Effect of wastewater as sustainable concrete material on concrete performance : A critical review

A massive amount of water has been consumed to produce concrete. The lack of sufficient water for drinking and other essential processes reduces the quantity of water that should be delivered to the people because of the high water consumption by concrete production. All the waste from commercial buildings, households, institutions, and hospitals are known as wastewater. Generally, the water demand is anticipated to increase considerably in the near future. Energy and industry production are expected to witness essential rises in water demand. The enormous quantities of water and generating large quantities of various wastewater from different treatment processes led to exploring different ideas to overcome these issues. One of these ideas is the utilization of wastewater in the construction industry, particularly in concrete mixtures and curing. In the literature, a lack of sufficient studies is obtainable for concrete production from wastewater. This study reviews the chemical composition and physical properties of wastewater and the durability properties of concrete. The treated wastewater from sewage treatment plants (STP) is utilized acceptably for particular utilization. Using treated effluent (TE) in concrete improves cement paste's setting time and compressive strength more than drinking water. The concrete samples containing wastewater recorded 7%–27% lower porosity than control concrete because of the hydration process of cement with time, in addition to the pozzolan reactions. In terms of rapid chloride penetration examination, the authors detected that the samples containing wastewater recorded higher Coulomb charges than that of the control concrete sample without wastewater at 28 curing days because of the high chloride ions in wastewater than that of tap water. The chloride ion penetration increased due to an increase in the domestic wastewater content. Consequently, there is a critical need to improve various processes to adopt and use wastewater in concrete mixtures. This study recommends using a high volume of wastewater to get sustainable concrete with high performance

The durability of concrete produced from pozzolan materials as a partially cement replacement : A comprehensive review

Recently, the construction industry used innovative, cost-ecofriendly, and efficient materials in infrastructure development to mitigate the negative impact on the environment due to manufacturing Ordinary Portland cement (OPC). Many efforts have been conducted to improve sustainable materials to be used as cementitious material in pozzolanic materials such as fly ash (FA), slag, metakaolin (MK), rice husk ash (RHA), palm oil fuel ash (POFA), silica fume (SF), etc. Therefore, this paper introduced to review the results from previous studies that investigated the influence of waste materials with high pozzolanic materials on the numerous durability properties. The results show many advantages due to using those pozzolanic materials as partial cement replacements for the environment, saving energy and cost, and improving durability. Ground quartz and SF have the highest silica oxide (SiO2) content, it was recorded as higher than 90%, producing more pozzolanic activity than other waste materials. The resistance of the concrete containing POFA against acid and sulfate attacks increased when increasing POFA fineness. Besides, sorptivity values were reduced importantly for the blended concrete samples, the addition of 55% FA in binary blended concrete considerably reduced sorptivity of cement concretes. In addition to that, these pozzolanic materials improved other concrete properties. This paper can be a good base for researchers and construction players to adopt waste materials in improving the durability of concrete. Lastly, numerous possible studies were recommended for future studies

Geopolymer concrete incorporating recycled aggregates: A comprehensive review

Several industrial by-products are extensively used again as a supplementary cementitious material or aggregates in the interest to reduce environmental footprints in terms of energy depletion, pollution, waste disposition, resource depletion, and global warming related with conventional cement. A remarkable quantity of industrial scrap materials, primarily designated as construction and demolition waste from the construction industry, has transformed into crucial apprehension of governments. In the recent past, substantial explorations have been accomplished to appreciate the distinct characteristics of concrete, employing recycled aggregates from construction and demolition waste. Geopolymer composite is a new cementitious material, and it appears to be a potential replacement for conventional cement concrete. This paper summarises the previous research concerning the utilisation of recycled aggregate as a partial or complete supplants for conventional aggregates in geopolymer concrete. The influence of recycled aggregate addition on the fresh and hardened properties of geopolymer concrete is comprehensively reviewed in this paper. The studies suggest significant improvement in the workability on addition of recycled aggregates to geopolymer concrete. However, the addition results in increased water absorption and sorptivity

Perspectives of HER2-targeting in gastric and esophageal cancer.

