhizosphere was found to stimulate the occurrence of Acinetobacter, which played a critical role to help resist HABs disturbance. This study also observed an increased dissimilatory nitrate reduction metabolic pathway which promoted denitrification and enhanced the nitrogen removal efficiency of CWs. Additionally, the structural equation model further suggested that dissolved oxygen exerted a significant influence on the microbial activities and then affected the pollutants removal performance. Overall, our findings shed light on the mechanism for CW stability maintenance during HABs disturbance.

Towards the carbon neutrality of sludge treatment and disposal in China: A nationwide analysis based on life cycle assessment and scenario discovery.

Motivated by the carbon neutrality target, strategic planning for a low-carbon transition of sludge treatment and disposal in China is challenging due to the unpredictability of technical, regional, socioeconomic, and political factors affecting greenhouse gas (GHG) emissions. This study combines the use of a Life Cycle Assessment and the Patient Rule Induction Method, accounting for possibilities that could achieve net-zero carbon emissions by exploring multiple plausible future profiles of sludge treatment and disposal. Results show that reducing sludge landfill and increasing anaerobic digestion are effective methods to facilitate GHG reduction. Achieving carbon neutrality is closely linked to developing a cleaner electricity mix. Based on a cascaded scenario analysis considering regional differences for 31 Chinese provinces, results demonstrated a maximum cumulative reduction potential of 371 Mt CO2 equivalents from 2020 to 2050, equal to 59.84% of the business-as-usual scenario. Together with GHG reductions, terrestrial acidification and ecotoxicity as well as freshwater ecotoxicity are synergistically reduced. However, the shifting environmental burden results in freshwater eutrophication, human toxicity, marine ecotoxicity, marine eutrophication, and photochemical oxidant formation. This study presents a novel method for systematically identifying possible future development paths toward carbon neutrality. The findings may support policy designs for achieving target carbon reduction effects for sludge disposal.

Microalgae-based constructed wetland system enhances nitrogen removal and reduce carbon emissions: Performance and mechanisms.

Combination of constructed wetlands (CWs) and microalgae-based technologies has been proved as effective wastewater treatment option; however, little attention was paid to investigate the optimal combination ways. This study showed that the integrated system (IS) connecting microalgal pond with CWs exhibited improved pollutant-removal efficiencies and preferred carbon reduction effects compared to other alternatives such as coupled system or independent CWs. Microbial analysis demonstrated that core microorganisms (e.g., Acinetobacter and Thermomonas) of the IS were mostly associated with carbon, nitrogen, and energy metabolism. Based on co-occurrence networks, microbial quantity with denitrification function in the IS accounted for 71.01 % of the microorganism related to nitrogen metabolism, which was higher than that of 48.84 % in the independent CWs, indicating that the presence of microalgae in IS played important role in promoting biological denitrification. These findings provide insights into the microbial mechanism and highlights the complementary effects between microalgae and CWs.

Synergistic analysis of performance, functional genes, and microbial community assembly in SNDPR process under Zn(II) stress.

One of the most prevalent heavy metals found in rural sewage is Zn(II), while its effect on simultaneous nitrification, denitrification and phosphorus removal (SNDPR) remains unclear. In this work, the responses of SNDPR performance to long-term Zn(II) stress were investigated in a cross-flow honeycomb bionic carrier biofilm system. The results indicated that Zn(II) stress at 1 and 5 mg L-1 could increase nitrogen removal. Maximum ammonia nitrogen, total nitrogen, and phosphorus removal efficiencies of up to 88.54%, 83.19%, and 83.65% were obtained at Zn(II) concentration of 5 mg L-1. The functional genes, such as archaeal amoA, bacterial amoA, NarG, NirS, NapA, and NirK, also reached the highest value at 5 mg L-1 Zn(II), with the absolute abundances of 7.73 × 105, 1.57 × 106, 6.68 × 108, 1.05 × 109, 1.79 × 108, and 2.09 × 108 copies·g-1 dry weight, respectively. The neutral community model demonstrated that deterministic selection was responsible for the system's microbial community assembly. Additionally, response regimes with extracellular polymeric substances and cooperation among microorganisms facilitated the stability of the reactor effluent. Overall, the findings of this paper contribute to improving the efficiency of wastewater treatment.

Prospective Life Cycle Assessment for the Electrochemical Oxidation Wastewater Treatment Process: From Laboratory to Industrial Scale.

