Based on the field research data of 424 large-scale pig farmers in Zhejiang Province, this paper takes the biogas fermentation as the main adoption behaviour of pollution treatment, and make the quantitative analysis on the biogas investment intention and its influencing factors on large-scale pig farmers under the emission trading system. The research shows that the emission trading system can encourage large-scale pig farmers to adopt biogas fermentation to deal with pollution and make environmental protection investment for waste resources utilization, which mainly depends on the pig breeding scale, the biogas digesters purchased or not, the benefit evaluation of biogas fermentation and the biogas fermentation technology service existed or not, rather than environmental awareness. Therefore, it is feasible to introduce the emission trading system into the agricultural non-point source pollution control with pig breeding pollution as the typical example. For the pig breeding industry, emission trading can be transformed from the traditional redistribution of environmental capacity to the redistribution of production scale.

Sewage sludge composting is a process entailing a continuous succession of microorganisms. To understand the microbial mechanisms involved in sewage sludge composting, we performed an aerobic static composting of sewage sludge and sawdust (ratio = 3:1 m/m) in medium-scale bioreactor systems. The associated changes in physico-chemical parameters (i.e., temperature, organic matter, pH, ammonium nitrogen) were studied parallelly to those in the microbial (i.e., bacteria, fungi, archaea) succession. Additionally, we discussed correlations between these physico-chemical parameters and the microbial communities. The results showed that the pile temperature went through mesophilic phase, thermophilic phase, and cooling phase. The pile temperature reached a maximum of 78.68°C by day 3 and remained above 55°C for more than 6 days, complying with the harmless composting requirements. The organic matter content decreased gradually, the pH increased after a first decrease and the NH4 +-N content showed a consistent trend. The dominant bacteria during composting were Ureibacillus, Bacillus, Sphaerobacter, and Thermobifida, while the dominant fungi were unclassified_f_ Trichocomaceae, unclassified_d_Eukaryota, Hypocrea and Thysanophora; finally, the dominant archaea were Methanobrevibacter, Methanosaeta, Methanobacterium, and unclassified_k_norank. The composting stages were characterized by different microbial compositions. The mesophilic phase presented a relatively uniform proportion of bacterial genera, while the thermophilic and cooling phases were dominated by Ureibacillus and Bacillus, respectively. The fungus unclassified_f_Trichocomaceae played a major role during the mesophilic, thermophilic, and cooling phases, while unclassified_d_Eukaryota played a major role during the mesophilic and thermophilic phases. For what concerns the archaea, Methanobrevibacter played a major role in the mesophilic, thermophilic, and cooling phases, Methanosaeta during the mesophilic and thermophilic phases, and Methanobacterium during the thermophilic and cooling phases. Additionally, the bacterium Ureibacillus and the archaea Methanospirillum were positively correlated with temperature, while the bacteria norank_Pem15, norank_JG30-KF-CM45 and the archaea Methanosphaera were negatively correlated with temperature. The fungi Thysanophora, unclassified_d_ Eukaryota, and unclassified_p_Ascomycota were negatively correlated with pH. Moreover, the bacterium norank_c_1-20, the fungi Trichosporon, norank_o_Saccharomycetales, unclassified_o_Pleosporales, and the archaea Methanosaeta, Methanomethylovorans were positively correlated with organic matter. On the other hand, the bacteria Bacillus, Thermobifida, the fungus unclassified_f_Trichocomaceae, and the archaea Methanobrevibacter were negatively correlated with organic matter. Finally, the bacteria Bacillus, Thermobifida, the fungus unclassified_f_Trichocomaceae, and the archaea Methanobrevibacter were positively correlated with ammonium nitrogen, while the bacterium norank_c_1-20, the fungi Trichosporon, norank_o_Saccharomycetales, unclassified_o_Pleosporales, and the archaea Methanosaeta, Methanomethylovorans were negatively correlated with ammonium nitrogen. This paper provides new solid bases to understand changes in microbial composition and their correlation with physico-chemical parameters during sewage sludge composting.

