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Background: Homelessness is a traumatic experience, and can have a devastating effect on those experiencing it. People who are homeless often face significant barriers when accessing public services, and have often experienced adverse childhood events, extreme social disadvantage, physical, emotional and sexual abuse, neglect, low self‐esteem, poor physical and mental health, and much lower life expectancy compared to the general population. Rates of problematic substance use are disproportionately high, with many using drugs and alcohol to deal with the stress of living on the street, to keep warm, or to block out memories of previous abuse or trauma. Substance dependency can also create barriers to successful transition to stable housing. Objectives: To understand the effectiveness of different substance use interventions for adults experiencing homelessness. Search Methods: The primary source of studies for was the 4th edition of the Homelessness Effectiveness Studies Evidence and Gaps Maps (EGM). Searches for the EGM were completed in September 2021. Other potential studies were identified through a call for grey evidence, hand‐searching key journals, and unpacking relevant systematic reviews. Selection Criteria: Eligible studies were impact evaluations that involved some comparison group. We included studies that tested the effectiveness of substance use interventions, and measured substance use outcomes, for adults experiencing homelessness in high income countries. Data Collection and Analysis: Descriptive characteristics and statistical information in included studies were coded and checked by at least two members of the review team. Studies selected for the review were assessed for confidence in the findings. Standardised effect sizes were calculated and, if a study did not provide sufficient raw data for the calculation of an effect size, author(s) were contacted to obtain these data. We used random‐effects meta‐analysis and robust‐variance estimation procedures to synthesise effect sizes. If a study included multiple effects, we carried out a critical assessment to determine (even if only theoretically) whether the effects are likely to be dependent. Where dependent effects were identified, we used robust variance estimation to determine whether we can account for these. Where effect sizes were converted from a binary to continuous measure (or vice versa), we undertook a sensitivity analysis by running an additional analysis with these studies omitted. We also assessed the sensitivity of results to inclusion of non‐randomised studies and studies classified as low confidence in findings. All included an assessment of statistical heterogeneity. Finally, we undertook analysis to assess whether publication bias was likely to be a factor in our findings. For those studies that we were unable to include in meta‐analysis, we have provided a narrative synthesis of the study and its findings. Main Results: We included 48 individual papers covering 34 unique studies. The studies covered 15, 255 participants, with all but one of the studies being from the United States and Canada. Most papers were rated as low confidence (n = 25, or 52%). By far the most common reason for studies being rated as low confidence was high rates of attrition and/or differential attrition of study participants, that fell below the What Works Clearinghouse liberal attrition standard. Eleven of the included studies were rated as medium confidence and 12 studies as high confidence. The interventions included in our analysis were more effective in reducing substance use than treatment as usual, with an overall effect size of –0.11 SD (95% confidence interval [CI], −0.27, 0.05). There was substantial heterogeneity across studies, and the results were sensitive to the removal of low confidence studies (−0.21 SD, 95% CI [−0.59, 0.17] − 6 studies, 17 effect sizes), the removal of quasi‐experimental studies (−0.14 SD, 95% CI [−0.30, 0.02] − 14 studies, 41 effect sizes) and the removal of studies where an effect size had been converted from a binary to a continuous outcome (−0.08 SD, 95% CI [−0.31, 0.15] − 10 studies, 31 effect sizes). This suggests that the findings are sensitive to the inclusion of lower quality studies, although unusually the average effect increases when we removed low confidence studies. The average effect for abstinence‐based interventions compared to treatment‐as‐usual (TAU) service provision was –0.28 SD (95% CI, −0.65, 0.09) (6 studies, 15 effect sizes), and for harm reduction interventions compared to a TAU service provision is close to 0 at 0.03 SD (95% CI, −0.08, 0.14) (9 studies, 30 effect sizes). The confidence intervals for both estimates are wide and crossing zero. For both, the comparison groups are primarily abstinence‐based, with the exception of two studies where the comparison group condition was unclear. We found that both Assertative Community Treatment and Intensive Case Management were no better than treatment as usual, with average effect on substance use of 0.03 SD, 95% CI [−0.07, 0.13] and –0.47 SD, 95% CI [−0.72, −0.21] 0.05 SD, 95% CI [−0.28, 0.39] respectively. These findings are consistent with wider research, and it is important to note that we only examined the effect on substance use outcomes (these interventions can be effective in terms of other outcomes). We found that CM interventions can be effective in reducing substance use compared to treatment as usual, with an average effect of –0.47 SD, 95% CI (−0.72, −0.21). All of these results need to be considered in light of the quality of the underlying evidence. There were six further interventions where we undertook narrative synthesis. These syntheses suggest that Group Work, Harm Reduction Psychotherapy, and Therapeutic Communities are effective in reducing substance use, with mixed results found for Motivational Interviewing and Talking Therapies (including Cognitive Behavioural Therapy). The narrative synthesis suggested that Residential Rehabilitation was no better than treatment as usual in terms of reducing substance use for our population of interest. Authors' Conclusions: Although our analysis of harm reduction versus treatment as usual, abstinence versus treatment as usual, and harm reduction versus abstinence suggests that these different approaches make little real difference to the outcomes achieved in comparison to treatment as usual. The findings suggest that some individual interventions are more effective than others. The overall low quality of the primary studies suggests that further primary impact research could be beneficial. [ABSTRACT FROM AUTHOR]

