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Accurate and reliable measurement of key biological parameters during penicillin fermentation is of great significance for improving penicillin production. In this research context, a new hybrid soft sensor model method based on RF-IHHO-LSTM (random forest-improved​ Harris hawks optimization-long short-term memory) is proposed for penicillin fermentation processes. Firstly, random forest (RF) is used for feature selection of the auxiliary variables for penicillin. Next, improvements are made for the Harris hawks optimization (HHO) algorithm, including using elite opposition-based learning strategy (EOBL) in initialization to enhance the population diversity, and using golden sine algorithm (Gold-SA) in the search strategy to make the algorithm accelerate convergence. Then the long short-term memory (LSTM) network is constructed to build a soft sensor model of penicillin fermentation processes. Finally, the hybrid soft sensor model is used to the Pensim platform in simulation experimental research. The simulation test results show that the established soft sensor model, with high accuracy of measurement and good effect, can meet the actual requirements of engineering. • RF is used for feature selection of the auxiliary variables for penicillin fermentation process. • Elite opposition-based learning and Golden sine algorithm are used to improve HHO. • The improved HHO algorithm is introduced to optimize the LSTM network. • The effectiveness of the proposed method was confirmed through case studies using real datasets. [ABSTRACT FROM AUTHOR]

In this study, comparative investigations on the effects of crop straw and its derived biochars on soil Cd and Zn mobility and availability were conducted. Crop straws (i.e. maize straw, rapeseed straw, and wheat straw) and their derived biochars were incubated with two contaminated alkaline soils (FX and TG soils) at 2.5% (w/w). The changes of soil properties like pH, EC, organic matter content, and dissolved organic matter content were investigated along with metal mobility, speciation distribution, and accumulation in ryegrass (Lolium multiflorum Lam.). Results indicated biochar, especially those were high in pH, enhanced soil pH (>0.2 units, p < 0.05), whereas a continuous reduction of soil pH was observed among treatments with crop straws. Both soil EC and the organic matter content increased with the application of both crop straws and biochars. In term of metals, Cd and Zn mobility were reduced with 6–14%/1–5% and 6–27%/7–15% reduction in the DTPA extractable Cd and Zn contents in TG and FX soil treatments, respectively. Moreover, distinct changes of metals in different fractions were also observed (acid soluble and reducible fraction → oxidizable fraction in straw treatments; acid soluble fraction → reducible soluble fraction in biochar amendments). Furthermore, the biological analysis revealed that the growth of ryegrass was promoted, but the accumulation of metals in ryegrass shoots was reduced, especially in MS 700 treatment. Apart from the amendments, metal immobilization efficiencies were negatively correlated with the contamination status. Despite that, a higher rate of biochar application (>10%) could dramatically reduce the amount of available metal in soil extracts, except for Zn in FX soil treatments. This present work demonstrated that biochars, especially those produced at a higher temperature, are superior to crop straws to immobilize metals in soils. However, the remediation efficiencies were strongly restricted by soil pH and contamination status. Image 1 • Crop straw and biochar both facilitated metal immobilization in smelter-contaminated alkaline soils. • Biochars were more effective in immobilizing soil heavy metals than straw materials. • Amendments have better performance on reducing Cd2+ mobility than Zn2+. • Increasing biochar application rates reduced water extractable metal contents. • Remediation efficiencies of biochars were reduced in the severely polluted soils. [ABSTRACT FROM AUTHOR]