The blockade of HER2 signaling has significantly improved the outlook for esophagogastric cancer patients. However, targeting HER2 still remains challenging due to complex biology of this receptor in gastric and esophageal cancers. Areas covered: Here, we review complex HER2 biology, current methods of HER2 testing and tumor heterogeneity of gastroesophageal cancer. Ongoing and completed clinical research data are discussed. Expert opinion: HER2 overexpression is a validated target in gastroesophageal cancer, with therapeutic implications resulting in prolonged survival when inhibited in the front-line setting. With standardized HER2 testing in gastro-esophageal cancer, the ongoing trials are testing newer agents and combinations including combination of anti-HER2 antibodies with immunotherapy. Clonal heterogeneity and emergence of resistance will challenge our approach to treating these patients beyond the frontline settings

Evaluating the role of nanoparticles in enhancing bone regeneration in dental implantology

Background: Dental implantology has witnessed substantial progress in recent years, driven by a growing emphasis on optimizing bone regeneration around dental implants. Nanoparticles have emerged as a potential tool for enhancing osseointegration and bone tissue regeneration. Materials and Methods: This human clinical trial enrolled 60 adult participants requiring dental implants. Patients were randomly assigned to one of two groups: a control group receiving conventional dental implants, and an experimental group receiving dental implants with nanoparticle-coated surfaces. Radiographic imaging, histological analysis of bone biopsies, and implant stability assessments were conducted at three and six months post-implantation. Results: Histological examination of bone biopsies revealed a statistically significant increase in new bone formation in the experimental group compared to the control group at both three and six months (P < 0.05). Radiographic assessment demonstrated a 25% higher bone density around nanoparticle-coated implants (P < 0.01) at the six-month mark. Implant stability quotient (ISQ) measurements indicated a 20% greater stability in the experimental group (P < 0.05) at the same time point. Conclusion: This human clinical trial provides strong evidence that the incorporation of nanoparticles on dental implant surfaces enhances bone regeneration and osseointegration in a human population

Application of Coffee Husk Ash as Partial Replacement of Fine Aggregate in Concrete

The task of turning agricultural waste into practical construction and building materials has been placed before civil engineers. Coffee husk is produced in vast amounts due to the global commerce of coffee beans, which are incinerated into ash when used as fuel, producing coffee husk ash (CHA). Even though many researchers have worked on the utilization of CHA in concrete, they have been used as partial cement replacement but not as a replacement of aggregates. The experimental study of the performance of concrete on fine aggregate replaced partially with CHA is represented in this paper. The fine aggregate is replaced by 0%, 2%, 4%, 6%, and 8% by weight of CHA. The performance of the partially replaced fine aggregate with CHA is reviewed by considering the compressive strength and workability of fresh concrete and the splitting tensile strength, flexural strength, durability under acid and alkaline media, thermal conductivity, and rapid chloride permeability test of hardened concrete. The results indicate that the partial replacement of fine aggregate with 4% of CHA (CHA04) in concrete provides a positive impact to all the selected performance parameters. The compressive strength, flexural strength, and splitting tensile of the CHA04 mix were 43.4 MPa, 3.7 MPa, and 2.44 MPa, respectively, which were 28.4%, 19.35%, and 1.66%, respectively, greater than normal concrete mix (CHA00). Even the study of acid and alkaline attack on the CHA04 mix showed lesser strength reduction as compared to other mixes. The RCPT showed less chloride permeability, and the thermal conductivity is higher for CHA04, indicating lesser voids compared to other mixes. With the help of this investigation, it can be said that fine aggregate replacement with 4% CHA has the best strength and durability properties compared to regular concrete

Comparative characteristics assessment of calcined and uncalcined agro-based waste ash with GGBS and its application in an alkali-activated binder system