Based on the experience of evaluating 2 cross-age peer-tutoring interventions, we argue that researchers need to pay greater attention to causal mechanisms within the context of school-based randomised controlled trials. Without studying mechanisms, researchers are less able to explain the underlying causal processes that give rise to results from randomised controlled trials. Studying implementation fidelity is necessary but not sufficient for causal explanation; the study of causal mechanisms through the application of mixed methods is also required. Due to the increasingly complicated nature of many classroom-based innovations that are subject to evaluation, and the potentially distal nature of hypothesised effects, particularly on attainment, programme theory and articulation of mechanisms are essential in enhancing causal explanation and promoting the accumulation of knowledge of what works and why in classroom settings.

Access to and the use of irrigation water of adequate quality and targeted nutrient supplementation have become more widespread in recent years. Both crop quality and the irrigation system lifetime are affected by the quality of the water used for irrigation. Micro-irrigation (e.g., drip and sprinkle) is becoming increasingly common alongside the more typical irrigation methods, but it requires expertise and pre-treatment to ensure a proper water supply. The most significant problem is clogging, which can greatly reduce irrigation efficiency. Treatment for irrigation purposes mainly depends on the contaminants that are present in the water. The main treatment options available are biological, electromagnetic and electrostatic treatments, but these have a wide range of effectiveness levels compared to membrane separation technologies. In addition, adsorption treatments are also available, which, depending on the adsorbent used, can greatly improve the pre-treatment of irrigation water. This work provides an overview of adsorbents suitable for the treatment of irrigation water and their effectiveness. The separation of interfering components via adsorption is effective and promising for future application as the expected irrigation demands increase. [ABSTRACT FROM AUTHOR]

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Oily wastewaters are one of the major environmental pollutants in aquatic systems. This is due to the emission of a variety of industrial oily wastewaters from sources such as crude oil mining (production), refineries, petrochemical plants and transportation. The aims of this work were to investigate the treatment of oil-contaminated wastewaters with a pre-ozonation/microfiltration combined system and the effect of pre-ozonation on the microfiltration parameters. The results demonstrated that ozone pre-treatment modified the chemical nature (pH and conductivity) of oil-in-water emulsion, resulting in higher wettability of the polyethersulphone membrane. In case of salt-containing model emulsions compared to pure oil emulsions, ozone treatment was found to be more effective for membrane resistance reduction and in chemical oxygen demand retention. [ABSTRACT FROM PUBLISHER]

In process industries, a large amount of wastewater is generated in the form of oil-in-water emulsions, which cannot be treated effectively using traditional physical methods. The aim of our investigation was to examine the applicability of the membrane technique and the effect of pre-ozonation in oily wastewater treatment. Pre-ozonation followed by microfiltration (MF) was investigated to determine the main effects of ozonation on the oily water and the filtration parameters such as permeate flux, organic content retention and membrane fouling. Experiments were carried out with a laboratory-scale batch-stirred filtration device, using polyethersulphone MF membranes with a pore size 0.2 μm. The model oily wastewater that was used in these experiments contained petroleum. The results demonstrated that the chemical oxygen demand could be eliminated more effectively through the combination of ozone pre-treatment and membrane filtration, compared to membrane filtration alone. [ABSTRACT FROM PUBLISHER]

Membrane and Advanced Oxidation Processes (AOPs) are increasingly being considered as an alternative to conventional water and waste water treatment methods in anticipation of future demands for high standards and reduced environmental impact. However, the use of membranes for these applications is currently limited by the high capital and operating costs. This work investigate the economics of membrane processes for modell remediation oily waste water (0.01 wt.% petroleum) applications. The AOPs (eg. Preozonation) may increase the membrane separation process efficiency, especially the retention values. Compared the fixed capital and the working costs at the preozonation combinated microfiltration and for a two stage (MF/UF) membrane separation processes. [ABSTRACT FROM AUTHOR]