Response of Physicochemical and Microbiological Properties to the Application of Effective Microorganisms in the Water of the Turawa Reservoir

Effective microorganisms (EM) technology was used to find the optimal method of water restoration in the designated experimental area. The study aimed to evaluate the impact of EM biopreparation on selected physicochemical and microbiological properties using ISO methods. A week after the application of biopreparations, a slight decrease in the nitrates content (0.375–0.531 mg L−1) and a significant decrease in the content of phosphorus compounds (0.130–0.304 mg L−1) compared to the control date were observed. Moreover, on the second date, the decrease in most values of microbiological properties was noted. Two weeks after the application, in most cases, the values of water quality properties were shaped close to values obtained in the control date (before EM application). The EM effect was rather short-term, but optimization of application properties may prolong the effect and thus, include the EM technology among the best eco-friendly technologies used for freshwater ecosystem restoration.

Comparison of photosynthetic fluorescence characteristics of several submerged plants in Honghu Lake, China

Submerged plants are the pioneer species of eutrophic water remediation, and they are important for maintaining the health of aquatic ecosystem, while light is the main limiting factor for the growth of submerged plants. In this study, we measured the maximal quantum yields of photosystemⅡ(Fv/Fm) and rapid light curves (RLCs) of five dominant submerged macrophytes in situ by using pulse-amplitude modulated fluorometer (Diving-PAM). Results revealed that P. crispus L. and M. verticillatum L. had the highest Fv/Fm value, all species’ Fv/Fm are less than 0.8. In addition, the variation trends of Fv'/Fm' and Fv/Fm were same. All species showed statistically significant differences in α, while P. crispus L. and M. verticillatum L. showed the highest α value in the five species. And the variation trends of rETRm and Ek were basically the same. It indicated that P. crispus L. and M. verticillatum L., both of which had high photosynthetic efficiency, had excellent ability to withstand hard light. Compared five species, P. crispus L. and M. verticillatum L. had resistance capacity to hard light as well as faster photosynthetic rate, and V. natans (Lour.) Hara had higher resistance capacity to low light. Thus, when submerged plants are used for water restoration, V. natans (Lour.) Hara could be regarded as a pioneer species in eutrophication water restoration. P. crispus L. and M. verticillatum L. will have better effects when used in shallow water areas.

Combined effects of salinity and temperature on grazing activity of invasive Gammarus tigrinus on charophytes

Charophytes are a refuge for zooplankton and stabilize sediments, but they are also a food source for various animal species (water birds, fishes, invertebrates). This grazing pressure may be an important factor prohibiting macrophyte re-colonization in eutrophic coastal waters. Especially the introduction of new species, like Gammarus tigrinus, into the Baltic Sea led to yet not understood changes in the food web. Furthermore, the occurrence of native and invasive species is determined by their capacity to acclimatize to changing abiotic factors. In this study we investigated the influence of temperature and salinity on the grazing pressure of Gammarus tigrinus on two charophyte species: Chara tomentosa and Chara aspera. The grazing experiments were conducted in a full factorial design with the factors salinity (3 – 13 PSU), temperature (5 – 30 °C), and charophyte species. Grazing rates were determined as mass deviation within 48 hours considering simultaneous growth of the charophytes. Experimental results were further used to determine gross macrophyte biomass within the ecosystem, using field data. Gammarids preferred C. aspera before C. tomentosa, but both were grazed within their respective growth optima. The potential grazing peak of 24 °C is not yet reached in these coastal waters. Furthermore, calculation of gross production revealed that macrophytes could show up to 60% and 15% more biomass without grazing in deeper light-limiting, and shallow, not light limited water depths, respectively. The impact of food web on coastal water restoration should therefore be equally considered, as the nutrient control.