University-industry knowledge collaboration is one of the keys to overcoming the current development bottleneck in water pollution abatement technology in China. To explore university-industry knowledge collaboration in Chinese water pollution abatement technology innovation system, characteristics and dynamic evolution law of knowledge collaboration were analyzed by using patent data from China for the period 2000-2018. Results show that university-industry knowledge collaboration continues to increase and experiences three development phases in Chinese water pollution abatement technology innovation system. University-industry knowledge collaboration in each province (city) keeps growing and the difference between provinces (cities) is decreasing, but the difference remains significant. The scale, scope, and depth of inter-regional university-industry knowledge collaboration continue to increase, but they are still not large enough. Although the scale and linking efficiency of university-industry knowledge collaboration improve significantly, the subgroups are too many and the agglomeration degree of networks is low.

Construction of pavement layers on subgrade soil with excellent properties reduces the thickness of pavements and consequently reduces the initial cost of construction. However, construction of pavement on poor soil subgrade like black cotton soil is unavoidable due to several constraints. In such a situation, the enhancement of subgrade properties can be attained by the addition of foreign materials. The worldwide growing usage of cement has led to a larger collection of crystalline silica from the cement manufacturing plants. The disposal of the crystalline silica is extremely challenging and also causes an environmental impact. Hence this waste material can be used for enhancement of the strength of the weak soils. Chemical analysis has revealed that crystalline silica is rich in oxides such as silicon oxide, aluminium oxide and calcium oxide. In this study, the black cotton soil is blended with 8%, 12%, 16%, 18% and 20% crystalline silica by the weight of the dry soil. Laboratory tests, namely, standard proctor compaction test, California Bearing Ratio (CBR) test and Unconfined Compressive Strength (UCC) test were carried out to examine the performance of crystalline silica mixture in black cotton soil. The outcome suggests that a potential increase in crystalline silica content enhances the maximum dry density (MDD). The results also indicate there is a huge potential to use crystalline silica as an admixture to strengthen the black cotton soil. Moreover, the employment of crystalline silica might also benefit the environment and construction cost.

Atmospheric precipitation in Sri Lanka occurs mainly through rain whose terrestrial composition significantly varies based on the location as the regional geography and anthropogenic factors can largely affect environmental pollutants that are added to the atmosphere. It is therefore very important to have baseline data on the chemical composition of the atmosphere to take regulatory measures to control atmospheric pollution although very limited data available in Sri Lanka. The main objective of this study was thus to quantitatively determine selected trace metals (Al, Cr, Cu, Fe, Mn, Pb, and Zn) in bulk precipitation samples collected weekly in three sampling locations, namely the University of Peradeniya (UoP), Polgolla, and Kandy City Central (KCC), for a period of 1 year from March 2018 to March 2019. Trace metals determined using atomic emission spectrophotometry indicated that the KCC site showed the highest contamination following the sequence (with respective volume-weighted mean (VWM) concentration values) of Al (79.7 μg L⁻¹) > Fe (42.8 μg L⁻¹) > Zn (39.3 μg L⁻¹) > Mn (13.9 μg L⁻¹) > Cu (9.8 μg L⁻¹) > Cr (2.4 μg L⁻¹). The corresponding values of the Polgolla site showed the sequence Zn (64.3 μg L⁻¹) > Al (52.1 μg L⁻¹) > Fe (17.9 μg L⁻¹) > Mn (11.1 μg L⁻¹) > Cu (5.4 μg L⁻¹) > Cr (1.8 μg L⁻¹). Due to less industrialization and less traffic congestion, the UoP site showed low trace metal levels in the order Zn (29.8 μg L⁻¹) > Al (21.3 μg L⁻¹) > Fe (14.2 μg L⁻¹) > Cu (7.4 μg L⁻¹) > Mn (4.3 μg L⁻¹) > Cr (0.9 μg L⁻¹). Principal component analysis indicated that Cu, Mn, and Zn originated mainly from anthropogenic activities, such as combustion of fossil fuel and burning of municipal waste, while Al and Fe mainly originated from natural sources.

Municipal wastewater reverse osmosis concentrate (ROC) poses health and environmental risks on its disposal as it contains nutrients and harmful organic compounds at elevated concentrations. This study compared a freshwater microalga Chlorella vulgaris and a marine microalga Nannochloropsis salina in suspended and alginate-immobilised cultures for batch and semi-continuous treatment of the ROC. The immobilised algae gave comparable nutrient removal rates to the suspended cells, demonstrating immobilisation had no apparent negative impact on the photosynthetic activity of microalgae. Semi-continuous algal treatment illustrated that the microalgae could remove significant amounts of nutrients (> 50% and > 80% for TN and TP, respectively), predominantly through algal uptake (> 90%), within a short period (48 h) and generate 335–360 mg DCW L⁻¹ d⁻¹ of algal biomass. The treatment also removed a significant amount of organic matter (12.7–13.3 mg DOC L⁻¹ d⁻¹), primarily (> 65%) through the biotic pathway.