AbstractA lot of energy is released during the cement manufacturing process, and a large amount of carbon dioxide (CO2) is discharged into the environment. Presently, researchers are focusing on reducing CO2 emissions by researching sustainable alternatives to traditional Portland cement-based materials. A comparative study on the material characterization of both calcined agro-based waste ash (calcined ash) and uncalcined agro-based waste ash (uncalcined ash) and its utilization as a binder along with granulated blast furnace slag (GGBS) in the alkali activation process is carried out in this paper. The study regarding calcined and uncalcined ash would help in better understanding the variation in the properties of the material and its behavior during the alkali activation process. The tests conducted on both calcined and uncalcined ash along with GGBS include specific gravity, X-ray fluorescence, X-ray diffraction, scanning electron microscopy, reaction degree, Brunauer-Emmett-Teller (BET) analysis, particle size distribution, and the Puntke test for understanding its microstructural characteristics. Later, alkali-activated mortars are prepared using 30% weight of agro-based waste ash (both calcined and uncalcined) and 70% weight of GGBS. A comparison of the compressive strength of alkali-activated mortars prepared using calcined and uncalcined ash was studied, which showed a promising increase in the strength by 11.02% of mortar prepared using calcined ash (23.46 MPa) for 28 days when compared to mortar prepared using uncalcined ash (21.13 MPa). The major finding from this study indicates that calcined agro-based ash with GGBS shows better results compared to uncalcined agro-based ash with GGBS

Isolation, identification, and screening of biosurfactant-producing and hydrocarbon-degrading bacteria from oil and gas industrial waste

Qatar is one of the biggest oil and gas producers in the world, coupled with it is challenging environmental conditions (high average temperature: >40 °C, low annual rainfall: 46.71 mm, and high annual evaporation rate: 2200 mm) harbors diverse microbial communities that are novel and robust, with the potential to biodegrade hydrocarbons. In this study, we collected hydrocarbon contaminated sludge, wastewater and soil samples from oil and gas industries in Qatar. Twenty-six bacterial strains were isolated in the laboratory from these samples using high saline conditions and crude oil as the sole carbon source. A total of 15 different bacterial genera were identified in our study that have not been widely reported in the literature or studied for their usage in the biodegradation of hydrocarbons. Interestingly, some of the bacteria that were identified belonged to the same genus however, demonstrated variable growth rates and biosurfactant production. This indicates the possibility of niche specialization and specific evolution to acquire competitive traits for better survival. The most potent strain EXS14, identified as Marinobacter sp., showed the highest growth rate in the oil-containing medium as well as the highest biosurfactant production. When this strain was further tested for biodegradation of hydrocarbons, the results showed that it was able to degrade 90 to 100% of low and medium molecular weight hydrocarbons and 60 to 80% of high molecular weight (C35 to C50) hydrocarbons. This study offers many promising leads for future studies of microbial species and their application for the treatment of hydrocarbon contaminated wastewater and soil in the region and in other areas with similar environmental conditions

Characterization of humoral and cellular immune responses elicited by reduced doses of Brucella abortus S19 (calfhood) vaccine in cattle calves of India

Brucella abortus S19 vaccine is a stable attenuated smooth strain, globally used as calfhood vaccine for the prevention of bovine brucellosis. Various agencies demonstrated different doses for vaccinating cattle and buffalo calves leading to ambiguity in selecting a suitable immune vaccine dose. The current study aimed at evaluating four graded doses of S19 vaccine to arrive at the dose which could produce comparable effectiveness as that of full dose prescribed by Indian Pharmacopeia among the Indian calves. Four vaccine doses of which the first dose consisted of full dose (40 × 109 CFU/dose) and the other three were 1/10th, 1/20th, 1/100th reduced doses along with control were tested. Each vaccine dose was administered to 13 cattle calves of 4–5 months of age maintained in separate groups. The blood samples were collected on 0 to 240 days post-vaccination (DPV) at the intervals of 0, 14, 28, 45, 60, 90, 150, 180 and 240 for assessment of vaccine-induced innate, humoral and cell-mediated immune responses. The sero-conversion of all vaccinated animals on DPV 45 and persistence of antibody till DPV 240 were noticed. No significant differences were observed in antibody response between animal groups that received full and 1/10th reduced doses. Innate and cell-mediated response by IL-6, TNF-α¸ IFN-γ, CD4+ and CD8+ cell counts showed dose-dependent responses with no significant difference between full dose and 1/10th reduced doses. The results suggest a possible one log reduction of full dose without compromising immune responses to aid larger vaccination coverage for creating herd immunity