Water is a vital component for sustaining life on the earth because it is interacted with all metabolic activities of all living beings (human, plants, and others). The decomposition of organic pollutants, in general, causes oxygen deficiency in water bodies that can lead to severe damages in the ecosystem. Therefore, cost-effective innovative methods for the purification of wastewater is always needed. One of the most important methods that has gathered attention is adsorption. This method has witnessed continuous development in the case of the selected materials as adsorbents. Low cost as well as the production of new nano-materials have been used for the decontamination of water. In this chapter, a general overview based on the information available in the literature was produced to highlight the importance of adsorption as a method for the purification of water from conventional and emerging organic compounds.

In this research, biogas production potential from beach wrack collected in Riga Gulf (Ragaciems, Jaunķemeri, Bigauņciems) and in coastline of Sweden (Kalmar) was studied using an anaerobic digestion method. Selected beach wrack masses laying ashore and containing macroalgal biomass of common macroalgae types specific to the Baltic Sea were mixed for consolidated samples. Anoxic fermentation of untreated beach wrack was carried out in 16 bioreactors applying a single filling mode at 38 °C. The study revealed that by utilizing beach wrack accumulated ashore as a feedstock for anaerobic digestion methane can be utilized if pretreatment and conditioning of the samples are performed. The study was continued for selected brown algae containing biomass tested with three dewatering pretreatment methods: a) keeping in tap water for 24 hours; b) washing with running fresh water for one hour, and c) drying to relatively constant weight. The resulting methane outcome was compared with the data corresponding to raw brown algae. The study confirmed that washing of macroalgal biomass applied as pretreatment prior to anaerobic fermentation avoids inhibition of salts and promotes biomethane production.

Extraction of hazardous metals from dumped crystal glass waste was investigated for site decontamination and resource recovery. Mechanically activated glass waste was leached with biodegradable chelating agents of ethylenediamine-N,N'-disuccinic acid (EDDS) and nitrilotriacetic acid (NTA), where the concentration and reaction time were determined by using Box-Wilson experimental design. Hazardous metals of lead (Pb), arsenic (As), antimony (Sb) and cadmium (Cd) with concentrations higher than regulatory limits were extracted wherein the extraction yield was found to vary Pb > Sb > As > Cd. Extraction was influenced more by type and concentration of chelator rather than by reaction time. A maximum of 64% of Pb could be extracted by EDDS while 42% using NTA. It is found that increase of chelator concentrations from 0.05 M to 1 M did not show improved metal extraction and the extraction improved with reaction time until 13 h. This study provides sustainable alternative for treating hazardous glass waste by mechanical activation followed by extraction using biodegradable chelator, instead of acid leaching.

In this study, Ailanthus altissima sawdust was chemically activated and characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), Energy Dispersive X rays (EDX), and surface area analyzer. The sawdust was used as an adsorbent for the removal of azo dye; Acid Yellow 29 (AY 29) from wastewater. Different kinetic and equilibrium models were used to calculate the adsorption parameters. Among the applied models, the more suitable model was Freundlich with maximum adsorption capacities of 9.464, 12.798, and 11.46 mg/g at 20 °C, 30 °C, and 40 °C respectively while R2 values close to 1. Moreover, the kinetic data was best fitted in pseudo second order kinetic model with high R2 values approaching to 1. Furthermore, adsorption thermodynamics parameters such as free energy, enthalpy, and entropy were calculated and the adsorption process was found to be exothermic with a value of ∆H° = −9.981 KJ mol−1, spontaneous that was concluded from ΔG° values which were negative (−0.275, −3.422, and −6.171 KJ mol−1 at 20, 30, and 40 °C respectively). A positive entropy change ∆S° with a value of 0.0363 KJ mol−1 indicated the increase disorder during adsorption process. It was concluded that the activated sawdust could be used as a suitable adsorbent for the removal of waste material, especially dyes from polluted waters.