• An evolutionary deep learning model is proposed for AQI prediction. • TVFEMD-SE is employed for the pretreatment of hourly AQI series for the first time. • The GWO algorithm is improved using the opposite search and DLH strategies. • The proposed IGWO algorithm is better than standard GWO is optimizing DBN-ELM. • The proposed model has excellent performance in AQI prediction. Accurate forecast of air quality index (AQI) can provide reliable guarantee for air quality early warning and safe production. In this paper, a hybrid model for predicting AQI is presented. Firstly, the original AQI data is decomposed into multiple intrinsic mode functions (IMFs) components by using time varying filter based empirical mode decomposition (TVFEMD). To reduce the amount of calculation, sample entropy (SE) is introduced to estimate multiple IMF components. Secondly, the grey wolf optimization (GWO) algorithm was improved, the dimension learning-based hunting (DLH) search strategy was introduced to avoid falling into local optimum. Meanwhile, the opposite search strategy was introduced in the initialization of DLH strategy to enrich population information. Thirdly, the parameters of deep belief network - extreme learning machine (DBN-ELM) model is optimized by IGWO algorithm. Then the DBN-ELM model with optimal parameters are used to forecast each IMF component, respectively. Finally, the predicted value of each IMF component is reconstructed to get the total AQI predicted value. The comparison between the presented model and the other benchmark models used in this paper shows that presented model is better than other model in accuracy and generalization, which demonstrates that the presented model can effectively predict AQI. [ABSTRACT FROM AUTHOR]

Soil microbes influence the uptake of toxic metals (TMs) by changing soil characteristics, bioavailability and translocation of TMs, and soil health indicators in polluted environment. The potential effect of Streptomyces pactum (Act12) and Bacillus consortium (B. subtilis and B. licheniformis ; 1:1) on soil enzymes and bacterial abundance, bioavailability and translocation of Zn and Cd by Symphytum officinale , and physiological indicators in soil acquired from Fengxian (FX) mining site. Act12 and Bacillus consortium were applied at 0 (CK), 0.50 (T1), 1.50 (T2), and 2.50 (T3) g kg−1 in a split plot design and three times harvested (H). Results showed that soil pH significantly dropped, whereas, electrical conductivity increased at higher Act12 and Bacillus doses. The extractable Zn lowered and Cd increased at each harvest compared to their controls. Soil β-glucosidase, alkaline phosphatase, urease and sucrase improved, whereas, dehydrogenase reduced in harvest 2 and 3 (H2 and H3) as compared to harvest 1 (H1) after Act12 and Bacillus treatments. The main soil phyla individually contributed ∼5–55.6%. Soil bacterial communities' distribution was also altered by Act12 and Bacillus amendments. Proteobacteria , Acidobacteria , and Bacteroidetes increased, whereas, the Actinobacteria , Chloroflexi , and Gemmatimonadetes decreased during the one-year trial. The Zn and Cd concentration significantly decreased in shoots at each harvest, whereas, the roots concentration was far higher than the shoots, implicating the rhizoremediation by S. officinale. Accumulation factor (AF) and bioconcentration ratio (BCR) of Zn and Cd in shoots were lower and remained higher in case of roots than the standard level (≥1). BCR values of roots indicated that S. officinale can be used for rhizoremediation of TMs in smelter/mines-polluted soils. Thus, field trials in smelter/mines contaminated soils and the potential role of saponin and tannin exudation in metal translocation by plant will broaden our understanding about the mechanism of rhizoremediation of TMs by S. officinale. • Symphytum officinale was found as metal-resistant plant in mines polluted soil. • Streptomyces pactum and Bacillus improved the metals uptake in mines polluted soil. •Soil amendments improved the soil enzymes except dehydrogenase at each harvest. •Soil microbial abundance at each harvest was influenced by microbial amendments. • Streptomyces pactum and Bacillus consortium promoted rhizoremediation in mines soil. Streptomyces pactum and Bacillus consortium influenced the bioavailability and uptake of toxic metals by Symphytum officinale and enzymatic activities and bacterial abundance. [ABSTRACT FROM AUTHOR]