Research on Water Restoration System in Wuhan City Based on Pocket Park Concept

Wuhan city in Hubei Province is endowed with unique natural water resources and numerous lakes. It has a good framework of natural “green sponge”, which provides a broad space for stormwater regulation and storage. However, with the increase of infrastructure construction in Wuhan, many lakes have been buried and the city is becoming a “hard shell city” made of steel and cement. This article combines the natural landform of Wuhan and the pocket park system theory to make an organic combination of the ongoing urban infrastructure construction and the restorative construction of the municipal water supply system in Wuhan, so as to make an exploratory research for the early construction of Wuhan into a sponge city.

Research progress on ecological restoration of landscape water

With the rapid development of my country’s economy and the advancement of urban-rural integration, the urban population has increased sharply, people’s basic survival problems have been solved, and more and more attention has been paid to landscapes and landscape water. The sources of water pollution were described, the effects and characteristics of water restoration methods were analyzed and compared, and suggestions were made for landscape water restoration.Immobilization technology has great advantages in ecological restoration of landscape water bodies, with strong environmental adaptability and high tolerance to environmental conditions.

Physiological and biochemical parameters of apricot cultivars under drought conditions on the Southern Coast of the Crimea

In order to determine special features of the photosynthetic apparatus activity and the content of thread compounds in various apricot cultivars during the period of maximum drought probability on the Southern Coast of the Crimea, we studied the concentration of proline, phenolic compounds and chlorophylls, as well as the parameters of chlorophyll fluorescence induction (CFI) in some apricot cultivars ( Prunus armeniaca Lam.), characterized by various degree of drought tolerance (‘Alupkinsky’, ‘Krymskiy Amur’) are weakly resistant; Khurmai cultivar is characterized by labile resistance, and the cultivars Kazachok, Professor Smykov, Nagycorosi Orias are drought tolerant cultivars). It has been found out that drought-resistant cultivars are characterized by a relatively low content of proline in their leaves. It is supposed that this amino acid is involved in the protective reactions of apricot plants under water stress. The results of the photosynthetic apparatus studies in the presented cultivars demonstrated that in leaves, water loss less than 20% caused reversible changes in the parameters of CFI. An increase in the water deficit up to 25-30% caused the destruction of PS2 in weakly drought-resistant cultivars. The most stable photosynthetic apparatus activity was noticed in the cultivar Nagycorosi Orias. Deviations in photosynthesis processes were most pronounced during the period of water restoration in leaves.

Assessment of the Nutrient Removal Potential of Floating Native and Exotic Aquatic Macrophytes Cultured in Swine Manure Wastewater

Although eutrophication and biological invasion have caused serious harm to aquatic ecosystems, exotic and even invasive plants have been used extensively in phytoremediation water systems in China. To identify native aquatic plants with excellent water restoration potential, two representative native floating aquatic plants from Guangdong Province, namely Ludwigia adscendens (PL) and Trapa natans (PT), were selected, with Eichhornia crassipes as a control, to study their growth status, adaptability, and nutrient removal potentials in swine manure wastewater. The results demonstrated that the two native plants offered greater advantages than E. crassipes in water restoration. Within 60 days, PL and PT exhibited excellent growth statuses, and their net biomass growth rates were 539.8% and 385.9%, respectively, but the E. crassipes decayed and died with an increasing HRT (hydraulic retention time). The PL and PT could adjust the pH of the wastewater, improve the dissolved oxygen and oxidation-reduction potential, and reduce the electrical conductivity value. The removal rates of NH4+–N, NO3−–N, NO2−–N, total nitrogen, total phosphorus, chemical oxygen demand (COD), and Chl-a in the PL group reached 98.67%, 64.83%, 26.35%, 79.30%, 95.90%, 69.62%, and 92.23%, respectively; those in the PT group reached 99.47%, 95.83%, 85.17%, 83.73%, 88.72%, 75.06%, and 91.55%, respectively. The absorption contribution rates of total nitrogen (TN) and total phosphorus (TP) in the PL group were 40.6% and 43.5%, respectively, while those in the PT group were 36.9% and 34.5%, respectively. The results indicated that L. adscendens and T. natans are both promising aquatic plants for application to the restoration of swine manure wastewater in subtropical areas.