The significance of heterophasic ion exchange in active biomonitoring of heavy metal pollution of surface waters.

We have carried out studies to examine the possibility of using biosorbents: the epigeic mosses Pleurozium schreberi (Willd. ex Brid.) Mitt., and the epiphytic lichens Hypogymnia physodes (L.) Nyl. in active biomonitoring of heavy metal pollution of surface waters. The dried sea algae Palmaria palmata (L.) Weber & Mohr were used as the third biosorbent. The studies were conducted in the waters of the Turawa Reservoir, a dam reservoir with a significant level of eutrophication in south-western Poland. Incremental concentrations of Mn, Ni, Zn, Cu, Cd, and Pb were determined in the exposed samples. It was shown that a 2-h exposure period increases the concentration of some metals in the exposed samples, even by as much as several hundred percent. High increments of nickel concentrations in the algae Palmaria palmata (mean: 0.0040 mg/g, with the initial concentration of c0 < 0.0016 in the algae) were noted, with negligible increments in concentrations of this metal in mosses and lichens. In contrast, mosses and lichens accumulated relatively high amounts of Cd (mean: 0.0033 mg/g, c0 = 0.00043 mg/g) and Pb (mean: 0.0243 mg/g, c0 = 0.0103 mg/g), respectively.

The use of a natural substrate for immobilization of microalgae cultivated in wastewater.

The methods of separation of microalgae has a significant impact in the economic aspects of their cultivation. In this study, pine bark was used as a substrate for immobilization of microalgal biomass cultivated in raw municipal sewage. The experiment was conducted in cylindrical photobioreactors (PBRs) with circulation of wastewater. Biomass was cultivated for 42 days. After that time, abundant growth of the biofilm with microalgae on the surface of pine bark as well as improvement of the quality of treated sewage were observed. The efficiency of removal of nutrients from wastewater was 64-81% for total nitrogen and 97-99% for total phosphorus. Moreover, the concentration of suspended solids in sewage was reduced, which resulted in a decrease in turbidity by more than 90%. Colorimetric analysis and Volatile Matter (VM) content in the substrate showed a decrease in the Higher Heating Value (HHV) and concentration of VM due to the proliferation of biofilm.

LED light use for the improvement of wastewater treatment in the hydroponic system.

Effective removal of nitrogen and phosphorus from sewage before its discharge to the receiving water body is now a key task for scientists and technologists around the world. The widespread problem of eutrophication in the watercourses as well as in the seas and oceans obliges to take actions leading to more effective protection of water resources and implementation of sustainable development principles. One of the methods of increased wastewater treatment from nutrients is the use of a third stage of treatment with the use of macrophytes for the uptake of nitrogen and phosphorus. These systems, called hydroponic, under moderate climate conditions show little effectiveness due to the lack of sufficient light intensifying the growth of aquatic plants. The aim of this study was to evaluate the reduction of biogenic compounds concentrations in wastewater where additional lighting of plants was provided by the use of LED (Light Emitting Diodes), in two different conditions of experiment: with aeration and with carbon dioxide supplementation. Analyses show that the effectiveness of purification was higher in the wastewater supplemented with CO2 and artificial lighting had no significant influence on the reduction of nitrogen forms concentrations. In wastewater with aeration, higher effectiveness of nitrogen removal was observed in the tank with artificial lighting. In both cases, aeration or CO2 supplementation as well as artificial lighting or its lack, had no influence on total phosphorus and phosphates removal.

Influence of Insolation on the Efficiency of NO3 Removal from Wastewater Treated in the Hydroponic System.

The use of plants and natural processes for wastewater treatment is an issue that arouses interest among technologists and scientists around the world. The aim of the article was to analyze the influence of the air temperature and insolation on the removal of nitrate nitrogen from the wastewater treated in the hydroponic system, under greenhouse conditions. Samples of sewage for its quality tests were taken from a wastewater treatment plant (WWTP) located in the southwestern part of Poland. Data regarding daily sunshine duration and average daily air temperature values in selected periods of 2013-2016 come from a meteorological station located 30 km from WWTP. The conducted research and analyses of the results clearly indicate that under moderate climate conditions, the amount of solar radiation reaching the Earth's surface is insufficient to ensure the year-round, effective wastewater treatment process in the hydroponic system. In the case of air temperature, no correlation was found between the tested parameters, which indicates the lack of temperature influence on the efficiency of NO3 removal from the wastewater by macrophytes growing in the lagoon.

Analysis of Granulometric Composition of Algal Suspensions in Wastewater Treated with Hydroponic Method.

The aim of the study was to determine the changes in suspension particle size identified in biologically treated wastewater, which was then treated in hydroponic system with use of engineering lighting by the light-emitting diodes (LED). The study was subjected to wastewater purified under laboratory conditions, in a hydroponic system using the effect of macrophytes Pistia stratiotes and growing algae. Measurement of particle size was made using a laser granulometer. Analysis of the results showed that the additional lighting of the hydroponic system with LED can significantly influence the ability of the suspension particles to agglomerate and, consequently, determine their sedimentation properties. In hydroponic system supported by additional lighting, more particles were observed with equivalent diameter D(3.2) smaller than 10 µm than those in the tank without additional lighting, indicating a higher reactivity of the particles. Determining the size of equivalent diameters D(4.3) allowed us to observe that in hydroponic system, particles of relatively small size predominate, which negatively affects the sedimentation process of the suspensions. Determination of particle size of suspensions consisting mainly of algae and the dynamics of their changes are the basis for specification of an effective method of removing particles from the system to protect the receiver from excessive suspension concentrations.