Cost Estimations of Water Pollution for the Adoption of Suitable Water Treatment Technology

Sources and toxicological effects of metal and metalloids on human health through fish consumption in mineral-rich city, Ranchi, India

Ranchi is the administrative capital of Jharkhand and is located in the southern part of the Chhotanagpur Plateau. It is rich in forest and mineral resources and hence is suitable for the establishment of many large- and small-scale industries. The estimated population of Ranchi for the year 2023 is 3.54 million. These demographic characteristics make the capital more vulnerable to environmental degradation. Also, previous water quality research focused on river, water, and oceans separately; however, little or no work has been carried out on the comparison of metal or metalloid analysis in rivers, waterfalls, and lakes. Hence, the present study aims to assess the pollution status of mineral-rich and industrial hub city, Ranchi, through analysis of metals or metalloids in abiotic (water and sediment) and biotic (fish and human) components. The water, sediment, and fish (Labeo rohita and Catla catla) samples were collected from Subarnarekha river, Jumar river, Dassam fall, Getalsud dam, Hundru fall, Jonha fall, Kanke dam, and Sita fall. Samples were collected following standard methods and analyzed in inductively coupled plasma mass spectrometry (ICP-MS). Among three aquatic systems (rivers, dams, and falls), dams were highly polluted with metals or metalloids, which may be due to effluent discharge from different industries. Additionally, the high population in the city also contributed to metals or metalloids pollution. The reason may be the direct sewage disposal and agricultural and surface runoff in the water systems. It was observed that most of the aquatic systems in Ranchi were severely polluted with metals or metalloids. The fish also accumulated these metals or metalloids in their body and can be life-threatening to the human population consuming them. The THQ (above 1) and HI (2.95) values for As showed that children are more vulnerable to health risk through consumption of contaminated fish. Hence, proper planning and management are needed to overcome the metals or metalloids pollution in Ranchi.

Towards Sustainable Distributed Sensor Networks: An Approach for Addressing Power Limitation Issues in WSNs

Distributed wireless sensor networks (WSNs) have been implemented in multiple applications. Those networks are intended to support the quality of operations and enhance applications' productivity and safety. WSNs are constructed of a large amount of sensor nodes that are battery powered. Typically, wireless sensors are deployed in complex terrain which makes battery replacement extremely difficult. Therefore, it is critical to adopt an energy sustainability approach to enhance the lifetime of each sensor node since each node contributes to the lifetime of the entire WSN. In this work, we propose an approach to reduce power consumption in wireless sensors. The approach addresses power reduction in a sensor node at the sensing level, as well as the communication level. First, we propose configuring the microcontroller of the sensor to conserve energy based on the performed tasks. Then, we implement an interface to reduce consumed power by the radio module. Based on the approach, we carried out field experiments and we measure the improvement of power-consumption reduction. The results show that the approach contributes to saving up to 50% of the wasted energy at the sensor node and it improves communication reliability especially when the number of sensors in a network scales.

Benefit Analysis of Economic and Social Water Supply in Xi’an Based on the Emergy Method

In order to manage regional water resources efficiently and sustainably and promote the rational utilization of water resources, it is necessary to evaluate the water-supply benefit reasonably. On the basis of emergy theory, this paper constructs the water-supply-benefit model of economic (industry, agriculture, and the tertiary industry) and social (domestic, employment security, entertainment, scientific research) systems. Taking Xi’an from 2014 to 2020 as an example, by analyzing the energy flow of each system and the multisource water transformities, the water contribution rate, the water-supply benefit, and the unit-water-resource value in each system are calculated. For the water-supply benefits: Industry > Agriculture > Domestic > Tertiary industry > Employment Security > Entertainment > Scientific research. For the unit-water-resource values: Industry > Tertiary industry > Agriculture > Domestic > Entertainment > Employment security > Scientific research. In the economic system, the water-supply benefit and the unit-water value of industry were always the largest, followed by agriculture and the tertiary industry. However, the Pearson correlation coefficient between the water contribution rate and the output of the industrial system was only 0.52, which was less than that of other production industries, which indicates that there might be a waste of water and that industrial water conservation needs to be further strengthened. In the social system, the domestic-water-supply benefits and the water-resource value were the largest. This is because water resources, as a basic resource, always affect people’s health and quality of life.

Description of a Fe/Al Electrocoagulation Method Powered by a Photovoltaic System, for the (Pre-)Treatment of Municipal Wastewater of a Small Community in Northern Greece

Small and insular communities are sometimes not served by an efficient Wastewater Treatment Plant, and this is a hazard for both the environment and public health. A wastewater treatment apparatus based on the electrocoagulation process (EC) was tested with municipal wastewater from a small community in Northern Greece with a maximum of 6500 population equivalents. COD decrease was assessed under various parameters: current intensity, time duration, pH and use of Fe or Al electrodes. A simulation of meeting the community’s electricity needs with this apparatus was tested through RETScreen software. The results showed a satisfactory COD decrease through electrocoagulation which was affected by all the parameters mentioned; Fe electrodes could efficiently be used at 300 mA for 60 min for 55% COD removal. It was also shown that a photovoltaic panel system covers the electricity needs of the apparatus, thus no external electricity source is needed for its use. This apparatus could be used effectively by this community, so that the running costs are minimal.

Decolorization mechanisms of reactive yellow 145 and ponceau S in microbial fuel cells during simultaneous electricity production

Environmental pollution is increasing in parallel with the increase in the world population. Azo dyes are one of the most important causes of environmental pollution. Microbial electrochemical cells are biotechnological systems that generate energy from renewable sources such as electricity. This study investigated simultaneous electricity generation with the decolorization of two different azo dyes in microbial fuel cells. And also, changes in pH values, chemical oxygen demand analysis, hourly color removal rate, dye spectral scanning were investigated. Reactive Yellow 145 dye with a concentration of 10 mg/L, 20 mg/L, and 40 mg/L, and Ponceau S dye with 20 mg/L and 40 mg/L concentration were tested in microbial fuel cells, respectively. Results indicate that the maximum voltage obtained was 0.11 V at the same time as the 100% decolorization rate in Reactive Yellow 145 and was achieved at a concentration of 10 mg/L also, the maximum voltage obtained was 0.24 V at the same time as the 100% decolorization rate in Ponceau S. It was achieved at a concentration of 20 mg/L. In conclusion, microbial fuel cells appear to be promising tools in treating textile azo dye wastewaters, and computational methods can be applied to estimate the degradation mechanisms of complex organic molecules found in wastewaters.