Determining the amount of rainfall that will eventually become runoff and its pathway is a crucial process in hydrological modelling. We proposed a method to better estimate curve number by adding an additional component (AC) to better account for the effects of daily rainfall intensity on rainfall-runoff generation. This AC is determined by a regression equation developed from the relationship between the AC series derived from fine-tuned calibration processes and observed rainfall series. When incorporated into the Soil and Water Assessment Tool and tested in the Anxi Watershed, it is found, overall, the modified SWAT (SWAT-ICN) outperformed the original SWAT (SWAT-CN) in terms of stream flow, base flow, and annual extreme flow simulation. These models were further evaluated with the data sets of two adjacent watersheds. Similar results were achieved, indicating the ability of the proposed method to better estimate curve number.

In this paper, the anionic surfactant sodium dodecyl sulfate (SDS) and the bio-surfactant rhamnolipid are mixed to achieve micellar-enhanced ultrafiltration, and the associated aniline removal efficiency is investigated. The impacts of five factors, including the mixing ratio of the SDS concentration to the rhamnolipid concentration, the pH, the salinity, the operating pressure, and the aniline concentration in the feed solution, on the aniline rejection and the membrane permeation flux are explored. The aniline rejection mechanism of the rhamnolipid mixture surfactant is analyzed. This study shows that the effect of these factors on the aniline rejection is in the order of pH > mixing ratio > operating pressure > aniline concentration > salinity; the factors that affect the membrane permeation flux are in the order of mixing ratio > operating pressure > salinity > pH > aniline concentration. Under the optimal test conditions (i.e., SDS:rhamnolipid = 8:2, pH = 5, salinity = 250 mmol/L, operating pressure = 3.5 bar, aniline concentration = 1.5 mM), the verification test results showed an aniline rejection of 78.36%.

In a visible-light-driven GaN:ZnO@α-Ga₂O₃ heterostructure, the GaN:ZnO core absorbed O₂ and stored photo-electrons at V_O sites to form ·O₂⁻, while the α-Ga₂O₃ shell absorbed H₂O/O₂ at V_O and trapped photo-holes at V_Ga to generate ·OH/¹O₂.

We selected two organic acids, heptanoic acid and benzoic acid, with the same carbon length but with different molecular structures to study their mechanisms of algal inhibition and to examine their combined algal inhibition ability. The results showed that the algal inhibition ability of benzoic acid was greater than that of heptanoic acid. The median lethal concentrations of benzoic acid and heptanoic acid were 55.02 mg/L and 83.90 mg/L, respectively. Heptanoic acid and benzoic acid could decrease the Total Superoxide Dismutase (T-SOD) and Catalase(CAT) activities of Microcystis aeruginosa and cause increased Malondialdehyde(MDA) production. The T-SOD and CAT activities initially increased and then decreased. The MDA content quickly decreased after reaching a maximum value. Benzoic acid had a greater effect on the antioxidant enzyme system of Microcystis aeruginosa than heptanoic acid. A hybrid evaluation was performed on the combined algal inhibition effect of heptanoic acid and benzoic acid. The results indicated that benzoic acid and heptanoic acid showed a synergistic effect and that their compound algal inhibition effect was superior to the separate effects of the two organic acids acting independently.

Biosurfactants can be applied to improve the micro-environment and efficiency of composting, but their biosurfactant effects on the adsorption of heavy metals and humic acid (HA) remain undefined. This study aims to deal with the effects of biosurfactant rhamnolipid (RL) on the adsorption of Pb²⁺ onto compost HA at various concentrations, temperatures, and pH values. Adding RL solution influenced the adsorption of Pb²⁺ onto compost HA without fitting the Langmuir or the Freundlich isotherm. Moreover, Pb²⁺ adsorption onto compost HA was accelerated by RL at low concentrations until maximum at 40 mg L⁻¹. However, the adsorption was weakened at sufficiently high RL concentration. Furthermore, Pb²⁺ adsorption was enhanced with increasing pH values and was weakened with rising temperature. This study provides reference for applying biosurfactants in compost.

A mixture of the environmentally friendly biosurfactants rhamnolipids and sophorolipids was used as a source of micelles in this study. The Box-Behnken design and response surface methodology was used to investigate the influence of factors on micellar-enhanced ultrafiltration (MEUF). Simulated Cd-containing wastewater was used for testing. Based on single-factor experiments, the initial Cd²⁺ concentration, biosurfactant mixing ratio (α) and pH were chosen as influential variables, and both the Cd²⁺ rejection coefficient and permeation flux were used as responses. A predictive model based on a quadratic polynomial regression equation was established to determine the optimized enhanced ultrafiltration conditions for Cd. The results show that the regression equation is extremely significant and fits the data accurately. The optimal enhanced ultrafiltration conditions are as follows: initial Cd²⁺ concentration of 10.0 mg/L, α of 0.30 and pH of 9.58. Under these conditions, the rejection coefficient and the permeation flux of Cd²⁺ are 99.14% and 37.36 L/m²·h, respectively. The experimental results confirm that the experimental values agree well with the values predicted by the model. Further, these results provide theoretical support for using MEUF to treat heavy metal-containing wastewater when biosurfactants are used for micelle formation.