The Silica monolith particles (SMP) were prepared from Tetra-Methyl-Ortho-Silicate (TMOS) and characterized by Fourier transforms infrared (FTIR), Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and surface area analyzer. FTIR analysis showed the Si-O stretching confirming SMP formation. SEM analysis provided information about the mean diameter of SMP (1-5 mu m). EDX confirmed the presence of silicon and oxygen in the SMP. Moreover, the calculated surface area for SMP was found to be around 367 m(2)/g, whereas BJH pore size distributed particles were 87.15 along with the total pore volume and pore radius of 0.073 cm(3)/g and 16.627 & ANGS;, respectively. Besides, the removal efficiency was found to be about 96%. Various kinetic equations were used to calculate the adsorption parameters. Overall, the results show that the most appropriate model for the kinetics data was the pseudo-second order kinetics model while the mechanism of adsorption was best explained by the Langmuir isotherm. The highest removal of Basic Red 5 dye after 120 min at 298 K was 576 mg/g. Moreover, the thermodynamics parameters (Enthalpy, Gibb's energy, and Entropy) were also estimated. The & UDelta;H & DEG; (0.995 kJ/mol) value depicted the endothermic nature of the process. The non-spontaneous aspect of the process was evident from the & UDelta;G & DEG; values which were 60.431, 328.93, and 339.5 kJ/mol at 293, 303, and 313 K, respectively. From the high removal efficiency value, it can be concluded that the prepared adsorbent can be a potential adsorbent in the reclamation of dyes from wastewater.</p>

Worldwide, sediments are dredged from water bodies to guarantee proper water levels and remediate aquatic ecosystems. Dredged sediments contain metals that could interfere with recycling if the concentrations overpass permissible limits. Washing of elements from sediments represents a technique to decrease the concentration of metals, and it could introduce a new source of elements. The current study aimed to employ ethylenediamine-tetraacetic acid (EDTA) and ethylenediamine-disuccinic acid (EDDS) and investigate the effect of operational parameters (concentration and pH) on the chemical extraction of metals from dredged sediments. Core sediments were extracted from sampling stations around Malmfjärden bay, Sweden. The results suggested that lead, zinc and copper were the elements with higher extraction rates, followed by arsenic and nickel. Chromium was poorly extracted. EDTA was more efficient than EDDS in dissolving the elements. Moreover, acidic conditions offered higher extraction rates for As using both chelators and for Pb employing EDTA. The 0.05 M concentration presented a higher mean extraction rate than 0.01 M for Cu, Cr and Ni for EDTA and EDDS. The findings in this study suggest that sediment washing is a promising technique to decrease metal concentrations in sediments and enhancing the feasibility to use the material for beneficial uses.

In Indonesia, seaweed has a critical role in improving the welfare of coastal communities. As asource of nutrition, seaweed consists of carbohydrate, protein, fat, fiber and ash, vitamin, and beta-carotene.Right drying methods are needed to preserve the quality of dried seaweed. This study aims to compare thetrend of weight reduction in seaweed during drying by natural and cabinet methods. The methods wereused experimentally in the field and laboratory. And the data were analyzed using simple linear regressionto formulate a trend of reduction in the weight of seaweed while drying. The results showed that the weightreduction in seaweed by the natural method can be illustrated by the simple regression linear equation Y =-2.385 3x + 943.65 with R² = 0.985 9, which means a reduction in weight of seaweed i.e. 2.385 3 g min–1during 340 min. While cabinet dryer method can be illustrated by Y = -0.858 8x + 913.55 with R² = 0.9315, which means a reduction in seaweed weight i.e, 0.858 8 g min–1 during 340 min. The reduction of seaweedweight per minute by the natural drying method is higher than the cabinet drying method. Still, the cabinetdrying method is more stable because it does not depend on the weather during the drying process.