Reusing by-products such as cow bones in agriculture can be achieved thorough pyrolysis. The potential of bone-derived biochar as a promising material for metals immobilization in contaminated mining soils has not yet been sufficiently explored. Therefore, cow bones were used as biochar feedstock were pyrolyzed at 500 °C (CBL) and 800 °C (CBH) and. The two biochars were applied to a mine contaminated soil at 0 (control), 2.5, 5 and 10%, w/w, dosages; then, the soils were incubated and cultivated by maize in the greenhouse. Cadmium (Cd) and zinc (Zn) bioavailability and their sequentially extracted fractions (acid soluble, reducible, oxidizable, and residual fraction), soil microbial function, and plant health attributes were analyzed after maize harvesting. Bone-derived biochar enhanced the content of dissolved organic carbon (up to 74%), total nitrogen (up to 26%), and total phosphorus (up to 27%) in the soil and improved the plant growth up to 55%, as compared to the control. The addition of CBL altered the acid soluble fraction of both metals to the residual fraction and, thus, reduced the content of Zn (55 and 40%) and Cd (57 and 67%) in the maize roots and shoots, respectively as compared to the control. The CBL enhanced the β-glucosidase (51%) and alkaline phosphatase activities (71%) at the lower doses (2.5–5%) as compared to control, while the activities of these enzymes decreased with the higher application doses. Also, CBL improved the antioxidants activity and maize growth at the 2.5–5% application rate. However, the activity of the dehydrogenase significantly decreased (77%), particularly with CBH. We conclude that CBL, applied at 2.5–5% dose, can be utilized as a potential low cost and environmental friendly amendment for stabilization of toxic metals in contaminated mining soils and producing food/feed/biofuel crops with lower metal content. [Display omitted] • Cow bones derived biochar (CB) was produced at 500 (CBL) and 800 °C (CBH). • The CBL and CBH transformed a proportion of soluble Zn and Cd to the residual fraction. • The CBL and CBH reduced Zn (40–55%) and Cd (57–67%) uptake of maize. • The impact of CBL and CBH on soil enzymes activity was selective. • The CBL improved the antioxidant activities and maize growth. [ABSTRACT FROM AUTHOR]

Microorganism-assisted phytoremediation is being developed as an efficient green approach for management of toxic metals contaminated soils and mitigating the potential human health risk. The capability of plant growth promoting Actinobacteria (Streptomyces pactum Act12 - ACT) and Firmicutes (Bacillus subtilis and Bacillus licheniformis - BC) in mono- and co-applications (consortium) to improve soil properties and enhance phytoextraction of Cd, Cu, Pb, and Zn by Brassica juncea (L.) Czern. was studied here for the first time in both incubation and pot experiments. The predominant microbial taxa were Proteobacteria , Actinobacteria and Bacteroidetes , which are important lineages for maintaining soil ecological activities. The consortium improved the levels of alkaline phosphatase, β-D glucosidase, dehydrogenase, sucrase and urease (up to 33%) as compared to the control. The bacterial inoculum also triggered increases in plant fresh weight, pigments and antioxidants. The consortium application enhanced significantly the metals bioavailability (DTPA extractable) and mobilization (acid soluble fraction), relative to those in the unamended soil; therefore, significantly improved the metals uptake by roots and shoots. The phytoextraction indices indicated that B. juncea is an efficient accumulator of Cd and Zn. Overall, co-application of ACT and BC can be an effective solution for enhancing phytoremediation potential and thus reducing the potential human health risk from smelter-contaminated soil. Field studies may further credit the understanding of consortium interactions with soil and different plant systems in remediating multi-metal contaminated environments. [Display omitted] • Application of Streptomyces pactum promoted plant growth & metals uptake. • Application of Bacillus sp. improved enzymes activity & metals availability. • Co-inoculation improved microbial community, enzymes activity, & plant growth. • Co-inoculation altered Cd, Cu, Pb, &Zn fractions & increased their bioavailability. • Co-application enhanced metals phytoextraction by Brassica juncea. Bacterial consortium-of Actinobacteria (Streptomyces pactum) and Firmicutes (Bacillus subtilis and Bacillus licheniformis) promoted soil enzymes activities, metals availability, plant growth and thereby enhanced metals phytoextraction efficiency by Brassica juncea. [ABSTRACT FROM AUTHOR]