Electrochemical oxidation (EO) is a promising technology for water purification, but indirect environmental burdens may arise in association with consumption of materials and energy during electrode preparation and process operation. This study evaluated the life cycle environmental impacts of emerging EO technology from laboratory scale to industrial scale using prospective life cycle assessment (LCA) on a quantitative basis. Environmental impacts of EO technology were assessed at laboratory scale by comparing three representative anode materials (SnO2, PbO2, and boron-doped diamond) and other two typical processes (adsorption and Fenton method), which verified the competitiveness of the EO process and identified the key factors to environmental hotspots. Thereafter, LCA of scale-up EO was performed to offer guidance for practical application, and the life cycle inventory was compiled upon thermodynamic and kinetic simulations, empirical calculation rules, and similar technical information. Results demonstrated EO to be effective for destructing recalcitrant organic pollutants, but visible direct benefits might be outweighed by increased indirect environmental burdens associated with the preparation of anode materials, use of electrolytes, and energy consumption during the operation stage at both laboratory scale and larger scale. This necessitated attention to overall life cycle profiles by taking into account reactor design, anode materials, electrolyte and flow pattern, and decentralized location with a large share of renewable power station and rigorous contamination control strategies for wastewater treatment plants.

Vertical-scale spatial influence of radial oxygen loss on rhizosphere microbial community in constructed wetland.

Complex interactions between plants and microorganisms form the basis of constructed wetlands (CWs) for pollutant removal. In the rhizosphere, radial oxygen loss (ROL) plays a key role in the activity and abundance of functional microorganisms. However, little has been done to explore how ROL would influence the niche differentiation of microbial communities at different vertical spatial scales. We demonstrate that ROL decreases with depth, promoting an oxidation-reduction rhizosphere microecosystem in CWs. The high level of ROL in the upper layer could support the oxygen supply for aerobic bacteria (Haliangium), facilitating the COD (60%) and NH4+-N (50%) removal, whereas the enrichment of denitrifiers (e.g., Hydrogenophaga and Ralstonia) and methanotrophs (Methanobaterium) in the lower layer could stimulate denitrification. The function prediction results further certified that the abundance of genes catalyzing nitrifying and denitrification processes were significantly enhanced in the upper and bottom layers, respectively, which was attributed to the oxygen concentration gradient in the rhizosphere. This study contributes to further unraveling the rhizosphere effect and enables an improved understanding of the decontamination mechanisms of CWs.

SCC-UEFAS, an urban-ecological-feature based assessment system for sponge city construction.

An effective sponge city construction evaluation system plays a crucial role in evaluating sponge city construction schemes. The construction of a sponge city evaluation system still faces challenges related to incomplete index selection and unscientific weight division. Limited studies have focused on the comprehensive assessment of sponge city construction in the early stages. This study constructed a scientific assessment indicator system and a quantitative indicator weight at all levels by literature review and statistical analysis methods from an objective perspective. To demonstrate how to utilize our evaluation methods, three construction schemes randomly generated by MATLAB were evaluated under evaluation states of constant weight and variable weight, respectively. Scheme 3 had the highest score of 0.638 under the constant weight assessment, but it cannot practically be the final construction scheme due to the imbalance between indicators. Compared to the constant weight assessment, a variable weight assessment can effectively balance the states of the evaluation index with changes in the decision variable. Among the three schemes, Scheme 2 is the best choice with a value of 0.0355 under variable weight evaluation due to punishment and incentives in the variable weight method. The concept of "punishing" a disadvantageous indicator and "motivating" an advantageous indicator increases the relative advantages of the indices, ultimately affecting the assessment results of schemes and leading to a more balanced state. This study provides reasonable analysis and decision-making mechanisms to support decision-making and guide the scientific selection of a construction scheme.

Successional dynamics of microbial communities in response to concentration perturbation in constructed wetland system.

Constructed wetlands (CWs) are widely considered as resilient systems able to adapt to environmental perturbations. Little attention has been paid, however, to microbial dynamics when CWs withstand and recover from external shock. To understand the resilience of CWs, this study investigated rhizosphere microbial dynamics when CWs were subjected to influent COD perturbation (200 mg/L-1600 mg/L). Results demonstrated that CWs had strong adaptability to different influent perturbations, characterized by transitions from fluctuating to stable pollutant removal. Microbial analysis showed that rhizosphere microorganisms competed for niches in response to increased COD concentrations, and Trichococcus played key roles in resisting concentration perturbations. Structural equation modeling indicated that rhizosphere community succession and microbial energy metabolism were shaped by pH and DO. These findings provide insights into the mechanism for CW stability maintenance when facing concentration perturbations.

Single-cell sorting of microalgae and identification of optimal conditions by using response surface methodology coupled with life-cycle approaches.