The increasing demand for electrical energy and the decreasing supply of fossil fuels in recent years have increased the cost of electrical energy. So that the culture of saving electrical energy is a habit that must be cultivated in the community. On the other hand, energy-saving behavior cannot be realized massively without a support system that can control energy use. With these concerns, it is necessary to develop a method that encourages a culture of saving electrical energy. This paper proposes a system that supports active energy efficiency methods that can support an energy-efficient culture. This system is an electric power monitoring system that is integrated with a smart electrical panel that continuously monitors the use of electrical energy and can control electrical loads automatically, record electricity usage, provide comprehensive reports and analyze energy usage. The method used to carry out this research is research and development. This research has produced a prototype of electrical power control and monitoring system that has a smart panel based on a raspberry PI 3 and PZEM-004t power energy meter. The monitoring system performs and executes automatic control of electrical loads. The system can also provide reports in the form of data monitoring in daily, weekly, monthly or annual period. From the test results, it can be concluded that the system can work well. This research is expected to contribute to providing a system that can support government efforts in saving energy. © Pakistan Academy of Sciences.

In the present study, we determined the levels of chlorinated pesticide residues in surfacewater samples collected from the Charsadda district (KPK, Pakistan). SPME-GC-ECD with COMBIPAL CTC autosampler was used for extraction and analysis of 20 organochlorine pesticides in thecollected water samples. For maximum efficiency of the SPME procedure, several parameters werestudied, including the extraction and desorption time of the fiber, solution pH, agitation of samples,and stirring speed, etc. This method showed good liner response, with R2 values in the range of0.9887 to 0.9999 for all pesticides. This method also provided good percent recoveries at 1 µg L−1(87.5to 106.0%) and at 2 µg L−1(88.5 to 109.2%). Lower limits of detection for all 20 chlorinated pesticideswere found to be lower than their maximum permissible contamination levels. Approximately 50%of the surface water samples collected from the Charsadda district were found to be contaminatedwith the pesticides γ-BHC, heptachlor, aldrin and dieldrin, with maximum concentrations of 0.023,0.108, 0.014 and 0.013 µg L−1, respectively. For adults and children, the cancer risk from water dueto contamination by various pesticides ranged from 0 to 33.29 × 10−6. The non-carcinogenic riskfrom each pollutant in the water samples of the Charsadda district was found to be in the order ofheptachlor > aldrin > dieldrin > γ-BHC. However, the pesticides α-BHC, β-BHC, heptachlor epoxide,chlordane, endrin, 4,40-DDD, endrin ketone, 4,40-DDT, endosulfan sulfate and methoxychlor werenot detected in any of the surface water samples of investigated in the present study.

Groundwater heavy metal pollution is a major concern all around the world. For the assessment of heavy metals and physico-chemical characteristics. groundwater samples were collected from different locations of the Karak District, Pakistan. With the help of the global information system device (GIS), groundwater samples were collected and studied from 47 locations. The present study focused on the water table (WT), water source depth (WSD), pH, electrical conductivity (EC), dissolved oxygen (DO), total dissolved solids (TDS), lead (Pb(II)), silver (Ag(I)), iron (Fe(II)) and chromium (Cr(VI)) parameters. Heavy metals were analyzed by the Atomic Absorption Spectrophotometer (AAS). The Pearson's matrix of correlation showed relationships between several parameters, such as the EC and the TDS which had close interactions between all the three different groundwater samples (collected by hand pump (HP), bore holes (BH) and tube wells (TW)). The strong correlation was detected in all the sources of water between the TDS and the EC, the regression coefficient (r) of which was 1. In the hierarchical clustering (by dendrograms) the HP samples show two clusters: Cluster 1 contains seven parameters and Cluster 2 has four parameters. The BH samples have two clusters: Cluster 1 contains three parameters and Cluster 2 has eight parameters. The TW dendrogram also shows two clusters: Cluster 1 contains six parameters while Cluster 2 has five parameters.