Traceability offers significant information about the quality and safety of Chinese Angelica, a medicine and food homologous substance. In this study, a systematic four-step strategy, including sample collection, specific metal element fingerprinting, multivariate statistical analysis, and benefit-risk assessment, was developed for the first time to identify Chinese Angelica based on geographical origins. Fifteen metals in fifty-six Chinese Angelica samples originated from three provinces were analyzed. The multivariate statistical analysis model established, involving hierarchical cluster analysis (HCA), principal component analysis (PCA), and self-organizing map clustering analysis was able to identify the origins of samples. Furthermore, benefit-risk assessment models were created by combinational calculation of chemical daily intake (CDI), hazard index (HI), and cancer risk (CR) levels to evaluate the potential risks of Chinese Angelica using as traditional Chinese medicine (TCM) and food, respectively. Our systematic strategy was well convinced to accurately and effectively differentiate Chinese Angelica based on geographical origins.

A dead-end ultrafiltration cup was continuously operated to investigate the underlying mechanisms of membrane fouling caused by gel layer in this paper. Anionic polyacrylamide was used as a model foulant for gel formation process in various ultrafiltration processes by two kinds of ultrafiltration membrane, e.g., polyvinylidene fluoride (PVDF) membrane (OM) and TiO₂/Al₂O₃-PVDF membrane (MM); then, a gel formation model was established and systematically assessed. The results show that the gel formation process in ultrafiltration can be divided into three stages: “slow-rapid-slow” flux decay curve. The R² value of the simulation curve was still higher than 0.90 for both OM and MM. Based on the current cognition, the proposed gel layer formation mechanism and mathematical model were feasible.

In order to unravel the cadmium (Cd) enrichment patterns in rice (Oryza sativa L.) grown under different exogenous exposure pathways, the pot experiment was conducted in a greenhouse. Cd was added to the soil-rice system via mixing soil with Cd-containing solution, irrigating the pots with Cd-containing water and leaf-spraying with Cd solution to simulate soil pollution (SPS), irrigation water pollution (IPS), and atmospheric deposit pollution sources (APS), respectively. No significant (p > 0.05) differences in plant height and rice grain yield were observed among all treatments including three different Cd pollution sources and control. The contents of Cd in rice plants significantly (p < 0.05) increased with increase in Cd concentrations in three pollution sources. The distribution pattern of Cd in the rice plant organs treated with SPS and IPS followed the order: roots > stems > leaves > husk > brown rice, while it was leaves > roots > stems > husk > brown rice treated with APS. At the same level of treatment, the highest concentration of Cd was observed in rice organs (except for middle and high concentrations treatment roots) grown under APS, followed by IPS and SPS, suggesting that the Cd bioavailability from different pollution sources followed the order of APS > IPS > SPS. It is concluded that the atmospheric pollution contributed more enrichment of rice with Cd. Therefore, in field environment, air deposits should also be analyzed for toxic metals during assessment of food chain contamination and health risk.

Anabaena flos-aquae, a typical species of cyanobacterial bloom, was employed as a useful biosorbent for uranium removal. Batch experiments were conducted to examine the effects of different parameters on the uranium uptake amount of Anabaena flos-aquae. The maximum adsorption capacity of 196.4 mg/g was obtained under the optimized experimental conditions. The calculations of kinetic and thermodynamic results proved the adsorption process was endothermic, chemisorption, and spontaneous. The adsorption of uranium onto Anabaena flos-aquae was better defined by the Langmuir model, which indicated the process was a monolayer sorption. In addition, the characterization of the biosorbent before and after uranium sorption implied that the dominant functional groups participated in the uranium adsorption process were hydroxyl, amino, and carboxyl. In conclusion, the environmentally friendly and biocompatible characteristics of Anabaena flos-aquae suggest that it can be a promising biosorbent for uranium removal.