Response surface methodology (RSM) has been widely used to identify optimal conditions for environmental microorganisms to maximize degrading pollutants and accumulating biomass. However, to date, environmental impact and economic cost have rarely been considered. In this study, a single cell of microalgae Chlorella sorokiniana ZM-5 was sorted, and its enrichment was carried out for the first time. The optimized conditions by RSM for achieving the highest COD, TN, TP removal and 352.61 mg/g lipid production were 24 h light time, 4.3:1C/N, 7.2 pH, and 30 °C temperature, respectively. Life-cycle approaches were then carried out upon this illustrative case, and the results indicated that the implementation of the above optimal conditions could reduce the total environmental impact by 48.0% and the total economic impact by 10.2%. This study showed the feasibility of applying life-cycle approaches to examine the optimal conditions of a biological process in terms of minimizing environmental impact and economic costs.

Runoff control simulation and comprehensive benefit evaluation of low-impact development strategies in a typical cold climate area.

With the acceleration of urbanization, the proportion of surface imperviousness is increasing continuously in cities, resulting in frequent waterlogging disasters. In this context, storm water management, based on the low-impact development (LID) concept, offers an effective measure for the management of urban storm waters. First, the storm water management model (SWMM) was built for a typical cold climate city (Changchun) in China. Next, the two-stage calibrated model was employed to explore the surface runoff and storm sewer control effects of four LID combination plans. Finally, these plans were put through a "cost-benefit" evaluation through an analytic hierarchy process. According to the results, after using four LID plans, the reduction rates of peak runoff exceeded 40% and the problem of overflow load of the storm sewage was significantly mitigated. The infiltration-oriented Plan I proved to be the optimal plan, with the lowest proportions of the overflow nodes and full-load pipe sections in each return period, as well as with maximum overall performance. This study offers technical and conformed methodological support to cold cities for the prevention and control of waterlogging disasters and recycling of rainwater resources.

A microbubble-assisted rotary tubular titanium cathode for boosting Fenton's reagents in the electro-Fenton process.

To improve cathodic H2O2 accumulation and Fe3+ reduction synchronously in the electro-Fenton (EF) process, a microbubble-assisted rotary tubular titanium cathode (MRTTC) was designed for the first time. By utilizing this MRTTC, H2O2 accumulation improved by 4.05-fold, along with a 200% enhancement in iron reduction compared to the conventional EF process. This promotion is mainly attributed to a considerably higher oxygen mass transfer, which reduces the thickness of the adhered diffusion layer. The oxygen mass transfer coefficient (KLa) also improved from 0.0073 s-1 to 0.012 s-1 at a rotational speed of 300 rpm. In addition, the microbubble-assisted cathode further improved the KLa to 0.047 s-1. The synergistic effect between the rotating and microbubble-assisted cathodes further intensified H2O2 accumulation in MRTTC. Apart from H2O2 promotion, the iron reduction rate was elevated because the newly formed O2-• provided an additional reduction pathway for Fe3+ reduction in addition to the cathodic path. The effectiveness of MRTTC was confirmed by treating a benchmark organic pollutant, sulfamerazine (SMR), where approximately 100% SMR decay was obtained in 3 h. The results show that MRTTC is a novel and promising design in EF for antibiotic wastewater treatment.

Resource recovery in life cycle assessment of sludge treatment: Contribution, sensitivity, and uncertainty.

This study focused on the resource recovery of sludge treatment by quantifying the environmental contributions, identifying the influential factors, and comparing different scenarios. Life cycle assessment (LCA) of sewage sludge treatment was carried out to estimate the environmental impacts of six scenarios: (1) co-digestion of sludge and food waste; (2) co-gasification of sludge and woody waste; (3) co-incineration of sludge and used oil; (4) landfilling; (5) incineration; and (6) anaerobic digestion combined with incineration. Results demonstrate that the resource recovery had a substantial contribution to the environmental performance of the sludge treatment, while the degree of contribution was largely affected by various treatment scenarios and diverse impact categories. To gain deep insight into the parameters related to resource recovery, sensitivity analysis was performed to investigate the influence of the parameters on the LCA results, including the organic content, conversion efficiency of organic matter to methane, and other energy conversion efficiencies. After integrating the inventory variation of those parameters into the decision process via the Monte Carlo simulation, results indicate that no obviously superior scenario could be identified. Conversely, when parameter uncertainty was not considered, co-gasification of sludge and woody waste exhibited the most preferable environmental performance. Overall, this study demonstrates that considering the parameter uncertainty of resource recovery will contribute to a more transparent evaluation process, but will inevitably increase the complexity of the decision-making process based on LCA results because it is difficult to determine a sludge treatment scenario that decisively outperforms the others.

Comparative life cycle assessment of sewer corrosion control by iron salts: Suitability analysis and strategy optimization.