The aim of this study was to elucidate the effects of apricot shell-derived biochar (ASB) and apple tree-derived biochar (ATB) on soil properties, plant growth, microbial communities, enzymatic activities, and Zn and Cd fractionation and phytoavailability in mining soils. Smelter soil contaminated by Zn (1860.0 mg kg−1) and Cd (39.9 mg kg−1) was collected from Fengxian, China, treated with different doses (0 (control), 1, 2.5, 5, and 10% w/w) of both biochars and cultivated by Brassica juncea in a greenhouse pot experiment. The acid-soluble, reducible, oxidizable, and residual fraction and plant tissue concentrations of Zn and Cd were determined. Biochar addition improved plant growth (22.6–29.4%), soil pH (up to 0.94 units), and soil organic matter (up to 4-fold) compared to the control. The ASB and ATB, particularly ATB, reduced the acid-soluble (21–26% for Zn and 15–35% for Cd) and the reducible (9–36% for Zn and 11–19% for Cd) fractions of Zn and Cd and altered these fractions in the organic and residual fractions. Therefore, the biochars decreased the metal concentrations in the roots (36–41% for Zn and 33–37% for Cd) and shoots (25–31% for Zn and 20–29% for Cd), which might be due to the increase in pH, biochar liming effects, and metal sorption by the biochar. The biochars impact on the bacterial community composition was selective. The ASB and ATB decreased the activities of soil β-glucosidase, dehydrogenase, and alkaline phosphatase while increasing the urease activity. The biochars, particularly ATB, can be considered as effective soil amendments for reducing the phytotoxicity of Zn and Cd in contaminated soils, improving plant growth, enhancing the abundance of specific bacterial groups and increasing urease activity; however, more attention should be paid to their negative effects on the activities of β-glucosidase, dehydrogenase, and alkaline phosphatase. Image 1 • Apricot shell- (ASB) and apple tree-biochar (ATB) immobilized soil Zn and Cd. • ASB and ATB reduced acid soluble and reducible Zn (26–36%) and Cd (19–35%). • ASB and ATB altered soluble and reducible Zn and Cd to organic and residual fraction. • ASB and ATB decreased Zn (31–41%) and Cd (29–37%) in plant tissues. • Both biochars improved bacterial community, but decreased enzymes activity. [ABSTRACT FROM AUTHOR]

Biochar is a stable carbonaceous by-product of pyrolysis and can be used for toxic metals (TMs) retention in polluted soil. Wheat (Triticum aestivum) was grown in three polluted soils collected from Chenzhou (CZ), Tongguan (TG) and Fengxian (FX), China. Wood biochar (WBC) was applied at 0, 0.5, 1.0 and 2.0% to each pot filled with 2 kg polluted soil. The results showed that WBC was efficient to alter soil pH and electrical conductivity (EC). The changes in soil pH and EC had a direct relationship with the immobilization and phytostabilization of TMs in the three soils. The bioavailable TMs (Zn, Pb, Cd, and Cu) were reduced in the soil after WBC amendments due to ion exchange, precipitates of metal-carbonates and metal-phosphates, and chemisorption on WBC surface. The reduction in the bioavailable TMs content also resulted in the diminution in TMs shoot uptake in wheat. Similarly, the TMs uptake in wheat root were also reduced as a result of WBC application. The reduction in bioavailable TMs and the release of essential nutrients and base cations from the WBC also increased the wheat shoot and root dry biomasses production. The application of WBC in polluted soil also improved soil health and the urease and β-glucosidase enzymes were also enhanced. The results concluded that WBC was efficient to reduce the bioavailability of TMs and shoot and root uptake, improved wheat dry biomasses production and soil enzymatic activities in industrial and smelter/mines polluted soils. Image 1 • Wood biochar linearly raised the values of soil pH and EC. • Application of wood biochar immobilized HMs in contaminated soils. • Shoot and root uptake of HMs content was reduced after wood biochar amendments. • Wood biochar amendments significantly improved shoot and root dry biomass production. • Wood biochar enhanced the enzymatic activity of mine and industrial polluted soils. [ABSTRACT FROM AUTHOR]