Sewer deterioration caused by sulfide-induced concrete corrosion is spreading worldwide. Within the strategies to overcome this problem, dosing iron salts into the pipeline has attracted more attention. However, there is not yet research that evaluates this method whether it is overall environmentally friendly. Here, we conducted a comparative Life Cycle Assessment (LCA) to adjudge the benefits of dosing ferric chloride over non-dosing option in three different H2S concentration levels (High, Medium, Low). Compared with taking no precautions, dosing ferric chloride performs better for all impact categories only in High H2S situation, which can reduce the environmental impacts by 10% to 50%. In Medium H2S situation, dosing ferric chloride shows lower environmental impacts of Global Warming, Fossil Fuel Depletion, Acidification, and Eutrophication, while leads to the deterioration of Human Toxicity and Freshwater Ecotoxicity by 10% and 13%, respectively. In Low H2S situation, dosing ferric chloride performs even worse for all impact categories. Therefore, from an LCA perspective, this study recommends iron salts dosing technology to be applied in severe corrosion conditions caused by high H2S concentrations. Contribution analysis shows that asphalt and diesel consumed during the sewer construction and renovation dominate all impact categories for non-dosing option, whereas the main contributor of Human Toxicity and Freshwater Ecotoxicity is shifted to ferric chloride production in dosing option, average at around 50%. Sensitivity analysis on the length of pipes protected by iron salts confirms that the initial dosing location is more preferable to be set at upstream of the sewer system. From an LCA perspective, as alternatives to ferric chloride, ferrous chloride is superior in all impact categories, and ferric sulfate could reduce the toxicity-related impacts and other effects at the expense of exacerbation of acidification. In the end, a systematic optimization of salts dosing should be considered in urban sewer management practice.

Confirmation of biodegradation of low-density polyethylene in dark- versus yellow- mealworms (larvae of Tenebrio obscurus versus Tenebrio molitor) via. gut microbe-independent depolymerization.

Tenebrio obscurus (Coleoptera: Tenebrionidae) larvae are capable of biodegrading polystyrene (PS) but their capacity for polyethylene (PE) degradation and pattern of depolymerization remains unknown. This study fed the larvae of T. obscurus and Tenebrio molitor, which have PE degrading capacity, two commercial low-density PE (LDPE) foams i.e., PE-1 and PE-2, with respective number-average molecular weights (Mn) of 28.9 and 27.3 kDa and weight-average molecular weights (Mw) of 342.0 and 264.1 kDa, over a 36-day period at ambient temperature. The Mw of residual PE in frass (excrement) of T. obscurus, fed with PE-1 and PE-2, decreased by 45.4 ± 0.4% and 34.8 ± 0.3%, respectively, while the respective decrease in frass of T. molitor was 43.3 ± 0.5% and 31.7 ± 0.5%. Data analysis showed that low molecular weight PE (<5.0 kDa) was rapidly digested while longer chain portions (>10.0 kDa) were broken down or cleaved, indicating a broad depolymerization pattern. Mass balance analysis indicated nearly 40% of ingested LDPE was digested to CO2. Antibiotic suppression of gut microbes in T. molitor and T. obscurus larvae with gentamicin obviously reduced their gut microbes on day 15 but did not stop depolymerization because the Mn, Mw and size- average molecular weight (Mz) decreased. This confirmed that LDPE biodegradation in T. obscurus was independent of gut microbes as observed during previous PS degradation in T. molitor, suggesting that the intestinal digestive system could perform LDPE depolymerization. High-throughput sequencing revealed significant shifts in the gut microbial community during bran-fed and unfed conditions in response to LDPE feeding in both Tenebrio species. The respective predominant gut genera of Spiroplasma sp. and Enterococcus sp. were observed in LDPE-fed T. molitor and T. obscurus larvae.

Identifying environmental hotspots and improvement strategies of vanillin production with life cycle assessment.

Vanillin, an important aroma chemical, can be synthesized through industrial oxidation processes and biotechnological processes. Studying the environmental impacts of synthetic vanillin production processes is fundamental to making these processes feasible and sustainable; however, few studies have focused on such analyses. This study involved performing a life cycle assessment (LCA) to evaluate multiple industrial synthesis and biosynthesis processes for producing synthetic vanillin. The results indicated that human toxicity potential (HTP) appeared to be the most affected indicator among all the impact categories considered. The dominant drivers of the HTP of the vanillin synthesis process were electricity consumption and ultrapure water consumption. Improvement strategies were then proposed to investigate the possibility of reducing the environmental burdens created by vanillin synthesis. Natural gas power generation was determined to be the best choice for replacing traditional coal-fired power generation, thus reducing the negative impacts of these processes on the environment. The best ways to reduce chemical consumption were to recover organic solvents and to replace ultrapure water with industrial or distilled water. All these improvement strategies were demonstrated to be able to effectively reduce the HTP. In addition, suggestions for evaluating scaled-up vanillin production, increasing the LCA coverage to include technological advancements in biosynthesis techniques, and introducing cost-benefit analysis into the LCA were discussed.